Microplastic pollution in urban green-belt soil in Shihezi City, China.

The problems are associated with microplastic (MP) pollution of global concern. However, little is known about the pollution characteristics and sources of MPs in urban green-belt soils. Therefore, this study investigated MP pollution in 11 sampling sites (22 green belts) in Shihezi City. The results showed that the abundance of MPs (0.02-5.00 mm) ranged from 287 ± 100 items/kg dw to 3227 ± 155 items/kg dw (mean + SD). Fibers (69.9%) accounted for the majority of MPs, and the MPs were mainly black (36.7%) and 0.02-0.5 mm (64.8%). The main types of MPs were polystyrene (PS) and polyethylene (PE). Compared with agricultural soil, the color and composition of green-belt soil MPs are diverse, which means that the source of green-belt soil MPs is more diverse. In different types of green-belt soil, MP pollution of industrial green land is more serious. Through cluster analysis and spatial distribution, fragments and fibers were found to have similar sources, mainly originating from food and textile industrial activities. This study provides important information for revealing MP pollutions in urban green-belt soils.

Evaluation of microplastic pollution in Shihezi city, China, using pine needles as a biological passive sampler.

Microplastic (MP) pollution has attracted much attention. To understand the characteristics of atmospheric MP pollution in Shihezi, Northwest China, this study used pine needles from trees in Shihezi City as passive samplers. MP contamination was found in all pine needle samples, with an average concentration of 16.52 ± 3.76 items/g. MPs were mainly in the shape of fragments (<0.05 mm). Differences in MP pollution were observed in different functional areas. The abundance of MPs in pine needles was the highest on the main traffic road (19.02 ± 2.52 items/g). Spectral analysis showed that the main polymer of MPs was polyethylene (17.2%), followed by polystyrene (15.5%) and polypropylene (13.8%). By analyzing the principal components and spatial distribution, fragments and pellets were found to have similar sources (mainly industrial activities), whereas films and fibers were influenced by traffic flow. The source of films was related to the packaging industry. The purpose of this study was to provide a reference for the future use of pine needles as atmospheric MP passive samplers, for the traceability and prevention of urban atmospheric MP pollution and for the formulation of national atmospheric MP environmental standards.

Seasonal variation and risk assessment of microplastics in surface water of the Manas River Basin, China.

The ubiquity of microplastics in the environment has caused great influence to ecosystems and seriously threatened human health. To better understand the variation in microplastics in different seasons in an inland freshwater environment and determine the sources of microplastic pollution and its migration features, this study investigated the characteristics of microplastic pollution during dry (April) and wet (July) seasons in surface water of the Manas River Basin, China. The size, color, shape, area distribution and compound composition of microplastics were studied. Moreover, the risk of microplastic contamination was explored based on risk assessment models. The results demonstrated that the degree of pollution caused by microplastic abundance was minor in this study area. The average abundance of microplastics in April (17 ± 4 items/L) was higher than that in July (14 ± 2 items/L). The range in the abundance of microplastics in April and July were 22 ± 5-14 ± 3 items/L and 19 ± 2-10 ± 1 items/L, respectively. Highly hazardous polymers such as Polyvinyl chloride (PVC) and Polycarbonate (PC) have a significant impact on the results of the evaluation of the presence of microplastics. This study is an important reference for understanding the characteristics of the seasonal variation in microplastics in inland freshwater environments and has practical significance, as it will allow relevant agencies to accurately assess the pollution level of microplastics in different seasons. It is of practical significance to understand the sources and sinks of microplastics in inland freshwater environment.

Occurrence and pollution characteristics of microplastics in surface water of the Manas River Basin, China.

Microplastics, as a new type of pollutant, are widely found in various environmental media, and their effects on organisms are of great concern to society. However, research on the characteristics of microplastic pollution in inland rivers in China is still rare. The Manas River, which is located in the interior of Northeast China, was selected as the research object. The occurrence and pollution characteristics of microplastics in the surface water of the river were explored. The range of abundance of microplastics in the Manas River Basin was 21 ± 3-49 ± 3 items/L. Fibrous microplastics were dominant in all sites (88.0%); their size was mainly distributed between 0.1 and 1.0 mm (82.6%), and white and black were the dominant colours (82.9%). In addition, the size range of flaky-type microplastics were investigated in this study, which was principally between 2.5 × 103-9.0 × 104 µm2 (84.5%). Infrared spectral analysis revealed that most of the selected particles were identified as microplastics, and polymer types of microplastics were dominated by polypropylene and polyethylene terephthalate (48.3%). This study can be used as a reference to better understand the contamination features of microplastics in inland rivers.