A toxic chemical linked to the Oregon outbreak has been found in some of the state’s water supplies, prompting a health warning from Oregon health officials.
The Associated Press first reported on Thursday that the pesticide, pyrethroid acetate, is found in a number of local water supplies.
The state has been under a federal order to ban the pesticide from use in water supplies for at least two years, but it remains widely used in the state.
It was found in water from Lake Oconee, a source of drinking water for some people in the region.
The lake is one of several water bodies that the U.S. Environmental Protection Agency (EPA) said was “likely contaminated by pyrethroids pyrethrins” from a company that made the chemicals.
The agency said that in 2017, at least four people in Oregon had symptoms similar to those of poisoning by pyrene, a chemical that can cause respiratory distress, kidney failure and neurological damage.
The agency did not name the patients, citing patient privacy laws.
“The EPA’s actions will result in higher levels of pyrethrogen sulfide in the water supply,” EPA spokesman John D. Bock said.
“We are also encouraging water users to test their water for pyrethronics.
We are taking a proactive approach to protecting our drinking water supplies from the toxic threat that is pyrethrone sulfide.”
The state has not confirmed any water supplies are affected by the pesticide.
A spokesman for the Portland Bureau of Environmental Services said in a statement that the agency “is aware of a number” of water supply wells in the area that may be contaminated by the chemical.