Runners exposed to high pollution levels during Delhi marathon

Delhi’s marathon for health was far from what it was intended to be. Air quality monitoring conducted by city-based non-profit Centre for Science and Environment (CSE) showed unacceptable levels of exposure to tiny particles—PM2.5.

Runners were exposed to high levels of pollution, since with every breath, athletes typically take in 10 to 20 times as much air, and thus pollutants, as sedentary people. The risk increases as marathons are generally held after the onset of winter when cool and calm weather conditions trap pollutants close to ground level and cause high exposure.

CSE carried out real-time exposure monitoring during the marathon event (08:30-11:00 am) along the route near India Gate, Rashtrapati Bhawan, Rajpath, Shahjahan Road, Khan Market and Jawaharlal Nehru Stadium. This monitoring is different from the ambient monitoring done by the government. Exposure monitoring captures the pollution on the road within our breathing zone, which normally records higher levels than the ambient level monitored by Delhi Pollution Control Committee (DPCC). But the trends correlate.

Findings by CSE

• The exposure to the average PM2.5 during the event was as high as 1,210 micrograms per cubic metre during the marathon period. During this time, the real-time exposure of runners was more than four times higher than the average background ambient air quality level at the closest station in Mandir Marg monitored by DPCC. Winter inversion has aggravated this trend. CSE analysis has already shown that during November, the pollution levels in morning hours have usually remained higher than in the afternoon.
• Local leaf burning in Lutyens’ Delhi spiked the peak exposure during the marathon. CSE encountered smoke plume from leaf burning on Shahjahan Road. The PM2.5 levels nearby peaked to a staggering 7,220 micrograms per cubic metre. This shows that even when vehicles were off the road, leaf burning in Lutyens’ Delhi—where houses of ministers, politicians and prominent industrialists are located—was contributing profusely to local pollution and exposure during the marathon.
• Exposure levels doubled during the hour immediately after the marathon was over and traffic volume increased. Citywide official ambient monitoring done by DPCC shows significant build-up of overall ambient pollution level over the last few days. The 24-hour average PM2.5 level on November 24-25 (6 am to 6 am) of PM2.5 was 134 micrograms per cum. The levels on November 28-29 (6 am to 6 am) had increased by nearly 86 per cent since November 24-25.

CSE says this winter will require nearly day-to-day and hour-to-hour pollution management for public health protection. It demands that the action agenda for winter pollution management must be rolled out immediately. Some of the measures suggested include reducing traffic volume and cutting down pollution from open burning, construction and power plants. CSE also says Delhi needs daily health alert and contingency plan during severely polluted days.