WASHINGTON: A constant dose of chronic lead poisoning from contaminated soil affects hundreds of thousands more children in the US than the more-publicised acute attacks of lead poisoning that are linked to imported toys or jewellery.
According to 2007 US Census Bureau data, there are approximately 20 million children below five in the US who are most susceptible to the harmful affects of lead poisoning.
Gabriel M. Filippelli, professor of earth sciences at Indiana and Purdue universities, noted that about two percent of these children (approximately 400,000) have lead poisoning, many in epidemic proportions.
Filippelli conducted a review of studies of urban soils as a persistent source of lead poisoning and also investigated the lead burden in the soils from a number of cities, including Indianapolis.
His findings revealed that older cities like Indianapolis have a very high lead burden resulting in a lead poisoning epidemic among their youngest citizens.
While acute lead poisoning from toys and direct ingestion of interior paint has received more publicity, these cases account for only a portion of children with lead poisoning.
Many health officials are increasingly concerned with chronic lead poisoning, which occurs at lower levels of lead in the blood and are harder to diagnose.
"These national numbers for chronic lead poisoning are staggering but the percentage of affected children in older urban areas is much higher than in rural areas or newer cities.
The blowing soil and dust young children ingest contains large amount of lead from lead paint and leaded petrol deposited decades ago, and from industrial contamination.
Spraying clean water with high power shower systems when tests show that soil moisture is low (usually mid-July to mid-September), would significantly decrease chronic lead poisoning in children, according to Filippelli.
Since contaminated dirt blows from one property to another, this cannot be done on a house by house basis but must be carried out on a regional basis.
A better but less feasible remedy would be to put a layer of clean soil on top of the contaminated soil and to hydroseed the fresh dirt with grass.
The high end remedy, removal of all contaminated dirt, perhaps two feet deep, is unattainable, except in small areas around industrial sites such as lead smelters.
Young children, especially those who crawl, put objects in their mouth, eat dirt, or are exposed to blowing dirt, and can consume a significant amount of lead.
Children's developing digestive systems are very susceptible to lead poisoning. To a child's body, lead looks like calcium because they both have same ionic charge and size.
The study appeared in the August issue of Applied Geochemistry.
6 months ago