Microcystin in source water: pollution characteristics and human health risk assessment

Simin Ge; Xiaocui Qiao; Xingru Zhao; Xue Li; Yan Liu

doi:10.1039/d0ra08983d

Microcystin in source water: pollution characteristics and human health risk assessment

RSC Adv. 2021 Feb 4;11(11):6415-6422. doi: 10.1039/d0ra08983d. eCollection 2021 Feb 2.

Authors

Simin Ge^{1

2}, Xiaocui Qiao^{1

2}, Xingru Zhao^{1

2}, Xue Li^{1

2}, Yan Liu^{1

2}

Affiliations

¹ National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Chinese Research Academy of Environmental Sciences Beijing 100012 China liuyan@craes.org.cn.
² State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences Beijing 100012 China.

Abstract

Frequent cyanobacterial blooms in eutrophic waters produce a variety of toxins such as microcystins (MCs), which are seriously harmful to waterbodies and human health. The spatiotemporal distribution characteristics of the MC-LR concentration in drinking water sources in seven river basins in China were investigated in this study. The removal rate of MC-LR in the purification process of water treatment plants and the human health risk of MC-LR in drinking water are also discussed. The results show that the detection frequency of MC-LR in source water was 55.46% and its concentration ranged from 0.06 × 10^-3 to 52 × 10^-3 μg L^-1 (mean of 12.47 × 10^-3 μg L^-1), which are both below China's drinking water quality standard for algal toxins. The MC-LR concentration in lakes and reservoirs was higher than that in rivers, and exhibited an obvious spatiotemporal variation. The mean removal rate of MC-LR varied with river basin, and was also slightly higher for the advanced water treatment process (97.46%) in comparison to that of the conventional process (96.74%). The concentration of MC-LR in 8.26% of treated water samples was higher than that of raw water, thus indicating that MC-LR may be further released during the purification process. The risk index of MC-LR in treated water samples ranged from 2.29 × 10^-3 to 8.40 × 10^-3 (mean of 4.73 × 10^-3), which corresponded to an extremely low level of risk. However, intensive monitoring should still be carried out in some high-concentration watersheds during the summer to ensure the safety of public drinking water.