Current concerns of Lead Toxicity


This article presents an overview of lead toxicity and a number of public concerns. It has been discovered that 10-15 micrograms/dL of lead in the bloodstream of newborns and infants can result in cognitive defects. At this blood stream concentration of lead, newborns and infants experience a reduction of 4-7 IQ points. These effects on newborns and infants are dose-dependent so the higher the lead exposure, the higher the reduction in IQ observed.

Lead has also been discovered to disrupt the central nervous system. The reason lead causes this problems are due to lead’s interactions with calcium mediated intracellular messenger systems and neurotransmission. These effects have been more readily observed in developing brains due to the higher susceptibility of immature endothelial cells to the negative effects of lead.

Low-level exposure to lead has also been discovered to raise blood pressure in adults. Researchers did not initially observe this effect due to the fact that a change in blood pressure is not really observed in high amounts of exposure to lead. The exposure to small amounts of lead (2-15 ug/dL in the bloodstream) leads to systolic pressures that vary from 102 to 173 mmHg and diastolic pressures from 61 to 105 mmHg.

Adverse health defects caused by lead exposure are preventable. The major factors of lead toxicity are age, nutrition, and housing and socioeconomic status. Younger children have been discovered to be at increased risk of lead toxicity due to their high lead intake according to their body size and greater absorption of lead through their gastrointestinal tract. Lead has been detected in water, beverages, and food. An initiative has started in the US to reduce the lead exposure through nutrition. The last major factor in lead exposure is housing and socioeconomic status. The housing of people with lower socioeconomic status has a high tendency to have lead paint and contain toxic materials. This invariably increases this section of the population’s exposure to lead and is a major reason why their bloodstream lead concentrations are elevated.

The article can be found here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1519587/

No comments:

Post a Comment