The Lancet study which highlighted the severe impact of poor air quality on mortality rates in 10 major Indian cities suffers from some limitations, said the Central Pollution Control Board (CPCB) in its reply to the National Green Tribunal, November 4, 2024.
The first one, it noted, is that ground monitors based data and satellite study based data has been used for PM2.5 measurements using a generalised model. Satellite data and modelling techniques used for extrapolations may not necessarily represent the realistic Indian scenario.
Another limitation is that mortality data was acquired from mortality records from each municipal corporation, according to CPCB. As International Classification of Diseases codes were not available for most cities, cause specific mortality was not conducted. In absence of cause of death data, several extrapolations of data take place. Therefore, the deaths cannot be attributed to air pollution alone and thereby may not portray correct comparison.
CPCB has identified 130 non-attainment and million-plus cities in 24 states and Union territories including Ahmedabad, Bengaluru, Chennai, Delhi, Hyderabad, Kolkata, Mumbai, Pune and Varanasi.
The key objective of the National Clean Air Programme (NCAP) is to reduce PM10 concentration in these 130 cities by 40 per cent by 2025-26, in comparison to levels of 2019-20 or achievement of National Ambient Air Quality Standards (NAAQS) 2009 annual standards for PM10, the body added.
With the implementation of comprehensive NCAP and various policy interventions, out of 130 identified cities, decrease in PM10 concentration has been observed in 95 cities during 2023-24, as compared to 2017-18 levels. These 95 cities included the nine cities of Ahmedabad, Bengaluru, Chennai, Delhi, Hyderabad, Kolkata, Mumbai, Pune and Varanasi, CPCB pointed out. Similar decreasing pattern was also observed in the city Shimla, it added.
The matter was related to a study published in Lancet Planetary Health, which highlighted the severe impact of poor air quality on mortality rates in 10 major Indian cities. It found that around 33,000 deaths annually are linked to air pollution levels that exceed the World Health Organization guidelines.
The cities examined included Ahmedabad, Bengaluru, Chennai, Delhi, Hyderabad, Kolkata, Mumbai, Pune, Shimla and Varanasi. It alleged that this was largely due to emissions from vehicles, industrial activities and construction dust.
Untreated domestic effluent is being discharged through various nallas into River Pawana from Pimpri-Chinchwad Municipal Corporation (PCMC) area. This was mentioned in a response filed by the Maharashtra Pollution Control Board (MPCB) October 29, 2024.
The matter related to pollution of River Pawana in Pune due to lack of sewage infrastructure, urbanisation and industrial development.
Pawana is polluted from Ravet to Dapodi village, all of which falls within the jurisdiction of PCMC. The river passes through the areas of Ravet, Chinchwad, Thergaon, Pimpri, Kasarwadi, Sangavi and Dapodi in PCMC.
MPCB is monitoring Pawana water quality on a monthly basis under the National Water Monitoring Programme (NWMP) at various locations at Talegaon, Ravet, Chinchwad, Pimpri, Kasarwadi, Sangavi and Dapodi, the affidavit my PCMC stated.
As per a 2022 CPCB report on polluted river stretches, the stretch of Pawana from Sangavigaon to Dapodi village is classified under Priority-II.
PCMC has provided nine STPs with a total capacity of 260 MLD in the Pavana catchment area, from which total 218.18 MLD sewage is treated. Three STPs of total capacity of 23 MLD are under construction. PCMC has proposed three STPs with total capacity of 60 MLD, taking into consideration the population for the year up to 2041.
The quality of treated effluent from STPs is regularly monitored by the MPCB. "On perusal of the analysis reports, it has been found that BOD, COD, suspended solids and detergents in the treated effluent were more than the prescribed limits and not meeting the consented standards and substandard effluent is being discharged into Pawana river," MPCB wrote in the report.
Based on the water quality data for 2024 (January-July), the entire stretch of River Ganga in Uttarakhand was meeting primary water quality criteria for outdoor bathing in terms of pH, dissolved oxygen, biochemical oxygen demand (BOD), faecal coliform and faecal Streptococci. This was stated in the compliance report by CPCB November 4, 2024.
CPCB, along with Uttarakhand Pollution Control Board, monitored 176 drains discharging directly into River Ganga, Ganga-forming river tributaries Alaknanda, Bhagirathi, Mandakini, Pindar and Nandakini (151) and its tributaries Ramganga and tributaries (18), Suswa (2), Song (3), Banganga and Sukhi (2) in Uttarakhand during post-monsoon 2023. These drains carry wastewater which comprises sewage and industrial effluent.
Out of 176 monitored drains, 113 were found tapped to various sewage treatment plants (STP). Significant BOD load was observed in one drain namely, Rispana drain, discharging into Song River with flow of 755.56 MLD and BOD 32 mg / l.
There are 53 STPs located in 19 Ganga-front towns in Uttarakhand, the affidavit added. Three of these STPs were found non-operational, according to CPCB monitoring during April-July 2024 in Uttarakhand.
Even among the 50 operational STPs, only two were found complying to norms prescribed by the NGT vide order dated April 30, 2019, while 48 were not.
With respect to the treated sewage discharge norms notified by the Union Ministry of Environment, Forest and Climate Change dated October 13, 2017, nine STPs were found complying and 41 non-complying.