Evidence of toxic chemicals used as fire retardants has been found in all U.S. coastal waters, including throughout Puget Sound, a National Oceanic and Atmospheric Administration (NOAA) report issued Wednesday says. Polybrominated diphenyl ethers (PBDEs) are common in such household products as mattresses, computers and televisions. The chemicals are thought to affect brain development and reproduction in humans and animals. The NOAA report drew upon sediment and shellfish tissue samples from the mid-2000s and a decade earlier. Scientists found the chemical in samples from both decades, with higher concentrations near cities and industrial areas. Mussels tested from sites that included Grays Harbor, Elliott Bay and Hood Canal all showed evidence of PBDEs. The chemicals accumulate in the fatty tissue of mussels. The levels of PBDEs found in samples from Puget Sound ranked in midrange of those from throughout the country. The highest levels were recorded in California's Anaheim Bay. Still, the report's authors say, any amount of the chemicals is significant. "Because they are human-made, just the mere presence of these [chemicals] shows contamination," said Gunnar Lauenstein, program manager for NOAA's Mussel Watch and one of the report's authors. PBDEs can build up in human blood and tissue, and also leach into the environment through burning and through wastewater runoff. Tests have found higher concentrations of PBDEs in Americans' blood, body fat and breast milk than in any other country where testing has occurred, said Renee Sharp, director of Environmental Working Group's California office. The use of the chemicals has been banned throughout Europe, but not entirely in the United States. The Washington Legislature passed a bill two years ago to phase out PBDEs in household products and electronics.