Exposure of Agroforestry Workers to Airborne Particulate Matter and Implications Under Climate Change: A Review

Abstract

Climate change significantly intensifies agroforestry workers’ exposure to atmospheric particulate matter (PM), raising occupational health concerns. This review, based on the analysis of 174 technical and scientific sources including articles, standards and guidelines published between 1974 and 2025, systematically analyses the main sources of PM in agricultural and forestry activities (including tillage, pesticide use, harvesting, sowing of treated seeds and mechanized wood processing) and focuses on the substantial contribution of agricultural and forestry machinery to PM emissions, both quantitatively and qualitatively. It highlights how changing climatic conditions, such as increased drought, wind and temperature, amplify PM generation and dispersion. The associated health risks, especially respiratory, dermatological and reproductive, are exacerbated by the presence of toxicants (such as heavy metals, volatile organic compounds and pesticide residues toxic for reproduction) in PM. Despite existing regulatory frameworks, significant gaps remain regarding PM exposure limits in the agroforestry sector. Emerging technologies, such as environmental sensors, AI-based predictive models and drone-assisted monitoring, are proposed for real-time risk detection and mitigation. A multidisciplinary and proactive approach integrating innovation, policies and occupational safety is essential to safeguard workers’ health in the context of increasing climate stress.

1. Introduction

Climate change is one of the main global challenges of the 21st century, with increasingly evident effects on environment, economy and human health. This phenomenon is recognized as a priority by the UN 2030 Agenda for Sustainable Development, which dedicates Goal 13 to action against climate change and its consequences [1]. Effective and urgent mitigation measures are essential to limit its consequences and promote global sustainability. Among the direct and indirect effects of climate change, its impact on the health and safety of workers stands out [2]. Rising temperatures, greater exposure to ultraviolet radiation and exposure to pathogens (including alien ones), both indoor and outdoor air pollution and the intensification of extreme weather events can amplify existing general risks to health and safety at work or create new ones [3]. These factors lead to increasing health costs, reduced quality of life and losses in productivity [4]. The latest global report of the International Labour Organization (ILO), published in 2024, highlights six main areas in which climate change affects workers’ health and safety: excessive heat, ultraviolet radiation, extreme weather events, air pollution in the workplace, vector-borne diseases and changes related to the use of agrochemicals [5]. All work sectors are exposed to these risks, although the intensity and impact vary depending on the type of activity performed. Factors such as age, pre-existing medical conditions and socio-economic status can worsen health problems and increase safety risks at work [6].

Workers in the agricultural and forestry sectors are considered to be at high risk, given the close dependence of their activities on climatic conditions [7]. Considering that the Utilized Agricultural Area (UAA) at global level represents about a third of the emerged lands, corresponding to 5 billion hectares, of which 1.4 billion of arable land and 140 million hectares of permanent crops [8]. Despite deforestation and the conversion of forests into agricultural areas, the surface of arable land has remained almost stable [9]. According to the most recent statistics published by the Food and Agriculture Organization of the United Nations (FAO) in the Statistical Yearbook 2024, the global workforce employed in agriculture has decreased significantly, from 40% in 2000 to 26% in 2022.

Over the same period, pesticide use increased by 70%, with the Americas accounting for half of global consumption. Inorganic fertilizers used in agriculture reached 185 million tonnes with 58% of this being nitrogen, marking a 37% increase from 2000.

Greenhouse gas emissions from agri-food systems also increased by 10% between 2000 and 2022. In particular, emissions at farm level increased by 15%, with livestock accounting for around 54% [10].

These data highlight the importance of addressing emerging risks for agro-forestry workers, with a particular focus on airborne particulate matter (PM). In this context, the European Agency for Safety and Health at Work (EU-OSHA) has developed several risk mitigation strategies, which should be adapted to regional specificities and workforce diversity. A thorough understanding of the effects of climate change on occupational health and safety is also needed to adequately assess and manage the associated risks.

This work presents an in-depth analysis of scientific literature on PM generated by agricultural and forestry activities, focusing on its implications for occupational safety. The main objective is to understand the risks for the health and safety of workers in the primary sector, particularly focusing on the contribution of dust emission caused by machinery and the aggravating role of climate change. In the scientific literature there are numerous contributions that relate human exposure to dust from air pollution with climate change. This review seeks to provide more specific and updated information on occupational exposure to dust generated by agricultural and forestry practices, trying to fill a certain gap in systematic analyses in this context. The investigation explores how climate changes affect the quality and quantity of PM present in agricultural and forestry environments, and how exposure to this particulate matter can impact workers’ health, as shown in the flowchart in Figure 1.

2. Methods

The bibliographic review was conducted by consulting the Google Scholar and Scopus databases. The selection of scientific publications was carried out through a structured search, based on a Boolean string built with logical operators applied to specific keywords.

Below is a list of the keywords used for the literature search. Regarding dust, the following terms were employed: particulate matter (PM, PM₁₀, PM_2.5, PM₁), airborne dust, abrasion dust, aerosols, wood dust. In relation to emission source contexts, the keywords included: agricultural practices, soil tillage, sowing of treated seeds, harvesting, pesticide application, forestry operation, chainsaw use, wood chipping and fertilizer spreader.

With respect to thematic contexts, the following terms were used: agroforestry workers, agricultural workers, forestry workers, occupational exposure, outdoor workers, and exposure risk. The keywords were combined with each other, including climate change, in order to broaden and refine the search strategy.

The queries returned approximately 687 results, from which, after removing duplicates and applying the inclusion and exclusion criteria, 155 relevant studies were selected. The selection process was documented through a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) diagram, reported in Figure 2 [11].

A synthesis of the results is presented in Table S1, entitled “Comparative analysis of atmospheric PM emission sources, their typologies and prevalent risks: evidence from scientific literature”, contained in Supplementary Materials.

Figure 3 shows the time span between 1974 and 2025 of the documents considered for this review, including scientific articles, international standards, guidelines and projects, for a total of 175 documents. Starting from 2019, a significant increase in the number of contributions on the topic can be observed, likely attributable to the COVID-19 pandemic, which could have stimulated a growing interest in the study of atmospheric particulate matter.

3. Health Risks from Exposure to Airborne Particulate Matter (PM_2.5 and PM₁₀)

Since the mid-1980s, WHO (World Health Organization) has periodically published Air Quality Guidelines (AQGs), aimed at improving the quality of breathing air and reducing the negative effects of PM_2.5 and PM₁₀ [12]. The guidelines indicated reference values which cannot replace the binding regulations in force, at both international and national levels. At an international level, one of the first regulations on the subject has been the ILO Convention No. 148 of 1977 on the working environment, which addresses air pollution, noise and vibrations in the workplace [13]. Although it does not specify numerical limits for particulate matter, it establishes general principles for the prevention and control of workplace air pollution in the. This Convention established the International Programme for the Improvement of Working Conditions and Environment (PIACT), which offers a non-binding code of good practice for governments, employers and workers [14]. Subsequently, ILO Convention No. 155 of 1981, ratified by many countries, has introduced specific obligations for the assessment and reduction of occupational risks, including air pollution in the workplace [15].

In the European Union, Directive 98/24/EC has established obligations for the protection of workers from exposure to chemical agents, including particulate matter [16], while Directive 2004/37/EC has imposed binding limits for carcinogenic and mutagenic substances, including certain types of PM [17]. In the United States, Occupational Safety and Health Standards (OSHA) has set exposure limits for total and respirable particulate matter at 15 mg/m³ and 5 mg/m³ for PM₁₀ and PM_2.5 respectively, according to the standard 29 CFR 1910.1000 [18,19]. As regards the agricultural and forestry sectors, there are no international regulations that define specific limits for exposure to PM₁₀ and PM_2.5 in the workplaces. However, it is recognized that agriculture contributes significantly to PM emissions even if these vary between different regions of the world and the available information does not provide a precise estimate of the percentage of PM due to agriculture.

Exposure to fine dust and aerosols represents a significant risk factor for workers’ health, a risk that varies based on the concentration and chemical composition of PM, which in turn vary according to geographical location, climatic conditions and emission sources [20]. Exposure to fine particulate matter (PM_2.5) has a harmful impact on human health and is a major environmental cause of premature mortality, responsible for millions of deaths each year [21]. It is estimated that workplace air pollution represents a significant burden among occupational exposures, with an increased risk for approximately 1.6 billion outdoor workers [22]. Furthermore, several studies have highlighted the serious risk of dementia among those who are regularly exposed to indoor particulate matter and other pollutants [23,24]. Finally, the impact on health related to work is of considerable importance. Globally, approximately 860,000 premature deaths are attributable to air pollution each year, which particularly affects outdoor workers [25]. Air quality also affects well-being and quality of life, making emission control and reduction policies necessary [26,27]. Despite regulatory progress, much remains to be done to protect agricultural and forestry workers [28]. For this reason, action plans are underway to improve regulation and prevention [29].

3.1. Inhalation Risks

PM is one of the main agents of air pollutants. It can be released from various biogenic and anthropogenic sources or produced by secondary reactions that occur in the atmosphere [30,31]. It is widely accepted and supported by scientific evidence that, in addition to the diameter of the particles, the nature of the fractions [32,33] is also an important factor in determining their dangerousness. PM₁₀ particles, i.e., with an aerodynamic diameter not exceeding 10 μm, are able to penetrate the upper tract of the respiratory system while PM_2.5, by definition fine, reaches the pulmonary alveoli, inciting chronic inflammation, respiratory and cardiovascular diseases [34]. Among them, ultrafine PM₁ particles are able to cross cell membranes, generating oxidative stress and systemic inflammation that can compromise vital organs such as heart and brain [35]. Their dangerousness is amplified by the ability to transport toxic substances, such as heavy metals and volatile organic compounds, increasing the potential damage to the human body. In addition to the chemical-physical composition of PM, its dangerousness and harmful effects on human health also depend on the exposure time [36,37]. Since prolonged exposure to fine particulate has been associated with serious health effects, including chronic respiratory and cardiovascular diseases and an increased risk of cancer, in 2013 the International Agency for Research on Cancer (IARC), part of WHO, classified outdoor air pollution and airborne particulate matter as carcinogenic to humans (Group 1) [38]. There is sufficient evidence linking them to lung cancer, and positive associations were also observed with bladder cancer [39].

3.2. Contact Risks

Contact exposure to PM can cause irritation of the skin and mucous membranes and the absorption through the skin of any residues of active ingredients of pesticides transported by the dust itself. In the agricultural and forestry sectors, significant risks of irritation and inflammation for workers may arise following the use of inadequate protection that allows contact of PM with the skin. This process can promote the onset of dermatological disorders, the formation of wrinkles and alterations in pigmentation. Furthermore, pollutants present in the air can act in combination with ultraviolet light (intensified by climate change) amplifying skin damage [40].

PM can cause irritation of the skin and mucous membranes in two ways: either directly, through the absorption of air pollutants by the skin, in particular through intrusions formed by hair follicles in the stratum corneum [41], or indirectly through the absorption, by the lungs, of particles that are further transported by blood to the skin [42]. Furthermore, exposure to PM_2.5 and PM₁₀ is associated with atopic dermatitis and allergic reactions. A study has shown that both skin affected by atopic dermatitis and healthy skin, when exposed to such particulates, undergo an alteration of the skin barrier, attributable to a reduction in the expression of epidermal structural proteins [43].

A similar argument applies to exposure to contact PM which causes irritating effects on the eyes due to the deposition of fine and ultrafine particles on the ocular surface. Studies show that the interaction of PM with the tear film induces dryness, redness and discomfort, aggravated by the presence of toxic compounds adsorbed on the particles [44,45,46,47]. Furthermore, eye irritation can compromise visual performance and increase the risk of operational errors.

3.3. Environmental Risks

Considering the objectives of this review (Figure 1), environmental risks related to PM emitted by agro-forestry activities have not been addressed, and attention has been focused on the health risks of workers in the sector. Although this review focuses on the health risks of agroforestry workers, it is important to highlight that PM emissions from these activities also pose significant environmental risks. First, PM contributes to the deterioration of air quality, even in rural settings, due to practices such as burning of plant residues, use of agricultural machinery and intensive soil cultivation [48]. Furthermore, the deposition of PM on leaf surfaces can reduce the photosynthetic efficiency of plants, compromising agricultural and forestry productivity [49]. PM can also carry heavy metals and other contaminants that, once deposited on the soil, can leach and reach groundwater, altering the quality of water resources [50]. Such emissions can influence the local radiation budget, modifying microclimates and ecological conditions in agricultural and forested lands [51], exacerbating the greenhouse effect. Finally, particulate matter can have negative impacts on biodiversity, damaging sensitive ecosystems and affecting the health of key species, such as pollinators and soil organisms [52,53]. Authors assessed the importance of various factors potentially affecting dust drift and deposition of active substances, emitted during the sowing process of treated seeds and deposited on fields adjacent to the drilling field, i.e., on the ground, on flowers, and on nonflowering plant parts [54,55].

In addition to the risks already known, such as exposure to organic and inorganic dust [56], the analysis also focuses on emerging risks, including exposure to substances with reprotoxic activities [57], often present in pesticides used in agriculture.

4. Particulate Matter Generated by Agro-Forestry Machinery and Equipment

As shown in Figure 4, the paper is divided into two macro areas. The first concerns PM generated by agricultural activities with their respective sub-sections: cultivation practices, use of coated seeds and application of pesticides. The second macro area focuses on particulates from forestry activities, with the following sub-sections: timber production, use of chainsaws for felling and limbing trees, and production and handling of wood chips. In both cases, the known and emerging risks of PM exposure to workers are described, with a focus on climate change as a factor that can amplify these hazards.

4.1. PM Generated by Agricultural Practices

In the studies on atmospheric particulate emissions, there has been a relative lack of specific research on the effects of the use of agricultural machinery and different agricultural activities on the dust emitted. For this reason, it was considered appropriate to list the different factors that can influence PM emissions in this context, including the aggravation of climate change and its impact on the health and safety of workers.

In Figure 5 are shown some agricultural practices causing dust emissions.

4.1.1. Cultivation Practices: Soil Tillage, Sowing, Harvesting

In the agricultural sector, cultivation practices from tillage to sowing to harvesting contribute significantly to PM emissions, both in primary form and through secondary formation processes in the atmosphere. The types of agricultural practices adopted together with the physical characteristics of the soil and climatic conditions play a crucial role in the formation of the levels (low or high) of airborne particulate matter emitted during agricultural activities. For example, traditional practices, based on deep tillage, have been frequently associated with higher levels of PM emissions than conservation agriculture techniques (minimum tillage or no tillage) [58]. Another study compared PM emissions during tillage in wheat cultivation with conservation and traditional practices, highlighting that in addition to the speed of the machines, also the type of practice adopted affects dust concentrations. On average, traditional tillage methods generate 8.8 times more dust per unit area than conservation tillage [59]. Intensive soil tillage, in fact, disturbs the surface more, increasing the quantity of particles suspended in the air [60]. On the contrary, the adoption of sustainable agricultural practices, such as minimum tillage or the use of cover crops, can significantly reduce dust production [61]. Even the burning in the field of post-harvest residual biomass (wheat stubble, rice, etc.) or prunings, is a source of PM emissions that is subject to wind drift and fallout, with possible effects on human health [62,63].

Crop type also has a significant impact on PM emissions. In general, stem crops, such as grasses, Brassica napus, Helianthus annuus and Arundo donax [64,65,66], as well as tree crops (e.g., walnuts or hazelnuts), tend to release a greater amount of dust into the atmosphere as a result of practices such as mechanized harvesting and shredding of crop residues, which facilitate the dispersion of both soil and organic particles [67,68,69]. The dust raised can persist in the air, contributing to the formation of a post-harvest haze as demonstrated by some works on hazelnut harvesting [70]. The use of threshers also generates significant amounts of dust that is formed in the environment [71]. This was also verified by a study that during experiments on the mechanization of pre-pruning of vines evaluated the exposure of operators to dispersed dust and volatile organic compounds (VOCs) [72].

Another factor that affects PM emissions in agricultural activities is the type of soil and its physical characteristics [73]. Sandy and arid soils are generally more vulnerable to dust dispersion than clay or organic matter-rich soils [74]. In fact, sandy soils have a lower water retention capacity, which makes them more susceptible to disintegration and particle lifting during agricultural activities. On the other hand, clayey soils, thanks to their high cohesion, retain particles more, thus reducing PM emissions. This behavior has been confirmed by laboratory studies that have highlighted the influence of the soil granulometric distribution and the presence of water on PM₁₀ concentrations [75]. In fact, some studies have found that both humidity and soil texture play a significant role in PM emissions [76]. When the soil is sufficiently moist, particles are heavier and less likely to be lifted by the wind or by agricultural operations. Several studies have shown that higher levels of soil moisture can significantly reduce dust emissions, as water binds particles more firmly to the soil, preventing their dispersion [77,78].

Finally, local climatic conditions play an essential role in the dynamics of PM emission and dispersion. High temperatures, strong winds and low humidity can exacerbate PM emissions, especially in arid or semi-arid regions [79]. A hot and dry climate favours the formation of fine dust [80]. These conditions occur with increasing frequency as a consequence of ongoing climate change. Wind is the main responsible for the lifting of particles during soil processing, and for their drift, as demonstrated by several studies on soil erosion [81,82,83]. The operating speed of agricultural machinery also influences PM emission: a study carried out in Northern Italy analyzed the main factors of PM₁₀ emission during the use of the rotary harrow, evaluating the influence of the tractor speed and the height of the levelling bar. In all cases, PM₁₀ levels exceeded the WHO limits, raising concerns for the health of farmers. Furthermore, it was observed that in the finest fractions of resuspended particulate matter, sampled in the test fields, the concentrations of metallic elements were higher than those observed in soil samples, which however had not been subjected to polluting events. This concerned in particular Cu, Zn, Mo, Cd, Sn and Ba. Furthermore, the point concentrations of some elements (As, Cd, Ni) exceeded up to 50 times the legal limits imposed for PM₁₀ atmospheric pollution [84]. Such high concentrations of heavy metals are probably attributable to the close proximity of the experimental field to areas subject to intense human activity, both industrial and agricultural, as well as to the presence of a densely concentrated population.

4.1.2. Use of Dressed Seeds

Seed dressing is a widespread practice as it serves to protect the seed from attacks by soil-borne organisms. Due to the movement of the seeds in the seed drill hoppers, seed dressing involves the formation of abrasion dust containing, in addition to fragments of tegument, also residues of pesticides present in the seed coating [85]. The abrasion dust is released into the environment during sowing. Numerous studies have shown that pneumatic precision seed drills, which operate by means of a vacuum air flow, cause the emission of greater quantities of this form of particulate matter which, subject to drift, can affect large areas surrounding the sown fields [86,87]. Similar studies have analyzed the dispersion of dust from the sowing of other crops, such as wheat [88]. The active ingredients used in seed dressing are most commonly fungicides and insecticides and are potentially dangerous for the environment and for the health of agricultural workers [89,90].

From an environmental point of view, pollinating insects have been the organisms most affected by the drift of dust containing toxic active ingredients [91]. It has been shown that the exposure of bees to pesticides released during the sowing of different crops can have toxic effects [92,93]. In particular, during the sowing of maize with pneumatic seed drills, the dispersion of substances such as imidacloprid, clothianidin, thiamethoxam and fipronil was only partially reduced by the application of deflectors to the seed drill to direct the air flow containing abrasion dust towards the soil, exposing honeybees to a significant risk [94]. Subsequent studies have confirmed the persistence of this problem even after the replacement of the aforementioned active ingredients with others, highlighting their topicality [95]. More effective measures have been proposed, capable of reducing up to 98% of abrasion dust emissions [96]. The toxicity and mechanism of action of the above insecticides on pollinators, whose behavioral attributes are negatively influenced, are widely documented [94,97].

As regards agricultural workers, they are exposed to the risk of inhalation (and contact) of active ingredients contained in abrasion dust mainly during the loading phase of the seed in the seeder hoppers and during sowing in the field. In both cases, the quantities inhaled can be significant if, as often happens, suitable personal protective equipment, PPE (such as masks, gloves and protective glasses) are not adopted, respectively, and if sowing is carried out with an open cabin or with inefficient filtration systems [98]. In a first test on worker exposure to abrasion dust the quantities inhaled during the two operations were assessed to be far from the Acceptable Operator Exposure Level (AOEL) [99]. However, this point warrants further investigation, since given the seasonality of agricultural work, some workers such as contractors, could be exposed for many consecutive days to the abrasion dust and the residues of contained active ingredients during sowing season.

The amount of abrasion dust produced depends on the quality of the treatment used to coat the seed. To assess the quality of seed coating, a study compared the official Heubach method with two alternative methods: mechanical sieving and simulation with a seeding element. Different types of coated seeds were tested, including maize, pea, wheat and sugar beet. The results indicate that the Heubach method underestimates the amount of dust released, while the alternative techniques provide more accurate and realistic estimates [100].

4.1.3. Use of Pesticides for Crop Protection

The use of pesticides in crop protection raises growing concerns regarding the generation of PM and aerosols containing chemicals with toxic activities that pose a significant threat to both workers’ health and the environment. Scientific literature has confirmed the existence of such a risk through the collection of evidence highlighting the association between pesticide exposure and the incidence of chronic diseases [101,102,103]. The active substances can spread through mechanisms such as evaporation and volatilization, leading to the formation of aerosols.

Organophosphorus insecticides, such as chlorpyrifos, are known for their high neurotoxicity and have been associated with impairment of the nervous system [104]. A field study examined the fate and transport of chlorpyrifos, finding that in the days following application (0–2 days), concentrations measured in air up to 500 m from the field reached levels considered to be of concern for human health [105]. Similarly, neonicotinoids have been detected widely in the environment, drinking water and food, although at exposure levels below acceptable daily intake standards, as previously mentioned. However, some ecological and cross-sectional epidemiological studies have identified acute and chronic health effects, including respiratory, cardiovascular and neurological symptoms, as well as oxidative genetic damage and birth defects [106].

Among fungicides, carbendazim is a pollutant detectable in food, soil and water. Its widespread and repeated use can cause both acute and delayed toxic effects on humans, invertebrates, aquatic organisms and soil microorganisms. Studies have highlighted its toxicity and environmental impact, highlighting its ability to alter the structure of the microbial community in various ecosystems [107]. Thiabendazole, on the other hand, has shown a potential aneugenic risk in laboratory tests on human cells [108].

Many pesticides, especially organochlorines, have reprotoxic activity in humans that varies depending on the dose, duration and route of exposure [109]. Several studies have highlighted a correlation between chronic exposure to pesticides and reproductive dysfunction, suggesting that the toxic mechanisms involve oxidative stress and hormonal interference [110,111,112]. Epidemiological analyses have found an increase in endocrinological and reproductive alterations in agricultural workers exposed to high concentrations of organophosphorus and triazole substances. Studies on long-term effects indicate that exposure may also affect future generations, with impacts on semen quality and conception times [113]. Furthermore, an increased risk of spontaneous abortions, fetal loss and a lower number of male children has been observed from parents who frequently apply fungicides for work [114]. Even at low doses, exposure may have measurable biological effects [115]. From an environmental point of view, a study analyzed the history and classification of pesticides, dividing their use into three historical phases. Although used for the control of pests and weeds, pesticides contaminate the environment and can damage non-target organisms, affecting human health through air, water, soil and food. With regard to climate change, it is intensifying the use of pesticides and their impact on the environment [116]. The changing of climate factors like temperature, precipitation, CO₂ concentration, affect the growth, survival and reproduction of plant, modify their geographic distribution and crop yields also through indirect effects on the dynamics between nutrients and soil and on pests life cycles [117]. For example, warmer and more humid conditions favor the reproduction and winter survival of many plant parasites, allowing them to expand towards higher, previously inhospitable latitudes. Observational studies indicate an average movement of about 3 km/year towards the poles for insects and fungi pathogenic to corn (such as the “tar spot” in the USA), a sign of the expansion of the areas at agricultural risk [118]. Weeds are also affected by these changes: in warmer environments, C4 species, more adapted to high temperatures, tend to prevail over crops, modifying the composition of the weed flora. The intensification of heat and humidity further accentuates the pressure of weeds and can favor the appearance of new, more competitive species [119].

The expansion of pests, diseases and weeds (greatly enhanced by global warming) leads to an increasing use of chemical treatments. Future trends suggest an increasingly intensive and diversified application of pesticides, herbicides, insecticides, and fungicides, with higher doses and more frequent treatments. Therefore, climate change is expected to lead to increased use of pesticides in terms of doses, higher treatment frequency and application of more and different types of products. At the same time, when climate change involves higher temperatures precipitation and environmental humidity, it should reduce pesticide concentration in the environment by accelerating their volatilization and degradation [120]. Finally, some studies have documented the ability of particulates to spread and accumulate, with potentially long-lasting eco-toxicological effects [121]. More recent studies have investigated the relationship between the mechanisms of dispersion and the physical-chemical properties of pesticides (formulation, bioavailability and efficacy) and the interactions between these substances and local ecosystems [122].

4.1.4. Use of Fertilizers

The agricultural application of fertilizers—whether mineral fertilizers (e.g., nitrates, phosphates), organic amendments (e.g., manure, compost), or soil conditioners (e.g., agricultural lime)—is recognized as a significant source of airborne PM, contributing both to atmospheric pollution and occupational health risks for agricultural workers [123]. In addition to the solid fraction, inhalable particles can carry ammonia compounds and heavy metals, increasing the health hazard for exposed operators [124].

Centrifugal fertilizer spreaders are the most commonly used equipment for mechanical spreading. Their use is associated with the release of substantial quantities of primary dust. In particular, the use of finely ground (micronized) lime, especially in dry form, can promote the dispersion of respirable particles (PM₁₀ and PM_2.5), potentially causing irritation to the respiratory tract and eyes in the absence of adequate containment measures or personal protective equipment [125].

In the case of manure, particulate emissions depend on both environmental factors (such as wind, temperature, and relative humidity) and the physicochemical properties of the material, especially moisture content. One study found that dried manure generates significantly higher PM concentrations during spreading compared to composted or raw manure, with local PM₁₀ peaks reaching up to 10 mg/m³—levels considered harmful to human health. The intensity of the emission is strongly correlated with dry matter content: values exceeding 60% in poultry manure and 80% in swine manure favor aerosol formation [126].

Manure spreading is also a notable source of bioaerosols containing microorganisms and antibiotic resistance genes, with potential public health implications for nearby communities [127,128].

Although these are typically seasonal operations carried out in spring and autumn, the use of organic fertilizers constitutes a non-negligible source of particulate emissions, with significant local impacts and potential risks for both agricultural workers and the surrounding environment.

4.2. PM Generated by Forestry Activities

Most of the studies in scientific literature focus on the risk assessment of occupational exposure to PM in the wood processing industry, while the forestry context is less investigated. For this reason, the main factors that influence PM emissions in forestry activities are analyzed below. These emissions depend on various elements, including the type of wood, the characteristics of machinery, the moisture content, the nature of the operations carried out and the microclimatic conditions present during the work activity. For the U.S. forestry sector, Knecht et al. have recently provided a comprehensive occupational health review [129]. In Figure 6 are shown some common forestry practices producing wood dust.

4.2.1. Wood Characteristics

Structural properties of wood, such as hardness and moisture content, influence the amount of PM generated during processing [130]. Wood species with a higher density and a more compact cellular structure, typical of hardwoods, tend to produce finer particles (PM < 100 μm) than softwoods, which, due to their greater porosity, release slightly coarser dust during operations [131]. However, during the sawing phase, density has little influence on the particle size distribution [132]. It has also been observed that a high moisture content of wood reduces the formation of dust during processing [133,134].

Furthermore, it is known that wood dust, especially hardwood dust, is considered a Group 1 carcinogen for humans and there are occupational exposure limit values [135]. For example, in the United States, OSHA has set a PEL (Permissible Exposure Limit) of 5 mg/m³ as a time-weighted average over 8 h for total wood dust [136]. However, the ACGIH (American Conference of Governmental Industrial Hygienists) recommends a more restrictive limit: a TLV-TWA (Threshold Limit Value—Time-Weighted Average) of 1 mg/m³ specifically referring to the inhalable fraction of hardwood dust, always on an 8-h weighted average [137]. These values are also adopted as a reference by many European countries for the definition of occupational exposure limits. However, several studies have highlighted that PM concentrations in forestry often exceed the maximum limits permitted by law [138]. An analysis of occupational exposure to the inhalable fraction of PM from wood, conducted in 25 EU Member States, showed that the highest levels are found in the construction and furniture industries and that, in any case, a significant share of wood workers, approximately 150,000, equal to 4% of the total, are exposed to PM from forestry activities [139]. A study conducted on cutting different wood species most frequently used in the furniture industry using a computer numerical control machine at standard speed found that hard wood species due to their high hardness and density, generate significantly more PM_2.5 and PM₁₀ than softer wood species [140].

An in vitro study on human cells tested the toxicity of different species of both hard and soft wood dust at different concentrations. The results showed that all dust had a cytotoxic effect and induced the production of ROS (reactive oxygen species) in a dose-dependent manner, suggesting that the health risk does not depend exclusively on the type of wood or the size of the PM produced [141].

The toxicity of wood dust can be enhanced by the presence of heavy metals [142]. Biocca and coauthors have detected concentrations of nickel during wood cross-cuttings (likely deriving from the chainsaw wear), exceeding the exposure limit recommended by Italian legislation [143].

4.2.2. Timber Production: Use of Chainsaws for Felling and Limbing

The use of chainsaws for felling, cutting and limbing operations is particularly critical, since mechanical stresses and vibrations promote the dispersion of dust in the air, representing a significant source of emissions in the forestry sector to which operators are exposed. In particular, the intrinsic characteristics of the chainsaw can influence the emission of PM. The type of chainsaw chain (the pitch and shape of the teeth) influences PM emissions. In one study, two types of chain were tested both on living wood and on wood burned after a fire. The results showed that the conventional 3/8 chain generated the highest amount of dust, with peak emissions on burned wood [144]. Chainsaw chains with semi-chisel teeth were observed to generate higher concentrations of wood dust in the air than chains with full chisel teeth [145]. On the contrary, in a recent work that has compared three chains, the semi-chisel (round ground) teeth type has produced less dust than the full-chisel (square ground) and the full-chisel (hexagonal ground) [146].

Chainsaw maintenance also affects the concentration of PM produced during cutting. A study compared dust emissions under conditions of proper and inadequate maintenance, highlighting that poor maintenance significantly increased dust concentration, while less frequent use of the accelerator contributed to reducing it [147]. Different types of chainsaws (battery and combustion engine), tested on various wood species, were observed to produce similar amounts of dust with a significant presence of the finest fraction of particulate matter (<1 μm), often exceeding the legal concentration limits established by European legislation [148]. It is necessary to specify that internal combustion engines can release harmful exhaust gases such as nitrogen oxides and carbon monoxide, which can be inhaled by the operator during prolonged use of the equipment [149]. Furthermore, during cutting, significant quantities of chain oil are dispersed into the environment in the form of aerosols or adsorbed on dust and sawdust, further increasing exposure to potentially toxic substances [150,151,152]. In this context, the choice of quality oil, preferably biodegradable and low-toxicity, plays a crucial role in reducing risks to health and the environment [153]. In fact, a study evaluated the use of refined olive pomace oil with 2% food antioxidant as a lubricant for chainsaws, detecting a reduction in the concentrations of respirable wood dust and metal elements compared to a conventional fluid. The oil, retained in sawdust and fine dust, can contribute to the inhalation exposure of operators, highlighting the importance of the choice of lubricant in terms of safety and sustainability [154].

Further studies have investigated workers’ exposure to PM generated during different forestry operations, including clear-cutting in coppice forests, thinning, pruning and sanitary cutting with chainsaws. The results showed that exposure to wood dust varies widely depending on the activity performed and that average PM levels are significantly higher in coppice than in thinning and sanitary cutting [155]. One study analyzed PM concentrations during cutting operations for 8 working hours over 4 months, finding that the concentration of inhalable dust decreases with increasing tree diameter [156].

4.2.3. Woodchip Production

The use of wood chippers for shredding wood and vegetation generates a significant amount of airborne dust, composed of wood microfragments and plant residues. These particles can compromise air quality and pose a health risk to operators, especially in the absence of effective dust abatement systems and/or PPE [157]. A study analyzed PM emissions during the use of wood chippers in both industrial and small-scale operations, using personal samples installed on operators, both outside and inside protected cabins. The results showed that dust exposure varied depending on wood conditions and machine productivity, occasionally exceeding the legal limit. Operators in the cabin were three times less exposed than those outside and never reached concentrations above regulatory limits [158]. Moreover, the combined exposure to wood dust and diesel fumes can produce synergistic effects on the respiratory health of operators, enhancing inflammatory processes and oxidative stress due to the deep penetration of fine particles into the lungs and the presence of highly reactive substances (PAHs) in the fumes. In confirmation of these effects, a study conducted on rats exposed for three months to the sawmill environment showed that sawdust easily contaminates the air and, if chronically inhaled, induces not only lung damage, but also significant alterations of hematological and histopathological indices [159].

The effects of exposure to wood dust generated by chippers have been evaluated in Turkish forestry, with an average concentration of 6.04 mg/m³ over an 8-h shift, which is above the legal limit [160]. Furthermore, high humidity and the presence of organic material in wood chip piles during processing favor the development of fungal spores, which can be dispersed into the air as aerosols, increasing the risk of exposure to respiratory pathogens during materials handling operations. A survey of occupational exposure during manual and mechanized handling of wood chips for biofuels revealed that workers engaged in manual activities were more exposed to airborne fungal spores. Molecular analysis identified Alternaria and Cladosporium as the most prevalent fungal genera [161].

5. General Conclusions and Future Perspectives

Establishing a direct and quantitative correlation between climate change and airborne particulate matter emissions in the agroforestry sector remains a complex challenge. Nonetheless, it is evident that changing environmental conditions significantly affect agricultural and forestry activities, influencing both the quantity and dispersion of the particulate matter produced. PM emissions associated with these activities represent a well-documented risk to the health and safety of workers, particularly in scenarios characterized by increasing climate-related stress.

In light of these considerations, it is essential to strengthen a systemic approach to risk assessment, grounded in scientific data, monitoring activities, and predictive analyses. In particular, there is a need to deepen our understanding of emission dynamics across different operational contexts, taking into account interactions with meteorological variables and the evolving physicochemical transformations of PM processes that are further influenced by the use of new phytosanitary active substances.

5.1. Emerging Technological Solutions for Risk Monitoring and Management

The proliferation of innovative technologies is enabling a more effective and proactive approach to managing PM risk in the agroforestry sector. Among the most promising solutions are:

• IoT-based Environmental Sensing: Optical sensors integrated into portable or stationary platforms (e.g., Sensirion SPS30 on Arduino microcontrollers with Wi-Fi or LoRaWAN connectivity) allow for real-time detection of PM₁, PM_2.5, PM_4.0, and PM₁₀ concentrations. These systems, which can be mounted on agricultural machinery, in greenhouses, or along farm boundaries, feed cloud-based dashboards for dynamic visualization of emissions during critical operations (e.g., pesticide applications or plowing under dry conditions).
• Automated Mobile Monitoring: Drones and agricultural rovers equipped with multiparametric sensors (PM, temperature, humidity) enable three-dimensional mapping of particulate dispersion over large or hard-to-reach areas, such as sloped forested regions or isolated fields. These technologies are particularly valuable for identifying emission hotspots and assessing the impact of environmental conditions (e.g., dry winds) on PM accumulation.
• AI-based Predictive Modelling: Machine learning algorithms such as Random Forests or recurrent neural networks enable the development of predictive models to estimate the evolution of particulate emissions as a function of meteorological variables, agricultural activity schedules, and the specific characteristics of particulate matter. Trained on localized historical data, these models not only help anticipate emission peaks and support the planning of preventive measures (such as activating abatement systems or rescheduling operations) but also generate evolutionary scenarios and identify previously unrecognized risk patterns by correlating exposure levels with epidemiological data on occupational diseases.
• Integrated Alert Systems: Advanced ICT platforms can trigger automatic alerts (push notifications, SMS, field displays) when safety thresholds are exceeded. In operational applications, for example, pesticide treatments in vineyards can be suspended upon detection of critical PM concentrations, or irrigation systems can be activated to suppress airborne dust.

The promotion of emerging technologies such as IoT sensors and AI models for PM monitoring shows promising potential but faces both economic and operational constraints [162,163]. Cost quantification remains highly speculative due to the rapid pace of technological evolution, the gap between prototypes and commercial solutions, and the potential influence of public funding on market prices. Moreover, real-world implementation involves significant challenges, including calibration, data integration, long-term maintenance, and user acceptance, all of which require dedicated and in-depth analyses before large-scale deployment [164]. At present, the lack of consolidated cost data and standardized evaluation frameworks further complicates robust cost–benefit assessments. Consequently, pilot studies, scenario-based evaluations, and interdisciplinary research efforts are essential to determine the actual feasibility and sustainability of these technologies in occupational health and safety contexts.

5.2. Development Prospects and Operational Recommendations

The integration of IoT sensors, artificial intelligence, meteorological modelling, and adaptive management systems marks a critical step toward dynamic and predictive risk assessment. A notable example is the Worklimate 2.0 project developed by INAIL and CNR in Italy, which implemented early warning systems for heat stress risks based on environmental sensors and weather forecasts [165]. Expanding this infrastructure to include airborne particulate risk would enable the identification of synergistic risk scenarios, such as the interaction between heatwaves and elevated PM concentrations.

At the European level, initiatives such as EU VIDIS (2020–2024) have demonstrated the effectiveness of dense networks of low-cost sensors for environmental monitoring, paving the way for the application of such solutions in rural contexts [166]. Moreover, funding programmes like Horizon Europe (e.g., HORIZON-CL6-2025-ZEROPOLLUTION-01) support the development of intelligent networks for pollution control and the promotion of environmental sustainability [167].

To ensure these solutions translate into concrete and effective practices, a coordinated effort is required among farmers, research institutions, health authorities, and policymakers. The widespread adoption of technological tools for PM monitoring and mitigation can make a significant contribution to achieving the goals of the European Green Deal and the Zero Pollution Action Plan, delivering benefits for both worker health and the sustainability of primary sector activities [168,169].

This review is subject to several limitations. First, the available literature on occupational exposure to particulate matter in agroforestry is limited and highly heterogeneous, with differences in exposure assessment methods, geographic, social and cultural contexts, and agricultural and forestry tasks. This variability restricts direct comparison and meta-analytical synthesis. Second, many studies lack standardized reporting on particulate concentration, particle size (e.g., PM_2.5 vs. PM₁₀), and duration of exposure, making it difficult to assess cumulative risks and avoiding quantification of the specific contribution ratios of different climate scenarios. Third, language and publication biases may have excluded relevant data published in non-English journals or grey literature. Moreover, our systematic review yielded few papers from developing countries. One possible explanation is that, in these regions, both scientific and applied research on occupational safety tends to focus more on accidents than on occupational diseases, unlike in Europe and the United States. This interpretation was supported by a personal communication with E. Cavallo, a senior researcher specializing in work safety based in Senegal, who confirmed that this is indeed the case in several Central African countries.

Another highly relevant research area is the analysis of mechanisms and dose–response relationships of toxic substances. It requires a dedicated and comprehensive review beyond the scope of this paper. The toxicological behavior of specific agents, including their pathways of absorption, distribution, metabolism, and excretion, as well as their cellular and systemic effects, is generally investigated within the fields of medical and biomedical sciences rather than agronomic or forestry disciplines [170]. Moreover, such analyses are inherently complex, as they encompass a wide spectrum of chemical and biological agents, each characterized by distinct physicochemical properties and toxicokinetic profiles [171]. Dose–response relationships further depend on a variety of modifying factors, including the route and duration of exposure, the characteristics of the exposed population, and the presence of co-exposures or synergistic agents [172]. In addition, exposure thresholds and acceptable limits are not uniform but are established within different national and international regulatory frameworks, often relying on risk assessment methodologies that balance health protection with socio-economic considerations.

The quantification of climate change’s contribution to PM emissions represents a complex and relatively unexplored field of research. Particulate matter generation in agricultural and forestry operations is influenced by a wide range of interacting variables, including machinery type, operator expertise, agronomic practices, soil conditions, and the characteristics of applied agrochemicals. Superimposed on these factors are the effects of climate change, which may alter emission dynamics through shifts in temperature, relative humidity, precipitation, wind patterns, and the frequency of extreme weather events [173,174]. At present, the literature addressing the combined influence of these variables remains limited, and robust methodologies for disentangling climate-driven impacts from operational or environmental determinants are still lacking. Moreover, the variability of regional contexts adds further complexity to the definition of generalizable models. While preliminary approaches suggest that climate change could exacerbate dust emissions and prolong exposure windows, systematic evidence and modelization of the phenomenon remain scarce.

Finally, effective particulate risk management in the agroforestry sector must be accompanied by structural investment in training, applied research, and knowledge transfer. Only a fully integrated, multidisciplinary approach will be capable of meeting the challenges posed by climate change, enabling a shift from static risk assessment to adaptive and predictive management focused on prevention, operational resilience, and workplace health protection.