Lead: How and why lead is harmful to health?

As the European Union has proposed to ban the use of lead pellets in ammunition, studies have suggested that the discharge of the toxic metal into nature will have dire consequences on the environment and everything that comes into its contact.

At high concentrations, lead is known to wipe out populations of micro-organisms, thereby slowing down decomposition of matter. The micro-organisms themselves, along with plants and other animals, could develop a tolerance for the metal, resulting in permanent changes to the genetics of their population.

In plants, lead pollution has been shown to coat the surface of leaves, thereby hampering photosynthesis and respiration, and stunting their growth or killing them.

Studies show lead affects the central nervous system of animals, including their ability to form red blood cells.

In humans, exposure to lead has been widely researched to have impacted varied aspects of health.

Lead exposure during childhood has been documented to impair intellectual function, cause learning disabilities and elevate the risk for delinquent behaviour. Studies have also shown lead in blood affects sexual maturation in children and adolescents. In adults who were exposed to lead as children, consequences range from decreased brain volume to increased all-cause mortality.

The effects of lead exposure also hit foetuses. A study in a cohort of pregnant women in Mexico City found higher average lead levels in the blood of the women who suffered spontaneous abortion, which is a form of miscarriage occurring naturally within the first 20 weeks of pregnancy. The research found that the odds for a spontaneous abortion increased by 1.8 for every 5 micrograms per decilitre (ug/dL) increase in blood lead.

According to the World Health Organization (WHO), ''There is no level of exposure to lead that is known to be without harmful effects.'' WHO has estimated that ''nearly half of the 2 million lives lost to known chemicals exposure in 2019 were due to lead exposure.'' Further, ''lead exposure is estimated to account for 21.7 million years lost to disability and death worldwide due to long-term effects on health'', WHO said in a fact-sheet it issued in August 2022.

(This story has not been edited by Devdiscourse staff and is auto-generated from a syndicated feed.)