NEW DELHI -- The first week of India's unprecedented nationwide lockdown has dramatically improved the air quality here in the capital, part of the Delhi region that is deemed the most polluted city on the planet.
The 21-day lockdown, ordered by Prime Minister Narendra Modi to contain the spread of the novel coronavirus, went into effect March 25. The order forced factories to go idle, kept cars off the road and suspended most public transportation.
Blue skies suddenly have become a daily phenomenon, and the air is healthier to breathe. A French national working from home in New Delhi hailed the reduction in air pollution as the only good thing to come out of the lockdown.
Air quality is measured in the average concentration of PM2.5, or dangerous particulate matter smaller than 2.5 micrometers in diameter, per cubic meter. New Delhi's PM2.5 fell within the moderate range of 50 to 100 micrograms Thursday, down from its typical unhealthy readings of above 100 micrograms.
Higher PM2.5 concentrations raise the risk of individuals developing coughing fits, asthma and lung cancer. These concentrations are rated at six levels from ranging from "good" (0 to 50 micrograms) to "hazardous" (at least 301 micrograms).
In November, New Delhi recorded a PM2.5 exceeding 1,000 micrograms. A thick, white smog cut visibility to near zero, prompting citizens to label the capital a "gas chamber."
Delhi averaged a PM2.5 reading of nearly 99 micrograms in 2019, making it the worst among 85 capital cities, a report by Swiss research firm IQAir found.
India's capital endures not only traffic congestion that produces vehicle exhaust, but New Delhi also sources about 60% of its energy consumption from coal.
Smoke from neighboring areas contributes to the pollution as well. Rice and wheat farmers in the states of Punjab and Haryana burn fields every October or November after harvest. The practice clears the farms for the next crop, but it also produces a smog that descends upon New Delhi.
The burning of crop residue costs the regional economy around New Delhi $1.5 billion, according to a report by the International Food Policy Research Institute, a Washington think tank.
"The negative health effects of crop burning will also lower the productivity of residents and may lead to long-term adverse impacts on the economy and health," said an author of the report.