Atmospheric Microplastics: Perspectives on Origin, Abundances, Ecological and Health Risks.

Microplastic (MP) pollution has aroused a tremendous amount of public and scientific interest worldwide. MPs are found widely ranging from terrestrial to aquatic ecosystems primarily due to the over-exploitation of plastic products and unscientific disposal of plastic waste. There is a large availability of scientific literature on MP pollution in the terrestrial and aquatic ecosystems, especially the marine environments; however, only recently has greater scientific attention been focused on the presence of MPs in the air and its retrospective health implications. Besides, atmospheric transport has been reported to be an important pathway of transport of MPs to the pristine regions of the world. From a health perspective, existing studies suggest that airborne MPs are priority pollutant vectors, that may penetrate deep into the body through inhalation leading to adverse health impacts such as neurotoxicity, cancer, respiratory problems, cytotoxicity, and many more. However, their effects on indoor and outdoor air quality, and on human health are not yet clearly understood due to the lack of enough research studies on that and the non-availability of established scientific protocols for their characterization. This scientific review entails important information concerning the abundance of atmospheric MPs worldwide within the existing literature. A thorough comparison of existing sampling and analytical protocols has been presented. Besides, this review has unveiled the areas of scientific concern especially air quality monitoring which requires immediate attention, with the information gaps to be filled have been addressed.

Health implications, distribution and source apportionment of heavy metals in road deposited dust of Jammu City in northern India.

Road deposited dust (RDD) is an important indicators of heavy metal contamination in urban areas. In this study, we measured eight heavy metals (V, Cr, Mn, Fe, Ni, Cu, Zn, and Pb) in RDD collected from 34 different locations in Jammu city represented by different land uses such as industrial, urban-residential, high-density traffic, and sub-urban locations, and evaluated their ecological and health risks. The ratio of metal concentrations in RDD to their respective background levels varied as: Cu (3.94) > Pb (3.75) > Zn (3.01) > Cr (1.75) > Ni (1.51) > Mn (1.40) > V (1.35) > Fe (1.1) suggesting Cr, Ni, Cu, Zn and Pb were enriched anthropogenically. Geospatial maps revealed a heterogeneous distribution of metals in Jammu city with metal(s) specific hotspots primarily localized around high traffic density locations and industrial clusters. The index of geoaccumulation indicated 32%, 26%, 20%, 9%, and 8%, of samples belonged to "moderately polluted" category for Zn, Cu, Pb, Cr, and Ni respectively. Health index (HI) showed low non-carcinogenic hazards of metal contamination to adults but a high hazard to children. Though the values of total carcinogenic risks (TCR) (6.53E-05 to 3.71E-04) considerably exceeded the USEPA acceptable levels (1 × 10-6 ≤ TCR <1 × 10-4) suggesting high carcinogenic risks of metal contamination to both adults and children. Besides potential ecological risk index (PERI) revealed that 56% of samples had PERI >40 suggesting "moderate to high ecological risk" of metal contamination in the Jammu city RDD.