NEW DELHI: Air quality during the Republic Day parade may turn out to be slightly better than the bleak smoggy mornings the city has seen this winter, but it will continue to be in the "poor" and "very poor" categories. In fact, for president Barack Obama and guests from the US, the early morning air at Rajpath on Monday may seem nearly choking as PM2.5 levels here are several times the levels in Washington in the last couple of days.
The air quality index (AQI) for Metropolitan Washington was "good" on Sunday evening, but in the "unhealthy" range at the US Embassy in Chanakyapuri which has a real time PM2.5 monitoring system. Obama's brief comment on partnering with India on providing clean air to Indian cities was not surprising as alarmingly high air pollution in Delhi grabbed headlines quite frequently in national and international media.
A forecast based on the System of Air Quality Weather Forecasting and Research (SAFAR) model found that the hourly PM2.5 concentration on January 26 (5am to 10pm) will range from 90 to 118 microgram per cubic metre, which is about 2-3 times the US Environment Protection Authority (EPA) standard.
"The impact of sporadic rain, which improved the air quality significantly by washing out pollution during the past three days, is almost gone now. Cooler temperature and calm conditions are likely to enhance the concentration of overall particulate pollution from moderate to poor range on January 26," said Gufran Beig, project director, SAFAR.
The SAFAR model offers two scenarios: One in which traffic is like on any other day, or second where traffic is less due to diversions. Going by the latter, the air quality will be marginally above the Indian safe standard.
The US has extremely stringent air quality standards compared to India. Their annual safe standard for PM2.5 is 15 microgram per cubic metre and for 24 hours it's only 35 microgram per cubic metre. They also make sure that industries, vehicles and each city conforms to these standards. It's legally binding for each city administration (civil penalty provisions) to meet these standards. If they are not able to meet the clean air standard they are penalized with a cut on the development grant.
On Sunday evening at 7.30, PM2.5 levels at Mandir Marg hovered between 138 and 160 microgram per cubic metre. The visibility is also likely to be poor on early Monday morning. "There is no forecast for rain in the morning, but it may be foggy or partly cloudy. There is a 20% chance of very light rain in the afternoon. The temperature is likely to be 9-10 degrees," said BP Yadav, director of National Weather Forecasting Centre, IMD.
