Airborne Microplastic Concentrations in Five Megacities of Northern and Southeast China

Abstract

Airborne microplastics (MPs) are receiving increasing attention due to their ubiquitous nature and the potential human health consequences resulting from inhalation. The limited data for airborne MP concentrations vary widely among studies (∼4 orders of magnitude), but comparisons are tenuous due to the inconsistent collection and detection/enumeration methodologies among studies. Herein, we used uniform methodologies to obtain comparable airborne MP concentration data to assess MP exposure intensity in five Chinese megacities. Airborne MP concentrations in northern cities (358 ± 132 items/m 3 ) were higher than those in southeast cities (230 ± 94 items/m 3 ) but of a similar order of magnitude, unlike previous studies. The majority (94.7%) of MPs found in air samples were smaller than 100 μm, and the main shape of airborne MPs was fragments (88.2%). Polyethylene, polyester, and polystyrene were the dominant polymers comprising airborne MPs. No consistent relationships were detected between airborne MP concentration and typical socioeconomic indices, and the spatial and diurnal patterns for airborne MPs were different from various components of air quality indices (PM 2.5 , PM 10 , etc.). These findings reflect the contrasting source/generation dynamics between airborne MPs and other airborne pollutants. Maximum annual exposure of humans to airborne MPs was estimated in the range of 1−2 million/year in these megacities, highlighting the need for additional research examining the human health risks from the inhalation of airborne MPs.

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

“…7 Today, more MPs have been found in indoor rather than outdoor environments. 7 Although the concentrations 10 and deposition rates 18,19 are often used to characterize airborne MPs, the size and density of MPs would influence its deposition on the respiratory system, with smaller, less dense particles reaching deeper parts of the lungs. 20,21 Recently, the presence of 33 MPs in 13 human lung tissues was first reported.…”

Ecological and human health risks of atmospheric microplastics (MPs): a review

“…The same sampling and detection method was used to assess the intensity of exposure to MPs in the atmosphere of ve megacities in China. 72 The results showed that the concentrations of MPs in the air in northern cities (358 AE 132 items per m 3 ) were higher than those in southeast cities (230 AE 94 items per m 3 ). Signicant differences in the distribution of atmospheric MPs in different functional areas of the same city show that the above guesses are wellfounded.…”

“…The main source of airborne MPs is synthetic bers. 72,73 Globally, more than 90 million tons of textile bers were produced in 2016. Two-thirds of them were synthetic and plastic bers, and the production rate has grown at around 6.6% per year over the past decade.…”

Coronas of micro/nano plastics: a key determinant in their risk assessments

“…Atmospheric M/NPs have aroused substantial concerns in recent years because they can be quickly transported over long distances by wind. Airborne plastics mainly originate from synthetic clothing, synthetic fibers in building materials, plastic waste incineration and road dust [73]. Researchers have found atmospheric M/NPs both indoors and outdoors [74].…”