Delhi has lost the gains of its CNG programme. Its air is increasingly becoming more polluted and unbreathable, bringing back the pre-CNG days when diesel-driven buses and autos had made it one of the most polluted cities on earth.
According to the Society for Indian Automobile Manufacturers (SIAM), market share of diesel cars is expected to be 50 per cent of total car sales by 2010. This growth in personal diesel vehicle numbers will undo all the efforts to reduce pollution by phasing out diesel buses and converting them to CNG. According to CSE’s estimates, the total number of diesel cars presently in Delhi is equivalent to adding particulate emissions from nearly 30,000 diesel buses.
A recent analysis of Chennai’s air quality, done by Centre for Science and Environment (CSE), the New Delhi-based research and advocacy body, indicates that though Chennai shows deceptively low to moderate pollution levels because of its location near the sea, local impacts and exposure are high and the pollution levels are rising steadily, thereby increasing public health risks.
Air quality challenges in Bhubaneswar: After the shocking revelation of the global burden of disease estimates that one fifth of global deaths occur from outdoor air pollution in India, it became necessary to take stock of the problem and the solution to cut the killer pollution in all cities of India. But the air quality review carried out by CSE for Odisha has put the spot light on a rapidly worsening scenario.
CSE released the findings of its analysis here today at a stakeholder workshop conducted in association with the Tamil Nadu State Pollution Control Board. Bhure Lal, chairperson of the Supreme Court’s Environment Pollution (Prevention and Control) Authority, and Anumita Roychowdhury, executive director-research and advocacy, CSE addressed the participants.
• The inherent urban design display better design of pedestrian walkways: Bhubaneswar is among the very few planned cities in India. But other planned cities like Chandigarh have been designed as low density with segregated land use and wide roads for high traffic speed. Bhubaneswar has evolved with greater mixed land use. More than 50 per cent of the daily trip length in the city is below 4 km. This is an opportunity to maintain a compact city design and build densities to reduce distances. This makes the city very conducive to using non-motorised transport and public transport systems. The short trip length has also made this city very walkable. This is the low polluting and low carbon mobility that the world is trying to imbibe today.
There cannot be any room for complacency about comparatively lower level of particulates in Chennai. Though the overall particulate levels are comparatively lower than other regions in the country, they are much above WHO guidelines. Global assessments now available from the Global Burden of Disease estimates show that the most of the health effects occur at lower levels. Chennai has several local pollution hotspots, and road side exposures are also high. Annual averages do not help address the risks. Air quality monitoring would need to address these challenges and issue health advisories to people. There is therefore absolutely no reason to think that the risk in southern cities like Chennai is lower than other cities. In fact, a health study released by the Health Effects Institute in Chennai and Delhi in 2011 shows that in Chennai, there is a 0.4 per cent increase in risk per 10-µg/m3 increase in PM10 concentration. In Delhi, it is 0.15 per cent – thus Chennai indicates a higher impact.
• Health concerns: It may be noted that over the last two decade efforts have been made at local levels to assess the health impacts of air pollution. There is enough evidence to act urgently to reduce the public health risks to children, elderly, poor and all. India will have to take action now to reverse the trend of short term effects as well as the long term toxic effects. For toxic effects to surface there is a long latency period therefore exposure will have to be reduced today. Addressing air pollution and health risk has assumed greater importance after the release of the global burden of disease that has ranked air pollution as the fifth largest killer in India. This has not been assessed adequately in Bhubaneswar.
• Chennai records very high exposure to vehicular pollution: A study carried out by scientists of University of Berkeley published in Environmental Science and Technology in 2012 shows that the exposure to vehicular fumes (in terms of population-weighted intake fraction, or the grams of vehicle pollution inhaled per grams of vehicle pollution emitted) in Chennai (72) is one of the highest in cities studied in India – third after Kolkata (150) and Delhi (100).
• Studies indicate high traces of carcinogenic toxins: A group of air toxins that are not part of official routine monitoring have been studied by the scientists of Department of Environmental Management, Bharatidasan University, Tiruchirappalli in Ambathur, Kolathur, Saidapet, and Egmore areas. Results published in 2011 show high levels of polycyclic aromatic hydrocarbons (PAH), a group of toxic carcinogens. Average concentration of particle-associated PAHs ranged from 325.7 to 790.8 nanogramme/cu m, which is alarming. The same study found more toxic compounds, among them benzo-a-pyrene -- an indicator of carcinogenic risk – varying between 6.8 and 16.4 nanogramme/cu m, exceeding the national standard for annual average of 1 nanogramme/cu m. PAHs are known to come more from diesel vehicles. There is a need to spruce up air quality monitoring to track these toxins.
• No room for complacency: Though the overall particulate levels are comparatively lower than the other regions in the country, they are much above the WHO guidelines. Also the global assessments that are now available from the Global Burden of Disease estimates show that the most of the health effects occur at lower levels. Also, the cities have several local pollution hotspots, and road side exposures are also high. Annual averages do not help to address the risks. Air quality monitoring would need to address these challenges and issue health advisory to people.