Through the night of Diwali, long after the windows were shut tight, cracker noise could be heard. In the national capital, where the air quality index remained severe right through the cracker fest, there were inconsistencies in the readings of PM 2.5 levels on Airvisual.com that uses data provided by the Delhi Pollution Control Committee (DPCC) and AQICN.org, which is based on readings provided by the DPCC and Central Pollution Control Board (CPCB).
For instance, according to Airvisual.com, the PM 2.5 levels in Delhi's RK Puram in South Delhi was 247 at 3 pm on Thursday, whereas AQICN.org reported PM2.5 levels at 275 for the same area at the same time. There’s a 28 point difference, which is the PM 2.5 levels of Sydney. Experts believe that unless there is a fair and reasonable monitoring of air quality, the governments of the day won’t be able to tackle air pollution.
The National Environmental Engineering Research Institute (NEERI), Nagpur-based laboratory of the Council of Scientific and Industrial Research (CSIR), has developed a device to address air pollution at high traffic zones like traffic intersections and parking areas. The 5.5 ft tall and one foot wide device has been installed with filters made of non-woven fabric that can remove particulate matter with an efficiency of 80 to 90 percent efficiency and poisonous gases with an efficiency of 40 to 50 percent. The prototypes of the device called WAYU have been installed at the ITO Junction in central Delhi and Mukarba Chowk in north Delhi.
Dr Rakesh Kumar, director of NEERI said there are some key concerns in the inconsistencies to air quality monitoring that must be addressed. "In places like Anand Vihar and ITO, the air quality monitoring devices are placed at traffic junctions and the readings don’t amount to ambient air quality,” he shared, adding that proximity of the device to industrial emission or fire burning isn’t helpful.
In India, air monitoring is done manually using high volume samplers and respirable dust samplers with gaseous attachments or through data attenuation wherein monitoring stations generate data at time-intervals of minutes and transmit the data. “These techniques should be brought to the same location and the variations in results should be tested,” Kumar explained.
There are 10 stations in Delhi that were set up under the National Air Quality Monitoring Programme (NAMP).
In 2017, for the first time, efforts were made to collect and present station-wise daily average of monitored parameters of Delhi-NCR's air quality for the month of November in a tabular format, following a direction from the National Green Tribunal, Principal Bench.
The monitoring activity in Delhi-NCR was shared by Central Pollution Control Board, Delhi Pollution Control Committee, India Meteorological Department, Haryana PCB, Uttar Pradesh PCB and Rajasthan PCB, using Continuous Ambient Air Quality Monitoring Stations (CAAQMS) in ITO, Sirifort, Bawana, Dilshad Garden, Patel Nagar and Dwarka.
However, experts feel that the quantity of monitoring stations is low, and real time monitoring remains a challenge. Besides, there's also the question of accuracy as daily-average method has its own demerits.
"The average is easily influenced by the way these devices are placed. Ideally, they should be 20 metres above ground without any obstruction that can alter wind, velocity and dust particles," said Sunil Dahiya, air quality monitoring expert at Greenpeace International.
One city that Delhi can hope to emulate in this department is Beijing that has deployed a large number of sensors to crowdsource localised data into official stats sourced from expensive instruments.
“The results from low-cost sensors on air purifiers that cost upwards of Rs 2,000 can be incorporated into findings of instruments above Rs 10 lakh that can’t be placed everywhere. Crowdsourcing data and mixing it into official data will help Delhi monitor air quality better," said Amit Bhatt of the World Resources Institute.
Delhi’s problem is taken seriously because there are devices to monitor its intensity, but WHO’s list of 20 most polluted cities in the world featured 14 Indian cities and four of them were in the neighbouring Uttar Pradesh: Kanpur, Varanasi, Agra and Lucknow.
The Uttar Pradesh Pollution Control Board's (UPPCB) website flashes ambient air quality records from up to 24 cities but these cities are covered under CAAQMS system of testing that makes use of a small device with filter paper and its reports are sent to labs. Ravi Shekhar of The Climate Agenda, an NGO that has installed air monitoring devices in 43 districts of Uttar Pradesh including Yogi Adityanath's Gorakhpur, had earlier told Firstpost that the government must shift to NAMP which is monitored live. He alleged that in Varanasi, the pollution control board is under-staffed which sometimes results in four people managing six to seven districts.
“We need data in order to catalyse action both from policy makers and for citizens to protect themselves. Accurate data can also help identify sources of pollution and ultimately find solutions. If the government denies or obstructs the collection of data it is a clear signal to citizens that it does not have the will to solve air pollution,” said Reecha Upadhyay, campaigner at Help Delhi Breathe, summarising both the problem and the urgency in the need to find a solution to it.
Updated Date: Nov 09, 2018 10:59 AM