Environmental and Health Impacts of Pesticides and Nanotechnology as an Alternative in Agriculture

Abstract

The extensive use of conventional pesticides has been a fundamental strategy in modern agriculture for controlling pests and increasing crop productivity; however, their improper application poses significant risks to human health and environmental sustainability. This review compiles scientific evidence linking pesticide exposure to oxidative stress and genotoxic damage, particularly affecting rural populations and commonly consumed foods, even at levels exceeding the maximum permissible limits in fruits, vegetables, and animal products. Additionally, excessive pesticide use has been shown to alter soil microbiota, negatively compromising long-term agricultural fertility. In response to these challenges, recent advances in nanotechnology offer promising alternatives. This review highlights the development of nanopesticides designed for controlled release, improved stability, and targeted delivery of active ingredients, thereby reducing environmental contamination and increasing efficacy. Moreover, emerging nanobiosensor technologies, such as e-nose and e-tongue systems, have shown potential for real-time monitoring of pesticide residues and soil health. Although pesticides are still necessary, it is crucial to implement stricter laws and promote sustainable solutions that ensure safe and responsible agricultural practices. The need for evidence-based public policy is emphasized to regulate pesticide use and protect both human health and agricultural resources.

1. Introduction

The global population has steadily increased over the past decades, and with it, food demand has also risen. It is estimated that by 2050, the world’s population will exceed 10 billion people, posing a significant challenge to food security and necessitating the development of strategies to increase food production sustainably [1]. Agricultural pest management has been essential in addressing this need through the use of organic or inorganic pesticides, which are chemicals with varied structures used to eliminate pests and prevent plant diseases, including herbicides, insecticides, fungicides, and nematicides [2,3,4]. The most prevalent pesticides include organophosphates, chlorinated hydrocarbons, carbamates, and carbamide derivatives [5]. Although pesticides are useful, low-cost, and easy to use in agriculture, the intensive and often indiscriminate use of pesticides has raised serious concerns regarding their toxicological effects on living organisms and the environment. Pesticide residues are frequently detected in soil, water bodies, and food products, contributing to ecological imbalance, biodiversity loss, and the bioaccumulation of toxic compounds across trophic levels [6].

Pesticides can have adverse impacts on ecosystems through runoff, leaching, drifting, and evaporation, harming aquatic life, and disrupting beneficial soil microbial communities and pollinators [7]. Persistent pesticides can remain active in the environment for extended periods, hindering sustainable land management and soil fertility [8]. A meta-analysis of 54 studies found that pesticides significantly reduced the abundance and diversity of soil fauna communities [9]. Broad-spectrum pesticides and insecticides were especially harmful, with long-term studies showing more pronounced and persistent adverse effects. In the context of pesticide harm to non-target organisms, research on pesticides used in sugar cane crops, specifically chlorantraniliprole, isoxaflutole, and simazine, has shown that they disrupt the organization and structure of lipid membrane models. Additionally, histological findings revealed severe gill damage in fish at low concentrations and after short exposure (24–96 h), highlighting the rapid effects on essential functions such as respiration and osmoregulation [10].

Moreover, pesticides can harm humans and animals through skin absorption, inhalation, and contaminated water and food. They may alter the levels of antioxidant and oxidant enzymes in the body, potentially leading to oxidative stress-related diseases [5]. One study evaluated the impact of 2,4-D (dichlorophenoxyacetic acid), a commonly used herbicide, on animals and found that it induces oxidative stress, particularly with oral and transgenerational exposure. It has been reported that pesticide exposure, both in humans and animal models, has been shown to interfere with multiple endocrine pathways that regulate stem cell proliferation, survival, and differentiation, potentially contributing to the onset of chronic diseases, such as cancer [8]. Prolonged exposure to pesticides can impair the immune system and reproductive health. Hamed et al. [11] conducted a systematic review and meta-analysis on the effects of organophosphate pesticides, involving 766 men (349 exposed and 417 controls), indicating that while specific sperm metrics showed no significant changes, pesticide exposure was linked to reduced sperm count, motility, and morphology, emphasizing the need for further research. Chronic exposure to pesticides in agricultural communities is linked to serious health issues, including endocrine disruption, neurotoxicity, reproductive disorders, and various cancers [12,13]. A recent meta-analysis involving 5177 participants found that only 43.1% of farmers in developing countries practiced safe pesticide use, with 30.4% experiencing acute health symptoms like cough, headache, and skin irritation. The study emphasized that education and experience significantly influence safe pesticide practices, as literate and experienced farmers were five times more likely to use pesticides safely compared to illiterate farmers [13].

The presence of pesticide residues in food also represents a growing concern. A study of 76 citrus fruit samples found that 83% contained multiple pesticide residues, with 28% exceeding maximum residue limits (MRLs) [14]. The most frequently detected pesticides were imazalil, azoxystrobin, and dimethomorph. Imazalil was classified as high-risk, while prochloraz, chlorpyrifos, and others were medium-risk; the majority were low-risk. Health assessments indicated that while chronic exposure posed minimal risk, acute exposure, particularly in children, often exceeded acceptable limits.

Considering the adverse effects on human health and the ecosystem, as well as the inherent limitations of conventional pesticide formulations, such as low solubility, limited efficacy, and high persistence in the environment, modern agriculture is seeking innovative strategies to develop more sustainable alternatives. These new technologies should allow for a reduction in pesticide use, be environmentally friendly and safe, and improve both the quality and efficiency of agricultural treatments [15]. In this context, nanotechnology has emerged as a promising tool for designing advanced formulations that encapsulate pesticides or release alternative compounds in a controlled manner. Although its application in agricultural products, such as nanofertilizers and nanopesticides, has revolutionized the sector, this technology is still in its early stages [16].

One of the main approaches is the development of nanopesticides, which encapsulate active ingredients in nanomaterials to enhance solubility and efficacy, reduce dosages, and potentially minimize environmental dispersal through the controlled and targeted release of the control agent [5,17]. For example, nanoencapsulation of the fungicide azoxystrobin in porous silica prevented phytotoxicity, facilitated greater absorption of the pesticide, and promoted healthy tomato growth, without affecting the soil microbiota, compared to a conventional pesticide [18]. Additionally, nanomaterials with intrinsic insecticidal properties, such as metal oxide nanoparticles (e.g., aluminum oxide, zinc oxide, silver), can disrupt pest physiology and serve as physical barriers, eliminating the need for synthetic chemicals. Nanotechnology also enables the creation of nanosensors for the early and specific detection of pests or pathogens, allowing for targeted intervention and promoting sustainable agriculture [19,20,21,22,23]. Recent reviews have explored various nanotechnology-based pesticides, including nanoemulsions, nanoencapsulates, nano-gels, and electrospun nanofibers [5].

Nanopesticides, while beneficial for pest control, could pose significant environmental and toxicological risks due to their nanoscale properties. There are still insufficient conclusive and robust ecotoxicological and health studies at various biological levels and species, making it difficult to assess their actual risks [17]. Some of the main potential toxicological impacts of nanotechnology-based pesticides were reviewed by Ale et al. [17]. Specifically, the large surface area and reactivity of nanoparticles can increase toxicity, cause bioaccumulation, and disrupt cellular membranes or metabolic processes in non-target species. Many of the nanoparticles formulated are resistant to degradation, remaining in the environment and accumulating in ecosystems, with the potential to cause long-term effects that are still unknown [24,25]. Due to the slow release of active ingredients, encapsulation may result in prolonged, chronic exposure, which can have different toxicological effects over time [26]. Their tiny size and high mobility enable inadvertent uptake by non-target organisms through ingestion, cutaneous absorption, or sorption, resulting in adverse effects [27]. However, nano-agrochemicals are much less hazardous to non-target aquatic species than their traditional counterparts [25].

Although pesticides are extensively used in agriculture, current regulations are insufficient to address the risks posed by both traditional and nanotechnology-based formulations. The lack of specific regulatory frameworks and standardized methods for evaluating the ecological and long-term safety of nanopesticides hinders proper risk management. There is an urgent need to update legislation to reflect the unique properties of nanomaterials and to harmonize global standards for both conventional and nanoformulated pesticides. Continued research on the use, dosage, and mechanisms of action of traditional pesticides is essential to prevent adverse effects on human and environmental health. This review aims to provide a comprehensive overview of the environmental and human health impacts associated with the use of conventional pesticides while critically evaluating the emerging role of nanotechnology as a sustainable and safer alternative in modern agriculture.

2. Environmental Impact of Conventional Pesticides

The use of pesticides entails various risks, which can be grouped into two main factors: environmental damage and health damage. The environmental damage caused by these compounds results from their interaction with the environment, whether through contact during application, degradation, or the production of specific metabolites (Figure 1). The most significant environmental risks associated with pesticides include their physicochemical properties, persistence, and resistance to natural degradation, which can result in the long-term contamination of soil, water, and air, depending on their molecular weight, ionizability, volatility, solubility, and polarity [7]. Pesticides can bioaccumulate and biomagnify through the food chain, posing threats to biodiversity and ecosystem stability [28]. Access to these fractions of the environment can culminate in the accumulation of potentially toxic compounds in considerable quantities in the food environment, for example, in vegetables, which typically ranges from 0.1 to 100 mg/kg depending on the nature of the food and the pesticide. This is why the environment to which each food is exposed must be studied; the response to these components will depend on the exposure, species, and susceptibility [29]. The harm caused to the environment is related to the alteration of an ecosystem’s balance, primarily affecting flora and fauna [30]. Poor practices with pesticides and inadequate regulation of compounds generate waste that ends up in channels or aquifers, affecting marine species [31].

The most significant risk associated with pesticides in soil is their potential to accumulate due to their persistence and chemical stability, which can lead to long-term soil contamination [7]. This accumulation can affect soil microbial communities and reduce soil fertility, thereby disrupting soil health and ecosystem functions. For example, Streletskii et al. [32] found that changes in the relative abundance of the genera Terrabacter, Kitasatospora, Streptomyces, Sphingomonas, Apiotrichum, Solicoccozyma, Gamsia, and Humicola can be proposed as an indicator of pesticide contamination. Additionally, pesticides can leach and run off, transferring pollutants to water bodies and further contaminating groundwater and surface water systems [33]. The persistence and mobility of pesticides in the soil pose a long-term environmental risk by transforming soil into a secondary source of pollution, which can negatively impact plant growth, microbial diversity, and overall soil quality [34].

The meta-analysis by Beaumelle et al. [9] quantified the effects of pesticides on soil fauna abundance, biomass, richness, and diversity using 54 studies and 294 observations. The study identified scenarios with the most detrimental effects on soil fauna communities by analyzing different pesticides, application rates, temporal extents, and functional groups. The results showed that pesticides overall decreased the abundance and diversity of soil fauna communities, with a more pronounced effect on diversity. Multiple substances, including broad-spectrum pesticides and insecticides, had the most detrimental effects, even at recommended rates. Additionally, the effects of pesticides on soil communities appeared to persist over time. Both short-term and long-term studies exhibited similar mean effect sizes, with only long-term effects showing a significant negative impact. Long-term studies, which often involved repeated applications, tended to reveal more pronounced adverse effects, especially from insecticides and multiple substances, whereas short-term studies primarily addressed single applications with comparatively less impact. Thus, the effects of pesticides tend to persist and remain concerning over extended periods.

This contamination poses serious threats to aquatic ecosystems by affecting the health and diversity of marine organisms. Pesticides entering water bodies can lead to the mortality of fish and invertebrates, cause sub-lethal effects, such as behavioral changes, and impair physiological functions [35]. Additionally, pesticides can affect algae and aquatic plants, which are crucial to the food web, resulting in decreased primary productivity and altered habitat structures. For example, a study found that the pesticides acetochlor, dicofol, and chlorpyrifos significantly inhibited the growth and photosynthesis (measured by chlorophyll a) of the microalga Skeletonema costatum [36]. The bioaccumulation of pesticides in aquatic organisms can also biomagnify through the food chain, impacting higher trophic levels, including fish consumed by humans [28]. Water contamination by pesticides represents a critical environmental and public health concern due to their toxicity, persistence, and ability to enter human drinking water supplies [37].

Moreover, pesticides can have a significant impact on the ecosystem due to their toxic effects on non-target organisms and disruption of ecological balance [38]. After the application of pesticides, the remaining can disperse into the surrounding environment, posing risks to human health and harming non-target organisms within the agricultural ecosystem [39]. Pesticides can damage or eliminate beneficial species by disrupting essential biological functions. In earthworms, they compromise growth, reproduction, DNA integrity, and enzymatic activity. In pollinators such as honeybees, pesticides impair memory, learning, and alter foraging behavior. Additionally, they affect critical life history traits in predators and parasitoids, including reproduction, development, longevity, and feeding patterns [39]. Widespread pesticide application often leads to resistance among target pests, necessitating the use of higher doses or the development of new chemical agents. This approach simultaneously suppresses natural enemies, such as predators and pollinators, which can lead to pest resurgence or secondary outbreaks that may be even more severe than the initial infestation. These impacts collectively threaten ecosystem stability, reduce biodiversity, and impair essential ecological services, including pollination, nutrient cycling, and water purification. The nature of many pesticides makes their environmental impact a long-lasting and widespread concern, emphasizing the need for effective management and remediation strategies [28].

To mitigate the environmental risks associated with conventional pesticides, it is essential to develop sustainable pest management strategies. Investing in environmentally friendly alternatives, such as biopesticides and nanotechnology-based formulations, is recommended. These technologies can reduce environmental persistence, bioaccumulation, and effects on non-target organisms. Research should assess their long-term ecological safety. It is also crucial to strengthen regulatory frameworks and controls on the use and disposal of pesticides. Establishing environmental monitoring systems using microbial bioindicators is proposed. Farmer training is key to promoting integrated pest management. Awareness campaigns can reduce the overuse of pesticides. These actions promote safer and more sustainable agricultural practices. A coordinated approach is essential to protect biodiversity, ecosystems, and human health.

3. Oxidative Stress Risk Associated with Pesticide Exposure

Exposure to pesticides represents a significant risk to human health, both through immediate acute effects and through chronic consequences that can manifest years after exposure. In the short term, the main routes of absorption are through the skin, especially in agricultural workers, as well as inhalation and ingestion of residues in food and water [40]. This can cause immediate symptoms, such as eye and skin irritation, nausea, vomiting, headaches, dizziness, respiratory distress, acute bronchitis, and even seizures. Long-term, chronic exposure to pesticides has been associated with a significantly increased risk of various types of cancer, neurological disorders (such as Parkinson’s, Alzheimer’s, and autism), endocrine and reproductive disruptions, immunotoxicity, autoimmune disorders, and premature aging [40,41,42,43,44]. These effects are mediated by multiple toxicity mechanisms, including oxidative stress, mitochondrial damage, genetic and epigenetic alterations, interference with key neurotransmitters, such as acetylcholinesterase, and disruption of the gut microbiota. The most vulnerable populations include agricultural workers, children, pregnant women, and rural communities, who are at greater risk due to constant exposure or at sensitive stages of development [40]. These findings underscore the urgent need to implement stricter regulatory measures and promote sustainable agricultural alternatives.

The extent of damage to human health varies and is influenced by the chemical structure of the compound, which dictates its mechanism of action. Its physicochemical properties determine its affinity for specific biological systems. The dose and duration of exposure are critical factors that determine both the severity and nature of the resulting health effects [45]. In this context, regulatory oversight of pesticide use is essential. One of the critical parameters for evaluating the safety of these compounds in international trade is the determination of their median lethal dose (LD₅₀), which identifies the concentration at which a pesticide becomes toxic or poses a potential risk to human health through ingestion or exposure. The LD₅₀ represents the dose that causes mortality in 50% of a test population, typically determined using animal models, such as mice or rats, via oral or dermal administration. Normally, the lower the LD₅₀, the more toxic the pesticide, and, therefore, the more dangerous [46].

The potential harm associated with pesticide use is so broad that addressing it effectively requires classifying risks by compound type. Among the most studied pesticides are organophosphates, organochlorines, carbamates, pyrethroids, and their derivatives.

Table 1. Highly used pesticides and the harm associated with their exposure in in vivo studies.

Pesticide	Type	Target Organism	Associate Damage	DL50	Reference
Parathion/Methyl parathion	Organophosphate	Herbicide	In vivo studies have linked its use to the development of heart disease, an increase in CAT, TBARS, and GPx biomarkers, and a decrease in SOD, resulting in an overload of oxidative stress, alterations in acetylcholinesterase levels, and overstimulation of the central nervous system.	6–14 mg/kg/2–30 mg/kg	[47,48]
Rotencidal	Coumarin	Bromadiolone	At low concentrations, it has been linked to the appearance of oxidative stress in short exposures and the destabilization of biomolecules. For acute exposures, bromadiolone has been linked to the inhibition of the carboxylation of vitamin K-dependent coagulation factors (II, VII, IX, and X), producing an anticoagulant effect. It is also widely related to the deterioration of the intestinal mucosa and bleeding in the digestive and urinary tract. There have been cases related to exposure to bromadiolone and the development of diseases of the central nervous system or conditions affecting the brain mass, such as leukoencephalopathy.	1.125 mg/kg	[49,50,51,52]
Carbofuran	Carbamates	Herbicide and insecticide	After exposure to humans, a considerable increase in oxidative stress has been reported in several organs, including the liver, brain, kidney, and heart, which leads to the propagation of necrosis in hepatic and nephrotic cells.	8–14 mg/kg	[53,54,55]
2,4-D	Phenoxyacetic Acid	Herbicide	It is a widely used compound that causes significant damage to the environment and humans. In addition to the increase in oxidative stress and destabilization of biomolecules, it has been highly related to the inhibition of growth in cells and tissues. Its effects have been studied in different in vivo models, which found a behavioral pattern in terms of neurotoxicity and a decrease in motor skills was observed. Biochemically, it showed a decrease in serotonin levels or a decrease in dopamine levels and its metabolites depending on the brain area analyzed.	639–764 mg/kg	[56,57]
Cypermethrin	Pyrethroid	Acaracide	Often used in mixtures, its acute and subacute exposure causes clinical symptoms, such as pneumonia, acute kidney injury, tearing, acute respiratory failure, and diarrhea. Cypermethrin primarily acts by delaying the closure of voltage-sensitive sodium channels. Most of the effects caused by poisoning with this pesticide are neurotoxic, particularly in the respiratory and gastrointestinal tracts. Cases of cardiotoxic conditions have been reported, but these are insufficient to associate them with cypermethrin poisoning.	240–4123 mg/kg	[58,59,60,61]
Imidacloprid	Neonicotinoid	Insecticide	The most widely used neonicotinoid in the world is known to produce oxidative stress upon exposure. It has also been observed that, in the case of oral ingestion, the main symptoms and associated damage are gastrointestinal without corrosive lesions and neurological effects, such as dyspnea, coma, and diaphoresis. There is a particular relationship between imidacloprid poisoning and the development of various types of liver damage, which sometimes occurs late.	450–650 mg/kg	[62,63,64,65]
Benomyl	Carbamate	Fungicide	Linked to the generation of systemic oxidative stress. In vitro studies in rat cardiomyoblasts (H9c2) demonstrated a 2-fold increase in ROS and glutathione levels measured in cells exposed to benomyl compared to controls. Exposure to benomyl has been shown to induce apoptosis, oxidative stress, and DNA damage.	>10,000 mg/kg	[66,67]
Acetamiprid	Neonicotinoid	Insecticide	The severe oxidative stress generated by this pesticide is linked to genotoxic damage and the formation of cleavages in tRNA due to the changes it generates in biomolecules. Isolated cases have been reported where poisoning with acetamiprid triggered lactic acidosis, hyperglycemia, and intestinal obstruction.	217 mg/kg	[68,69,70]
Glyphosate	Organophosphate	Herbicide	Exposure to pesticides during the early stages of development can severely disrupt normal cell growth by interfering with several critical signaling pathways, leading to significant changes in cell differentiation, neuronal development, and myelination. Furthermore, glyphosate appears to have a notable toxic effect on neurotransmission, generating oxidative stress, neuroinflammation, and mitochondrial dysfunction, which can result in neuronal death through mechanisms such as autophagy, necrosis, or apoptosis. These neurotoxic effects are also associated with the development of behavioral disorders and impaired motor skills.	4320 mg/kg	[71,72]

2,4-D: 2,4-dichlorophenoxyacetic acid, CAT: catalase, TBARSs: thiobarbituric acid reactive substances, GPx: glutathione peroxidase, SOD: superoxide dismutase, ROS: reactive oxygen species.

presents commonly used pesticides and the associated health risks resulting from exposure to them.

Organophosphates are highly lipophilic pesticides derived primarily from phosphoric acid and widely used as insecticides, fungicides, acaricides, and nematicides. Their primary mechanism of toxicity is their potent inhibition of acetylcholinesterase, which is attributed to the presence of a quaternary nitrogen group in their structure. Due to their high reactivity, some organophosphates have historically been employed as chemical warfare agents. Their lipid solubility and elevated vapor pressure at ambient temperatures enable rapid absorption through oral, dermal, and respiratory routes. Once inside the body, they distribute efficiently into lipid-rich tissues and can readily cross the blood–brain barrier. Despite this, they do not typically bioaccumulate due to their rapid and effective biotransformation [73]. Some examples of organophosphate pesticides are chlorpyrifos, diazinon, malathion, and parathion, among others.

Organochlorine pesticides are halogenated organic compounds widely recognized for their high chemical stability and environmental persistence [74]. Their mechanism of action involves altering nerve transmission by acting as modulators of sodium channels in neuronal membranes that remain abnormally open, thereby generating continuous hyperexcitation of the nervous system. Furthermore, some organochlorines interfere with GABA-regulated chloride channels, which exacerbate their neurotoxic effects. One of the main problems associated with their use is their capacity for bioaccumulation, as they are stored in the fatty tissues of organisms, including humans, and biomagnify throughout the food chain, increasing their concentration at higher trophic levels and posing a significant ecological and toxicological risk. Some types of organochlorines are dichlorodiphenyltrichloroethane (DDT), hexachlorobenzene, polychlorinated biphenyls, lindane, endosulfan, dieldrin, methoxychlor, chlordane, taxophene, and dicofol [75].

Carbamates are chemical compounds belonging to the family of esters derived from N-methyl or dimethyl carbamic acids, widely used as insecticides, nematicides, herbicides, and fungicides [76]. Their mechanism of action involves the reversible inhibition of the enzyme acetylcholinesterase through a carbamylation process, resulting in the accumulation of acetylcholine in neuronal synapses [77]. Although this mechanism is similar to that of organophosphates, the neurotoxic effects caused by carbamates are usually less prolonged and severe due to the reversible nature of the inhibition. In cases of acute toxicity, symptoms typically include manifestations of cholinergic syndrome, such as excessive salivation, muscle spasm, and respiratory distress, although with less duration and intensity. Unlike other more persistent pesticides, carbamates have a low capacity for bioaccumulation due to their short half-life and rapid metabolism and elimination by the body, which reduces their risk of long-term systemic accumulation [76].

Pyrethroids, such as permethrin, deltamethrin, resmethrin, tetramethrin, γ-cyhalothrin, and cypermethrin, are synthetic compounds designed to mimic the structure and function of natural pyrethrins and are widely used as insecticides in agriculture, public health, and domestic pest control. Pyrethroids are categorized as neurotoxins that target the peripheral and central nervous system axons by modulating sodium channels in neurons, causing them to remain open for longer than usual. This leads to hyperexcitation, paralysis, and, ultimately, death in insects [78]. These compounds are more toxic to insects and fish than to mammals due to differences in metabolism rates and neuronal sensitivity. However, toxicity has been documented in aquatic organisms; in humans, exposure to high doses can cause paresthesia, skin irritation, seizures, and even severe neurological effects in extreme cases [79]. Although they present lower bioaccumulation and carcinogenic potential compared to organochlorines, their intensive use has favored the emergence of resistance in various insect species, posing a growing challenge for effective pest management.

There are various mechanisms and pathways of pesticide damage; however, one mechanism stands out as common to different types of pesticides: oxidative stress. This concept was coined by Helmut Sies, who defined it as an imbalance between the production of oxidizing agents and antioxidant defenses. Oxidative stress leads to the generation of free radicals and reactive oxygen species (ROS), which are highly reactive and capable of damaging lipids, proteins, and DNA [80]. Among free radicals and ROS, the most studied include hydroxyl, peroxyl, alkoxyl, hydroperoxyl radicals, as well as nitric oxide, all of which directly contribute to oxidative damage. In addition to ROS, reactive nitrogen species (RNS) are unstable, nitrogen-containing molecules that also participate in redox imbalance and contribute to cellular dysfunction and inflammation [81].

ROS are primarily produced during oxidative metabolism, such as in the mitochondrial electron transport chain, where molecular oxygen (O₂) serves as the final electron acceptor and is ultimately reduced to water (H₂O) (Figure 2). If only a single electron is transferred to oxygen, a superoxide anion (O₂⁻) is formed. This unstable species is converted into less reactive molecules by the action of the enzyme superoxide dismutase (SOD), which catalyzes its dismutation into hydrogen peroxide (H₂O₂) and oxygen. These intermediate products, in turn, can give rise to other reactive oxygen species. At the end of the electron transport chain, after the transfer of protons (H⁺) and electrons (e⁻), the complete reduction of molecular oxygen to water requires the addition of four electrons and four protons, highlighting the delicate balance in redox homeostasis [82].

ROS are essential to the body at very low concentrations, serving as a cellular signaling system and providing protection against infectious agents. However, if this balance is disrupted, ROS, given their limited stability, can generate highly reactive free radicals. Multiple factors, including poor diet, stress conditions, exposure to UV radiation, and metal ions, among others, can trigger the overproduction of these radicals. Once generated, free radicals interact with cellular components, causing damage proportional to their concentration and persistence. ROS can overcome the endogenous antioxidant system; given their reactivity, they are capable of oxidizing biomolecules. When oxidized, there is a change in their structure, resulting in the total or partial inhibition of their normal function. The most susceptible biomolecules are proteins, lipids, and nucleic acids (DNA). In search of stability, the free radical can steal an electron from any available biomolecule, initiating a chain reaction known as oxidative stress [83,84].

Oxidative stress is associated with the development of diseases, which can be classified as those generated by prooxidants that modify the redox state and alter glucose tolerance, promoting mitochondrial oxidative stress in diseases such as cancer and diabetes mellitus. The second group includes inflammatory oxidative stress and increased activity of the enzyme nicotinamide adenine dinucleotide phosphate oxidase (NADPH-ox), leading to atherosclerosis and chronic inflammation. The third group is derived from the xanthine oxidase system, generating ROS that are implicated in ischemic reperfusion injury. Furthermore, the aging process is linked to the damaging effects of free radicals, which cause the oxidation of biomolecules such as lipids, DNA, and proteins, thereby directly impacting the aging process [85].

Pesticides, being a widely used product in agriculture, are an important factor to consider when studying the means of oxidative stress as a generator of chronic degenerative diseases. Exposure to pesticides significantly increases the production of ROS, which are responsible for altering the oxidation–reduction state of cells. Faced with these stimuli, the first line of defense against oxidative imbalance is the endogenous antioxidant system, which neutralizes reactive species, thereby correcting the imbalance. Figure 3 illustrates how pesticides induce oxidative DNA damage, resulting in numerical and structural chromosomal alterations, single- and double-strand DNA breaks, and epigenetic changes. These alterations result in changes in the expression of genes involved in maintaining cellular homeostasis and in the progression of diseases. Direct interaction with the pesticide can destabilize the cell membrane, resulting in the loss of essential membrane functions. Constant exposure to pesticides generates imbalances in antioxidant enzymes (depending on the nature of the pesticide), resulting in a deficient antioxidant system.

SOD is an endogenous antioxidant enzyme that is the first line of defense against oxidative imbalances. It is a catalyst in the conversion of the superoxide radical into hydrogen peroxide and molecular oxygen. The resulting products are much less toxic and more stable, which contributes to cellular homeostasis. SOD activation due to pesticide exposure varies, depending on the nature and duration of exposure. It has been observed that SOD levels differ depending on the stimulated areas. In the brain, they decrease during exposure, while erythrocyte SOD increases, mainly with exposure to organophosphates and organochlorines [87].

On the other hand, the primary function of CAT (catalase) is to protect cells from the harmful effects of hydrogen peroxide generated by metabolism and various external factors, such as pesticide exposure. It is essential when it comes to tolerance to oxidative stress, and its action is crucial to combat hemoglobin peroxidation. The behavior of cells upon exposure to pesticides varies widely depending on the concentration to which they are exposed and the nature of the pesticide. Glutathione S-transferase is a dimeric enzyme responsible for phase 2 biotransformation of various electrophilic compounds and a mediator of tyrosine catabolism and prostaglandin biosynthesis, as well as cell apoptosis [88]. They are divided into three groups: cytosolic, mitochondrial, and membrane-associated proteins. When exposed to pesticides, they can be considered an inducer of enzyme activation [89].

Several studies have demonstrated that pesticides can significantly alter the antioxidant systems of non-target organisms, thereby affecting their ability to neutralize oxidative stress. In Labeo rohita fish exposed to the insecticide pyriproxyfen, a significant increase in oxidative stress biomarkers (such as ROS and thiobarbituric acid-reactive substances (TBARSs)) was observed, along with a decrease in the activity of antioxidant enzymes such as SOD, glutathione peroxidase (GPx), peroxidase (POD), and CAT [90]. Similarly, in prepubertal mice treated with malathion, a depletion of SOD, CAT, and GPx was reported, along with a specific reduction in the expression of GPx-4 in the liver and GPx-3 in the kidney, indicating severe damage to liver and kidney function [91]. In honeybees (Apis mellifera), the combination of the pesticides imidacloprid and amitraz with the fungal compound zymosan A resulted in synergistic inhibition of SOD and glutathione-S-transferase (GST), although CAT activity remained unchanged. These findings demonstrate that pesticides from different classes converge to affect redox balance, weakening key antioxidant defenses, such as SOD, GPx, CAT, and GST, and increasing the organism’s vulnerability to oxidative damage and disease [92].

Genotoxic damage is a significant risk factor in evaluating potential diseases resulting from repeated exposure to pesticides over several years. There are various types of genotoxicity-related damage (carcinogenic, neurological, and reproductive processes). Genetic alterations occur through mutagenic and non-mutagenic processes, with the first signs being the appearance of micronuclei, chromosomal aberrations, and nuclear abnormalities, which are the most frequently observed. Research in the field confirms a strong relationship between occupational exposure to pesticides and the development of these types of damage. The different kinds of pesticides produce this genotoxic damage, in addition to their effects on the immune, nervous, and endocrine systems [93].

Various investigations have examined the health risks associated with pesticide exposure from different perspectives, considering the conditions under which they interact with xenobiotics. Singh et al. [94] determined the relationship between polymorphisms and susceptibility to genotoxic damage from organophosphate pesticides in farm workers. This point escalates further when addressing the possibility that various diseases may be triggered by prenatal exposure. A relationship was found between prenatal exposure in children and the development of a polymorphism in the paraoxonase-1 (PON1) gene, specifically a substitution of glutamine for arginine at position 192, which alters normal antioxidant properties [95].

Children exposed prenatally had similar characteristics to unexposed children, such as a larger waist circumference, a higher percentage of body fat, and higher blood pressure, serum concentrations, and metabolic biomarkers, compared to children not exposed to pesticides [96]. These observations have made a significant contribution to linking pesticide exposure with the development of type 2 diabetes mellitus and cardiovascular diseases due to the genotoxic damage and mutations it can cause [97].

Hilgert Jacobsen-Pereira et al. [93] found that metabolic biomarkers, such as CAT and TBARs, were modified in exposed individuals compared to unexposed individuals, indicating consistently greater oxidative stress. There was also a greater number of micronuclei in the cells analyzed compared to those of unexposed individuals, indicating genotoxic damage. The damage caused by pesticide exposure or poisoning covers a wide range of effects, which is why there are different approaches to studying their toxicity. Among the most common tests evaluating the toxicological potential of pesticides are those listed in

Table 2. Main toxicological tests for pesticides.

Test Name	Evaluated Focus	Basis	Reference
Acute Toxicity Evaluation (Oral, dermal, inhalation) LD50. LC50. Skin irritation test (Draize Skin Test). Eye irritation test (Draize Eye Test). Acute inhalation test (exposure of animal models in chambers).	Acute toxicity tests.	Designed to assess the immediate effects of exposure to different pesticides. Tests are classified by exposure routes and evaluated within 24 to 96 h.	[98,99,100]
Chronic Toxicity Evaluation Carcinogenicity studies (OECD TG 451). Prenatal developmental toxicity study (OECD TG 414). Reproductive toxicity study (OECD TG 416).	Chronic toxicity tests.	Chronic toxicity tests evaluate the effects of prolonged and repeated low-dose exposures.	[98,99,100]
Genotoxicity Tests Ames test. Micronucleus test (OECD TG 487). Comet assay. Chromosomal aberration test (OECD TG 473).	Toxicological studies based on a pesticide’s ability to damage DNA and cause point mutations.	Due to the high reactivity of pesticides, they can induce mutations, chromosomal aberrations, or DNA strand breaks. These tests encompass the main mechanisms of DNA damage caused by pesticides.	[101,102,103,104]
Neurotoxicity Studies Behavioral tests. Measurement of cholinesterase inhibition. Functional tests in rats or mice (Functional Observational Battery).	Evaluation of pesticide effects on the central nervous system, especially those caused by organophosphates and carbamates.	By detecting the inhibition of key enzymes in the central nervous system, it is possible to identify motor or behavioral alterations in animal models and relate them to cognitive impairment.	[105,106,107]
Toxicokinetic Assays ADME tests (Absorption, Distribution, Metabolism, and Excretion). Radio-labeled isotopes. In vitro models (cell cultures simulating liver metabolism).	General evaluation of a pesticide.	Analyzing ADME helps understand how long a pesticide can remain reactive in the body and where it might accumulate.	[108,109,110]
Biochemical Tests Cholinesterase inhibition (Ellman test). Alterations in liver enzymes (alanine transaminase and aspartate transaminase).	Evaluation of alterations in enzymatic systems based on the central nervous system.	These tests assess a pesticide’s effects on specific metabolic and enzymatic systems, usually in the liver or nervous system, depending on the pesticide’s nature.	[111,112,113]

.

It is crucial to promote multidisciplinary research on the cumulative effects of pesticide-induced oxidative stress. Authorities must strengthen regulations, establish residue limits, and monitor vulnerable populations. The use of safer and more sustainable pesticides must be encouraged. Responsible agricultural practices that reduce dependence on toxic products are essential. Awareness campaigns and agricultural education are key to disseminating the risks. Integrated pest management must be promoted as a viable alternative. Furthermore, biomarkers of oxidative stress and genotoxicity should be used as early signs of exposure. This will prevent adverse effects on human health. A comprehensive preventive approach is essential to protect exposed communities.

4. Pesticides in Food and Their Effect on Human Health

The presence of pesticide residues in food is an undeniable reality. Numerous studies have reported that fruits and vegetables frequently contain trace amounts of these chemicals, in some cases exceeding the MRLs established for consumer safety [114,115]. The leading causes of these residues are often related to improper pesticide use, such as applications made outside the recommended pre-harvest intervals or at concentrations higher than those approved to preserve crop yield and quality. These poor agricultural practices increase the likelihood of detecting pesticide residues above legal limits, thereby posing a potential health risk to consumers [116]. The problem posed by this situation escalates significantly when evidence of contamination is found outside of agricultural fields where direct pesticide treatment is carried out. Jia et al. [117] noted that the migration of pesticide residues into foods of animal origin and during the breeding of these species could lead to accumulation, migration, and the formation of secondary metabolites, which pose a potential risk to human health. Among the foods identified are meat, eggs, and milk [117,118].

The presence of pesticide residues in citrus fruits and the acute and chronic human health risks in adults and children were assessed [14]. Seventy-six samples were analyzed, of which 83% contained multiple residues and 28% had levels at or above MRLs. The most frequently detected pesticides were imazalil, azoxystrobin, and dimethomorph. Using a risk classification matrix, imazalil was identified as a high-risk pesticide, while prochloraz, chlorpyrifos, azinphos-methyl, tebufenpyrad, and fenpyroximate were considered medium-risk pesticides; the remaining 74% were classified as low-risk. The health risk assessment revealed that the chronic risk was generally negligible for the population, while the acute risk of imazalil and thiabendazole exceeded acceptable levels in critical scenarios. The cumulative assessment showed that chronic risk was acceptable in all cases, but acute risk was unacceptable in 5.3% of the adult samples and 26% of the child samples. Finally, the sensitivity analysis indicated that the most significant risk determinants were intake rate and individual body weight, highlighting the need for ongoing monitoring to ensure food safety [14].

It has been reported that pesticide residues are present in coffee after processes such as washing, drying, roasting, and grinding [119]. In a study, 71 coffee samples sold in supermarkets in Serbia were examined, and nine distinct pesticide residues were found. Seven of them are not permitted for use on coffee under European Union legislation, and carbaryl, permethrin, and cypermethrin quantities were above the MRL. Residues were detected in 79.2% of the samples, with mepiquat chloride (88.9%) and permethrin (81.9%) being the most frequent. Despite these regulatory infractions, acute, chronic, and cumulative risk studies revealed that coffee is safe for both short- and long-term consumption. However, the authors cautioned that the total cumulative risk is caused by exposure to multiple pesticides across various meals, and they emphasize the importance of continued surveillance, particularly given the high-risk ratings for mepiquat chloride, permethrin, and methiocarb sulfone. As a drawback, the study assessed residues in coffee beans using a conservative scenario in which all pesticides were assumed to be transmitted to the brew, thereby overestimating actual consumer exposure.

In a similar context, pesticide residues in tomatoes and their associated risks to human health were reviewed in a meta-analysis conducted through a systematic review of 47 studies [120]. The authors assessed the concentration of five common pesticides (metalaxyl, malathion, cypermethrin, diazinon, and chlorpyrifos) in tomatoes and calculated the non-cancer risk for consumers. The results showed that metalaxyl presented the highest concentration, but malathion was the pesticide with the most significant health risk, especially among Iranian consumers. The study concluded that given the growing demand for food and the potential for increased pesticide use, governments must regulate their use and promote alternative pest control methods [120].

The risks associated with consuming foods containing pesticide residues are varied; in general, they are attributed to an increased risk of developing chronic degenerative diseases, such as various types of cancer or endocrine and reproductive disorders [116]. Pesticides are known as potential mutagens due to the reactivity of their active ingredients. Although these vary depending on the nature of the chemical, the main damages are usually chromosomal aberrations and DNA damage. This mechanism has been linked to accelerated telomere shortening thanks to exposure to and consumption of pesticides, mainly organochlorines. Five groups of occupational exposure associated with this phenomenon have been identified, namely, pesticides, organic solvents, dust and particles, metals, and ionizing radiation [121,122].

The damage mentioned above is focused explicitly on modifications resulting from interactions with pesticides. However, consuming foods with pesticide residues produces various health effects.

Table 3. Health effects of pesticide consumption and exposure.

Pesticide	Study	Conclusion	Reference
Mixtures of organochlorine and organophosphate pesticides, most notably 2,4-DDE, 4,4-DDE, γ-BHC, and β-BHC	A group of 29 adolescents was studied, with 75% of them belonging to families of agricultural day laborers. Additionally, 43.7% had gardens at home, and 64.28% used pesticides. The study linked interactions with pesticides to menstrual cycle disruption.	In serum levels of sexual hormones, more than 40% of adolescents presented alterations in their hormonal profile, and 96.9% of adolescents had detectable plasma levels of pesticides. However, some indications suggested a relationship between 4,4-DDE in plasma and alterations in the menstrual cycle; no statistically significant differences were found. This may be due to the group chosen and the time designated for the study.	[123]
More than 100 pesticides classified as carcinogenic by the EPA	A meta-analysis of the presence of pesticides in different fruits and vegetables.	Within the study, various pesticides found in fruits and vegetables, including grapes, mangoes, tomatoes, strawberries, apples, and peppers, were compiled. These pesticides are widely linked to the development of chronic degenerative diseases, alterations in the endocrine system, and disruptions in reproductive health in both adults and children.	[124]
A total of 91 samples were identified as exceeding the permitted MRLs in Korea, including Chlorfenapyr, Procymidone, Etofenprox, Pendimethalin, and Fluopyram	A total of 1146 fruits and vegetables were collected from a Korean market and tested for 15 pesticides of interest.	Although the identified pesticides are related to damage to the central nervous system, endocrine system, and liver conditions, it is necessary to note that they were identified in only 8.9% of the total samples, compared to other countries, where this percentage is lower.	[125]
Pesticides such as DDT, dieldrin, and HCB	The factors influencing the presence of organochlorine pesticides in breast milk and the resulting damage to children were addressed.	Organochlorine pesticides can act as endocrine disruptors, and estrogen-inducing pesticides can accumulate with exposure to water, soil, environmental exposure, or food. Levels of HCB or DDT residues have been linked to decreased birth weight and head circumference. The opposite effect can occur with certain OGC pesticides, thanks to lipogenesis.	[126]

2,4-DDE: 2,4-dichlorodiphenyldichloroethylene; 4,4-DDE: 4,4-dichlorodiphenyldichloroethylene; β-BHC: beta-hexachlorocyclohexane; DDT: dichlorodiphenyltrichloroethane; EPA: Environmental Protection Agency; HCB: hexachlorobenzene; γ-BHC: gamma-hexachlorocyclohexane (Lindane); MRLs: maximum residue limits.

presents various health effects associated with the consumption of foods containing residues and exposure to pesticides.

Future recommendations should focus on stricter regulation of pesticide residues in food. It is crucial to ensure that pesticides are applied correctly and that pre-harvest intervals are strictly adhered to. Therefore, more research is needed on the effects of chronic exposure, especially in vulnerable populations. Children, pregnant women, and agricultural workers are priority groups for protection. Additionally, post-harvest technologies and alternative pest control methods should be promoted. Investing in these technologies will help reduce residues in food. On the other hand, public health campaigns are essential to inform consumers. It is also important to promote safe food handling and purchasing practices. Routine biomonitoring programs should be established among the population. Finally, strengthening food safety infrastructure will protect public health in the long term.

5. Nanotechnology as an Alternative to Pesticides in Agriculture

Nanotechnology is emerging as a promising alternative to alleviate the environmental and health impacts of conventional pesticides, offering more precise, biodegradable, and efficient solutions. Nanotechnology holds significant promise for addressing prevalent agricultural challenges, particularly through the development of nanofertilizers, nanopesticides, and nanobiosensors utilizing nanomaterials. These innovations aim to increase crop yield and mitigate adverse environmental impacts [127,128]. This review will focus on nanotechnology as an alternative to pesticides in agriculture (Figure 4).

It is essential to highlight that pesticides play a crucial role in agriculture, enabling the production of a greater number of crops without waste and providing food for the population. Furthermore, without them, the loss of human lives could be significant due to vector-borne diseases and crop losses [129]. However, as mentioned above, they have adverse effects on the environment, ecosystem, and human health because only a small amount of the applied pesticides reaches the target pests, and the rest is dispersed into the environment due to their volatility and leaching. In this sense, nanotechnology, through the development of different materials, is a viable option to overcome these limitations. Thanks to their slow degradation and the controlled release of active ingredients through the use of appropriate nanomaterials, these products enable effective pest control over extended periods.

Unlike conventional pesticides, nanopesticides exhibit distinct behaviors that improve their effectiveness [130]. Nanopesticides are nanoscale materials (measuring between 1 and 100 nanometers, or even larger, depending on the application), where the physical and chemical properties of the compounds are significantly modified, giving them unique advantages. One of the primary characteristics of these nanomaterials is their high surface-to-volume ratio, which increases their contact area and enhances adherence to plant surfaces or the bodies of pest insects, also facilitating penetration through biological barriers [128,131,132]. Furthermore, they enable the encapsulation of compounds and the creation of systems for the prolonged, targeted, and specific release of the active ingredient, which responds to specific environmental stimuli, such as changes in pH, temperature, or the presence of enzymes specific to the pest organism [133,134]. Furthermore, these nanomaterials can be functionalized with molecules that bind to specific receptors of the biological target, thereby increasing their precision and reducing side effects [135].

Nanoencapsulation also protects the active ingredient from adverse environmental factors, such as ultraviolet radiation, humidity, and volatilization, thereby increasing its stability and prolonging its activity in the field, which allows for reduced application frequency. Nanoformulations also improve the solubility of many poorly water-soluble pesticides, increasing their bioavailability and, consequently, their efficacy. Furthermore, by increasing the solubility of the active ingredient, these systems facilitate its mobility and biodegradation by microorganisms present in the soil. For these reasons, nanoparticle-based pesticides are considered to have a lower environmental impact compared to their conventional counterparts [129]. Moreover, some nanomaterials, especially metallic nanoparticles such as silver, zinc, or copper, possess intrinsic pesticidal effects. These materials can act by ROS, releasing metal ions that are toxic to pest cells or disrupting fundamental cellular processes, thereby providing new modes of action that complement or replace traditional pesticides [136].

Nanopesticides are developed from a wide range of materials and formulations. One of the most common applications is the nanoencapsulation of conventional pesticides. It involves encapsulating the active ingredients of synthetic pesticides, such as insecticides, fungicides, and herbicides, in nanovesicles (e.g., liposomes and micelles), polymeric nanocapsules (e.g., chitosan, starch, and polylactic acid), or inorganic matrices (e.g., silica and zeolite). This improves their stability, reduces leaching and volatilization, and allows for gradual and targeted release [134]. For example, azoxystrobin, a fungicide, was encapsulated in porous silica and compared with the unencapsulated pesticide during application to agricultural soils under control conditions with Solanum lycopersicum (tomato) plants [18]. The results showed that the conventional pesticide had a severe impact on plant growth, reducing biomass by 3.85 times, whereas the nanoencapsulated formulation allowed for healthy plant growth. At the level of soil microbiota, no significant changes were observed with either formulation, indicating low environmental toxicity. Initial absorption of the pesticide was higher with the conventional form (2.7 times more per unit of biomass in 10 days), but this led to phytotoxicity due to its high bioavailability. In contrast, nanoencapsulation enabled a slow and controlled release, which prevented toxic effects and, after 20 days, resulted in greater total absorption and absorption by dry biomass (3 and 10 times more, respectively) [18].

Another application of nanotechnology is the use of nanoparticles with intrinsic pesticide activity. Specific nanomaterials, such as metal oxide nanoparticles (ZnO, CuO, AgNPs, TiO₂) or carbon nanoparticles (carbon nanotubes, graphene), have demonstrated insecticidal, fungicidal, and bactericidal properties on their own, even at low concentrations [129]. This opens the door to green pesticides that do not contain synthetic chemical active ingredients. In this context, suspensions of ZnO-NPs at three concentrations (300, 1000, and 3000 ppm) were tested on controlled populations of Puto barberi (mealybug) [137]. The results showed a mortality rate of approximately 55%, demonstrating its potential as a nanopesticide. However, the authors emphasize that additional studies, particularly focused on surface characteristics and other physicochemical parameters, are needed to optimize the effectiveness and safety of the nanomaterial in agricultural applications [137]. Similarly, green-synthesized CuO nanoparticles exhibited dual functionality, demonstrating high insecticidal efficacy against storage pests and stimulating plant growth in wheat. Specifically, CuO-NPs were tested against Sitophilus granarius and Rhyzopertha dominica, observing mortality rates of 55–94.4% for S. granarius and 70–90% for R. dominica [138]. In the same approach, ZnO-NPs biosynthesized with the alga Ulva fasciata demonstrated superior efficacy as nematicides compared to their bulk form or to oxamyl alone [139]. Their ability to adhere to nematodes and potentially cause structural disruption represents a promising and environmentally friendly strategy for nematode control in plantain crops. The treatment with ZnO-NPs + oxamyl (chemical nematicide) produced the highest mortality of second-stage juveniles (J2s) with 98.91% after 72 h, while ZnO-NPs alone reached 72.86% mortality. Under in vivo conditions, the same treatment significantly reduced the J2 population in the soil (82.77%) and the number of root galls (81.87%). However, treatments with ZnO-bulk + oxamyl and oxamyl alone promoted the most significant plant growth in terms of shoot height and weight [139].

Nanoemulsions and nanosuspensions are another approach to applying nanotechnology in the delivery of conventional pesticides. These formulations enable the active ingredient to be presented in nanometer-sized droplets or particles, thereby increasing its efficacy and improving the dispersion and penetration of poorly soluble pesticides [140]. Zhang et al. [141] developed an efficient and environmentally safe pyraclostrobin nanoemulsion, characterized by improved retention and lower surface tension, which facilitates better plant adhesion and dispersion. In addition, the formulation showed high bactericidal activity and lower toxicity in zebrafish, representing a sustainable alternative to conventional pesticide formulations. Similarly, a nanoemulsion of fenpropathrin, a lipophilic insecticide, presented an LC₅₀ of 50.01 mg/L against Helicoverpa armigera larvae, a lower value than the commercial formulation, indicating greater insecticidal efficacy [142]. Treated larvae showed darkening, shrinkage, and rapid immobilization. Regarding toxicity to the earthworm Eisenia fetida, the LC₅₀ values were 96.60 mg/kg at 7 days and 47.99 mg/kg at 14 days, suggesting low toxicity in soil. Regarding cellular cytotoxicity, cell viability in human L02 cells was 85.32% and 68.95% after 24 and 48 h of exposure, respectively. Furthermore, the apoptosis rate was significantly lower with the nanoemulsion (8.52%) compared to the commercial formulation (63.18%), demonstrating lower cytotoxicity associated with the use of the nanoemulsion [142].

On the other hand, nanotechnology has also been used to encapsulate bioactive compounds, such as natural compounds extracted from plants, other than pesticides. In this regard, biodegradable nanoparticles of zein, a corn protein, were prepared for the encapsulation of limonene and carvacrol [133]. This system proved to be a targeted release system, activated by insect intestinal enzymes, allowing for controlled and specific release. The formulations were stable over time and nontoxic to bean plants (Phaseolus vulgaris). Furthermore, in in vivo tests with Spodoptera frugiperda larvae, the nanoparticles showed higher mortality compared to controls, indicating high insecticidal efficacy [133]. In a similar approach, the efficacy of nanoemulsions formulated with essential oils of basil, cumin, marjoram, and chamomile as botanical insecticides against Aphis craccivora was evaluated, compared to chemical insecticides such as dinotefuran and pymetrozine [143]. These nanoemulsions exhibited high toxicity against both laboratory and field strains of the cowpea aphid A. craccivora, with basil having an LC₅₀ of 45 mg/L, compared to 992 mg/L for the unencapsulated essential oil and the synthetic insecticides. This was attributed to the small size of the nanoemulsion and its ability to penetrate the body of the pest. Furthermore, significant enzymatic alterations were detected in treated insects, suggesting toxicity mechanisms associated with the inhibition of key enzymes, such as acetylcholinesterase [143]. These studies indicate that nanotechnology can be utilized to promote more sustainable and environmentally safe pest management.

One of the primary applications of nanotechnology is the development of nanobiosensors, which are now being utilized as a crucial tool for rapid and sensitive detection of pathogens or pests, enabling earlier and more localized intervention and reducing the need for widespread pesticide applications. Additionally, nanosensors are used to identify soil moisture levels, pesticide residues, and nutrient requirements [19]. Nanobiosensors possess essential properties, including smaller detection limits, robustness, selectivity, sensitivity, rapid response times, high surface-to-volume ratios, and cost-effectiveness, which contribute to their overall effectiveness. Detection limits reported in studies are at the parts per trillion level for atrazine, ranging from nanomoles to micromoles for acetamiprid, and at nanogram levels for glyphosate and glufosinate [144].

Biosensors function by detecting a specific stimulus and converting it into a measurable signal, such as an electrical wave, heat, or another quantifiable response. This conversion typically occurs through chemical or enzymatic reactions or via light absorption. These sensors are capable of detecting changes in wavelength, intensity, polarity, light phase, and, in some cases, fluorescence [145]. One of the most common applications of biosensors is the use of colorimetric methods. For example, Ahmed et al. [20] proposed the use of red-colored selenium particles, a product of bioreduction with heavy metals, for field identification and toxicity testing. Similarly, a colloidal gold immunochromatographic assay using nanobodies as recognition elements was developed to detect parathion, an organophosphate pesticide banned due to its high toxicity in agricultural products [21]. Under optimal conditions, the assay demonstrated good recoveries in detecting parathion in real samples of cabbage, cucumber, and orange, with a high correlation to UPLC-MS/MS analysis, thereby validating its accuracy [21].

Additionally, the electronic nose (e-nose) and electronic tongue (e-tongue) are examples of biosensors used in agriculture and food analysis [146,147]. These devices replicate the sensory roles of the human tongue and nose, respectively. With its combination of chemical sensors and pattern recognition software, the e-nose can detect and distinguish volatile organic compounds with great precision, making it a powerful tool for identifying particular odors or alterations in aroma profiles [148,149]. In a similar manner, the e-tongue employs a collection of non-specific, cross-reactive sensors to identify dissolved substances associated with taste (such as bitterness, sweetness, sourness, saltiness, and umami) [147]. These sensors produce electrical signals when they detect chemical stimuli, and these signals are analyzed using statistical or machine learning models. Both tools have extensive applications in the quality control of food products, monitoring crop freshness, detecting contamination or spoilage, and assessing the impact of various agricultural treatments on flavor and aroma. Because they are highly sensitive, respond quickly, and perform non-destructive analyses, they serve as valuable substitutes for traditional sensory panels and chromatographic techniques [128,147].

The adoption of nanotechnology in pest management offers multiple benefits, including reduced pesticide use, as increased efficiency and direct delivery can result in lower amounts of active ingredients, thereby reducing costs for farmers and minimizing environmental impact. The use of nanotechnology in agriculture helps reduce soil and water contamination by lowering the risks of volatilization and leaching, thereby decreasing the accumulation of toxic residues in the environment and throughout the food chain. Furthermore, nanotechnology, by offering controlled and even targeted release, could present lower toxicity to non-target organisms, control pesticide resistance in pests, and increase safety for pesticide applicators in the field. Moreover, nanoencapsulated pesticides or active ingredients can offer greater stability and a longer shelf life.

Regarding the toxicity effects of nanotechnology-based products, there are still insufficient, conclusive, and robust ecotoxicological and health studies at various biological levels and species, making it difficult to assess their actual risks [17]. It has been reported that nanopesticides could pose significant environmental and toxicological risks due to their unique nanoscale properties [26]. The large surface area and reactivity of nanoparticles can increase toxicity, cause bioaccumulation, and disrupt cellular membranes or metabolic processes in non-target species such as algae, invertebrates, and fish [17]. Many of the nanoparticles formulated are resistant to degradation, remaining in the environment and accumulating in ecosystems, with the potential to cause long-term effects that are still unknown [24,25]. For example, nanoformulations of clothianidin enhanced its water half-life by up to 21%, indicating a longer-lasting presence compared to conventional products [150]. Additionally, due to the slow release of active ingredients, encapsulation may result in prolonged, chronic exposure, which can have various toxicological effects over time [26]. The small size of nanotechnology-based products could enhance their transportability, allowing them to penetrate sediments and accumulate in various environmental sites, potentially reaching non-target organisms, including higher organisms and possibly humans [27]. For example, a study reported that the toxicity of SiNPs against Spodoptera frugiperda Sf9 (corn earworm) cells increased as particle size decreased; the LD₅₀ of 1430 was 4.709 mg/mL and dropped to 0.133 mg/mL for the 14 nm sized NPs [27]. However, nano-agrochemicals are much less hazardous to non-target aquatic species than their traditional counterparts [25].

A review by Xuan et al. [26] compiled studies on the effects of nanoparticles on health, which, although many of them are not related to the development of nanopesticide formulations, can provide insight into the behavior and toxicity of these products in various cellular and animal models. In the respiratory system, nanoparticles such as TiO₂, SiO₂, Ag, and CuO are deposited in the lungs, where they trigger oxidative stress, inflammation, fibrosis, epithelial damage, and airway remodeling [151]. In the nervous system, NPs such as SiO₂, Ag, Fe₂O₃, and PbO can cross the blood–brain barrier, leading to neuroinflammation, neuronal apoptosis, and alterations in the gut–brain axis [152,153]. At the endocrine level, metallic NPs, such as Ag, ZnO, and TiO₂, have been shown to act as hormone disruptors by mimicking hormones, altering thyroid function, and dysregulating the hypothalamic–pituitary–gonadal axis [154]. Likewise, some metallic NPs (ZnO, Cr(VI), Ni) have been associated with carcinogenic effects by inducing mutations, genetic damage, and chronic inflammation [155]. However, as stated before, more studies are needed to determine the potential health and environmental risks, specifically those related to nanotechnology-based products and alternatives to pesticides.

Despite their many advantages, the adoption of nanopesticides in agriculture faces several challenges. Further studies are needed to assess the toxicity of these technologies to different organisms, as well as their persistence in the environment, bioaccumulation in the food chain, and long-term effects on non-target organisms and human health. Production costs and the lack of clear regulatory frameworks for commercializing these nanopesticides also need to be addressed. Public education and acceptance of these emerging technologies are crucial components for their practical application. With rigorous research, appropriate regulatory frameworks, and effective dissemination strategies, nanopesticides have the potential to become a vital tool for more efficient, sustainable, and environmentally responsible agriculture.

Nanotechnology must be carefully evaluated to ensure its long-term safety for health and the environment. Specific regulatory frameworks must be established, and the development of safe and biodegradable nanomaterials must be encouraged. Investment in education for farmers and consumers is recommended. Furthermore, the use of nanobiosensors and controlled-release systems must be promoted. Finally, these innovations must be integrated into public policies and integrated pest management programs.

6. Regulations

The increasing awareness of the potential harm associated with pesticide use has led to the implementation of extensive legislation regulating these chemicals. However, such regulations vary significantly across countries, depending on specific crop requirements and legal thresholds for plant protection [156]. Typically, developed nations tend to enforce stricter regulations than developing countries, mainly due to differences in available resources and experience in implementing and monitoring pesticide legislation [157]. These disparities often pose challenges to international trade, prompting efforts to harmonize standards at the global level. To address this, organizations such as the Codex Alimentarius Commission, the North American Free Trade Agreement (NAFTA), and the European Union have sought to harmonize standards by establishing MRLs. Nonetheless, these limits still differ across regions, influenced by economic interests [158].

Among the bodies responsible for legislating, the Food and Agriculture Organization of the United Nations (FAO) establishes international standards through the Codex Alimentarius, which are not mandatory. In the United States, pesticide regulation is overseen by the Environmental Protection Agency (EPA) through the Federal Insecticide, Fungicide, and Rodenticide Act. The EPA, in collaboration with the U.S. Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA), is responsible for setting MRLs and ensuring the safe use of pesticides, including the sale, distribution, storage, waste disposal, and usage records [159].

The European Union is also recognized as having the most stringent regulatory system, as outlined in Regulation (EC) No. 1107/2009, which governs the marketing and authorization of plant protection products. This regulation prioritizes human and environmental safety, requiring comprehensive testing to verify the efficacy and safety of pesticides before they are authorized [160,161]. Despite these advances, regulatory gaps remain. For instance, in Mexico, approximately 141 pesticides are currently in use that are banned in other countries. As of 2017, many of these substances were still classified as highly hazardous pesticides by the FAO, underscoring the need for greater international alignment and enforcement in pesticide regulation [162].

Although pesticides are widely used in agriculture, current regulations are insufficient to adequately address the risks associated with both traditional formulations and newly developed technologies. Most regulatory frameworks were designed to evaluate traditional pesticides and do not account for the unique physicochemical properties of nanomaterials. This regulatory gap poses significant challenges for the safe use of nanotechnology in agriculture, as there are no standardized methods to assess the ecological toxicity and long-term safety of nanopesticides. Consequently, the lack of specific guidelines and harmonized testing procedures may result in unforeseen adverse effects on ecosystems and human health. Therefore, it is crucial to update existing laws and establish new regulations that account for the distinct behavior of nanoformulated pesticides.

Furthermore, advancing towards a more uniform global regulation, including the alignment of MRLs and risk assessment protocols, would reduce regional disparities and ensure consistent safety standards across regions. Strengthening regulations in developing countries through investment in infrastructure, training, and collaboration is essential. It is also necessary to phase out hazardous pesticides and promote safer alternatives. To prevent toxic effects on human and environmental health, rigorous scientific studies on the use, dosage, and mechanisms of action of traditional pesticides should be continued, reinforcing an integrated and preventive management of these compounds. Public access to information and stricter trade controls are key. Ultimately, environmentally friendly methods must be integrated into national policies to safeguard both health and the environment.

7. Conclusions

This review identified that, while conventional pesticides are effective for pest control when used under regulatory guidelines, their widespread and indiscriminate use has generated multiple adverse effects on human health and the environment. A relationship has been documented between chronic exposure to pesticides and chronic degenerative diseases, such as cancer, attributed primarily to the oxidative stress and genotoxic damage these compounds induce from prenatal development through old age. These findings emphasize the urgent need to adopt a more preventive, responsible, and sustainable approach to pest management.

Alternatively, agricultural nanotechnology is positioned as a promising tool that can improve the effectiveness of pest control while simultaneously reducing the health and ecological risks associated with traditional pesticides. Technologies such as nanoencapsulation, nanocarriers, and the targeted and prolonged release of active ingredients have demonstrated a significant capacity to reduce the excessive use of pesticides and their side effects. Likewise, the development of agricultural nanobiosensors enables real-time monitoring of pests, pathogens, and residues, which favors more precise and streamlined interventions.

From an environmental perspective, nanoformulations can mitigate the runoff, leaching, and volatilization of active compounds, thus reducing their accumulation in soils, water bodies, and food webs. Furthermore, a reduction in human exposure levels has been observed, both for agricultural workers and consumers, thanks to the reduction in required doses and improved release mechanisms.

However, significant challenges remain, related to long-term toxicity, bioaccumulation in non-target organisms, and the lack of harmonized regulatory frameworks for nanotechnology products in agriculture. Therefore, future recommendations could include strengthening interdisciplinary research on the long-term effects of pesticides on non-target organisms and their interaction with complex ecosystems, as well as promoting clear, robust, and evidence-based regulatory frameworks that guarantee safety in the production, commercialization, and application of nanotechnology-based technologies. For example, integrating smart monitoring technologies, such as nanobiosensors, into agricultural systems can reduce dependence on broad-spectrum pesticides.

With the support of appropriate public policies and cooperation between the scientific, agricultural, and regulatory sectors, nanotechnology can be a key strategy for more sustainable, efficient, and safe agriculture.