Search Results (25)

Tortillas are an essential food in Mexico, and they are usually packaged in low-density polyethylene (LDPE) bags, but these packages can release microplastics (MPs) into the food. On the other hand, MPs have been associated with conditions such as the release of toxic substances, damage to mitochondrial membranes, and the generation of oxidative stress and inflammation, among others. Currently, there are no studies on the presence of MPs in corn tortillas, so the objective of this work was to study samples of tortillas acquired at five points of sale in central Mexico, namely, supermarkets (A and B) and tortilla shops (C, D, and E), as well as to evaluate the presence of MPs and their identification by Fourier-transform infrared spectroscopy (FTIR), optical microscopy, and scanning electron microscopy (SEM). In addition, an abundance interval and an estimate of the consumption rate were established considering the available information on per capita consumption of tortillas in Mexico. The results show that the samples of tortillas purchased at sampling points A and B presented MPs in the form of films with an abundance between 155.56 and 177.78 MPs/kg of tortilla; however, no microplastics were identified in the samples of tortillas acquired at sites C, D, and E. The analysis suggests that the identified MPs may have come from the plastic bags in which tortillas are packaged. In addition, it was established that the daily consumption rate of microplastics per person is 2.48 to 5.15 pieces. Full article

Plastic pollution in terrestrial and freshwater environments and its accumulation along food chains has been poorly studied in birds. In this paper we reported evidence of microplastic (MP) contamination in pellets collected in rural and urban sites for a set of species: common kestrel, Falco tinnunculus; great cormorant, Phalacrocorax carbo; barn owl, Tyto alba; little owl, Athene noctua; long-eared owl, Asio otus; Eurasian scops owl, Otus scops; European bee-eater, Merops apiaster; and little egret, Egretta garzetta. A total of 559 pellets were collected and analyzed; among them, 78 microplastics were found on 77 pellets (13.8% compared to the total number of pellets sampled). The following polymers were recorded: polyvinylchloride (PVC), polyethylene (PE), expanded polyester (EPS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyester (PES), polymethyl acrylate (PMA), rubber, and starch-based biopolymer. We found significantly higher MP frequency in the most anthropized site. Pellets with the highest number of microplastics were those produced by Falco tinnunculus, Asio otus, and Tyto alba, with 30.0%, 29.6%, and 27.1%, respectively. Of a total sample of 78 MP items, 59.0% are represented by fibers, 23.1% by fragments and 17.9% by films. Among the microplastics, fragments of balloons (in a remote area) and biopolymer shopping bags were found. Our results suggest that pellet analysis may represent a cost-effective method for monitoring MP contamination along food chains in terrestrial ecosystems. Full article

Bioplastics are plastics derived from natural resources like corn starch, biomass, sugarcane bagasse, and food waste. Unlike fossil-fuel-based plastics, they are entirely or partially bio-degradable. Cellulose- and starch-based bioplastics are already used for applications like packaging, cutlery, bowls, straws, and shopping bags. With the aim of developing eco-friendly biofilms for various applications, cellulose nanocrystals (CNCs) were obtained by sulfuric acid hydrolysis of waste cellulose and functionalized by transesterification with exhausted oils. The resulting transesterified nanocellulose (TCNC) was used as a reinforced material of PLA at different concentrations to develop biofilms using the solvent casting method. The biofilms composed of PLA and TCNC were assessed through Fourier-transform infrared spectroscopy (FTIR), mechanical properties, moisture barrier property (water vapor permeability rate—WVTR), and measurements of the water contact angle (WCA). A scanning electron microscopy (SEM) analysis confirmed the high compatibility of the PLA blended with TCNC at 1% and 3%. The inclusion of transesterified cellulose nanocrystals (TCNCs) to PLA increased the hydrophobicity, the film tensile strength, and the water vapor barrier properties of the final composite films. Full article

(1) Background: A bioplastic poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is used in agriculture and in other applications like shopping bags, toys, and containers. Since the production of bio-based plastics, including PHBV-based materials, is expected to increase within the next few years, they are prone to becoming ubiquitous pollutants of the soil compartment. (2) Methods: An innovative PHBV-based plastic material was tested for its effect on higher plants and earthworms at the community level in a small-terrestrial model ecosystem (STME). The leachates obtained from PHBV-based plastic were studied with the use of ecotoxicological tests with regard to their impact on the early stages of the growth of higher plants and with the use of LC/MS toward the identification of the released chemical compounds. (3) Results: PHBV-based plastic microparticles at the relatively high but environmentally relevant concentration of 2.5% w/w neither affected the germination of higher plants nor inhibited their growth. The synthesis of chlorophyll and the C:N ratio in the plant biomass did not deteriorate, but the content of dry matter of the plant biomass was reduced at a statistically significant level. PHBV-based microplastics did not contribute to the mortality of Eisenia andrei, whereas they affected the depth distribution of these earthworms in the soil. Their downward movement indicated the avoidance behaviour under unfavourable living conditions. In the leachates from PHBV-based bioplastic, lactic acid and glycerol triacetate, commonly used plastic additives, were identified. These leachates did not inhibit the germination and the early stages of growth of higher plants. (4) Conclusions: PHBV-based bioplastic was studied at a concentration not higher than 2.5% w/w, and its leachates do not pose a threat to soil biota and should not affect the sustainability of the terrestrial ecosystem. Full article

Plastic pollution in freshwater ecosystems is an increasing environmental concern, prompting the search for biodegradable polymer (BP) alternatives. However, their degradation in natural aquatic environments remains poorly investigated and understood. This four-month in situ study compared the degradation in a lentic freshwater ecosystem of two compostable items, Mater-Bi^® shopping bag and disposable dish, with their respective pure polymer matrices, poly(butylene adipate-co-terephthalate) (PBAT) and polylactic acid (PLA). Additionally, biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and oil-based polypropylene (PP) were also tested. Changes in morphology, chemical composition and thermal and mechanical properties, as well as microbial colonization, were analyzed over time. A validated cleaning protocol was employed to ensure accurate surface analysis. Results showed detectable but limited degradation of pure polymers and their matrices in commercial products after 120 days of immersion with variations observed among polymer materials. Compostable materials exhibited significant leaching of fillers (starch, inorganic particles), leading to morphological changes and fragmentation. PHBV showed the fastest degradation among tested polyesters. PP exhibited only minor surface changes. Microbial colonization varied with polymer structure and degradability, but long-term degradation was limited by polymer properties and the gradual development of the plastisphere. This study highlights that standard laboratory tests may overestimate the environmental degradability of BPs and emphasizes the importance of in situ assessments, careful cleaning procedures and property characterizations to accurately assess polymer degradation in freshwater systems. Full article

Single-use plastics (SUPs) are deeply embedded in everyday consumption in rapidly developing Asian cities, yet their widespread use contributes to marine debris, microplastic pollution, and health risks. This study aimed to inform evidence-based policymaking to mitigate marine plastic pollution in the ASEAN+3 region. Stratified random sampling surveys (n = 1492) were conducted both face to face and online across five representative cities between September 2022 and February 2023. We quantified and compared the consumption and disposal patterns across nine SUP categories, assessed demographic influences, evaluated the impact of COVID-19, and derived insights for targeted policy interventions. Non-parametric tests were used to evaluate the differences. The results reveal significant inter-city variation: Shanghai and Harbin reported high overall SUP use despite a lower consumption of plastic shopping bags; Hanoi and Depok showed lower overall use but distinct preferences for plastic shopping bags and party cups; and Phnom Penh had the highest consumption of plastic shopping bags, bottles, and straws. Plastic shopping bags were the most used item in all cities (18–34 bags per week), with no significant differences between urban and rural areas, ages, or genders. In contrast, urban residents reported a higher use of plastic takeout containers, cutlery, coffee cups, and party cups. The COVID-19 pandemic notably reshaped SUP consumption patterns. Additionally, over half of SUPs were disposed of without proper separation. These findings underscore the need for flexible, phased, and context-specific interventions to support a resilient circular economy. Full article

This study aimed to compare the environmental performance of plastic bags made of three different polymers, considering two product functions: carrying goods and packing municipal solid waste. The three polymers studied were HDPE, LDPE, and thermoplastic starch (TPS). Life cycle assessment and emergy accounting were used to evaluate the environmental performance of each scenario in analysis. To develop this research, eight scenarios were created to represent the customs of use and consumption in the Brazilian population. The LCA results showed that, in general, the scenarios with HDPE plastic bags presented the best environmental performances, while those with TPS presented the worst. The processes that contributed most to these results, representing 70% or more of the environmental impact in each impact category, are related to the use of raw materials, electricity, and water for the manufacture of plastic bags and the treatment in landfills. In other words, the fact that TPS has a mass around six times greater than that of HDPE and two times greater than that of LDPE ends up leaving this type of polymer with the worst environmental performance. In the comparative analysis of scenarios for the same polymer, scenarios that involve the use and reuse of plastic bags present the lowest potential environmental impacts. In contrast, those related to the use and disposal in landfills present the highest possible environmental impacts. The results of emergy accounting showed that the HDPE scenarios had the lowest total emergy flow, ranging from 1.77 × 10¹³ seJ to 2.40 × 10¹³ seJ. In contrast, the LDPE scenarios had the highest total emergy flow, ranging from 1.15 × 10¹⁴ to 1.21 × 10¹⁴ seJ. Although LDPE had the highest total emergy flow values, these results are similar to those obtained by the fossil resource scarcity impact category, which focuses on resource consumption analysis. Thus, through a real approach to the use of plastic bags and solid waste management in the Brazilian context, this study brings essential insights to direct public policies related to the consumption of plastic bags. Full article

Bans on single-use plastic shopping bags (SUPBs) are a popular policy to tackle plastic pollution. However, their success has been evaluated solely based on reduced SUPBs consumption, ignoring the impacts of substitutes. This article addresses this gap by analyzing the Chilean plastic bag ban law. Results show a reduction of ~249 kilotons of SUPBs consumed and a change in the materiality of shopping bags (mainly toward paper), but also an increase of more than 50% of bin liners after the enactment of the ban. Despite some undesired effects, an improvement in the environmental performance of the bag market is obtained in fifteen of the eighteen categories studied. The environmental impacts are on average 38% lower than in the counterfactual scenario. This suggests that the law is being effective in protecting the environment. The strictness of the ban and its rapid enforcement were positive aspects of its design, but ignoring the end-of-life of the bags could be limiting its impact. To reduce the environmental impact of substitutes, it is recommended to create design guidelines for shopping bags and bin liners. Full article

Material flow analysis of plastics has attracted considerable attention for achieving sustainable production and consumption. However, the direct weights of each plastic have been analyzed alone, not considering the amount of natural resources as inputs for plastic production. Therefore, we analyzed the cradle-to-gate resource intensity of 21 types of plastics in terms of mining activity, using the total material requirement under the life cycle concept. It was found that the resource use for plastic production differs by up to approximately 10 times depending on the plastic type. By applying these findings to the material flow analysis of some countries and regions, we found that the quantity of natural resources was more than 20 times the original weight attributed to plastic production. By comparing resource use with greenhouse gas emissions, plastics with higher greenhouse gas emissions were found to have higher resource use, indicating a positive correlation, whereas the opposite trend was also found for some plastics. Considering plastic alternatives, we found that the quantity of natural resources in plastic-based shopping bags is nearly equivalent to that in paper-based bags, whereas that in plastic-based straws is greater than that in paper-based bags. Focusing only on the direct weight of plastic may mislead the decision-making process. Full article

The present study aims to explore the degradation process of compostable, starch-based (i.e., Mater-Bi^®) shopping bags in the marine environment using isotope ratio mass spectrometry and Fourier-transform infrared spectroscopy (FTIR). The mixing model applied to the isotopic data suggested that the compostable shopping bags had a mixed composition with a higher percentage of polyesters (61% to 72%). Changes in the isotopic composition over a 73-day period of marine water immersion showed a decrease in the corn starch constituent (of 14% to 13%), with a similar rate in both types of bags in accordance with the evidence derived from the infrared spectra. The time required for complete degradation of the starch fraction was estimated by an isotopic approach from 124 to 180 days, following zero-order kinetics. The coupled application of these two analytical methodologies promises to (i) show complementary evidence regarding the time-course degradability of different polymers via FTIR changes, and (ii) infer potential degradation mechanisms via carbon isotope analyzes. We encourage the use of this information to support advancements in the development of more sustainable-by-design plastic materials. Full article

Plastic shopping bags are often discarded as litter and can be carried away from roadsides and become tangled on cotton plants in farm fields. This rubbish plastic can end up in the cotton at the gin if not removed before harvest. These bags may not only cause problems in the ginning process but might also become embedded in cotton fibers, reducing the quality and marketable value. Therefore, detecting, locating, and removing the bags before the cotton is harvested is required. Manually detecting and locating these bags in cotton fields is a tedious, time-consuming, and costly process. To solve this, this paper shows the application of YOLOv5 to detect white and brown colored plastic bags tangled at three different heights in cotton plants (bottom, middle, top) using Unmanned Aircraft Systems (UAS)-acquired Red, Green, Blue (RGB) images. It was found that an average white and brown bag could be detected at 92.35% and 77.87% accuracies and a mean average precision (mAP) of 87.68%. Similarly, the trained YOLOv5 model, on average, could detect 94.25% of the top, 49.58% of the middle, and only 5% of the bottom bags. It was also found that both the color of the bags (p < 0.001) and their height on cotton plants (p < 0.0001) had a significant effect on detection accuracy. The findings reported in this paper can help in the autonomous detection of plastic contaminants in cotton fields and potentially speed up the mitigation efforts, thereby reducing the amount of contaminants in cotton gins. Full article

The effect of 96 h exposure of the goldfish Carassius auratus to two different types of bioplastic particles, originating from commercial shopping bag (Bag, ~5 mm) and polylactic acid-based (PLA) cup (Cup, ≤5 mm), and petroleum-based polyamide particles (PA, 0–180 µm) was studied. All particles were studied as virgin and after simulated UV-degradation (at concentration 30 mg L⁻¹). The experiments were conducted according to OECD 203 test guidelines. The toxicity endpoint evaluated in fish brain and gills was lipid peroxidation (LPO) quantified as nmol thiobarbituric acid reactive substances (TBARs) mg⁻¹ protein. The results indicated that indicatively compostable PLA bioplastic Cup induced significant LPO in the brain and/or gills of the goldfish, in contrast to the particles from Bag and PA (in the brain, Cup > Bag > PA; in the gills, Cup > Bag). The UV-degradation of the particles of all studied types had no significant effect on the LPO level compared to virgin particles. While the increase of LPO in fish gills and brain upon exposure to PLA-plastic particles can be transitory in the long-term perspective, our results point to the necessity of a thorough investigation of the hazard of bioplastics at different state of environmental degradation/weathering. Full article

Single-use plastic bags are increasingly becoming unpopular across the globe due to growing concerns over plastic pollution, which is threatening both terrestrial and marine ecosystems. Creating policy interventions to reduce plastic consumption requires objective information about local conditions. This study uses a choice experiment to elicit consumer preference for attributes of shopping bags from a sample of 250 consumers in Cape Town. Following the literature, we estimate the conditional logit model and the mix logit model and perform appropriate tests to establish a model which fits our data. Our results show that consumers in Cape Town prefer small and medium-sized bags relative to the status quo. They also care about durability, reusability, style, and recyclability of shopping bags. The highest willingness to pay is associated with a medium-sized shopping bag (R3.76), followed by a shopping bag that is reusable (R3.35), then a shopping bag that is styled (R2.16), then a small-sized shopping bag (R1.74), then a durable shopping bag (R1.50) and finally a recyclable shopping bag (R1.25). By aggregation, the willingness to pay of a small-sized shopping bag that is recyclable is R2.99 which is equivalent to the maximum price that the respondent is offering for a single-use plastic bag (R2.92). The willingness to pay of a medium-sized and reusable shopping bag is R7.11 per unit which is at least as high as the minimum price that respondents would consider for alternative packaging (R7.37). Finally, taking into consideration all the important attributes, we arrive at a willingness to pay ranging from R9.99 to R12.01 per bag for a small and medium shopping bag, respectively. Our results call for a combination of policy instruments such as a subsidy on expensive durable and reusable shopping bags to increase demand while at the same time increasing the levy on single-use plastic bags to reduce demand. More effort is needed to increase appreciation and perception of recyclable products. Full article

The purpose of this study is to determine whether there are gender differences in people’s pro-environmental psychology and behaviors in China. An online survey was conducted with the snowball sampling technique, and a sample of 532 Chinese respondents was obtained for the research. This study finds that gender does affect green psychology and behaviors, with females reporting a higher level of environmentalism in China. Specifically, females are more concerned with environmental problems, more supportive of plastic ban policies, more positive towards reducing plastics (reduce), and have stronger intention to bring a reusable bag for shopping (reuse and recycle). Moreover, females use fewer disposable toiletries when checking in a hotel and require less disposable tableware when ordering takeout. This study contributes to the current literature by identifying the relationship between gender and environmentalism in China. Implications for anti-plastic policy design and environmental management are also presented. Full article

Bringing a reusable bag for shopping is a typical pro-environmental behavior and has been shown to be effective in reducing plastics, but research regarding this green behavior is limited. In this regard, using the snowball sampling technique, this study conducts a survey on a sample of 361 Chinese consumers to investigate their intention to bring a reusable bag for shopping based on the theory of planned behavior. To increase the explaining power for behavioral intention, this study extended the TPB by adding two additional variables: locus of control and environmental concern. Data was analyzed using the structural equation modeling technique. Results show that attitude, perceived behavioral control, and subjective norm exert significant and positive influence on consumers’ intention to bring reusable bags for shopping, and the perceived behavioral control exerts the greatest influence, followed by attitude and subjective norm. Both locus of control and environmental concern fail to directly impact consumers’ bringing intention, but they could impact consumers’ intention indirectly. Specifically, the external locus of control exerts a negative influence on attitude and perceived behavioral control. Environmental concern positively impacts consumers’ attitudes towards bringing reusable bags for shopping. Results of this study could provide valuable insights into plastics management and policy design to promote consumers’ green shopping behaviors. For instance, the finding that perceived behavioral control is the greatest contributor to consumers’ intention to bring reusable bags highlights the importance of clearing reusable bag preparation and use barriers. Full article