In a worrying trend noted by oncologists, lung cancer is increasing rapidly among Indian women. The foremost reason, much against popular perception, is not smoking but environmental pollution.

India has just slipped 32 ranks in the global Environment Performance Index (EPI) to a low of 155, and capital Delhi has earned the dubious tag of being the world's most polluted city.

While the fact that pollution harms health is known, that environmental pollution is now the main reason behind increasing cases of lung cancer should make people, and especially the government, sit up and do something to put a cap on the smoke and other pollutants.

According to the National Cancer Registry of the Indian Council of Medical Research (ICMR), in 1998 in Delhi, the ratio of lung cancer cases in men was nine per 100,000 males and was negligible in women. In 2008 the figure for men was still nine per 100,000, while for women, it was three per 100,000.

"So, while in 1998, lung cancer was negligible in women and was not one of the top 10 cancers affecting females, in 2008 the ratio between men and women became 3:1. In our experience in the clinic too, we have seen a rise in the number of women affected by lung cancer. Most of these women are from metro cities and are non-smokers...they are not even passive smokers," A.K. Anand, chief, Radiation Oncology at Max Hospital, told IANS.

The incidence of lung cancer, Anand further said, is the highest among women in the 45-55 age group.

"If you see the numbers in rural areas, there has been no change in the incidence of such cases. Vehicular pollution and industrial pollution are, therefore, the foremost cause behind the rising number of lung cancer cases," he added.

While the Cancer Registry data may indicate that there has been no rise in similar cases among men, doctors say that there has been a proportionate rise in head and neck cancer among men during this time. "Maybe because there has also been a rise in throat cancer, tongue cancer during this time, incidence of lung cancer has not shown any change in men over that period," Anand said.

Preeti Jain, consultant Oncology surgeon at Columbia Asia Hospital, further said that harm by vehicular and environmental pollution starts early. "Pollution is definitely a big factor in the rising number of respiratory ailments and now in lung cancer cases. Fine particulate matter in the air that lodges itself in the lungs causes harm over time, and damage starts early," Jain told IANS. Smoking, even passive smoking, she added, are the next two factors.

The comparative study of 178 countries on nine environmental parameters by US-based Yale University shows that Delhi has the highest particulate matter (PM) reading at 2.5, beating Chinese capital Beijing. The high PM caused by high vehicle density and industrial emissions is the reason behind the dense fog engulfing the city in the winter over the past few years, wreaking havoc on one's health.

At a personal level, doctors say that using masks, especially while on the go, could offer some respite, especially to children and the elderly who are among the most vulnerable lot.

"But for actual change to take place, people must raise their voices against pollution and the government must take steps like asking industries to shift out of cities," Anand said. Encouragement of car pooling, especially while going to work, can also have an impact, reducing traffic congestion and vehicular pollution. So will the improvement of public transport do, not just in Delhi but across the country.

At the end, doctors yet again harp on the importance of awareness about cancer in order to manage it successfully. "One of the reasons why you hear so often about cancer cases is because people are becoming aware and are getting diagnosed early, and that is very important. We have better diagnostic techniques and chemotherapeutic drugs today; so screening and diagnosing early means we can conserve the organ and the person can lead a good quality of life. So awareness is very important," said oncologist Rajesh Majumdar.