Distribution and bioaccumulation of microcystins in water columns: A systematic investigation into the environmental fate and the risks associated with microcystins in Meiliang Bay, Lake Taihu

• Published in: Water research (Oxford) Vol. 41; no. 13; pp. 2853 - 2864
• Main Authors: Song, Lirong, Chen, Wei, Peng, Liang, Wan, Neng, Gan, Nanqin, Zhang, Xiaoming
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.07.2007; Elsevier Science
• Subjects: Alternanthera philoxeroides; Animals; Applied sciences; aquatic plants; Bellamya aeruginosa; Bioaccumulation; biosafety; Carassius auratus auratus; case studies; Cristaria plicata; Cyanobacteria - metabolism; detection; Distribution; drinking water; Environmental fate; eutrophication; Exact sciences and technology; Fresh Water - chemistry; Freshwater; Goldfish - metabolism; Invertebrates - metabolism; Lake Taihu; lakes; Macrobrachium; Microcystin; microcystins; Microcystins - chemistry; Microcystins - metabolism; Myriophyllum spicatum; Other industrial wastes. Sewage sludge; pollutants; Pollution; Potamogeton maackianus; Risk assessment; seasonal variation; Seasons; sediments; Time Factors; Wastes; water; water analysis; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - metabolism; water pollution; Water Pollution, Chemical; water quality; water resources; Water treatment and pollution; China; Asia; China, People's Rep., Tai Hu L; China, People's Rep., Jiangsu Prov., Meiliang Bay; China, People's Rep; Microcystin; Environmental fate; Bioaccumulation; Risk assessment; Distribution; Lake Taihu; Drinking water; Haloragidaceae; Amaranthaceae; Alternanthera; Myriophyllum spicatum; Trophic chain; Pollution; Health and environment; Seasonal variation; Dicotyledones; Pisces; Angiospermae; Sampling; Public health; Edible species; Sediments; Toxin; Vertebrata; Carassius auratus; Microcystin;Environmental fate;Distribution;Bioaccumulation;Risk assessment;Lake Taihu; Surface water; Water quality; Health hazards; Lakes; Spermatophyta; Bay; Biological accumulation; Bathing water; Interface
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2007.02.013

For the purpose of understanding the environmental fate of microcystins (MCs) and the potential health risks caused by toxic cyanobacterial blooms in Lake Taihu, a systematic investigation was carried out from February 2005 to January 2006. The distribution of MCs in the water column, and toxin bioaccumulations in aquatic organisms were surveyed. The results suggested that Lake Taihu is heavily polluted during summer months by toxic cyanobacterial blooms (with a maximum biovolume of 6.7×10 8 cells/L) and MCs. The maximum concentration of cell-bound toxins was 1.81 mg/g (DW) and the dissolved MCs reached a maximum level of 6.69 μg/L. Dissolved MCs were always found in the entire water column at all sampling sites throughout the year. Our results emphasized the need for tracking MCs not only in the entire water column but also at the interface between water and sediment. Seasonal changes of MC concentrations in four species of hydrophytes ( Eichhornic crassipes, Potamogeton maackianus, Alternanthera philoxeroides and Myriophyllum spicatum) ranged from 129 to 1317, 147 to 1534, 169 to 3945 and 124 to 956 ng/g (DW), respectively. Toxin accumulations in four aquatic species ( Carassius auratus auratu, Macrobrachium nipponensis, Bellamya aeruginosa and Cristaria plicata) were also analyzed. Maximum toxin concentrations in the edible organs and non-edible visceral organs ranged from 378 to 730 and 754 to 3629 ng/g (DW), respectively. Based on field studies in Lake Taihu, risk assessments were carried out, taking into account the WHO guidelines and the tolerable daily intake (TDI) for MCs. Our findings suggest that the third largest lake in China poses serious health threats when serving as a source of drinking water and for recreational use. In addition, it is likely to be unsafe to consume aquatic species harvested in Lake Taihu due to the high-concentrations of accumulated MCs.