mumbai's air pollutionIt is a pity that Mumbai's air pollution is threatening the cities growing importance as a player on the global economic stage. Industrial emissions, the burning of refuse and vehicle exhausts are combining to produce unacceptably high levels of nitrogen oxides and Particulate Matter (PM) in Mumbai's air. Mumbai's air pollution has grown dramatically in recent years and has now reached 18 million – the fourth highest in the world and the most densely populated. The World Health Organization (WHO) urban air pollution database finds that average levels of PM10 pollution in Mumbai is 132 micrograms per cubic metre. Even though Mumbai's air is very polluted, it is far from being the most polluted city in the world. That dubious distinction goes to the city of Ahwaz in Iran, whose levels of PM10 are a staggering 372 micrograms per cubic metre. It is not even the most polluted city in India for it comes in at number 10. Ludhiana scores a level of 251 micrograms per cubic metre. What is concerning is that WHO maximum exposure levels for PM10s (particles of size 10 microns or less, known to be linked to respiratory and heart disease) is only 20 microns per cubic metre.

A recent report from the National Environmental Engineering Research Institute points to widespread construction activity throughout the city as the major cause of air pollution in Mumbai. The city's transport department noted that the amount of heavy machinery like diggers, forklifts, and cranes has more than trebled in the last ten years, with an accompanying massive increase in dust and PM pollution.

Meanwhile, the Brihanmumbai Municipal Corporation (BMC) latest report on the status of the environment in Mumbai points to a dramatic increase in carcinogenic Polyaromatic Hydrocarbons (PAH) in the city's air. Specifically, the report shows that levels of highly carcinogenic benzopyrene have gone up eight times and there have been similar increases in levels of other PAHs, including phenanthrene, pyrene, and benzanthracene. These PAHs come from smoke arising from combustion of rubbish and from vehicle exhaust, and the BMC attributes the added pollution to the massive increase in construction activity and rapid industrialization in Mumbai. Unsurprisingly, the citizens of Mumbai are beginning to pay the price in terms of their health. Deaths from respiratory disease are up 20 percent, with a focus on asthma and Chronic Obstructive Pulmonary Disease.

However, the city authorities are doing something to try to address the problem. First, a bridge has been built across the Arabian Sea to join the suburbs of Bandra and Worli, which will ease traffic congestion. This is the first bridge of its kind ever to be built in India. Furthermore, a monorail is being piloted in the city which will save on fuel and cut down pollution.

There are also new measures to improve waste disposal procedures, with medical waste carrying vehicles now being fitted with sophisticated tracking devices. And, as with other cities around the world, including London, cycling is being made higher-profile, as an alternative to driving. These measures are a start – but much more needs to be done to tackle Mumbai's air pollution which is rapidly escalating.