It may be the city of dreams for a large majority of people but Mumbai also features among the cities with high pollution levels, according to a list published by the World Health Organisation (WHO). The WHO’s Urban Air Quality database reveals that only 12 per cent of people living in cities for which air quality data is available, including Mumbai, are breathing “safe” air.

Nearly half of Mumbai’s population faces a 2.5 times higher risk of air pollution than the levels recommended by WHO, putting these people at an additional risk of serious, long-term health problems. Mumbaikars are exposed to an average of 172 micrograms of suspended particulate matter per cubic metre of air. According to doctors, any level above 100 micrograms is harmful to health.

Dr Ramraje, pulmonary specialist, J.J. Hospital, said, “Episodes of difficulty in breathing can be triggered by allergens, infections and environmental pollutants. A large chunk of patients with asthma and bronchitis suffer from dust allergy.”

“We are getting more number of cases where the condition of patients is worsening due to pollution. In winters, it is almost impossible for asthmatic patients to go out due to the smog and dust. This was not the case a few years back,” he added.

According to the WHO, in cities like Mumbai where there is enough data to compare the present situation with that in the past, air pollution is getting worse. The contributing factors include growing reliance on fossil fuels like coal-fired power plants, motor vehicles, inefficient use of energy, and use of biomass for cooking and heating.

Going by the Maharashtra Pollution Control Board’s 2010 reports, the major contributors include vehicular emission and power plants followed by road dust.

In April 2014, the WHO issued new information estimating that outdoor air pollution was responsible for the deaths of some 3.7 million people under the age of 60 in 2012. Latest available data from the WHO directs towards greater awareness of health risks associated with air pollution, implementation of effective air pollution mitigation policies, and close monitoring of the situation in cities worldwide.