Risk Management of Cyanotoxins in Singapore  

作　　者：Mong Hoo Lim Hui Shi Melissa Tay Denise A. Devotta Maxine A. D. Mowe Simon M. Mitrovic Mong Hoo Lim;Hui Shi Melissa Tay;Denise A. Devotta;Maxine A. D. Mowe;Simon M. Mitrovic(Water Quality Department, Public Utilities Board (PUB), Singapore;Freshwater and Invasion Biology Laboratory, Department of Biological Science, National University of Singapore (NUS), Singapore;Freshwater and Estuarine Research Group, School of Life Sciences, University of Technology Sydney, Sydney, Australia)

机构地区：[1]Water Quality Department, Public Utilities Board (PUB), Singapore [2]Freshwater and Invasion Biology Laboratory, Department of Biological Science, National University of Singapore (NUS), Singapore [3]Freshwater and Estuarine Research Group, School of Life Sciences, University of Technology Sydney, Sydney, Australia

出　　处：《Journal of Water Resource and Protection》2020年第6期512-525,共14页水资源与保护（英文）

摘　　要：Cyanotoxins produced by cyanobacteria pose significant challenges to water resource management due to the potential impacts they have on human health. Cylindrospermopsin (CYN) and microcystins (MC) are the more commonly detected cyanotoxins in Singapore’s reservoirs. Among the MC congeners monitored locally, the most frequently detected variants are MC-RR (37.6%), followed by MC-LR (25.6%). MC-LA and MC-YR are the least frequently detected variants (7.1%). No cyanotoxins have been detected in Singapore’s treated drinking water. Singapore’s National Water Agency (PUB) and the National Environment Agency (NEA) developed recreational water quality guidelines using Chl <em>a</em> concentrations of 50 μg/L. In local surface waters, long-term data showed that at 50 μg/L of Chl <em>a</em>, MC-LR concentrations ranged from <0.025 μg/L to 1 μg/L. In addition to using Chl <em>a</em> concentrations, <em>Microcystis</em> cell counts in reservoir water have also been used to manage cyanotoxin risk in drinking water. Specifically, routinely monitored data from all 17 Singapore reservoirs indicated that to keep MC-LR concentrations below the WHO provisional guideline of 1 μg/L in drinking water, <em>Microcystis</em> cell counts needed to be <10,000 cells/ml. Culture experiments using local <em>Microcystis</em> isolates showed M. <em>aeruginosa</em> produced the most MC compared to <em>M</em>. <em>ichthyoblabe</em>, <em>M.</em> <em>flos-aquae</em>, and <em>M</em>. <em>viridis</em>. Based on the maximum toxin cell quota equivalent to the WHO provisional guideline for MC-LR of 1 μg/L in drinking water, a 5000 cells/ml cell count guideline was derived for <em>M</em>. <em>aeruginosa</em>. This cell count has also been incorporated into Singapore’s cyanotoxin risk management framework for reservoirs.Cyanotoxins produced by cyanobacteria pose significant challenges to water resource management due to the potential impacts they have on human health. Cylindrospermopsin (CYN) and microcystins (MC) are the more commonly detected cyanotoxins in Singapore’s reservoirs. Among the MC congeners monitored locally, the most frequently detected variants are MC-RR (37.6%), followed by MC-LR (25.6%). MC-LA and MC-YR are the least frequently detected variants (7.1%). No cyanotoxins have been detected in Singapore’s treated drinking water. Singapore’s National Water Agency (PUB) and the National Environment Agency (NEA) developed recreational water quality guidelines using Chl <em>a</em> concentrations of 50 μg/L. In local surface waters, long-term data showed that at 50 μg/L of Chl <em>a</em>, MC-LR concentrations ranged from <0.025 μg/L to 1 μg/L. In addition to using Chl <em>a</em> concentrations, <em>Microcystis</em> cell counts in reservoir water have also been used to manage cyanotoxin risk in drinking water. Specifically, routinely monitored data from all 17 Singapore reservoirs indicated that to keep MC-LR concentrations below the WHO provisional guideline of 1 μg/L in drinking water, <em>Microcystis</em> cell counts needed to be <10,000 cells/ml. Culture experiments using local <em>Microcystis</em> isolates showed M. <em>aeruginosa</em> produced the most MC compared to <em>M</em>. <em>ichthyoblabe</em>, <em>M.</em> <em>flos-aquae</em>, and <em>M</em>. <em>viridis</em>. Based on the maximum toxin cell quota equivalent to the WHO provisional guideline for MC-LR of 1 μg/L in drinking water, a 5000 cells/ml cell count guideline was derived for <em>M</em>. <em>aeruginosa</em>. This cell count has also been incorporated into Singapore’s cyanotoxin risk management framework for reservoirs.

关 键 词：CHLOROPHYLL-A CYANOBACTERIA CYANOTOXINS NUTRIENTS TROPICAL 

分 类 号：X52[环境科学与工程—环境工程]