Atmospheric microplastic fallout in outdoor and indoor environments in São Paulo megacity.

Plastics are widely used by society, and their degradation into millimetre fragments, called microplastics (MPs), has become a global environmental threat to ecosystems and human health. However, airborne MPs' presence and fallout fluxes from the atmosphere are poorly understood and can vary significantly by different conditions, especially in megacities of low- and middle-income countries, where high levels of vehicular air pollution, a high-density population, high plastic use, and inadequate disposal are environmental threats related to airborne MPs. In this study, we investigate the amount, chemical composition, and morphological characteristics of outdoor and indoor airborne MPs fallout in the megacity of São Paulo and assess the influence of weather and seasons on airborne MPs fallout. The results were as follows: MPs were found in all samples with an average fallout rate of 309.40 ± 214.71 MPs/m2/day in the indoor environment, and 123.20 ± 47.09 MPs/m2/day in the outdoor environment; MPs concentrations were higher in the indoor environment than the outdoor environment, with more fibres than particles; polyester fibres (100%), polyethylene (59%) and polypropylene (26%) particles were the dominant polymers indoors, while in outdoors, polyester fibres (76%) and polyethylene (67%) and polyethylene terephthalate (25%) particles were dominant. Fragment was the dominant morphology of particles found in indoor and outdoor samples (64% and 74%, respectively). Outdoor MPs fallout correlated positively with rainfall, wind velocity, and relative humidity. This evidence is the first on airborne MPs in a Latin America megacity and highlights the relevant role that this source plays in different environments.

Airborne microplastics and SARS-CoV-2 in total suspended particles in the area surrounding the largest medical centre in Latin America.

Microplastics (MPs) have been reported in the outdoor/indoor air of urban centres, raising health concerns due to the potential for human exposure. Since aerosols are considered one of the routes of Coronavirus disease 2019 (COVID-19) transmission and may bind to the surface of airborne MPs, we hypothesize that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could be associated with the levels of MPs in the air. Our goal was to quantify the SARS-CoV-2 RNA and MPs present in the total suspended particles (TSP) collected in the area surrounding the largest medical centre in Latin America and to elucidate a possible association among weather variables, MPs, and SARS-CoV-2 in the air. TSP were sampled from three outdoor locations in the areas surrounding a medical centre. MPs were quantified and measured under a fluorescence microscope, and their polymeric composition was characterized by Fourier transform infrared (FT-IR) microspectroscopy coupled with attenuated total reflectance (ATR). The viral load of SARS-CoV-2 was quantified by an in-house real-time PCR assay. A generalized linear model (GzLM) was employed to evaluate the effect of the SARS-CoV-2 quantification on MPs and weather variables. TSP samples tested positive for SARS-CoV-2 in 22 out of 38 samples at the three sites. Polyester was the most frequent polymer (80%) found in the samples. The total amount of MPs was positively associated with the quantification of SARS-CoV-2 envelope genes and negatively associated with weather variables (temperature and relative humidity). Our findings show that SARS-CoV-2 aerosols may bind to TSP, such as MPs, and facilitate virus entry into the human body.

Presence of airborne microplastics in human lung tissue.

Plastics are ubiquitously used by societies, but most of the plastic waste is deposited in landfills and in the natural environment. Their degradation into submillimetre fragments, called microplastics, is a growing concern due to potential adverse effects on the environment and human health. Microplastics are present in the air and may be inhaled by humans, but whether they have deleterious effects on the respiratory system remain unknown. In this study, we determined the presence of microplastics in human lung tissues obtained at autopsies. Polymeric particles (n = 33) and fibres (n = 4) were observed in 13 of 20 tissue samples. All polymeric particles were smaller than 5.5 µm in size, and fibres ranged from 8.12 to 16.8 µm. The most frequently determined polymers were polyethylene and polypropylene. Deleterious health outcomes may be related to the heterogeneous characteristics of these contaminants in the respiratory system following inhalation.

An emerging class of air pollutants: Potential effects of microplastics to respiratory human health?

It is increasingly recognized that the ubiquity of convenient single-use plastic has resulted in a global plastic pollution challenge, with substantial environmental and health consequences. Physical, chemical, and biological processes result in plastic weathering, with eventual formation of debris in the micro to nano size range. There is an increasing awareness that plastic fragments are dispersed in the air and can be inhaled by humans, which may cause adverse effects on the respiratory system and on other systems. Urban environments are often characterized by high concentrations of fine airborne dust from various sources. To date, however, there is limited information on the distribution, shape, and size of microplastics in the air in urban and other environments. In this article, we review and discuss our current understanding of the exposure characteristics of airborne plastic debris in urbanized areas, focusing on concentration, size, morphology, presence of additives and distributions of different polymers. The natural and extend data are compiled and compared to laboratory-based analyses to further our understanding of the potential adverse effects of inhaled plastic particles on human health.