Lead taking slow toll on city: study

A study commissioned by the Quality Council of India,and conducted by the National Referral Centre for Lead Poisoning in India (NRCLPI),has found that many Delhi children whose blood was tested had between 10 and 15 micrograms of lead per 100 millilitre — safe levels are below 5 mg per 100 ml. Sixty per cent groundwater sources also tested positive for presence of lead in Delhi,according to the study.

Lead,a non-biodegradable heavy metal,is one of the most dangerous pollutants to affect the human body — among others,it severely impacts mental growth of children,experts said.

The problem,experts said,is likely to escalate,as settled lead rises and becomes lead dust in the summer. Besides,inverters with lead batteries are used more during summer months,which also raise the levels of contamination.

Batteries,from sources like inverters,are dismantled crudely and recycled at scrap markets in the city with virtually no checks. Monitoring lead contamination is a prominent mandate of the state pollution control committee.

“We tested 23,500 people from several metros and cities for this study,” NRCLPI director Dr Venkatesh Thuppil said,“and we found that the presence of lead is very high in all the metros. In Delhi,we found that groundwater is highly contaminated and high quantities of lead were found in blood samples.”

“Surface water usually does not have lead in it,” Thuppil said,“but groundwater was shown to have lead contamination,as lead is leaching into the soil.

“Industrialisation also results in poisoning.”

According to the study,there is a clear presence of lead in Delhi’s water. The study of five samples of municipal corporation-supplied water showed lead presence in the range less than 10 parts per billion (ppb). In groundwater,1 of 10 samples studied showed presence of lead above 50 ppb,5 had between 10 and 50 ppb,and 4 were less than 10 ppb.

The safe limit for water is less than 10 parts per billion,while in Delhi,samples have been found to be largely above that limit,according to the study.

Experts said lead poisoning is preventable,and there is a need for the government to put standards for lead levels in chemicals such as paints and batteries.

Above the safety limit

* Conducted over several cities,the study revealed 100 per cent of the groundwater samples in Kolkata and Cochin had very high levels of lead.

* In Madurai,Chennai and Guwahati,20 percent samples had high amounts of lead.

* More than 90 per cent of paints contained lead amounting to 35-45,000 parts per million (ppm). The Bureau of Indian Standards puts the safe limit at 1,000 ppm.

* It was found that a single chip of paint the size of a thumbnail contains 1 gram of lead,1,000 times higher than permissible limit.