Human occupational exposure to microplastics: A cross-sectional study in a plastic products manufacturing plant

Comparison of Microplastics between Lung Tissues and Intestinal Contents in Finless Porpoises (Neophocaena asiaeorientalis)

Microplastics are ubiquitous environmental pollutants in terrestrial, marine, and atmospheric ecosystems. Plastic inputs into the atmosphere occur through weathering or abrasion, dispersing microplastics globally, which can enter the animals' respiratory systems through inhalation. We analyzed the lung tissues for the first time and the intestinal contents of 11 dead finless porpoises (Neophocaena asiaeorientalis) to assess the intake of microplastics from prey and atmospheric sources. The lung tissues and intestinal contents contained average concentrations of 0.14 ± 0.11 MPs/g and 0.35 ± 0.36 MPs/g, respectively. Microplastics found in the lung tissues and intestinal contents were similar in physical characteristics (e.g., fragment shape, transparent to white color, and size <100 μm). On the other hand, they differed in the polymer types, with a higher proportion of epoxy-type microplastics in the lungs. Epoxy is a highly hazardous polymer according to the polymer hazard index, and in the present study, the lung tissues had a higher plastic hazard index than the intestinal contents. Hence, the respiratory system is more vulnerable to microplastic pollution from atmospheric sources than the digestive system is from water and food intake. These findings underscore the growing threat of airborne microplastics to lung-breathing animals including marine mammals.

Identifying and analyzing the microplastics in human aqueous humor by pyrolysis-gas chromatography/mass spectrometry

Microplastics (MPs), an emerging global pollutant, pose potential risks to human health and have garnered increasing attention. Previous research has identified MPs in various human tissues and organs, but not in the aqueous humor of the eyes. This study used pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) to explore MPs in aqueous humor. Five types of MPs-polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polyamide 66 (PA66), and polystyrene (PS)-were found, with PE and PVC being most common. PP was more prevalent in children, while PA66 was more common in adults. MPs abundance generally followed the trend: adults > children > elders among age groups, and females > males between gender groups. Notably, this study is the first to confirm MPs in human aqueous humor, providing a foundation for future research on their impact on intraocular health and enhancing our understanding of the MPs' body distribution.

Microplastics in Agricultural Crops and Their Possible Impact on Farmers' Health: A Review

The indiscriminate use of plastic products and their inappropriate management and disposal contribute to the increasing presence and accumulation of this material in all environmental zones. The chemical properties of plastics and their resistance to natural degradation lead over time to the production of microplastics (MPs) and nanoplastics, which are dispersed in soil, water, and air and can be absorbed by plants, including those grown for food. In agriculture, MPs can come from many sources (mulch film, tractor tires, compost, fertilizers, and pesticides). The possible effects of this type of pollution on living organisms, especially humans, increase the need to carry out studies to assess occupational exposure in agriculture. It would also be desirable to promote alternative materials to plastic and sustainable agronomic practices to protect the safety and health of agricultural workers.

Recycle or Not? An Exploration of Microplastic Generation During Plastic Processing via a Local Case Study

Microplastic (MP), an emerging pollutant, has been identified as a critical target in tackling plastic pollution. Although a plethora of studies have explored MP generation from various sources, limited attention has been paid to plastic processing. This study investigated MP (10 μm-5 mm) generation in virgin and waste plastic extrusion processing. MPs at a density of 2.13 × 105-9.79 × 107 (approximately 0.01-10.85 g) were generated when processing 1 t of plastic. Feedstock sources, polymer types, and pelletizing techniques were found to influence the process. With a moderate weight (270.58-527.34 t) but enormous amount (1.34 × 1016-2.63 × 1016) of MPs generated globally in 2022, plastic processing is an underestimated but vital source of MPs, emphasizing the need for MP inspection and appropriate removal technologies in the industry, especially for virgin plastic processing and water ring pelletizing. Further simulation indicated that up to 84.35% of MPs could be removed using commonly available materials in the investigated plastic processing facility, with a higher removal efficiency for larger-sized particles. In this regard, plastic recycling was superior to virgin plastic processing with fewer and larger-sized MPs generated, which could facilitate MP removal and should be fostered.

Occupational exposures in low- and middle-income countries: A scoping review

Exposure to high levels of harmful agents in the workplace can significantly impact workers' health, contributing to morbidity and mortality. Levels of these exposures are often measured in high-income countries in research studies and, in some places, to monitor levels in line with health and safety regulations. However, less is known about workplace exposure levels in low- and middle-income countries (LMICs). Our aim was to describe the quantitative exposure measurements of different occupational agents across industries within LMICs. We conducted a scoping review of peer-reviewed publications available on Web of Science and PubMed from inception to 1 September 2023. Our search focused on quantitative occupational exposure measurements across industries in LMICs. We identified a total of 8,676 publications. After screening, 58 studies from 25 countries were retained for final review. China, Iran, and Tanzania contributed the greatest number of studies. Manufacturing, mining, and agriculture were the most studied sectors, with factory workers and miners being the most common job titles. Exposure measurements included vapour, gases, dust, and fumes (VGDF), solvents, metals, pesticides and particulate matter. Occupational exposure levels for the same industry varied widely across geographical regions. This review provides a comprehensive overview of occupational exposures in LMICs and highlights the absence of data in certain geographical areas and industries. The study contributes valuable insights for directing future research, and the need to optimise the assessment of occupational exposures in LMICs with the aim ultimately of reducing disease.

Microplastics in the Human Body: Exposure, Detection, and Risk of Carcinogenesis: A State-of-the-Art Review

Background: Humans cannot avoid plastic exposure due to its ubiquitous presence in the natural environment. The waste generated is poorly biodegradable and exists in the form of MPs, which can enter the human body primarily through the digestive tract, respiratory tract, or damaged skin and accumulate in various tissues by crossing biological membrane barriers. There is an increasing amount of research on the health effects of MPs. Most literature reports focus on the impact of plastics on the respiratory, digestive, reproductive, hormonal, nervous, and immune systems, as well as the metabolic effects of MPs accumulation leading to epidemics of obesity, diabetes, hypertension, and non-alcoholic fatty liver disease. MPs, as xenobiotics, undergo ADMET processes in the body, i.e., absorption, distribution, metabolism, and excretion, which are not fully understood. Of particular concern are the carcinogenic chemicals added to plastics during manufacturing or adsorbed from the environment, such as chlorinated paraffins, phthalates, phenols, and bisphenols, which can be released when absorbed by the body. The continuous increase in NMP exposure has accelerated during the SARS-CoV-2 pandemic when there was a need to use single-use plastic products in daily life. Therefore, there is an urgent need to diagnose problems related to the health effects of MP exposure and detection. Methods: We collected eligible publications mainly from PubMed published between 2017 and 2024. Results: In this review, we summarize the current knowledge on potential sources and routes of exposure, translocation pathways, identification methods, and carcinogenic potential confirmed by in vitro and in vivo studies. Additionally, we discuss the limitations of studies such as contamination during sample preparation and instrumental limitations constraints affecting imaging quality and MPs detection sensitivity. Conclusions: The assessment of MP content in samples should be performed according to the appropriate procedure and analytical technique to ensure Quality and Control (QA/QC). It was confirmed that MPs can be absorbed and accumulated in distant tissues, leading to an inflammatory response and initiation of signaling pathways responsible for malignant transformation.

First evidence of microplastic inhalation among free-ranging small cetaceans

Plastic is a ubiquitous environmental contaminant, resulting in widespread exposure across terrestrial and marine spaces. In the environment, plastics can degrade into microparticles where exposure has been documented in a variety of fauna at all trophic levels. Human epidemiological studies have found relationships between inhaled microplastics and oxidative stress and inflammation. Previous studies of bottlenose dolphins (Tursiops truncatus) have reported prevalent exposure to plasticizing chemicals (e.g., phthalates) as well as particle loads in gastrointestinal tracts, but exposure from inhalation has not yet been studied. The objective of this study was to determine if inhalation is a viable route of microplastic exposure for free-ranging dolphins. Exhalation samples were opportunistically collected from dolphins residing in Sarasota Bay, Florida (n = 5) and Barataria Bay, Louisiana (n = 6) during catch-and-release health assessments to screen for microplastic particles. All dolphin samples contained at least one suspected microplastic particle, and polymer composition was determined for 100% of a subset (n = 17) of samples. Additional studies are warranted to better understand the extent of inhaled microplastics, as well as to explore impacts, given potential risks to lung function and health.

The alarming link between environmental microplastics and health hazards with special emphasis on cancer

Microplastic contamination is a burgeoning environmental issue that poses serious threats to animal and human health. Microplastics enter the human body through nasal, dermal, and oral routes to contaminate multiple organs. Studies have advocated the existence of microplastics in human breast milk, sputum, faeces, and blood. Microplastics can find their ways to the sub-cellular moiety via active and passive approaches. At cellular level, microplastics follow clathrin and caveolae-dependent pathways to invade the sub-cellular environment. These environmental contaminants modulate the epigenetic control of gene expression, status of inflammatory mediators, redox homeostasis, cell-cycle proteins, and mimic the endocrine mediators like estrogen and androgen to fuel carcinogenesis. Furthermore, epidemiological studies have suggested potential links between the exposure to microplastics and the onset of various chronic diseases. Microplastics trigger uncontrolled cell proliferation and ensue tissue growth leading to various cancers affecting the lungs, blood, breasts, prostate, and ovaries. Additionally, such contamination can potentially affect sub-cellular signaling and injure multiple organs. In essence, numerous reports have claimed microplastic-induced toxicity and tumorigenesis in human and model animals. Nonetheless, the underlying molecular mechanism is still elusive and warrants further investigations. This review provides a comprehensive analysis of microplastics, covering their sources, chemistry, human exposure routes, toxicity, and carcinogenic potential at the molecular level.

Microplastics in the human body: A comprehensive review of exposure, distribution, migration mechanisms, and toxicity

Microplastics (MPs) are pervasive across ecosystems, presenting substantial risks to human health. Developing a comprehensive review of MPs is crucial due to the growing evidence of their widespread presence and potential harmful effects. Despite the growth in research, considerable uncertainties persist regarding their transport dynamics, prevalence, toxicological impacts, and the potential long-term health effects they may cause. This review thoroughly evaluates recent advancements in research on MPs and their implications for human health, including estimations of human exposure through ingestion, inhalation, and skin contact. It also quantifies the distribution and accumulation of MPs in various organs and tissues. The review discusses the mechanisms enabling MPs to cross biological barriers and the role of particle size in their translocation. To ensure methodological rigor, this review adheres to the PRISMA guidelines, explicitly detailing the literature search strategy, inclusion criteria, and the quality assessment of selected studies. The review concludes that MPs pose significant toxicological risks, identifies critical gaps in current knowledge, and recommends future research directions to elucidate the prolonged effects of MPs on human health. This work aims to offer a scientific framework for mitigating MP-related hazards and establishes a foundation for ongoing investigation.

Microplastics in the atmospheric of the eastern coast of China: different function areas reflecting various sources and transport

Suspended atmospheric microplastics (SAMPs) display varying occurrence characteristics on different underlying surfaces in urban areas. This study investigated the occurrence characteristics, source apportionment, and transportation patterns of SAMPs in two typical underlying surfaces: the downtown area (Site T) and the industrial area (Site C) of a coastal city in China. In the spring of 2023, a total of 32 types comprising 1325 SAMPs were detected. The average MP abundances were found to be 3.74 ± 2.86 n/m3 in Site T and 2.67 ± 1.68 n/m3 in Site C. In Site T, SAMPs attributed to living source constituted 78.05%, while industry was the main source in Site C with a proportion reaching 42.89%, consistent with the functional zoning of the underlying surface. Furthermore, HYSPLIT analysis revealed that there was no significant difference between these two sites in long-distance horizontal transport affected by external airflow regardless of altitude; conversely, PCA indicated a notable correlation between vertical velocity and both abundance and species diversity. According to the hourly average wind speeds, the maximum transmission distance was computed as 350 km for updraft and the minimum transmission distances was as low as 32 m for downdraft. Subsequently, the coincidence between the source proportion of SAMPs on random day and meteorological parameters confirmed the synergistic impact on SAMPs transport influenced by functional zoning, geographic environment, and vertical velocity.

The effects of nano- and microplastic ingestion on the survivorship and reproduction of Aedes aegypti and Aedes albopictus (Diptera: Culicidae)

Microplastics (MPs) and nanoplastics (NPs) are pervasive environmental pollutants that are commonly ingested by organisms at different trophic levels. While the effects of MPs on aquatic organisms have been extensively studied, the impacts of MP ingestion on the host fitness of terrestrial organisms, mainly insects, have been relatively unexplored. This study investigates the effects of MP and NP ingestion on the survivorship and reproduction of 2 medically important mosquito species, Aedes aegypti Linnaeus (Diptera: Culicidae) and Aedes albopictus Skuse (Diptera: Culicidae). Larval and pupal survivorship of Ae. albopictus were not significantly affected by particle size or concentration, but there was a reduction of Ae. aegypti pupal survivorship associated with the ingestion of 0.03 µm NPs. In addition, there was little observed impact of 0.03 µm NP and 1.0 µm MP ingestion on adult survivorship, fecundity, and longevity. To further investigate the effects of MP ingestion on mosquito fitness, we also examined the effects of MPs of varying shape, size, and plastic polymer type on Ae. aegypti immature and adult survivorship. The data suggest that the polymer type and shape did not impact Ae. aegypti immature or adult survivorship. These findings highlight that understanding the effects of microplastic ingestion by mosquitoes may be complicated by the size, composition, and amount ingested.

Psychosocial risks of workers in the plywood industry: A cross-sectional study in the Ecuadorian Amazon region

This work assessed the psychosocial risks of 124 workers from the plywood industry in Ecuador's Amazon region. Two psychosocial risk assessment (PRA) methods were selected due to their widespread use in Ecuadorian organisations: FPSICO from the Spanish National Institute for Occupational Safety and Health and the "Psychosocial Risk Assessment Questionnaire" (PRAQ) from the Ecuadorian Labour Ministry. Therefore, two surveys of 89 and 58 items were applied to evaluate nine scales and eight risk dimensions for FPSICO and PRAQ, respectively. Results show that according to FPSICO, the main psychosocial risks were detected in the scales of working time (WT), variety and content (VC), and workload (WL), with a prevalence of 34.8 % and 41.7 %. For PRAQ, the margin of action and control (D4), load and work rate (D1), and leadership (D3) were the most affected dimensions, with a risk prevalence between 29.1 % and 43.6 %. Although there is a lower risk prevalence in the rest of the scales and dimensions assessed, improvement actions are needed in the short term. Furthermore, the findings suggest an association between gender and risk prevalence, especially in the dimensions of Leadership (D3), Skills development (D2), and Self-perceived health (D8.8), where being a woman increases the likelihood of suffering from these conditions by up to three times. In addition, a brief comparative analysis was conducted, looking for coincidences in the scales that each PRA instrument assesses and the prevalence of the psychosocial risks detected.

Inhalation of Microplastics-A Toxicological Complexity

Humans are chronically exposed to airborne microplastics (MPs) by inhalation. Various types of polymer particles have been detected in lung samples, which could pose a threat to human health. Inhalation toxicological studies are crucial for assessing the effects of airborne MPs and for exposure-reduction measures. This communication paper addresses important health concerns related to MPs, taking into consideration three levels of complexity, i.e., the particles themselves, the additives present in the plastics, and the exogenous substances adsorbed onto them. This approach aims to obtain a comprehensive toxicological profile of deposited MPs in the lungs, encompassing local and systemic effects. The physicochemical characteristics of MPs may play a pivotal role in lung toxicity. Although evidence suggests toxic effects of MPs in animal and cell models, no established causal link with pulmonary or systemic diseases in humans has been established. The transfer of MPs and associated chemicals from the lungs into the bloodstream and/or pulmonary circulation remains to be confirmed in humans. Understanding the toxicity of MPs requires a multidisciplinary investigation using a One Health approach.

Oxidative stress-activated Nrf2 remitted polystyrene nanoplastic-induced mitochondrial damage and inflammatory response in HepG2 cells

Generated from plastics, microplastics (MPs) and nanoplastics (NPs) are difficult to completely degrade in the natural environment, which can accumulate in almost all lives. Liver is one of the main target organs. In this study, HepG2 and L02 cells were exposed to 0-50 μg/mL polystyrene (PS)-NPs to investigate the mechanism of mitochondrial damage and inflammation. The results showed mitochondria damage and inflammatory caused by NPs, and it can be inhibited by N-acetyl-L-cysteine (NAC). In addition, reactive oxygen species (ROS) activated nuclear factor erythroid-derived factor 2-related factor (Nrf2) pathway. Nrf2 siRNA exacerbated the injury, suggesting Nrf2 plays a protective role. Moreover, p62 siRNA increased ROS and mitochondrial damage by inhibiting Nrf2, but didn't affect the inflammation. In conclusion, Nrf2 was activated by ROS and played a protective role in PS-NPs-mediated hepatotoxicity. This study supplemented the data of liver injury caused by PS-NPs, providing a basis for the safe disposal of plastics.

Recent advances in micro (nano) plastics in the environment: Distribution, health risks, challenges and future prospects

Environmental micro(nano)plastics have become a significant global pollution problem due to the widespread use of plastic products. In this review, we summarized the latest research advances on micro(nano)plastics in the environment, including their distribution, health risks, challenges, and future prospect. Micro(nano)plastics have been found in a variety of environmental media, such as the atmosphere, water bodies, sediment, and especially marine systems, even in remote places like Antarctica, mountain tops, and the deep sea. The accumulation of micro(nano)plastics in organisms or humans through ingestion or other passive ways poses a series of negative impacts on metabolism, immune function, and health. Moreover, due to their large specific surface area, micro(nano)plastics can also adsorb other pollutants, causing even more serious effects on animal and human health. Despite the significant health risks posed by micro(nano)plastics, there are limitations in the methods used to measure their dispersion in the environment and their potential health risks to organisms. Therefore, further research is needed to fully understand these risks and their impacts on the environment and human health. Taken together, the challenges of micro(nano)plastics analysis in the environment and organisms must be addressed, and future research prospects need to be identified. Governments and individuals must take action to reduce plastic waste and minimize the negative impact of micro(nano)plastics on the environment and human health.