The U.S. Environmental Protection Agency today issued a nationwide health advisory that local water-treatment plants can use for deciding how much algal toxin can safely be in tap water, which numerous scientists and elected officials — including Gov. John Kasich, Ohio Environmental Protection Agency Director Craig Butler and former Toledo Mayor D. Michael Collins — said innumerable times was one of the biggest issues behind the Toledo water crisis last August when nearly 500,000 people were told to stay away from their tap water for nearly three days.
Until now, America has never had such an advisory from the U.S. EPA. It still has no binding standard.
Pushed in part by legislation on Capitol Hill co-sponsored by U.S. Sen. Sherrod Brown (D., Ohio), U.S. Sen. Rob Portman (R., Ohio) and U.S. Rep. Marcy Kaptur (D., Toledo), the federal agency came up with a two-pronged recommendation that is far more conservative for infants and other children younger than school age, a mere 0.3 parts per billion of microcystin. Ohio and most other states have been using a 1998 global recommendation of 1 ppb developed by the Geneva-based World Health Organization, the only available fallback because of the continuing lack of a standard in the United States.
But the U.S. EPA also said it's now OK for the greatest segment of America's population — those school age and older — to drink tap water with up to 1.6 ppb of microcystin in it, a value that is much more flexible than the WHO guideline and the one most states have been using. The Ohio Environmental Protection Agency ordered the city of Toledo to declare the crisis last summer once the toxin level in tap water went above 1.0 ppb. It was found to be above 1.6 ppb during the ordeal, but not consistently.
The health advisory values are based on exposure for 10 days, not a single drink of contaminated water.
They are based on animal studies that include a recent 28-day laboratory rat study in the United States, similar to one done in England years ago when the WHO guideline was developed, as well as other newer science and in collaboration with Health Canada. Canada has a standard of 1.5 ppb for microcystin, looser than the 1998 WHO guideline.
There are 80 known varieties, or congeners, of microcystin. The advisory is based solely on the most common one, microcystin-LR.
At least four were detected in tap water during the Toledo water crisis. Information on most of the others is lacking, the U.S. EPA said.
States are not compelled to follow the new advisory, but many are expected to do so because the research is U.S.-based and more recent.
Minnesota has the most conservative standard, forbidding water with a microcystin level of 0.45 or greater from being delivered to the general public.
The U.S. EPA said it believes its two-pronged recommendation will be easier for states and local water-treatment plants to follow.
The agency said it is soon going to post details about a Monday webinar it will be conducting to go over the science behind its new advisory in more detail for local water-treatment plant operators, regulators, and members of the general public who want more detail.
The agency also issued an advisory for another toxin, cylindrospermopsin, of 0.7 ppb for children younger than school age and 3.0 ppb for all other age groups.
“Nutrient pollution and harmful algal blooms are among America’s most serious and growing environmental challenges,” U.S. EPA Administrator Gina McCarthy said. “EPA has released health advisory values on algal toxins based on the best available science to ensure the safety of America’s drinking water. We will work closely with our partners at the state and local levels on monitoring, treating, and communicating about the toxins, as well as addressing the sources of nutrients that fuel these harmful algal blooms.”
Contact Tom Henry at: thenry@theblade.com, 419-724-6079, or via Twitter @ecowriterohio.
First Published May 6, 2015, 4:58 p.m.
