The exposure atlas for household air pollution (HAP) in India, put together by a collective of global experts and led by investigators at Sri Ramachandra University (SRU), Chennai, shows that even States that fare better in terms of HAP concentration are way beyond the safe limits recommended by the World Health Organisation. For instance, a relatively well off Tamil Nadu had a HAP exposure of 150-200 micrograms of PM 2.5 (particulate matter less than 2.5 micrometres and which is respirable) per cubic metre of air — almost five times the WHO’s guideline range of 10-35 micrograms per cubic metre.
For other States, the HAP exposure, measured over a 24-hour concentration of particulate matter in households using solid cook fuels, ranged from values of 163 (in living areas) to 609 g/m3 pf PM 2.5 in the kitchen area.
The exposure atlas — first of its kind on HAP — was compiled on the basis of data from a 24-hour monitoring of concentrations of PM 2.5 in 617 rural households (kitchen and living area) from four States, including Tamil Nadu. The other three “geographically and culturally distinct States” were Madhya Pradesh, Uttarakhand and West Bengal.
“The exposure atlas fills a long-felt gap in metrics on the assessment of HAP and can be a starting point to drive reduction measures across predominantly rural communities,” said Kalpana Balakrishnan, Director, WHO Collaborating Centre for Occupational and Environmental Health, Department of Environmental Health Engineering, SRU.
Dr. Balakrishnan was part of an international working group that prepared the exposure atlas and used the Indian data sets for launching the Global Burden of Disease 2010 — a comprehensive risk-disease assessment — a few months ago.
“This is certainly pioneering work,” said Kirk R. Smith, chair of the working group on HAP and Professor of Global Environmental Health at the University of California, Berkeley, which is in long-term collaboration with SRU.
For creating the atlas, researchers used measurements in the four States and then national household survey data to derive estimates for the rest of the country.
“While the atlas is not of much help in mapping household-level pollution, it is pretty good in getting averages for States as a whole,” said Dr. Smith who is currently a Fulbright Nehru Distinguished Chair at IIT-Delhi.