The level of PM2.5, tiny particles suspended in the air that can lodge in lungs and cause disease. Air pollution in India’s capital surged this week, with a haze reducing visibility to 50 meters at times and prompting calls for government action. View more at #Hindustan360.
New Delhi on Thursday recorded its second-worst day in nearly 10 years, with the low visibility mostly due to smoke and dust, said the country’s meteorological department. Delhi residents, who are reeling under severe pollution since Diwali night, may find respite by Tuesday as strong winds are expected here in next 24-48 hours, which will improve the air quality, predicted private weather forecaster Skymet.
Skymet Director Mahesh Palawat said strong winds from Punjab and Haryana will push the pollution away.
“Due to adverse weather condition like slow wind speed, high humidity and low temperature, pollutants are hanging close to the surface. However, strong winds of about 15-20 kmph are expected from the northwest in next 24-48 hours, which will help in fast dispersal of pollutants from the air,” Palawat said.
Mean wind speed dropped to 1.8 meters per second last week compared with 3.4 meter per second around the same time last year, reducing the amount of pollutants that were dispersed.
The problem was also aggravated by a reversal in normal direction of wind, said R. Vishen, in-charge of the regional weather forecasting center of India Meteorological Department, New Delhi. “Normally, the wind direction in Delhi is north westerly (west to east). But from October 28 till date, the north north easterly (east to west) component was prevailing, preventing pollutants from dispersing and allowing them to accumulate in the air,” he said.
“We saw an increase in pollutants this year because of very low wind speed,” said Dr. Dipankar Saha, scientist and in-charge of the air laboratory at the Central Pollution Control Board.
The World Health Organization recommends that PM2.5 is kept below 10 as an annual average. It says exposure to average annual concentrations of PM2.5 of 35 or above is associated with a 15% higher long-term mortality risk.
“No matter how adverse the meteorological conditions are, a high concentration of PM2.5 can’t occur without multiple sources of emissions,” said Sumit Sharma, a fellow at Earth Sciences and Climate Change Division of the Delhi-based Energy and Research Institute who has been studying air pollution in India.
Burning of stubble in paddy fields to prepare them for the next harvest in the neighboring states of Punjab, Haryana and Uttar Pradesh also add to Delhi’s own air pollution woes: emissions from vehicles, industries using coal for power and dust from construction activities and movement of vehicles. The burning of trash, which can contain plastic, rubber and metal items and gives off toxic emissions, also adds to the city’s acrid air.
— Hindustan 360 (@Hindustan360) November 7, 2016
View more at #Hindustan360.