News of radiation from Japan being found in U.S. air and water supplies could raise concerns.
Newspapers in Michigan, Pennsylvania, New Jersey and other locations sought to allay concerns by issuing statements from regional health departments. California's Department of Public Health said there are response plans for a radiological emergency in place but "Japan's nuclear emergency presents no danger to California."
The U.S. Environmental Protection Agency said it uncovered "trace amounts" of radioactive isotopes from Japan in monitors across the United States. The levels were "slightly higher" than those reported last week but weren't a health risk.
"These types of findings are to be expected in the coming days and are still far below levels of public health concern," the EPA said.
The EPA said Americans receive radiation doses 100,000 times higher than levels coming from Japan during a typical round-trip international flight.
Japan's nuclear reactors were crippled by a magnitude-9 earthquake March 11.