Health chiefs in the US city of Seattle have confirmed that further testing is underway in part of the city after elevated levels of lead were discovered in the vicinity of a lead battery manufacturing company.

Seattle & King County’s (SKC) public health department said on August 27 a specialised contractor had “cleaned known areas of contamination” and additional testing was underway to determine whether contamination extended to other public areas — and whether further cleanup was needed.

Testing found 55.3 parts per million (ppm) of leachable lead in a roadway sample and 451ppm in a catch basin sample. SKC said both levels are above Washington State’s hazardous waste threshold of 5ppm.

However, SKC said the extent and source of the contamination have not yet been determined.

The tests came after Washington State Department of Labor & Industries fined Dyno Battery, in March 2026, in relation to workplace conditions at the facility.

SKC said its public health department contacted Seattle Public Utilities in July, which conducted testing of soil and dust samples near the battery plant.

The elevated levels of lead were found in the public right-of-way along the 4200 block of 23rd Avenue W in Seattle’s Interbay neighbourhood. SKC said this prompted cleanup of known contamination, additional environmental testing and precautionary public health guidance.

Meanwhile, public health officials are “working with employees at Dyno Battery to advise them on the risks of lead and how to obtain and understand blood lead tests,” SKC said.

“Public health is also working with daycare to reduce lead levels and inform parents about lead testing and steps to protect children from lead and will continue to work with businesses in the area to raise awareness of lead risks and ways to protect their health.”

Dyno Battery describes itself as the premier battery manufacturer in Washington State, having been established in 1933 and family owned since 1947. Products include a range of lead batteries for a number of applications.

Dyno Battery has been invited to comment by Batteries International but the company had yet to respond at the time this article was published.