New Delhi: The carcinogenic risk associated with diesel exhaust fumes was raised to the same level as asbestos and tobacco by a World Health Organization agency, further sharpening the debate on the skewed pricing of the fuel in India and raising concerns over public health in the country.
India, which has relatively lax standards for containing diesel emissions, has seen a spurt in diesel car sales over petrol variants because the fuel is heavily subsidized. The subsidy is aimed at farmers, who use diesel to run irrigation pump sets but also benefits owners of a range of vehicles, including those made by BMW, Mercedes and Audi.
For about 20 years, the France-based International Agency for Research on Cancer (IARC), part of WHO, had classified diesel engine as “probably” carcinogenic to humans, or in group 2A of its five-step gradation of the risk of cancer posed by several substances.
Now, IARC has moved diesel exhaust to grade 1—the highest level possible—and holding that there was now sufficient, indisputable evidence of the cancerous impact of diesel exhaust.
Health hazard: WHO has raised the risk level of diesel fumes from ‘probably’ carcinogenic to carcinogenic
“The scientific evidence was compelling and the working group’s conclusion was unanimous: diesel engine exhaust causes lung cancer in humans,” said Christopher Portier, chairman of the IARC working group. “Given the additional health impacts from diesel particulate, exposure to this mixture of chemicals should be reduced worldwide.”
While the health hazards of diesel emissions are well known in India too, the significant difference in prices between petrol and diesel, as well as technological improvements in diesel engine technology over a decade have caused sales of diesel-driven passenger vehicles to surge.
According to the Society of Indian Automobile Manufacturers (Siam) figures, diesel vehicles made up nearly 60% of the two million cars sold in the last fiscal. In previous?years, they have been less than 30% of the total number of cars sold annually. A litre of diesel costs Rs 40.91, while a litre of petrol costs Rs 71.92 in Delhi.
“In general, diesel exhaust has a much higher proportion of fine particulate matter than petrol. These are absorbed by our respiratory systems and are associated with an increased risk of cardiovascular diseases as well as cancer,” said Anumita Roychowdhury of the Centre for Science and Environment (CSE), an activist organization.
A 2010 study by Tata Memorial Hospital and the Centre for Global Health Research said about 600,000 people in the country died of cancer in 2010, nearly 70% of them 30-69 years old. Among the prevalent types in India that are fatal are oral, stomach, lung and liver cancer in men, and cervical, breast and stomach cancer in women.
Most of India’s diesel vehicle engines are based on European standards and typically trail emission norms on that continent. The current Bharat Stage III and IV emission norms followed in India that are modelled on European emission norms, have different rules for petrol and diesel engines. Thus, a Euro III diesel engine, for instance, is allowed to emit far more nitrogen dioxide than a similar capacity petrol engine.
Though recent advances in diesel technology, such as particulate filters, are available in the international market, they require so-called ultra-clean diesel, which is currently defined as fuel containing less than 10 parts per million (ppm) of sulphur.
The Euro III norms that are currently in force in 13 major cities of India stipulate diesel with sulphur concentration ranging from 350 to 550 ppm. India’ auto industry said companies were in compliance with the norms.
“There are certain organizations which have been talking about it. The issue was discussed even at the last WTO summit. As far as diesel consumption by auto industry is concerned, we believe today’s diesel is much less polluting than before,” said Sugato Sen, senior director, Siam. “We have already brought down sulphur content in diesel to 50 ppm by adopting Euro IV norms and hope to further reduce to 10 ppm as and when the oil ministry agrees to supply Euro V fuel.”