Abstract
The rapid increase of aerosols over the Indian Subcontinent over the last decade has the potential for severe health implications. However, the lack of a dense network to measure PM 2.5 (particles with aerodynamic diameter<2.5μm) hinders health risk assessments at regional scale. Here, we utilize Multiangle Imaging SpectroRadiometer (MISR)-retrieved columnar aerosol optical depths to estimate surface PM 2.5 based on recently published conversion factors that account for the composition and vertical distribution of aerosols. We examine the space-time variability of bias-corrected (utilizing coincident in-situ observations) PM 2.5 over the Indian Subcontinent for the period Mar 2000-Feb 2010. We show that 51% of the subcontinent's 1.4 billion people are exposed to pollution that exceed the World Health Organization's highest annual air quality threshold of 35μgm -3, while another 13% and 18% are exposed in the ranges 25-35 and 15-25μgm -3 respectively. Of the remaining population who breathe clean air, only 25% live in urban areas. In many regions, the high-levels of pollution are persistent rather than episodic. PM 2.5 concentrations in the rural areas of the Indo-Gangetic Basin are higher than many urban centers in peninsular India. Five hotspots (where PM 2.5 increases by >15μgm -3 over the ten-year period) are identified, which cover parts of the eleven Indian states and Bangladesh affecting ~23% of the population. Our results highlight the urgent need to carry out local cohort studies at these hotspots to better understand the health impacts under local conditions.
Original language | English (US) |
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Pages (from-to) | 153-161 |
Number of pages | 9 |
Journal | Remote Sensing of Environment |
Volume | 127 |
DOIs | |
State | Published - Dec 2012 |
Keywords
- Health implications
- Indian subcontinent
- MISR
- PM2.5
- Remote sensing approach
- Variability
ASJC Scopus subject areas
- Soil Science
- Geology
- Computers in Earth Sciences