Microplastic (MP) Pollution: Environmental Fate, Eco-toxicity and Sustainable Remediation

The environmental impacts of plastic have attracted the interest of the scientists, media, and policymakers, but the impact of microplastics (MPs) on our environment remains largely unknown. These novel pollutants are so widespread that the scientific community has defined the present historical epoch as “The Plasticene”. There is growing concern over the bioaccumulation and entry of these miniature plastic particles released from almost every article of daily use into the food chains, which will ultimately contaminate the human population. Given the presence of these pollutants in almost every strata and biome of the earth, adsorption of other toxic pollutants and generation of novel categories of chemicals, MP pose an eminent challenge to almost every biotic community. At present times, we have very little knowledge about the possible effects of micropollutants as risk assessment and risk management rely on standardized data and reliable methodology adopted, so in present times it is impossible to evaluate the toxic response and deleterious effects on biotic communities. The detailed understanding of origin, exposure pathways, toxic response of biota, remediation options, and precautionary operations are of prime importance for averting the plastic disaster. MPs significant affect rooting ability of plants, reduce photosynthetic ability by dysregulation of chlorophyll a/chlorophyll b ratios and cause imbalance in carbon/nitrogen balance. MPs have most prominent effect on aquatic animals where they cause feeding disruption, alterations in metabolism, hormonal imbalance and henceforth reproductive problems. On cellular levels MPs causes cytotoxicity, nephrotoxicity, immune dysregulation, neurotoxicity and genotoxicity. MPs have been found to affect the microbes which results in replacement of beneficial organisms by harmful organisms at niche areas and MPs acts as vehicle and transport agents for transport and proliferation of harmful organism like Ostreopsis and Coolia and Vibrio genera. Owing to the deleterious effects on environment and biota, various remedial measures proposed by researchers includes biodegradation, coagulation, photo-catalytic degradation and thermal degradation. Therefore, current manuscript attempts to review the status of these pollutants in various biomes of the biosphere, their possible toxic effects on residents of the hydrosphere, atmosphere, and lithosphere, their effect on human health, and various remediation processes with the intention of special and surgical emphasis on future research in the area for fulfillment of the knowledge gap.