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DHS news release

Dec. 1, 2005


Contact: Bonnie Widerburg (971) 673-1282
Technical contact: Kathryn Toepel (503) 731-4025


Analysis calls for perchlorate testing in Morrow and Umatilla counties



A new analysis released Thursday by the Oregon Department of Human Services (DHS) recommends testing to determine the extent of human exposure to perchlorate in the northern parts of Morrow and Umatilla counties.


The analysis, called a "public health consultation," was unable to determine the full extent of human exposure because data are available only for drinking water, said Kathryn Toepel, DHS public health toxicologist.


"Our analysis recommends that food be tested to learn whether other sources also contribute to human exposure," she said. "Meanwhile, we are not advising residents to do anything different."


Although results are subject to rigorous review, she said she hoped they would be available by spring.

Perchlorate exposure is a particular concern for infants, small children, and women of childbearing age -- especially those who are pregnant and nursing -- because it can adversely affect iodide and thyroid hormone levels essential for proper physical and mental development. People with severe iodine deficiency or hypothyroidism are also a concern, Toepel said.


Since 1997 perchlorate, which is both naturally occurring and manmade, has been detected in soil, surface water or drinking-water wells in 35 states and Puerto Rico. As a result, the federal Environmental Protection Agency (EPA), which has no perchlorate standard for drinking water, is collecting data to help determine whether regulation would reduce human health risks.


Perchlorate moves easily from surface soils into groundwater and tends to accumulate in milk and some irrigated food crops.


Toepel said DHS will investigate perchlorate levels in milk and selected produce available to area residents. "We cannot fully assess potential exposure until we have this information," she said.


The health consultation was conducted after the Oregon Department of Environmental Quality (DEQ) and the EPA detected perchlorate in several groundwater wells in northern Morrow and Umatilla counties.


DEQ and EPA first tested wells for perchlorate in 2003 as part of an ongoing effort to track elevated nitrate levels in the Lower Umatilla Basin. Low levels of perchlorate were found in more than half of water samples from 133 tested wells. Additional sampling in 2004 and 2005 also showed low levels.


DHS' public health consultation is posted on the DHS public health Web site or is available by calling (503) 731-4025. The public is invited to comment until Jan. 31, 2006, to the Superfund Health Investigation and Education (SHINE) program, 800 N.E. Oregon St., No. 827, Portland, OR 97232.


The SHINE program conducted the analysis with assistance from the federal Agency for Toxic Substance and Disease Registry. Anyone wanting further information may contact Kathryn Toepel at (503) 731-4025 or via email at kathryn.toepel@state.or.us.