AWWA WQTC64114

Cyanobacterial blooms occur worldwide in marine, brackish, and freshwaters. At leastone-third of these genera are capable of producing toxins. In 1998 and 2005, freshwater algal toxins were added to the Contaminant Candidate List (CCL) by the UnitedStates Environmental Protection Agency (USEPA). Shortly after the 1998announcement, a priority list was released that included five hepatotoxins, microcystin-LR, -RR, -LA, -YR, and cyclindrospermopsin, and the neurotoxin anatoxin-a. CurrentWorld Health Organization (WHO) monitoring guidelines incorporate a sequence of alertlevels based on algal cell counts and/or taste and odor production that were establishedin 1993. These alert levels start at cell counts of 2000 units/mL and increase thefrequency of monitoring. This paper describes a preliminary study funded by the USEPA toevaluate the prevalence of the algal toxin microcystin in drinking water supplies. AnEnzyme-Linked Immunosorbant Assay (ELISA) was used to screen the source anddistribution water samples for microcystin. The ELISA kit has a range limit of 0.05 ppbto 0.83 ppb microcystin. Total and toxin-producing algal counts were conducted onweekly source and distribution water samples from utilities located in five US states.Four of the five utilities experienced algal blooms in their source water. All of theseconventional plants effectively removed the algae and all distribution water samplesshowed microcystin levels below the detection limit of 0.05 ppb. Four of the utilitiessource water did show detectable levels of microcystin within the range limits of the kit.Selected source water samples were analyzed by high pressure liquid chromatography(HPLC). The paper describes this HPLC method capable of quantifying intracellular microcystintoxin variants, as well as cylindrospermopsin and anatoxin-a, and compares it to theELISA. The WHO algal toxin monitoring framework and monitoring cost was evaluatedagainst for different analytical methods and scenarios. Includes 3 references, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2006

Number of Pages:

6

File Size:

1 file , 330 KB