toxicants are retained in ''biologic sanctuaries" (e.g., lead in bone and polycyclic aromatic hydrocarbons in fat), they can cause low-dose chronic exposure for a much longer period of time than would be experienced by exposed adults. Nurses caring for children in any setting—inpatient pediatric units, well-child clinics, home health agencies, and prenatal health centers—need to understand these factors if they are to detect, or more importantly, prevent adverse environmental exposures in children.

It is estimated that 3–4 million U.S. children have blood lead levels above the defined toxic level of 10 mcg/dl, a level known to cause irreversible deficits in attention and IQ scores (ATSDR, 1988; CDC, 1991a; Needleman et al., 1979, 1990). Although lead was banned from household paint in 1971, almost all houses built before 1960 and 20 percent of those built between 1960 and 1974 contain leaded paint (Needleman and Landrigan, 1994). Children at greatest risk for lead poisoning are those living in poorly maintained, substandard housing (e.g., those living in poverty-level conditions). Nurses, including nurse practitioners, must be alert to the risk factors for lead poisoning in young children and aware of measures to reduce those risks. As recommended by the CDC, nurses and other health care providers need to phase-in virtually universal screening of children for blood lead levels (CDC, 1991a). Other environmental hazards in the home that are of concern to both children and adults include radon, environmental tobacco smoke (DHHS, 1986; NRC, 1986), pesticides (Environmental Studies Board, 1988; Miller, 1993; Moses, 1993; Sherman, 1988; Tarcher, 1992), carbon monoxide and airborne particulates from wood-burning stoves (American Thoracic Society, 1990; Samet et al., 1987; Tarcher, 1992), nitrogen dioxide from natural gas stoves (Samet et al., 1987; Tarcher, 1992), formaldehyde and other chemicals that are released as "off-gases" from new carpets, blown-in foam insulation, and synthetic materials covering the indoor surfaces of many mobile homes (Leikauf, 1992; Needleman and Landrigan, 1994; Sherman, 1988; Tarcher, 1992).

Priority environmental hazards and environmentally related illnesses have been established by various public and private-sector organizations, including EPA, NIOSH, and the Agency for Toxic Substances and Disease Registry (ATSDR). A description of priority health conditions that were established by ATSDR is presented here as an example.

ATSDR is an agency of the U.S. Public Health Service responsible for investigating health effects related to hazardous wastes. ATSDR (Lybarger et al., 1993) classifies hazardous substances according to adverse