Heavy metals, including lead, are present in soils either as natural components or as the result of human activity. Metal-rich mine tailings, metal smelting, electroplating, gas exhausts, energy and fuel production, downwash from power lines, intensive agriculture, and sludge dumping are the human activities that introduce the largest quantities of lead into soils.Today, more is known about the effects of lead and the pathways of exposure. Currently, lead is listed as a known or suspected carcinogen in the EPA’s Toxic Release Inventory (TRI). If ingested, lead can accumulate in body organs, including the brain, and result in various degrees of lead poisoning. At high levels of exposure, lead cannot only severely damage the brain and kidneys of adults and children but can cause death (NSC, 2000).
the inhalation of lead-containing car exhausts or industrial emission
the ingestion of lead-based pain
the ingestion of contaminated soil or dust from hand-to-mouth activities of those living in lead polluted environment
and/or the inhalation of leaded dust carried on clothing or by the wind
The specific pathways for children are from:
swallowing lead paint chips
eating contaminated food
or putting hands, toys, or objects contaminated with lead dust or soil
in their mouths
According to the American Journal of Public Health, by 1943, it was demonstrated that there were, in fact, lasting effects due to exposure to high levels of lead (Needleman, 1998). In the 1970s and 1980s, regulations began to be shaped across the United States to accommodate the differences in vulnerability between adults and children and the realization that lead, even in small doses, can result in cognitive impairment in children.
Children face the most devastating effects of lead poisoning:
Children on average ingest less lead than adults do, but on a dose-per-body-weight basis, children may have two to three times the exposure.
Children absorb fifty percent of ingested lead, a rate five times greater than adults (NSC, 2000).
Effects of lead:
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As shown, even below 10 m g Pb/dl blood, which is the level at which one is considered to have an elevated blood-lead level, children are facing IQ, hearing and growth problems due to the lead. Also shown is that at a level just below what is considered lead poisoning, children are still facing developmental toxicity. While effects are worse at elevated levels,it is extremely important to realize that even at what is considered a safe level of exposure, permanent and irreversible effects can occur..
The neurotoxicity of lead may be the biggest threat to a person’s health. Adults with asymptomatic exposure to lead as children are at risk for later educational deficiencies, including failure to graduate and poorer reading abilities (Needleman et al., 1990; Fergusson et al., 1997).
The Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics have recommended that all preschool children in the United States be screened for lead. The public health benefits of the early detection of lead intoxication in children are so great that the performance of at least a single blood lead measurement on all American children is well justified. If a child is found through a brief history to have one or more of these risk factors, testing ought to proceed more frequently. It should be noted that even the CDC list of indicators does not incorporate whether or not the child lives in an urban environment or the time spent outdoors in contact with soil.
Does your child: