Investigators who analyzed the published literature have found significant gaps in our understanding of the effects of microplastics--plastic particles less than 5mm in size--in the environment.
In the Environmental Toxicology & Chemistry analysis, the researchers noted that microplastics occur in surface water and sediments and that fragments and fibers predominate, with beads making up only a small proportion of the detected microplastic types. Concentrations detected are orders of magnitude lower than those reported to affect feeding, reproduction, growth, tissue inflammation, and mortality in organisms. The available data suggest that these materials are not causing harm to the environment, but there is a mismatch between the particle types, size ranges, and concentrations of microparticles used in laboratory tests and those measured in the environment. Select environmental regions have also received limited attention.
"There is an urgent need for better quality and more holistic monitoring studies alongside more environmentally realistic effects studies on the particle sizes and material types that are actually in the environment," said co-author Dr. Alistair Boxall, of the University of York, in the UK. "We believe regulations and controls may be focusing on activities that are having limited impact and ignoring the most polluting activities such as releases of small particles from tyres on our cars."