EPOW - Ecology Picture of the Week

Delhi Haze

Smog, Smoke, Haze
New Delhi, India

Explanation:  What is doing on in the main image above?  Click on it and see what lies beneath ...

This week we have an aerial tour of a continuing scourge of New Delhi, India:  its toxic, recurring problem of air pollution.  

This is not to denigrate a fine nation, but to point out that such emergency conditions can occur from a variety of causes, and some of them can be surprising.

A popularized source of the haze is the annual burning of agricultural and grazing fields by farmers.  

And the surprising character here is enhanced aerosol particles that originate from chlorine, that causes aerosol particles forming as dense smog and haze.  Apparently, one culprit for this may be plastics that are burned and are part of the plastics industry of the region, that emit gaseous hydrochloric acid (Gunthe et al. 2021).  Other sources include sulfate and nitrate aerosols originating from burning of biomass, soil dust, vehicle exhausts, and others (Jaiprakash et al. 2017).

The conditions have severe, adverse impacts on human health, including respiratory conditions and premature mortality (Khilnani and Tiwari 2018).

But most surprising is that air pollution in Delhi seems to cause greater aggression -- more fighting -- in groups of resident Rhesus macaque monkeys (Macaca mulatta) (Xu et al. 2021)!  May this be a lesson for all of us.

And, finally, here is a photo essay of a flight I took into Delhi on a particularly pernicious day of dense smog and haze.  Here, I present my original, untouched photo, and then my enhanced photo to show the "city beneath the haze:"  

Information:
    Gunthe, S.S., P. Liu, U. Panda, and 20 others.  2021.  Enhanced aerosol particle growth sustained by high continental chlorine emission in India.  Nature Geoscience 14:77-84.
    Jaiprakash, A. Singhai, G.Habib, R.S.Raman, and T. Gupta.  2017.  Chemical characterization of PM1.0 aerosol in Delhi and source apportionment using positive matrix factorization.  Environmental Science and Pollution Research 24:445-462.
    Khilnani, G., and P. Tiwari.  2018.  Current Opinion in Pulmonary Medicine 24(2):108-116.
    Xu, A., C. Liu, Y. Wan, Y. Bai, and Z. Li.  2021.  Monkeys fight more in polluted air.  Scientific Reports 11:art. no. 654.