Delhi's suitability as international sporting venue comes

Delhi's suitability as an international sporting venue came under a haze today as mask- wearing Sri Lankan cricketers laid bare the bitter reality of the city's 'very poor' air, toxic enough to trigger serious respiratory ailments.
The city's image took a serious beating for the second time in a month -- the Delhi Half Marathon had taken place on November 19 under similar conditions -- replete with particulates and noxious gases, which experts said were hazardous for those undertaking strenuous outdoor activities.
According to the Central Pollution Control Board (CPCB) data, PM2.5 and PM10 are the most dominant pollutants in the city's air but it has also high presence of toxic gases such as nitrogen dioxide (N02) and, at places, ground-level ozone (O3).

Local authorities maintained that 'very poor' air quality is normal during this time of the year, but by wearing masks the Lankans may have followed one of the key elements of the Delhi government's recent health advisory -- "wear N95 masks during peak pollution hours".
"The pollution level is in very poor category. This is normal during this time of the year. Levels of particulate matter fluctuate depending on meteorological conditions. But I am not sure whether it is advisable to play in the open wearing masks," a senior Delhi Pollution Control Committee official said.
The India Meteorological Department (IMD) said pollution levels have spiked due to calm conditions, marked by low wind speed and moisture. A broken arm of the depression over Arabian Sea have reached north India, resulting in overcast conditions and spike in moisture, which traps pollutants, an official said.

The IMD has forecast possibility of light rains on December 5 and 6.

In fact, the Centre for Science and Environment (CSE) said as per data recorded by the ITO monitoring station, located close to the Feroz Shah Kotla Ground, pollution levels hover around the 'severe' category in that area during the morning and evening hours.
The city's Air Quality Index (AQI) was 351 on a scale of 500, classified as 'very poor', just a notch below the 'severe' category. The corresponding advisory says prolonged exposure to such air can trigger respiratory ailments.
The concentration of ultrafine particulates PM2.5 and PM10, which can measure up to 30 times tinier than the width of a human hair, were 235 and 399 micrograms per cubic metre (ug/m3) at 6 pm.

Around 12.30 pm, when the Lankans first halted the proceedings of the Test match, the volume of PM2.5 and PM10 were 378 and 223 ug/m3. The corresponding 24-hour safe standards are 60 and 100.
Places such as R K Puram and Punjabi Bagh recorded NO2 levels as high as 214 and 588 ug/m3 during a few days in November. The 24-hour safe standard is 80.
A monitoring station at North Campus captured an alarmingly high volume of ozone in November.
The city recorded just two 'good' air days this year, both in July. Between May 2015 and January 2017, there was not a single good air day in Delhi.

In November, when pollution levels had hit emergency levels and persisted for about a week, there were 20 'very poor' days and seven 'severe' days.
A 'very poor' AQI comes with the warning that people may develop respiratory illness on prolonged exposure while exposure to 'severe' air affects healthy people and seriously impacts those with existing respiratory or cardiovascular diseases.