Marine Plastic Pollution: Chemical Aspects and Possible Solutions

Plastics are formed from C–C single bonds which are flexible making them easily transformable. Thus, plastics have been widely utilized by the global society. However, the C–C single bond is easily breakable by UV radiation. Eventually, plastics are fragmented into microplastics (<5 mm) and ultimately will be washed off to marine environments. Microplastics are ubiquitously dispersed in marine environments, i.e., surface water, beaches, and bottom sediments. Plastics and microplastics are taken up and ingested by various marine organisms ranging from zooplanktons to whales. Concentrations of microplastics in urban coastal waters are considered to be critical in terms of particle toxicity. In marine environments, plastics retain hydrophobic additives and concentrate persistent organic pollutants (POPs) from surrounding waters. Recent field observations and exposure experiments demonstrated that microplastics accelerate indirect exposure of endocrine-disrupting additives to humans, through fragmentation of plastics, their ingestion by marine organisms, leaching of the additives to digestive fluids and their bioaccumulation and trophic transfer. The additives have the potential to disrupt endocrine and immune systems of humans. As a precautionary action, usage and consumption of plastics in our society should be reduced to protect human health. Reduction of plastic consumption is also deduced from the view of mitigating the impacts of global warming, resource efficiency, and sound waste management.