Microplastics in the Atmosphere and Water Bodies of Coastal Agglomerations: A Mini-Review.

Microplastics are ubiquitously in various environments from the equator to the poles. Coastal agglomerations act as both a source and sink connecting the global microplastic cycles of oceans and continents. While the problem of microplastics is particularly severe and complex in the coastal zones, where both inland and marine pollution are concentrated, the present study aimed to provide hot topics and trends of coastal urban microplastic studies and to review the researches on microplastic pollution in the atmosphere and water bodies in coastal agglomerations in terms of characteristics, behavior, and health threat of microplastics. The results of the bibliometric analysis showed an increase in the annual output of microplastic research. Research hot topics and clusters were analyzed using the VOSviewer. Characteristics of microplastics varied in abundance, size, and polymer type in different environments and countries. Furthermore, coastal cities are taken as a system to sort out the input, output, and internal transmission pathways of microplastics. The health threat of microplastics to urban residents was briefly reviewed and the exposure and health risks of microplastics to infants and young children were of particular concern. Detailed and comprehensive studies on intervention and reduction in the transmission of microplastics between the atmosphere and water bodies, whether microplastics are harmful to infants and young children, and measures to reduce the risk of microplastic exposure are needed.

Investigation of microplastic pollution in Arctic fjord water: a case study of Rijpfjorden, Northern Svalbard.

Microplastic contamination is an emerging issue in the marine environment including the Arctic. However, the occurrence of microplastics in the Arctic fjords remains less understood. Sample collections were conducted by trawling horizontally in surface water (0-0.4-m depth) and trawling vertically in the water column (0-200-m depth) to investigate the abundance, composition, and distribution of microplastics in the Rijpfjorden, Northern Svalbard, in the summer of 2017. Laser Direct Infrared chemical imaging technique was applied for the counting and identification of microplastic particles. A total of 1010 microplastic particles and 14 mesoplastics were identified from 41,038 particles in eight samples from the Rijpfjorden. The abundance of microplastics larger than 300 µm was 0.15 ± 0.19 n/m3 in surface water, and 0.15 ± 0.03 n/m3 in the water column of the Rijpfjorden. The microplastic particles identified in Rijpfjorden water consisted of 10 types of polymers. The dominant microplastics are polyurethane, polyethylene, polyvinyl acetate, polystyrene, polypropylene, and alkyd varnish. Historical ship activities and newly melted sea ice might be major sources of microplastics in the seawater of Rijpfjorden. In general, contamination of microplastics larger than 300 µm in Rijpfjorden water is at a low level in comparison to other polar waters. Further research is needed to confirm the origin and fate of microplastics below 300 µm in Arctic fjords.