Requests and data for public health assessments are received by telephone, letters, email, and fax. Sources of exposure are identified and the status of at-risk population is determined. Exposure data are evaluated by conducting literature searches and utilizing reference books. Public health actions and recommendations are determined based on exposure data and other environmental factors. Responses are provided by telephone, letters, email, or fax. A log will be kept noting the date and time of each request received and the date and time of the response provided. Measure will be calculated by dividing the number of requests for public health assessments of exposure to chemicals and biological agents responded to within 48 hours of receipt by the total number of requests for public health assessments of exposure to chemicals and biological agents received.