Although these values are applicable to the general population, individual persons may exhibit large variations based on their levels of physical activity. Exhibit D.1. illustrates how inhalation exposure doses can be estimated and provides inhalation minute volumes. To estimate exposure to a contaminant from the ingestion of potable water, the contaminant concentrations in tap water samples from individual homes should preferably be analyzed. In the absence of data on individual wells, the assessor may consider using data from monitoring wells to estimate upper limits for exposures to contaminants. Exhibit D.2. illustrates how exposure doses via drinking water can be estimated.
All children mouth or ingest non-food items to some extent.
The degree of pica behavior varies widely in the population, and is influenced by nutritional status and the quality of care and supervision. Both use of and accessibility to the site and surrounding areas must be considered when evaluating a site's soil exposure pathways. Sites with abandoned buildings, standing water, or streams may attract children, and exposures may occur at sites near playgrounds or school yards despite fencing and other efforts to restrict access. Workers at commercial or industrial properties could ingest contaminated soil at rates which depend upon the type of employment. Both residential and recreational areas are likely to provide access for exposure.