Poisoning still problem

In the late nineties, NUVO ran articles detailing the dangers of high blood-lead levels in children. It was told that classroom behavioral problems and difficulty learning show significant relations to individuals who tested positive. Since then, little has been done to correct the problem, and few are aware that a problem exists. Research is at a halt and the numbers of those affected by the lead in our environment have been shoved aside. "Part of the problem lies in the fact that lead poisoning results in chronic toxicity - which means that generally scores of people are not dropping dead, and another part of the problem lies in the misconception that the lead poisoning originates entirely from lead paint," says Mark Laidlaw, PhD student at the University of Western Australia who is researching local lead levels.

Most lead found in the human body comes from the very ground on which we walk.

Lead can be found in the soils surrounding Indianapolis as well as other parts of the world. Dr. Gabe Filippelli of Indiana University Purdue University of Indianapolis blames previous use of leaded gasoline for the contamination. When cars running on leaded gasoline emitted exhaust into the atmosphere, lead particles found their way back to earth and remain in the upper horizons of the soil - nearly twenty years after leaded-gasoline was banned. Most often the lead travels by wind when dry conditions create dust. Lead has been discovered over fifty meters from its roadside origin.

Blood-lead levels mirror the levels of lead found in the soil. Laidlaw notes that in Indianapolis, "The lead isotope ratio in the roadside soil (from leaded gasoline) was the same as the lead isotope ratio in the populations of blood."

Lead can be consumed when a child licks her hands after playing outdoors or inhaled from the air she breathes. Dust containing lead may also sneak indoors, making consumption possible within the comforts of a family's home.

"Exterior dust lead loading rates exceed the Environmental Protection Agency's interior dust lead loading rate limit by 10 to 20 times [the accepted value], which supports the supposition that lead dust in homes is originating from outside the home," says Laidlaw.

When ingested, lead can cause serious health problems and in certain cases, death. Adults who suffer from blood lead poisoning can experience hypertension, strokes, comas and death. Children, especially those six and younger, are at an even greater risk. Lead goes directly to a child's underdeveloped intestinal pathway where large amounts of lead enter the bloodstream. Finally it escapes to the bone marrow where it thrives with the help of bone growth. There the lead is stored and then released each year as the bone continues to grow. Lead also replaces calcium, which, in addition to aiding bone growth, transforms electrical neural signals into chemical signals in the brain. Lead does not properly transmit signals across the synapses. The results include mental retardation, learning disorders, attention deficit hyperactivity disorder and death.

Though the number of victims has declined, over 400,000 children, ages one to six, are still infected around the nation. "The decrease in numbers is encouraging, but medical doctors still consider those numbers to be characteristic of an epidemic," comments Dr. Filippelli. Of the two percent of children who tested positive with lead poisoning, 15 percent live in urban areas. Urban Indianapolis exhibits levels as high as 200 ppm of lead. Fifty ppm is the geologically accepted amount. Areas surrounding downtown also display high lead concentrations. Other neighborhoods, however, like the Meridian-Kessler cluster, show significantly low instances of blood-lead poisoning in children. The less wealthy, more diverse Washington Street surroundings exhibit definite problems. All areas sampled did not show large variation in population; thus, Filippelli and Laidlaw hypothesized that the socioeconomic status of the families are yet another variable.

According to Dr. Filippelli, the differences between the two neighborhoods are the level of education individuals obtain, nutritional values and a family's overall wealth. Laidlaw also adds access to legal representation. Other characteristics that can be seen in the Kessler area are well-maintained environments such as lush lawns and vegetation - useful in keeping the lead trapped in the soils.

But there is still one more step to end the spread of infection. "Lead abatement has been a success story, but the final process is lacking. It [addressing the soil issue] is the final kernel to ending the threat to children," says Dr. Filippelli.

After spending tax dollars to initiate the process, why is the government ignoring a community in desperate need of help? Laidlaw asks, "Would there be action if this was in Carmel?"

Though he offers no answer, he does give two options to spare future victims.

"The good news is that this problem affecting generally poor and minorities in inner cities can be almost completely eliminated by removing the top nine inches of soil or covering the soil with a thick layer of fresh topsoil. Whether this will be done is a matter of finances and political will."



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