Probabilistic environmental risk assessment of microplastics in marine habitats

Microplastics are ubiquitous in the environment and given large number of published hazard exposure studies, quantitative environmental risks assessments microplastics become feasible. We present here first risk assessment for marine waters based only on measured concentrations. The Thevariability uncertainty data was accounted assessment, while probabilistic species sensitivity distributions were used from which a probability distribution extracted predicted no-effect concentration (PNEC). By dividing by PNEC-distribution, we able to calculate characterisation ratios each water body measurements performed. Results show good coverage world's major bodies concentrations (MECs), could be improved aligning type particles tested studies (size, form, polymer) those actually found oceans. Overall, mean (PNEC) is 3.84·106 part m-3, with Oryzias melastigma being most sensitive (calculated NOEC 3.90·106 m-3). Interestingly, dose descriptor that literature above 10-20 ?m highest observed no effect (HONEC), indicates very low or null toxicity these larger MPs towards organisms. MEC 1.5·103 Atlantic Pacific Ocean. Although there small overlap associated RCR (0.00002 % points), 4·10-4 therefore unlikely available data. However, as increasing amounts plastic reach environment, RCRs can expected increase future.