Air pollution causes cancer, this has been medically confirmed. The World Health Organization (WHO) classifies air pollution as carcinogenic to humans. Continuous exposure to air pollution can cause lung cancer, and also increase the risk of bladder cancer, as per the International Agency for Research on Cancer (IARC) which is the specialised agency of WHO on cancer. According to WHO, it is estimated that close to 2.5 lakh people die every year from lung cancer caused by air pollution. In a statement, IARC said: "After thoroughly reviewing the latest available scientific literature, the world's leading experts convened by the IARC Monographs Programme concluded that there is sufficient evidence that exposure to outdoor air pollution causes lung cancer (Group 1). IARC also noted a 'positive association' with an increased risk of bladder cancer.
Eventually, depending on the level of exposure in different parts of the world, the pollutants in the air was found to be similar to that of breathing in second-hand tobacco smoke. The air we breathe has become much more polluted with a mixture of cancer-causing substances. We now know that air pollution is not only a serious risk to health in general but also a leading environmental cause of cancer deaths.
Range of diseases
Outdoor air pollution - emitted mostly by transport, thermal power generation, industrial and agricultural activities — is already known to cause a range of respiratory and heart diseases. It is estimated that more than 60% comes from vehicles burning petrol and diesel fuel. Lack of proper checks on factories and stubble burning also contributes to the high pollution levels.
IARC adds substances to Group I only when there is sufficient evidence of cancer-causing ability (carcinogenicity) in humans. The Group 1 list which contains substances responsible for causing cancer - includes well-known elements such as tobacco smoking, arsenic, asbestos, formaldehyde and ultraviolet rays present in sunlight.
The link between tobacco smoking and lung cancer is well known and has been established long back but now the focus is on other cancer-causing air pollutants. In June 2012, IARC declared that diesel engine fumes can certainly cause cancer, especially lung cancer, and upgraded it to Group l from earlier Group 2A of probable carcinogens." Classifying outdoor air pollution as carcinogenic to humans is an important step." says IARC Director
Dr Christopher Wild. "There are effective ways to reduce air pollution and, given the scale of the exposure affecting people ail worldwide; this report should send a strong signal to the international community to take action without further delay."
Air pollution is a collective term, which covers dozens of chemical compounds and particulates. These vary around the world due to differences in the sources of pollution, climate and weather. It is only in recent years that the diseases caused due to the effects of air pollution have been quantified. According to WHO, exposure to ambient fine particles contributed 3.2 million premature deaths worldwide in 2010. Much of this was due to heart disease triggered by bad air, but 223,000 deaths were from lung cancer. China and other East Asian countries contribute to more than half of the lung cancer deaths attributable to the ambient fine particle. The IARC has evaluated many individual chemicals and specific mixtures that are present in the air. These include exhaust from a diesel engine, solvents, metals, and dust. However, air pollution as a cause of cancer has been established for the first time. IARC report is based on the independent review of hundreds of research papers from worldwide.
Air pollution has been proven to cause serious damage to the health of human beings and therefore, one needs to take all steps possible to control the same. The responsibility of reducing air pollution lies with all of us.