Traffic Is Way Down Because Of Lockdown, But Air Pollution? Not So Much


“In some cities, the amount of one pollutant, ozone, has barely decreased compared with levels over the past five years, despite traffic reductions of more than 40%. Ground-level ozone, or smog, occurs when the chemicals emitted by cars, trucks, factories and other sources react with sunlight and heat.”

Tropospheric Ozone Pollution


Health Effects of Tropospheric Ozone Pollution

“NPR analyzed more than half a million air pollution measurements reported to the EPA from more than 900 air monitoring sites around the country. We compared the median ozone levels detected this spring with levels found during the comparable period over the past five years.”

“Our analysis revealed that, in the vast majority of places, ozone pollution decreased by 15% or less, a clear indication that improving air quality will take much more than cleaning up tailpipes of passenger cars.”

“In cities such as Los Angeles, stubbornly poor air quality during the coronavirus lockdown underscored how vast fleets of trucks are a dominant source of pollution. In industrial cities like Houston, refineries and petrochemical plants spew considerable air pollution. And in Pittsburgh and across a swath of the eastern U.S., much of the air pollution still comes from burning coal.”


1 thought on “Traffic Is Way Down Because Of Lockdown, But Air Pollution? Not So Much”

  1. The US is simply weird!

    Here, in India, there were several people in north India who reported seeing the Himalayas from several hundred kilometers away during the lockdown. Such a sight has never been possible for decades due to heavy smog and pollution. And 40% reduction in traffic is not as impressive compared to the continuous 21-day lockdown which stagnated more than 60% of traffic. Infact, the lockdown in the US I believe was mostly public motivated not strictly imposed by the government.

    Here are some quoted statements from reputable news sources:

    “The average traffic congestion in Mumbai in 2019 ranges from 60-80% in the morning rush hour (between 8 am and 10 am)” – Business Standard

    “The results showed that the lockdown reduced concentrations of harmful particles across all five cities [Delhi, Mumbai, Chennai, Hyderabad & Kolkata], from a 10% reduction in Mumbai up to a 54% reduction in Delhi. These reductions in PM2.5 were found to be comparable to reductions in other cities across the world, such as in Vienna (60%) and Shanghai (42%).”

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