Mumbai is seeing a rise in tuberculosis (TB), thanks to the city's poor air quality.

A stretch of road in Sion, in particular, gives reason for worry. The Maharashtra Pollution Control Board has found that the Respirable Suspended Particulate Matter (RSPM) level there to above 100 mg/cm (micrograms per cubic metre) consistently in May, sometimes even touching 300 mg/cm.

The threshold RSPM level in India is 100 mg/cm. World Health Organisation's air quality guideline level is 20 mg/cm.

"There is a stretch of road near the Sion hospital, which is terrible. Everywhere, there is dust. What's worrying is that the road faces two hospitals – the Sion hospital and a maternity hospital – across the road. This is not done," said Deepa Krishnan, a Sion resident.

Dr Jalil Parkar, chest physician at Lilavati hospital, said, "Air pollution has increased the number of cases of tuberculosis. Earlier respiratory tract infections were quite common. Broncho-spasms have become more common only now. TB was earlier a disease of the poor, but now even the rich contract it."

Data by Environment Policy and Research India (EPRI) is even more worrying. At construction sites in Mumbai, the RSPM level touches 700 mg/cm. EPRI collected this data from February to May. The ramifications of these numbers is clearly tangible as air pollution is the fifth largest killer in India.

A recent study by an economist, Michael Greenstone, and co-authors in their paper for the Proceedings of the National Academy of Sciences, Washington, calculated that an extra 100 mg/cm of RSPM will bring down life expectancy by about three years.

While chances of avoiding air pollution in the open is quite difficult, there is a way to regulate pollution within your home.

Avik Sil, regional director of EPRI, suggests: "Residents will do well to buy air filters. That can certainly reduce the amount of air pollution in homes as shutting windows is not really a solution. Unfortunately, air filters can be quite expensive and they will require maintenance. Ultimately, it is the onus of the government to take care of this problem and only they can effectively tackle it."

What is PM?Particulate matter, or PM, is the term for particles found in the air, including dust, dirt, soot, smoke, and liquid droplets. Particles can be suspended in the air for long periods of time. Some particles are large or dark enough to be seen as soot or smoke. Others are so small that individually they can only be detected with an electron microscope.

Mumbai

Date RSPM levels

08-05-2015 22110-05-2015 22111-05-2015 31420-05-2015 229