Atmospheric micro (nano) plastics: future growing concerns for human health

Abstract

Plastics are an integral but largely inconspicuous part of daily human routines. The present review paper uses cross-disciplinary scientific literature to examine and assess the possible effects of nanoplastics (NPs) concerning microplastics (MPs) on human health and summarizes crucial areas for future research. Although research on the nature and consequences of MPs has seen a substantial rise, only limited studies have concentrated on the atmospheric nanosized polymeric particles. However, due to the intrinsic technological complications in separating and computing them, their existence has been difficult to determine correctly. There is a consensus that these are not only existing in the environment but can get directly released or as the outcome of weathering of larger fragments, and it is believed to be that combustion can be the tertiary source of polymeric particles. NPs can have harmful consequences on human health, and their exposure may happen via ingestion, inhalation, or absorption by the skin. The atmospheric fallout of micro (nano) plastics may be responsible for contaminating the environment. Apart from this, different drivers affect the concentration of micro (nano) plastics in every environment compartment like wind, water currents, vectors, soil erosion, run-off, etc. Their high specific surface for the sorption of organic pollutions and toxic heavy metals and possible transfer between organisms at different nutrient levels make the study of NPs an urgent priority. These NPs could potentially cause physical damage by the particles themselves and biological stress by NPs alone or by leaching additives. However, there is minimal understanding of the occurrence, distribution, abundance, and fate of NPs in the environment, partially due to the lack of suitable techniques for separating and identifying NPs from complex environmental matrices. Highlights Micro (nano) plastics generated may reach the soil, water, and atmospheric compartments. Atmospheric currents serve as a way to transport, leading to micro (nano) plastics pollution. Exposure to micro (nano) plastics may happen via ingestion, inhalation, or absorption by the skin. Nanoplastics may be environmentally more harmful than other plastic particles; the focus should be on defining the exact size range. Visual classification of micro (nano) plastics is poor in reliability and may also contribute to microplastics being misidentified. Graphical abstract

Individual Exposure to Microplastics through the Inhalation Route: Comparison of Microplastics in Inhaled Indoor Aerosol and Exhaled Breath Air

“…45−47 The difference in MPs deposition may result from individual factors. 43,44 Given that some MPs are externalized through exhalation, our findings indicated that the exposure estimation based solely on inhaled air MPs concentrations would overestimate the actual airborne microplastics exposure by 33%, particularly 40% for smaller MPs (<10 μm).…”

“…The estimated deposition in the respiratory tract was 526 ± 203 (57–1037) MPs per day. During the period of sample collection, the temperature and humidity were kept moderate and relatively constant, avoiding potential effects on nasal mucociliary clearance. − The difference in MPs deposition may result from individual factors. , Given that some MPs are externalized through exhalation, our findings indicated that the exposure estimation based solely on inhaled air MPs concentrations would overestimate the actual airborne microplastics exposure by 33%, particularly 40% for smaller MPs (<10 μm).…”

“…Moreover, the concentrations of all size level MPs (Figure b), fragment- and fiber-shaped MPs (Figure c), and PET, PE, cellulose, and PP MPs (Figure d) from HIA were significantly higher than those from HEB. Inhaled MPs would reach the airways and might be deposited depending on the particle properties, human specificity, and respiratory structural characteristics. , …”

“…Inhaled MPs would reach the airways and might be deposited depending on the particle properties, human specificity, and respiratory structural characteristics. 43,44 Daily consumption of MPs from HIA was roughly 704 ± 254 items/day, but a mere 178 ± 75 items/day were discharged with HEB (Figure 3). The estimated deposition in the respiratory tract was 526 ± 203 (57−1037) MPs per day.…”

Quantifying the Chemical Composition and Real-Time Mass Loading of Nanoplastic Particles in the Atmosphere Using Aerosol Mass Spectrometry

“…The size limitations for analyzing plastic fragments are estimated to be 500 μm for visual methods, 20 μm for FTIR, and 10 μm for Raman spectroscopy, respectively. , For thermochemical methods, the traditional size limit for analyzing plastic particles was suggested to be 100 μm to obtain a clear result . However, there have been significant improvements with pyrolysis-GC/MS that can identify and quantify lab-generated and ambient plastic particles with much smaller size. ,, Considering these size constraints, previous studies have focused more on microplastics with sizes ranging from 5 mm to 1 μm. , NPPs have smaller sizes, higher cell affinity, and enhanced surface curvature, making them easier to penetrate into freshwater biological barriers and accumulate in organs than MPPs. − Despite their longer atmospheric resident time, enhanced accumulation in the environment, and adverse health effects, nanoplastic particles remain largely uninvestigated due to their small sizes. ,, Hence, it is imperative to identify the chemical composition and mass concentration of nanoplastic particles to accurately assess their potential climate effects and public health risks …”