California adopts perchlorate drinking water standard.
Press Release Summary:
The American Water Works Association announced that California has adopted a drinking water standard for perchlorate of 6 micrograms/L, equal to the public health goal that was set to protect fetuses of women with hypothyroidism or iodide deficiencies. Effective Oct. 18, the new standard is the second set by a state for the rocket fuel chemical. The USEPA will make a preliminary determination in May on whether to regulate perchlorate.
Original Press Release:
California Adopts Perchlorate Standard
As expected, California has adopted a drinking water standard for perchlorate of 6 micrograms/L, equal to the public health goal that was set in large part to protect fetuses of women with hypothyroidism or iodide deficiencies.
Effective Oct. 18, the new perchlorate standard is the second set by a state for the rocket fuel chemical (Massachusetts set a standard of 2 micrograms/L in 2006) that has turned up in water supplies and food products in the past several years. Perchlorate's primary health effect is that it interferes with iodide uptake by the thyroid, which can decrease production of hormones essential for prenatal and postnatal growth and development.
USEPA in 2005 set an official perchlorate reference dose of 0.0007 mg/kg/day, which equates to a drinking water equivalent level of 24.5 mg/L and is awaiting additional food and human exposure data before determining whether to regulate the contaminant.
In its preliminary determination in May on whether to regulate perchlorate and other contaminants on the second Contaminant Candidate List, the agency identified 11 chemicals that don't need to be regulated. Regarding perchlorate, USEPA said it "believes additional information may be needed to more fully characterize perchlorate exposure and determine whether it is appropriate to regulate perchlorate in drinking water (i.e., whether setting a national primary drinking water standard would provide a meaningful opportunity to reduce risk for people served by public water systems)."
A final determination is expected in early 2008.
