Health risks of lead

Populations at Risk

Children are at the greatest risk for experiencing lead-induced health effects, particularly in the minority, urbanized, low-income segments of this pediatric population, who live in pre-1950 housing (CDC 1997). Preschool aged children (2-5 years old) have increased susceptibility to the effects of lead due to their developing brain, nervous systems and bodies and have been documented to absorb lead via the gastrointestinal tract more efficiently (50% relative absorption) than adults (15% relative absorption). Furthermore, nutritional surveys indicate that children specifically of low-income groups consume less than recommended dietary allowances of calcium and iron, which may in turn increase the toxicity of lead (Eu 2001). Young children’s exposure to soil, dust, and other potentially contaminated items is also increased by their tendencies to crawl or play on the ground and in the grass or dirt, along with behaviors such as pica tendencies (2-3 years), increased hand-to-mouth activity, and thumb sucking, which results in an elevated transfer of lead-contaminated dirt and dust to the gastrointestinal tract (Xintaras 1992; NSW EPA 2003).

Children enrolled in Medicaid are at high risk for having elevated BLLs (≥10 μ g/dL) (U.S. GAO 1998). An estimated 8.4 percent of surveyed children enrolled in Medicaid, WIC or living in low-income and uninsured families targeted by the Health Center Program had elevated blood lead levels, a rate nearly five times the 1.7 percent of children not enrolled in or targeted by federal health care programs (US GAO 1999). Medicaid enrollees account for 60% of children aged 1-5 years who had BLLs ≥10 μ g/dL and 83% of young children with levels ≥20 μ g/dL (Bloch and Rosenblum 2000). Low screening rates among young children enrolled in Medicaid place this population at increased risk, where 81% of those aged 1-5 years have not received blood lead tests. Within the population of Medicaid children aged 1-5 years, 65% are thought to have elevated BLLs but have not been screened and, therefore, have not receive appropriate medical and public health case management, follow-up care, and environmental services (U.S. GAO 1998). Furthermore, 77% of children projected to have elevated blood lead levels nationwide are enrolled in Medicaid, WIC or are within the target population served by the Health Center Program (US GAO 1999).

Pregnant women are at increased risk because of the inherent susceptibility of the fetus from transplacental transfer of maternal lead. Lead has been demonstrated in animal studies to increase the incidence of fetal resoptions and to induce adverse neurobehavioral effects in offspring exposed in utero. Recent data suggest that conditions of pregnancy, lactation, and osteoporosis may intensify bone demineralization, thus mobilizing bone lead into the blood resulting in increased body burdens of lead (Eu 2001). Breast-fed infants of lead-exposed mothers are also a susceptible group since lead can be secreted in the breast milk (Eu 2001). Furthermore, pregnant women are more likely to be exposed to lead through remodeling for baby rooms and may therefore be exposed to high sources of lead (NSW EPA 2003).

Workers in industries dealing with lead are at high risks for lead exposure and lead poisoning as well as the families and children of these workers. Inadequate protective clothing and equipment may increase the dangers of lead exposure as well as a lack of awareness, understanding, or complacency towards hazards posed by exposure or methods of preventing exposures. Secondary occupational exposure to lead can occur when lead dust collected on work clothes during the day is worn home. Pants, shoes, socks and other fomites can then contaminate the car and home, increasing the levels of lead-contaminated dust (NSW EPA 2003; McDiarmid and Weaver 1993).

In addition, unsafe do-it-yourself renovators and their families in pre-1978 houses may be at increased risk due to the lead contaminated dust from remodeling, as well as point source community residents, specifically children, who live near landfills or industries polluting lead in the environment or from natural lead reserves (NSW EPA 2003).

Effects of lead exposure

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