The concentration of persistent organic pollutants in water resources: A global systematic review, meta-analysis and probabilistic risk assessment

The persistent organic pollutants (POPs) are environmentally stable and highly toxic chemicals that accumulate in living adipose tissue and have a very destructive effect on aquatic ecosystems. To analyze the evolution of the con-centration and prevalence of POPs such as alpha-HCH, beta-HCH, gamma-HCH, n-ary sumation -HCH, Heptachlor, Aldrin, p,p '-DDE, p,p '-DDT, n-ary sumation -DDT, and n-ary sumation -OCP in water resources, a search between January 01, 1970, to February 10, 2020, was followed using a systematic review and meta-analysis prevalence. Among the 2306 explored articles in the reconnaissance step, 311 articles with 5315 exemplars, 56 countries, and 4 types of water were included in the meta-analysis study. Among all studied POPs, the concentration of p,p '-DDT in water resources was the highest, especially in drink -ing water resources. The overall rank order based on the concentration and prevalence of POPs were surface water > drinking water > seawater > groundwater. To identify POPs-contaminated areas, the distance from the mean rela-tive to their distribution was considered. The most to the least polluted areas included: South Africa, India, Turkey, Pakistan, Canada, Hong Kong, and China. The highest carcinogenic risk was observed for beta-HCH (Turkey and China), followed by alpha-HCH (Mexico). The highest non-carcinogenic risk was identified for Aldrin (all analyzed countries), followed by Dieldrin (Turkey) and gamma-HCH (Mexico). The Monte Carlo analysis (under the assumption that gamma-HCH has a normal distribution), the mean obtained was 8.22E-07 for children and 3.83E-07 for adults. This is in accor-dance with the standard risk assessment approach. In terms of percentiles, the Monte-Carlo approach indicates that 75% of child population is under the 1.07E-06 risk and 95% of adults under 7.35E-06. (c) 2021 Elsevier B.V. All rights reserved.