Shirts and tees are back on the Maidan on Thursday morning with haze the only sign of winter on a day when the minimum temperature rose by more than seven degrees Celsius over the season’s low of 9 degrees. Picture by Pradip Sanyal
The increase in the particulate content of Calcutta’s murky air is causing permanent damage in children and raising adult mortality, warn doctors.
“The incidence of lung diseases, including cancer, has been increasing by more than 10 per cent every year. Worse, there seems to be little concern about the long-term damage we are exposing our young to,” said a doctor who did not wish to be identified because of her association with a government institute.
Data available with the Calcutta Municipal Corporation shows that the number of recorded deaths this winter has exceeded the average.
Metro had highlighted on Thursday how polluted Calcutta has become, citing official statistics about respirable particulate matter in the night-time winter air.
The pollution control board had recorded 735.8 micrograms of respirable particulate matter per cubic metre of air at Rabindra Bharati University on BT Road at midnight on New Year’s Eve. In the first week of January, the average RPM count in the city was 232.32 micrograms, lower than its night pollution level but close to two-and-a-half times the national standard of 100 micrograms per cubic metre.
The level of PM2.5, the tiniest yet deadliest particulates of 2.5 micron or less in diameter, in the first week of January was 184.8 micrograms per cubic metre, three times the permissible limit of 60.
Rohini Chowgule, director of the Indian Institute of Environmental Medicine in Mumbai, said the lungs and skin were the most vulnerable to polluted air. “Every minute, an adult person breathes in on an average 7,800cc of oxygen. Along with the oxygen, we inhale RPMs, bacteria and viruses. The deadliest is the PM2.5, which directly goes into the air sacks in the lungs,” Chowgule said.
These are carriers of deadly chemicals and germs causing asthma, pneumonia, bronchitis and other chronic pulmonary diseases. They also affect the heart.
Apart from causing lung diseases, the PM2.5 damage the air sacks, which in turn cause chronic obstructive pulmonary diseases over a period of six to 10 years. Children are the most vulnerable.
“There are fine bristles in the lungs called cilia, which catch the impurities. But this layer is spoiled by polluting particles that are continually deposited in the lungs. High levels of pollution can have drastic effects on children, especially those exposed to it over many years,” said Apurba Ghosh, director of the Institute of Child Health.
One in every four children in Calcutta suffers from respiratory distress, Ghosh pointed out.
Winter makes it worse. Cooler night temperatures trap air pollutants close to the ground and pollution levels become very high. Static air aids the process.
Given the pollution trends, pulmonologist Raja Dhar said 30 per cent of children below 10 years of age in the city would need medical treatment for respiratory ailments in winter. A third of them would require prolonged treatment.
“Children are affected more by pollution because their air passage is in the formative stage and there can be permanent scarring and narrowing,” Dhar warned.
According to scientific data, nine per cent of children below the age of 15 in Calcutta have asthma. That is significantly higher than the other metros, where incidence of asthma varies between six and seven per cent.
While the unusually chilly winter this year played its part in heightening the threat from poison air, the main culprit is an administration that doesn’t consider a crackdown on polluting commercial vehicles a priority.
The number of fume-belching trucks trundling through town in a single night is around 50,000, according to environment activist Subhas Datta.