Distribution of microplastics in the soils of a petrochemical industrial region in China: Ecological and Human Health Risks.

Abstract

Although microplastic pollution is a global concern, information on the distribution of microplastics in petroleum and petrochemical urban soils is limited. In this study, we investigated the occurrence, ecological risk, and human exposure risk of microplastics in different land-use types of soil in Daqing Administrative region, a prominent petroleum and petrochemical industrial base in China. Stereoscopic microscopy and Fourier transform infrared spectroscopy (μ-FTIR) were used to study the chemical composition and distribution characteristics of microplastics. We found that the abundance of microplastics in Daqing soil ranged from 714 to 11,122 items/kg, with the highest value in educational land and the lowest in parks and green land. The dominant particle size of microplastics was < 1 mm (65.7%), and the shape was mainly fiber (55.1%), with white (28.9%) and black (25.6%) as the predominant colors. The most common polymer types were rayon, polypropylene, and polyethylene. Using the potential ecological risk index (RI) and polymeric risk index (H), we found that all land-use types, except woodland (Level I), were classified into Level V of ecological risk, with the highest risk in industrial land (RI = 14,959.85, H = 588.31). The daily exposure of infants to microplastics was much higher than that of adults. These findings provide valuable data for the pollution and potential risk assessment of microplastics in urban and rural environments, suggesting the importance of taking action to minimize its harmful effects on ecological and human health. In order to control the pollution caused by microplastics, we suggest that people should reduce the unnecessary use of single-use plastic items, such as water bottles, plastic shopping bags, straws, etc. In addition, the government needs to strengthen rubbish collection to prevent plastic waste from leaking into the environment during the period from the rubbish bins to the landfills, and to build recycling systems to increase the recycling rate.