Saturday, December 3, 2016

Global warming and clean air (New Delhi)

Copyright © Françoise Herrmann 

And you thought that Los Angeles smog was bad! Here is what the worse air pollution on earth looks like in New Delhi.


 On Nov. 1, 2016, the airborne pollution of particles measuring less than 2.5 microns (PM2.5­ particulate matter < 2.5 microns) measured 1.2 ppm (or 1200 ɥg/m3 - micrograms per cubic meter of air), that is, 120 times more than the annual mean threshold (PM2.5­  = 10 ɥg/m3) set by the World Health organization for protecting public health, or close to 50 times more than the 24-hour mean average of 25 ɥg/m3 set by WHO for protection public health (WHO, 2005, p. 8).

Similarly, in comparison, the US EPA National Ambient Air Quality Standards (NAAQS) sets the threshold level of PM­2.5­ at 12 and 15 ɥg/m3 mean average for 3 years, respectively for primary and secondary air standards. Primary air standards are set to protect public health, including vulnerable populations such as the elderly, children and asthmatics. Secondary air standards are set to protect public welfare, including “protection against decreased visibility and damage to animals, crops, vegetation and buildings.” (US NAAQS)

For a 24 hour period, the EPA NAAQS for PM2.5­ is set at 35 ɥg/m3, for both primary and secondary air standards, averaged over three years. Thus, in New Delhi, on Nov 1, 2016, the air quality was about 35 times too dangerous even for buildings and vegetation, according to the EPA NAAQS standards. (US NAAQS)

And none of this is measuring any other pollutants, considered critical air quality criteria both by the US EPA NAAQS, and the WHO Air Quality Guidelines, such as levels of ozone (O3), sulphur dioxide (SO2), carbon monoxide (CO), lead (Pb) and nitrogen dioxide (NO2). 

Nor does the particulate matter measurements include those “well-mixed” GHG gasses and emissions such as: “carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6)incorporated in Section 202(a) of the Clean Air Act by the US Administration on Dec. 7, 2009, as “Endangerment and Cause or Contribute Findings” deemed threatening to the public health and welfare of current and future generations (Clean Air Act, Section 202(a), and Technical Report in support of the Findings). 👠

References
EPA – Table NAAQS – National Ambient Air Quality Standards
US Clean Air Act (1990)
WHO Air quality Standards (2005 – English)
US Clean Air Act - Endangerment and Cause or Contribute Findings for Greenhouse Gases under the Section 202(a) of the Clean Air Act
Technical support for the findings on GHG appended to the Clean Air Act on Dec. 7, 2009
https://www.epa.gov/sites/production/files/2016-08/documents/endangerment_tsd.pdf

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