Lead is a common element found in many different everyday objects. Despite the widespread knowledge of its toxicity to the human body, or any biological system, lead continues to be mined and used in items ranging from handheld electronic devices to batteries in cars to x-ray protective shields at the dentist’s office.
One of the most notable contributions of lead is its addition into gasoline in order to provide cars with more power. However, this provides a major hazard to society because lead and lead oxide dust become a part of the air people breathe.
When elemental lead is emitted from the tailpipe of a car, it lodges itself into the soils in the surrounding areas. Any disruption of the soil, such as from wind, children playing in the area or even animals passing through, can release the leaded soil into the air.
Studies have shown that areas with elevated leaded soil levels — such as near busy highways — correlate with decreased growth and reproductive rates in surrounding plants and animals.
A study conducted by Duke University, which was published in the Journal of the Medical American Association, investigated the effects of lead on cognitive abilities of 556 children born in 1972 and 1973 in Dunedin, New Zealand.
Results indicated that, on average, participants who had more than 10 micrograms of lead per deciliter of blood at the age of 11 had a 4.25 IQ point drop when evaluated 27 years later. Individually, researchers found that for every five microgram of lead per deciliter of blood increase, a person could lose about 1.5 IQ points.
In a similar study based in Rochester, N.Y., out of 172 children, researchers found that children between the age of three and five whose blood lead levels increased from one microgram per deciliter to ten encountered around a 7.4 IQ point drop.
“Regardless of where you start in life, lead is going to exert a downward pull,” Avshalom Caspi, Edward M. Arnett Professor at Duke University, said, according to Science Daily.
This was also true in a study conducted by the University of Pittsburgh where researchers found that compared to the law-abiding population, juvenile offenders typically had higher blood lead levels.
A blood lead level that is too high — greater than the reference level of five micrograms per deciliter for children between the age of one and five years old — negatively affects the body. Once lead enters the body, either by airborne particles or through consumption, it disperses throughout the body and is stored in the tissues and organs.
After a few weeks, the lead travels to the bones. During this process, lead, as a neurotoxic chemical, attacks the nervous system, possibly leading to life-altering neurological and physiological damage.
Children experiencing lead poisoning suffer from irritability, loss of appetite, abdominal pain, vomiting, brain damage, muscle weakness and organ damage.
Since lead is a neurotoxic chemical, too much exposure may cause severe learning disabilities, along with permanent and irreversible deficiencies in brain functioning.
Extremely high exposures to lead that result in a blood lead level of 100 micrograms per deciliter or more are likely to result in convulsions, coma and death.
Despite these adverse effects, the chelation therapy is used when blood lead level exceeds 45 micrograms per deciliter.
This treatment injects ethylenediaminetetraacetic acid (EDTA) into the bloodstream, which then latches onto the heavy metals and removes them from the body.
However, the damage to the nervous system might still remain.
“The cognitive deficits associated with lead persisted for decades and showed in the kinds of occupations people got,” Aaron Reuben, Duke University psychology graduate student, said, according to an article entitled “Lead exposure in childhood linked to lower IQ, lower status jobs, as adults” in Science Daily.
