Sri Lanka's interim coach Nic Pothas speaks about the difficulties his players faced after being affected by pollution on the second day of the Delhi Test (2:25)

India were almost forced to declare their innings in bizarre circumstances as Sri Lanka ran out of players healthy enough to field in the polluted Delhi air on day two of the Test. There were two stoppages - 17 minutes and five minutes - before the eventual declaration even as Sri Lanka trainer Nick Lee changed into his whites to step in as the 11th player on the field. The fielding coach Manoj Abeywickrama was also prepared to take the field.

In the post-lunch session, at least five of their fielders came out wearing masks. At 12.32pm, fast bowler Lahiru Gamage expressed concerns to his team, the physio walked out and looked after him, which caused a 17-minute delay. One more stoppage later, the other fast bowler Suranga Lakmal just walked off, leaving only 10 Sri Lanka players on the field. At 1.28pm, Virat Kohli, the India captain who fell for 243 during this stop-start period, called his unbeaten batsmen back in, seemingly suggesting they were okay to field in these conditions. Incidentally, Kuldeep Yadav, India's 12th man, wore a mask when he came on to the field with drinks in the first session. This was even before the first drinks break, when physio Patrick Farhart came on to check on Kohli's back.

Play was held up briefly due to the smog in Delhi BCCI

Pollution in Delhi has been a major health concern in recent winters. In November this year, the government had declared a public health emergency; schools were shut for a week, and the Delhi half marathon almost didn't go ahead. Back then, the air quality in Delhi had almost reached severe levels. On Sunday, air quality in some parts of Delhi was reported to be hazardous, and very unhealthy in the ITO area adjoining Feroz Shah Kotla.

During the interruptions, the match referee David Boon was seen talking to a doctor, who had a stethoscope around his neck, presumably for advice on how big a health hazard the current pollution was. Animated discussions between players and the match officials took place during these interruptions. At one point, India coach Ravi Shastri walked out to the middle. Nic Pothas, the Sri Lanka coach, was also seen talking to the umpires.

Last year, two Ranji matches - Bengal versus Gujarat, and Hyderabad versus Tripura, were called off because of heavy smog, but the air quality was much worse at that point.

Air Quality Index (AQI) in India is measured considering eight particularly harmful pollutants. The index ranges between 0 and 500. During the health emergency last month, the AQI nudged 400, which is considered severe. The air quality on Sunday was higher than 350 in most parts of Delhi, but in the early 200s in the surroundings of Feroz Shah Kotla.

The Central Pollution Control Board rates such conditions as "very poor". According to CPCB, exposure to them for a prolonged period can trigger respiratory illness. The most dominant pollutants are PM2.5 and PM10. These are ultrafine particulates, 30 times finer than a human hair. The concentration of PM2.5 and PM10 were 223 and 383 micrograms per cubic metre at 1pm. The acceptable highs are 100 and 60.

It didn't help that Sunday was a still day. Breeze usually helps dissipate the particulate matter in the air. Even the sun couldn't properly break through the haze. Floodlights were turned on around quarter past one in the afternoon.