Official air pollution monitoring tells us about ambient air pollution. But Delhiites breathe much more than the background air while doing their daily chores, shows CSE monitoring
As you do your morning walk in that so called 'fresh air', you are actually breathing in air which is thick and heavy with particulate pollution. And you are not safe from polluted air even within the confines of your homes or workplaces -- says a latest Centre for Science and Environment (CSE) monitoring and research programme in which some citizens of Delhi voluntarily participated. CSE has individually monitored the amount of pollution that each of these citizens is exposed to on a daily basis, and has come up with some startling truths.
Releasing the results of the study today, CSE director general Sunita Narain said: "This is an unique initiative to assess how much pollution people breathe on a daily basis in Delhi when the overall winter pollution levels are already high. Our data is quite shocking we have found that daily personal exposure to toxic air is significantly higher than the background ambient air pollution that is monitored by the Delhi Pollution Control Committee. This is a serious risk to public health."
What has CSE done
CSE has used a state-of-the-art portable air quality monitoring equipment to track how much pollution an individual is exposed to in Delhi while doing their daily chores. This dust track aerosol monitor measures both mass and size fraction of the particulate matter. A select group of prominent citizens of Delhi and also patients suffering from asthma participated in this monitoring exercise.
A 24-hour real time monitoring for each individual from the select group was carried out on assigned days in the period November 2014 till December 9, 2014. Their average exposure was compared with the background ambient levels monitored by the Delhi Pollution Control Committee at the nearest official monitoring station.
Says Anumita Roychowdhury, executive director-research and advocacy, CSE and the head of its air pollution control team: "The key lesson from this exercise is that exposure monitoring has to complement ambient monitoring to refine pollution control measures to reduce health risk as pollution levels especially linked with traffic vary widely within the city. This makes our breathe highly toxic."
Individuals are exposed to highest pollution levels during night and early morning
Pollution levels are usually expected to be low during nights and early mornings the CSE study says otherwise. Cool and calm nights worsen the inversion effect, coupled with high pollution from truck traffic entering Delhi. Harish Salve who lives in Vasant Vihar, close to the Outer Ring Road, recorded highest exposure between 10-11 pm on November 25-26 when the hourly average of PM2.5 was about 408 microgramme per cubic metre . The level continued to remain elevated all through the night.
Winter pollution worsens personal exposure
This year, winter pollution is back with a vengeance. Almost throughout the month of November and December 2014, the levels of PM2.5 have remained -- on an average -- at least three-four times the 24-hourly standard of 60 microgramme per cubic metre. Higher averages are reaching up to four to seven times the standards and smog episode peaks hit eight to 10 times the standards. This is extremely dangerous for people suffering from asthma and other respiratory and cardiac problems, and also for children and the elderly.
Says Roychowdhury: "When CSE applied the National Air Quality Index announced by the ministry of environment and forests to the pollution level in November, it found that 53 per cent of the days monitored for PM2.5 are in very poor category and 47 per cent of the days are in severe category. The cocktail of pollution can be deadly for Delhi which is already gasping for breath. Without a stringent roadmap, every winter will turn back the pollution clock. Air pollution is rising steadily over the years. Every year, asthma and respiratory and other diseases will only increase. Delhi will have to take tough measures to control growing air pollution and fast."