The toxic effect of lead on human health

Abstract

Increasing amounts of anthropogenic contaminants have heavily polluted the atmosphere. This is one of the global environmental problems. Deposition of atmospheric contaminants on the earth’s surface brings potential risks to human health. This review aims to identify risks posed by lead in the atmosphere and its impact on human health. Lead is one of the most dangerous toxic metals found in the earth’s crust. The lead-induced toxicity through oxidative stress mechanisms includes the effect of lead on membranes, DNA, and antioxidant defense systems of the cells. It affects various target sites including lungs, blood vessels, brain, testes, and liver. Acute exposure to high doses of lead is not the only source of lead-based neurotoxicity. Acute low-dose exposure also produces measurable effects on the nervous system. The most severe neurological effect of lead exposure is lead encephalopathy, a response to very high doses of lead that results in the development of irritability, headache, attention deficits, memory loss, mental dullness, and hallucinations. Lead exposure has effects on neuropsychological functioning that vary across the lifespan. Lead causes a number of adverse effects also on the reproductive system in both men and women, such as decreased libido, chromosomal damage, and impairment of spermatogenesis. Lead can cross the placenta and impairs the development of the fetus due to its interference with the calcium metabolism. Lead-exposed women are at risk of various complications during pregnancy, including spontaneous abortion. This article reviews the nature, cause, and importance of environmental exposure to lead and emphasizes requirements for future policy responses and interventions.