During January 31st through February 1, 2001, ATSDR staff collected hair samples from 28 children and 4 adults at the AU-CDC. Approximately one-half gram of hair was cut from the back of the head, at the nape of the neck. These samples were sent to a clinical medical laboratory for analyses; results were available in March 2001. Of the hair samples tested, none were found to have elevated levels of arsenic.

AU-CDC staff and parents of children who participated in the EI were notified of the test results, and ATSDR staff were available to those participants at a March meeting. The ATSDR issued a written public report which summarized the findings of the EI.

ATSDR has since been petitioned to conduct a public health assessment for the Spring Valley site, and we have also been requested by the government of the District of Columbia to assist them with an expansion of our previous exposure investigation. We are_collecting information needed to respond appropriately to both of these requests.

Madam Chairwoman, this concludes my testimony, and I would be happy to answer questions that you may have or those of your fellow subcommittee members.

Mrs. MORELLA. Thank you, Admiral Williams.

[The prepared statement of Admiral Williams follows:]

Good morning. Madam Chairwoman and members of the subcommittee, thank you for the opportunity to provide you with testimony on the activities of the Agency for Toxic Substances and Disease Registry (ATSDR) at the Child Development Center of American University, a day care facility.

ATSDR, an agency of the U.S. Department of Health and Human Services, is the lead public health agency responsible for implementing the health-related provisions of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). ATSDR's mission is to prevent exposure and adverse health effects and diminished quality of life associated with exposure to hazardous substances from waste sites, unplanned releases, and other sources of pollution present in the environment.

On January 18, 2001, ATSDR participated in a conference call with the U.S. Environmental Protection Agency (EPA), the U.S. Army, and the District of Columbia Department of Health (DOH). The Army indicated that elevated concentrations of arsenic were detected in surface soil samples recently collected from the playground of the Child Development Center at American University (AU-CDC). Parents of children attending the day care facility were notified of this finding, and they expressed concern for the health of their children. DOH asked ATSDR for assistance in addressing the parents' concerns.

ATSDR reviewed the request as it would a proposal for the agency to conduct an Exposure Investigation (EI). An EI is one approach ATSDR uses to better characterize potential exposures

to hazardous substances, generally through bio-medical testing. The request was evaluated

against ATSDR's selection criteria for conducting an EI, which include the following:

(1) Can an exposed population be identified?

(2) Does a data gap exist that affects the ability to interpret whether or not a health hazard exists?

(3) Can the data gap be addressed by an EI?

(4) How would the results of the EI impact public health decision making?

ATSDR determined that the request met the agency's criteria for conducting an EL, and, accordingly, agreed to conduct an EI for the children currently attending the AU-CDC. In addition, ATSDR agreed to include the adult staff at the AU-CDC in its EI.

Officials at American University had relocated the AU-CDC to another location on the campus as soon as the contamination was brought to their attention. Therefore, children and AU-CDC staff had no known current exposure to arsenic at the time of the EI request. After a person is exposed to arsenic, the arsenic is rapidly metabolized and excreted in the urine within a few days. Because the children had no known recent exposure to arsenic, it would not be useful to test their urine samples for arsenic.

Arsenic is deposited in the hair root as the hair grows. Therefore, measuring the arsenic concentration in a length of hair provides an indication of arsenic exposure over the life of the hair. ATSDR collected 2-inch lengths of hair from the EI participants, which corresponds to approximately 5 months of hair growth.

With the assistance of DOH and AU-CDC staff, written informed-consent forms were signed by parents or guardians of the children. The children ranged from 2 1⁄2 through 5 1⁄2 years of age. About half of the children had attended AU-CDC for 7 months or less; the remainder had attended for 1 year or more. During January 31 through February 1, 2001, ATSDR staff collected hair samples from 28 children and 4 adults at the AU-CDC. Approximately one-half gram of hair was cut from the back of the head at the nape of the neck. These samples were sent to a clinical medical laboratory for analyses; results were available in March, 2001. Of the hair samples tested, none were found to have elevated levels of arsenic.

AU-CDC staff and parents of children who participated in the EI were notified of the test results and ATSDR staff were available to those participants at a meeting in March. ATSDR issued a written public report which summarized the findings of the EI.

ATSDR has since been petitioned to conduct a public health assessment for the Spring Valley site. We have also been requested by the Government of the District of Columbia to assist them with an expansion of our previous EI. We are collecting information needed to respond appropriately to both of these requests.

Madam Chairwoman, this concludes my testimony. I would be happy to answer any questions

you or your fellow committee members may have.