CSE exposure monitoring on Diwali finds unacceptably high levels of pollution

CSE exposure monitoring of PM 2.5 on Diwali night found unacceptable levels of pollution people breathe despite a small dip in ambient pollution levels reported by official ambient monitoring systems

Official ambient monitoring shows slight improvement over last year; Less crackers and relatively better wind are the possible reasons

  • Overall ambient pollution level was significantly high

  • There was rapid build-up after the evening hours

  • Delhi experienced scary build up of sulphur dioxide (SO2) levels which is otherwise not the problem in the city

  • CSE exposure monitoring in different locations has shown exposure levels more than 1500 to 2500 microgramme per cubic metre while crackers were being burst

  • No room for complacency as the rapid build-up of pollution during the evening increases toxic exposure to dangerous levels

New Delhi, November 12, 2015: Centre for Science and Environment has released the results of the exposure monitoring that it carried out on Diwali night as well as the analysis of the official ambient monitoring data on the evening of Diwali. The data show a dramatic build-up of pollution as crackers begin to take effect and hit dangerous levels of exposure.

The ambient pollution level on Diwali may have seen a slight improvement over the previous year due to comparatively less crackers and mild wind in some parts. The recorded wind speed during 2015 Diwali was 1.19 metre per second in contrast to 0.62 m/s in 2014 – the wind speed in this Diwali had almost doubled. But from the public health perspective, direct exposure to toxic emissions matters most. “Delhiites will have to do a lot more to control crackers to reduce such dangerous levels of exposure and protect public health,” said Anumita Roy Chowdhry, Executive Director, CSE.

CSE exposure monitoring
CSE carried out exposure monitoring of PM 2.5 – the level of pollution within our breathing zone at the time crackers were burst and found alarming levels of exposure. The CSE team moved with monitoring devices in different parts of the city – covering diverse residential neighbourhoods – Pahar Ganj, Rajendra Nagar and Karol Bagh in the West, Lajpat Nagar in South, Mayur Vihar, Patparganj and Laxmi Nagar in the East and around Dhaula Kuan in West Delhi, Sita Ram Bazar in Old Delhi. CSE used TSI hand-held pollution exposure-measuring devices which can measure both the mass and size fraction of particulate matter (PM).  

Key highlight of CSE’s exposure monitoring:

  • People breathed several times higher pollution than the ambient level monitored by DPCC: Overall, during Diwali evenings people breathed an hourly average that is at least 3 to 4 times higher than the ambient monitoring recorded at the DPCC stations.

  • Exposure peaks in different locations were frightening – more than 2,500 microgramme per cubic metre (cum): After 8.30 p.m. Mayur Vihar Phase I recorded  one hourly average level as high as 1,763 microgramme per cum. In Patparganj, it peaked to 2114 microgramme/cum. At Laxmi Nagar, the exposure peaks were about 2,640 between 10.15 pm and 11.15 pm, and in Old Delhi 2,654 microgramme per cum after 11.30 pm.

Official real-time monitoring also indicates high peak build up during Diwali evening: CSE also tracked the changes in real-time data during Diwali evening and found rapid build-up as the evening progressed. The official release on Diwali pollution does not capture these changes in evening when the crackers are burst.

  • Ambient levels increased rapidly in the evening: Official monitoring shows rapid build-up of pollution peaks 8 pm onwards. Real-time data for the evening of Diwali showed a spike in PM 2.5 in the range of 399 to 608 microgramme per cum between 8pm and 12 pm.

  • Stunning build up of SO2: SO2 levels are not a problem in Delhi any more. During pre-Diwali days on November 6 and 7, the SO2 level was as low as 23 but on Diwali, the higher range in 24 hours reached 64 microgramme per cum – an increase of 2.6 times. SO2 in combination with PM is a dangerous combination. In some locations like that of RK Puram, the build-up of SO2 in the evening was dramatic. The short duration peaks hit more than 250 microgramme per cum.

Official ambient monitoring shows comparatively lower range for most pollutants compared with last year: DPCC has released results of the ambient monitoring on Dilwali day and compared them with last year. The plausible reasons are comparatively less cracker burning and also mild and improved wind compared to last year. The key highlights are as follow:

Particulate Matter –PM2.5: The average 24 hours average ranged from 184µg/m3 to 369 µg/m3. The minimum was observed at Civil Lines and maximum at R.K.Puram. On Diwali Day in 2014, the average concentration (for 24 hrs) for PM2.5 ranged from 145 µg/m3 to 500 µg/m3

Particulate Matter –PM10: The average 24 hour average ranged from 296µg/m3 to 778µg/m3. The minimum was observed at the airport and maximum at Anand Vihar. On Diwali Day in 2014, the average concentration (for 24 hrs) for PM10 ranged from 421 µg/m3 to 790 µg/m3.
Sulphur Dioxide (SO2): The average 24 hrs average varied from  26µg/m3 to 64µg/m3. The minimum was observed at IGI airport and maximum at Annad Vihar. On Diwali in 2014, the average concentration of SO2 (for 24 hrs) varied from  8 µg/m3 to 87 µg/m3.

Oxides of Nitrogen (NO2): The average 24 hour average varied from 37.0µg/m3 to 79.0µg/m3. The minimum was observed at Mandir Marg and maximum at R.K.Puram. On Diwali Day-2014, the average concentration of NO2 (for 24 hrs) varied from 39 µg/m3 to 194 µg/m3.

Carbon Monoxide (CO): The average 24 hrs average ranged from 1.1 mg/m3 to 4.0 mg/m3. The minimum was observed at Mandir Marg and maximum at Civil Lines.  On Diwali Day-2014, the average concentration (for 24 hrs) for CO ranged from 0.9 mg/m3 to 3.0 mg/m3.

CSE warning
CSE had issued a warning day before Diwali about the deadly impact of pollution caused by crackers at the onset of winter when the air is already saturated. The levels of tiny particles had already increased seven times since October 1 this year. This left no room for additional pollution in the city, especially from crackers that not only pushes up the pollution spike but also laces it with deadly cancer causing substances.

“It is not enough to quibble over marginal changes in Diwali peak pollution from year to year. This requires strong community sensitization as well as judicious mix of regulatory controls to protect public health,” said Roy Chowdhry.

Doctors have warned against breathlessness, cough, asthma, pulmonary disease, rhinitis, and lower respiratory tract infections. Those suffering from broncho constriction, wheezing; chronic obstruction pulmonary disease need precaution. High exposures to metal particles are known to be associated with lung cancer, pneumoconiosis, emphysema and high toxic effect on cells in the long run. Though Diwali is a short term exposure it adds to the already high exposure in the city.

But this issue cannot be tackled only with command and control measures. This requires strong public campaign to build awareness and support. “We need to put long-term measures in place immediately to reduce both air and noise pollution drastically to have a cleaner Diwali next year,” said Roy Chowdhry.

For further information, please contact Vrinda Nagar, CSE Media Resource Centre, at 9654106253/ vrinda.nagar@cseindia.org.



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