Occurrence and elimination of cyanobacterial toxins in two Australian drinking water treatment plants

Abstract

In Australian freshwaters, Anabaena circinalis, Microcystis spp. and Cylindrospermopsis raciborskii are the dominant toxic cyanobacteria. Many of these surface waters are used as drinking water resources. Therefore, the National Health and Medical Research Council of Australia set a guideline for MC-LR toxicity equivalents of 1.3 mg/l drinking water. However, due to lack of adequate data, no guideline values for paralytic shellfish poisons (PSPs) (e.g. saxitoxins) or cylindrospermopsin (CYN) have been set. In this spot check, the concentration of microcystins (MCs), PSPs and CYN were determined by ADDA-ELISA, cPPA, HPLC-DAD and/or HPLC-MS/MS, respectively, in two water treatment plants in Queensland/Australia and compared to phytoplankton data collected by Queensland Health, Brisbane. Depending on the predominant cyanobacterial species in a bloom, concentrations of up to 8.0, 17.0 and 1.3 mg/l were found for MCs, PSPs and CYN, respectively. However, only traces (,1.0 mg/l) of these toxins were detected in final water (final product of the drinking water treatment plant) and tap water (household sample). Despite the low concentrations of toxins detected in drinking water, a further reduction of cyanobacterial toxins is recommended to guarantee public safety. q

Changes in species composition during annual cyanobacterial dominance in a tropical reservoir: physical factors, nutrients and grazing effects

“…Anabaena, Cylindrospermopsis and Microcystis are common cyanobacterial genera in tropical waters (Huszar & Silva 1999, Hoeger et al 2004. However, as far as we know, their co-dominance has only been recorded in Brazilian reservoirs (Marinho & Huszar 2002, Molica et al 2005.…”

Guidance values for microcystins in water and cyanobacterial supplement products (blue-green algal supplements): a reasonable or misguided approach?

“…In addition, the overall toxicity of a bloom cannot be defined because of variations in toxin concentration temporally and spatially within a water body experiencing the bloom. There may be also large year-to-year fluctuations in the levels of cyanobacteria and their toxins (Hoeger, 2003;Hoeger et al, 2004b;Park et al, 1993) and seasonal variations with regard to the dominant species of toxic cyanobacteria and hence, the toxins present (Henriksen and Moestrup, 1997;Hoeger et al, 2004b;Xu et al, 2000). III.…”

“…The published cases of cyanobacterial toxins in raw water, during drinking water treatment and even in finished water are numerous and problematic worldwide. MCs have been reported in final water in Argentina, Australia, Bangladesh, Canada, Czech Republic, China, Finland, France, Germany, Latvia, Poland, Thailand, Turkey, Spain, Switzerland and USA (Westrick, 2003;Hoeger et al, 2004aHoeger et al, , 2004b. Up to 9000 cells/ml were detectable even after treatment in Argentina, Australia, Finland, Germany, Israel and Italy.…”

Human Exposure to Cyanotoxins and their Effects on Health

“…If the water is obtained from a surface water source during cyanobacterial bloom, it is possible that the water had become contaminated with toxins released during cell decomposition (1). There are numerous cases of cyanobacterial toxins detected in raw and fi nal water throughout the world (Argentina, Australia, Bangladesh, Canada, Czech Republic, China, Finland, France, Germany, Latvia, Poland, Thailand, Turkey, Spain, Switzerland, USA) (15, [17][18][19]. High levels of risk to human health are linked to the ingestion of large cyanotoxin quantities from water or the intake of small doses during extended chronic exposure (20).…”