Another name has been added to the long list of substances that pollute the air Mumbaikars breathe.
For the first time, benzo alpha pyrene, a substance that can cause cancer, has been found in the air. A polynuclear aromatic hydrocarbon (PAH), benzo alpha pyrene is present in coal tar and cigarette smoke. However, there is no cause for concern yet as benzo alpha pyrene levels are far below the danger mark, an environment study by the Brihanmumbai Municipal Corporation (BMC) has found.
The analysis of suspended particulate matter (SPM) in the city shows that benzo alpha pyrene’s volume in the air varies from 0.13-0.54 micro grams per 1,000 cubic metres, well below the permitted level of 1 micro gram per cubic metre, the BMC study says.
“Benzopyrene is a well known carcinogen (cancer-causing substance). Whenever tar burns — whether in a cigarette or in coal tar — it releases BAP,” says Dr Pankaj Chaturvedi, head and neck surgeon, Tata Memorial Hospital.
Benzo alpha pyrene, like sulphur dioxide (SO2), gets diluted, he said, adding there should not be any cause of concern at this stage. “More so, because air pollution has never been associated with lung cancer,” said the oncologist. Chaturvedi said that based on an isolated report, it could not be concluded that benzo alpha pyrene will cause problems.
“This will require far greater analysis,” he said.
“Though benzo alpha pyrene is a lethal carcinogenic pollutant, we use many such substances every day,” a senior chemical expert from the University Institute of Chemical Technology said.
Naphthalen, commonly used in the households to keep insects away, is a similar chemical, and so are many fertilisers, the expert said. However, benzo aplha pyrene, if found in high levels in the air, is considered a serious threat.
Among other PAHs found in the city air are phenanthrene (0.02-0.08 micro grams per 1,000 cubic metres), anthracene (0.001 micro grams), fluoranthene (0.07-0.17 micro grams), pyrene (0.06-0.16 micro grams), chrysene (0.14-0.32 micro grams) and benze anthracene (0.06-0.25 micro grams).
According to the report, SO2 and lead are found to be within the permitted limits, but nitrogen dioxide (2-47 %) and other SPM (9-71%) exceed the danger levels.
According to the report, the levels of nitrogen dioxide have seen a sharp increase at all sites while there has been a marginal rise in the level of ammonia.
On the whole, the emission load has increased marginally compared to last year, primarily because of an increase in the number of vehicles and resultant traffic bottlenecks.
