Delhi matches Beijing for air pollution threatening public health

Along with President Obama's state visit to India yesterday,  a number of news articles came with titles like "Obama is breathing world’s dirtiest air in New Delhi".

Such statement is presumably based on atmospheric particulate matter, which has impacts on climate and human health. Atmospheric aerosols affect the climate of the earth by changing the amount of incoming solar radiation and outgoing terrestrial long wave radiation retained in the earth's system. Particles smaller than 2.5 micrometers or PM2.5, tend to penetrate into the gas exchange regions of the lung (alveolus), and very small particles (< 100 nanometers) may pass through the lungs to affect other organs. Exposure of PM is associated with health effects such as asthma, lung cancer, cardiovascular disease, respiratory diseases, premature delivery, birth defects, and premature death.

In 2014, World Health Organization study finds Indian capital had dirtiest atmosphere of 1,600 cities around the world for PM2.5 particles. See the WHO Ambient (outdoor) air pollution database 2014 available at http://www.who.int/phe/health_topics/outdoorair/databases/cities/en/ and embedded below

Environment is one of the focuses during Obama’s India trip . Following the agreement in November with Chinese President for both countries to limit or cut carbon emissions, Obama is expected to meet with Indian Prime Minister to discuss topics such as educe greenhouse gas emissions and boost clean energy production. Currently, India heavily relies on fossil fuels as energy source, which has transformed New Delhi into the planet’s most polluted capital and made India the third biggest national emitter of greenhouse gases.

References and more to read: 

http://www.theguardian.com/world/2014/may/08/india-admits-delhi-matches-beijing-air-polllution-world-health-organisation-cities

http://globalnews.ca/news/1789010/obama-to-breathe-worlds-dirtiest-air-amid-climate-talks-in-new-delhi/