A new research has found that dust particles present in households in Delhi have high levels of lead, a toxic heavy metal that could expose people, especially children, to severe health risks, including eroding of the IQ.
Researchers tested dust from a sample-size of 57 households across the Capital and found that all samples had lead in them. What’s more, lead in 26 per cent of the samples was higher than the permissible limits in the US. India does not have any prescribed limits for lead in household dust.
“No amount of lead is safe. It is a chief ingredient in paints. Paint chipping off from walls or any other item could result in lead in household dust,” said Dr Abhay Kumar, lead researcher at NGO Toxics Link, which carried out the study called “Dusty Toxics”.
The randomly selected houses in six parts in Delhi — north, south, southwest, west, east and central — were used for sourcing dust from floors and windowsills. “Thirty-one per cent of samples from floors and 14 per cent from windowsills had lead in quantities considered hazardous by US standards,” Kumar said.
Experts associated with the study concluded children were at graver risk from lead poisoning because of their faster rate of metabolism than adults.
“Lead affects the central nervous system and erodes the IQ. Studies have found that for each microgramme of lead exposure to the body, the IQ decreases by .5 per cent. It could also cause anaemia, decrease in haemoglobin synthesis, and general cognitive and behavioural disorders,” said Dr Arvind Taneja, director of paediatrics at Max Healthcare.
“Children have the habit of frequently putting their hands in the mouth. Medically the habit is called Pica. That is also another way of exposure,” he said. The worst case of this poisoning, he said, was when lead breaches the blood-brain barrier and causes in the swelling of the brain.
“There is a standard formed by the scientific body, Bureau of Indian Standards, for paint manufacturers for regulating lead. But the standards are only voluntary” said Ravi Agarwal, director of Toxics Link. “There must be law to remove lead from paints, just the way it was removed from petrol, to ensure a healthy future generation, unaffected from this toxic heavy metal.”
Researchers relied on the methodology prescribed by the US Environmental Protection Agency (USEPA) for maximum accuracy; dust was collected from virtually all corners of the house, including under the furniture, inside the windowsills etc, the study said.