Real Potent Life of Lead

The long-term impacts of lead exposure have finally been revealed: reduced IQ levels and lower socio-economic status. For India, the implications are grave. 

- Vibha Varshney

THOUGH THE health impacts of exposure to lead were first reported in the 1970s, a new study, published in JAMA on March 28, has established the long-term effects—it can not only reduce IQ levels, but also lower socio-economic status.

Lead is a cumulative toxicant that affects multiple body systems and is particularly harmful to young children, according to the World Health Organization (who). It affects the brain, liver, kidney and bones. It is stored in the teeth and bones, where it accumulates over time and is released with age.

The researchers used data from the Dunedin Multidisciplinary Health and Development Study, an investigation of health and behaviour of children born between April 1972 and March 1973 in Dunedin, New Zealand. At that time, New Zealand was using gasoline which had high levels of lead. In 1983, when the children were 11 years old, the researchers measured the level of lead in the blood of 565 of the children, and found that all children had high levels of lead, irrespective of their socio-economic status.

When these children turned 38, the researchers tested them again for cognitive functions. They found that children with greater lead exposure in childhood had poorer cognitive functions at midlife. They studied the occupations of the children with that of their parents when they were about the same age. While the trend is children have better occupations than their parents, but in children with elevated lead levels, the trend was the opposite. The occupations they held at age of 38 tended to be slightly less well paid or prestigious than their parents had.