Back home after a hard day’s work, Bidyut Saha felt a twinge in the back of his head. The multinational bank executive, in his mid-40s, put it down to stress, till the pain persisted and finally a scan revealed his worst fears — a tumour in the brain.
Now, the scare over the city: Saha is no exception, says an epidemiological study conducted by the department of physiology, SSKM Hospital, and sponsored by the West Bengal department of science and technology.
The report holds carcinogens — particularly nitrogenous ones — in the environment responsible for the high incidence of brain tumour in Calcutta.
Of 758 cases scanned, Calcutta beat all other districts of Bengal when it came to the brain-tumour count. And if men were found more susceptible than women, the 40-49 age-group was the most vulnerable.
The team, led by Dr Swapna Chowdhury, scanned brain tumour patients across major government and private hospitals over a period of three years.
The report, already tabled, threw up a chilling fact — pollutants and toxins from nature were seeping into human blood and affecting the brain. The higher the pollution percentage, the more the tumour incidence.
Of the sample surveyed, the study — which has been accepted by the Asia Pacific Journal for Cancer Prevention — reveals incidence of brain tumour among 33.08 per cent of cases scanned in Calcutta alone. In North 24-Parganas, the figure stood at 18.2 per cent and 9.32 per cent in Howrah.
Calcutta figures high on the list owing to the perilously high presence of nitrogenous effluents in nature.
“The percentage of incidence of brain tumour reflects how the high concentration of industries that throw out toxins is affecting human health. The indiscriminate setting up of highly-polluting industries will continue to wreak havoc,” warned a senior member of the research team.
The study even identifies the types of industries and the pollutants they were spewing. “Nitrogenous products from the sewerage and effluents are gradually finding their way into the soil and, finally, into our bodies from the agri-produce. In the blood stream, these products get converted into nitroso compounds, inciting tumour growth. This has also been observed in animals,” said Dr Chowdhury.
Experts in cellular and molecular immunology suggest such incidence can be lowered if care is taken while consuming raw vegetables, including salads. Products with low or negligible percentage of pesticides are also advised as pollutants find their way into the food.
Besides, food products that are chemically treated should not find their way to the table.
The presence of carbon monoxide, carbon dioxide and sulphur dioxide in the air also poses a serious threat.
The study identifies electronic, electrical, leather, ceramic and pharmaceutical units and printing presses as some of the key polluting sources in the city that can be linked with tumour trauma.