Pollution-free and breathable air still a distant dream in India

Air pollution is among the top ten health risks in India. More than one-third of the world's 100 cities with the highest levels of respirable dust, or particulate matter (PM) are in India. A World Health Organisation (WHO) report in 2014 had 13 Indian cities among the top 20 most polluted cities of the world. Those 13 were Delhi, Patna, Gwalior, Raipur, Ahmedabad, Lucknow, Firozabad, Kanpur, Amritsar, Ludhiana, Allahabad, Agra and Khanna.

The major cause of increased air pollution in Indian megacities includes unprecedented surge in the number of vehicles, the expansion of road network and increase in built-up area. Almost all Indian megacities record poor to very poor air quality.

The Hindu (April 7, 2015, New Delhi) reported poor air quality at selected locations in Hyderabad, Kanpur, Varanasi, Faridabad, Pune and Mumbai in the first week of April, 2015. The article further informed that except the BTM Layout neighbourhood, other locations in Bangalore had poor or very poor air quality.

A study based on Lung Health Screening Test (LHST) identified Delhi as one of the most polluted Indian cities with 21 per cent schoolgoing children suffering from respiratory diseases, followed by 14 per cent in Bangalore, 13 per cent in Mumbai and nine per cent in Kolkata. (DNA, May 4, 2015).

The residents of Delhi are exposed to high levels of nitrogen oxides, ozone and PM throughout the year. IIT Kanpur recently submitted the first draft of its "source apportionment study" commissioned by the Delhi environment department in 2011 to understand the causes of air pollution.

Major sources identified for pollution in Delhi have been vehicular emission, and secondary particulates (particles that form in the atmosphere from other gaseous pollutants, particularly sulphur dioxide, nitrogen oxides, ammonia, and volatile organic compounds) constitute 60 per cent of the pollutants, and close to 30 per cent of the pollution is a result of biomass, garbage and leaf burning. Car-free routes and the odd-even vehicle scheme are praiseworthy initiatives in Delhi.

The story is no different for the other Indian cities. For instance, a closer look at Bangalore presents a grim picture. The Energy and Resources Institute (TERI) conducted a source apportionment study in Bangalore in 2007. The findings suggested the city witnessed a total of 54 tonne per day PM10 and more than 200 tonne per day NOx pollution load.

The surge in vehicles from less than three million in 2007 to 5.5 million in 2014 coupled with poor road network contribute to the poor air quality in the city. The fact that around 1,600 vehicles are added each day in Bangalore simply described the future of air quality in the city.

Recent monitoring by the pollution control board in Bangalore reveals that PM10 concentration exceeds the national standard by 75 per cent averaged for all 14 locations in 2013-'14 with the maximum violation (191 per cent) at the Central Silk Board location. PM10 remained within national standards at only two locations - Domlur and SG Halli. Bangalore has witnessed a 57 per cent increase in PM10 concentration in four years (2010-2014).

People like traffic policemen and professional drivers who are employed in hazardous occupations face a risk to their healths owing to the high level of exposure to pollutants. Studies conducted among subjects working as professional drivers and traffic policemen have shown increased frequency of cardiopulmonary problems compared to unexposed workers.

Integrated exposure (48 hours) to respiratory particulate matter (PM5) among 24 traffic constables during the winter was found to be 2.25 times higher than the ambient air quality monitoring data in a Mumbai-based study, which is in concordance with other studies carried out in different parts of the world.

Study conducted by TERI have reported high levels of PM2.5 and benzene at refuelling stations in Delhi with workers being exposed to high concentrations of air pollutants particularly. In another study, at toll plazas in Delhi, we reported higher levels of air pollution at almost all monitoring locations compared with other outdoor work locations, along with poorer lung capacities with longer duration of outdoor work.

High exposures and health risks are not limited to occupational settings but also noted in residential neighbourhoods. Indoor air quality monitoring in Lucknow showed that PM10 and PM2.5 values exceeded the WHO guidelines at polluted sites located near roads. A higher prevalence of bronchial asthma was also recorded.

Research has established an association between air pollutants like particulate matter (PM10 and PM2.5), VOCs, oxides of sulphur (SOx), oxides of nitrogen (NOx), ozone, and carbon monoxide (CO) with adverse health effects, especially respiratory and cardiovascular diseases.

Air pollutants have also been linked to carcinoma of a variety of human tissues, including the lung, larynx, nasopharynx, oesophagus, oral cavity, urinary bladder, uterine cervix, breast, and to leukaemia and lymphoma. However, only a few studies have attempted to assess exposure to air pollutants and association with human diseases in megacities of developing countries like India.

These megacities record extremely high levels of exposure to pollutants and thus there is a high demand for evaluation of association of air pollutants with health among these populations.

Instead of trying to find odd and even number plates for vehicles, a deeper systemic change is required. Some change can be achieved through quickly implemented short-term adaptations and others through long-term planning and designing.

The short-term could include apps for "ride share", a metro system that can be tweaked to ensure a "safe and secure" travel, eventually, reducing the number of vehicles carrying people over long distances at the break of dawn.

Active travel (by walking or on bicycles) to schools, and other frequently visited places such as banks, post offices, and kirana stores must be encouraged.

If more and more offices designate "core" hours for meetings and collaborative tasks, the vehicle volume on the road could be spread/distributed through the day, reducing congestion, halting time at traffic signals and honking at slow moving - often less polluting - vehicles.

It is evident that a variety of micro-environments exist in megacities such as Delhi and the exposure to pollutants varies across people involved in different activities. Newer technologies need to be adopted to reduce the exposure of people to pollutants in occupational settings such as petrol pumps, toll booths, inside vehicles (for professional drivers), and inside homes using traditional stoves for cooking.

Over 100 million households in India still use traditional biomass based cooking stoves with nearly 80 per cent in rural and close to 18 per cent in urban areas. Urgently attention to household air pollution in this large segment of population is needed. Exposure to air pollution is an important risk factor for a range of diseases, especially among adult women who are primarily cooks.

Use of biomass fuel leads to harmful health effects as a result of incomplete combustion of cooking fuel. A large number of air pollutants like carbon monoxide (CO), sulphur dioxide (SO2), respirable particulate matter (PM2.5 and PM10), poly-cyclic aromatic hydrocarbon (PAH), benzene, and metals like lead and copper are emitted. About 2.4 million of 5.6 million cases of chronic bronchitis, 0.3 million of 0.76 million cases of tuberculosis, 5.0 milion of 51.4 million cases of cataract among adult Indian women and 0.02 million of 0.15 million stillbirths across India are attributable to household air pollution as a reult of burning of biomass while cooking according to an estimate based on a study conducted by researchers of TERI and All India Institute Of Medical Science (AIIMS).

A similar source of air pollution is the burning of twigs or cow dung to stay warm inside homes and often practised by security guards who are oblivious to the silent smoke which rises up, which gradually affects the air passages of people.

Though, a ban on open burning could be proposed, alternately, a win-win approach would be to incentivise innovative minds of young entrepreneurs of technology institutes to develop technologies and affordable solar heating devices to ward off the chill for those who keep our streets safe or work in chilly quarters in a small scale industry.

Another related need is to adopt sustainable ways of disposal of waste. Innovative waste disposal ideas are being adopted by residents in Bangalore who instead of burning biomass, garbage and leaves, convert them into compost regularly. These methods can be adopted by apartment complexes, gated communities and the Delhi municipality.

The long-term approach would include addressing fuel quality and vehicular technology. Together these play an important role in defining emissions from the transport sector. Enhanced fuel quality itself reduces emissions and also enhances the performance of vehicular emission control technologies. In 2003, the Auto Fuel Policy suggested a road map for introducing more stringent emission and fuel quality norms together in India till the year 2010.

The BS-IV vehicular emission norms (Euro 4 equivalent) were prescribed for 13 selected cities, and BS-III norms (Euro 3 equivalent) were suggested for the rest of the country by 2010. This has led to a situation where India now has one set of ambient air quality standards, but two different standards for vehicular emission and fuel quality differentiating few cities with the rest of the country.

Moreover, heavy-duty trucks, which ply all across the country, are all still at the BS-III level as observed by TERI researchers. Considering the high contribution of heavy-duty trucks in PM emissions, the introduction of BS-IV in 13 cities has had a limited impact in reducing the PM concentrations.

Additionally, since the majority of India is supplied with BS-III fuel, BS-IV vehicles operating outside of BS-IV cities are likely to emit more than the prescribed BS-IV norms.

As pointed out earlier, steps are required not just for Delhi but several other cities across India to reduce exposure. We need to have a package of measures in place and translate it into health benefits.

Stricter norms for diesel vehicles are required along with the implementation/adherence to these norms, availability of better quality fuel should be considered, active transport (bicycle, walking) needs to be promoted, and reduced occupational exposures to toxic pollutants such as at petrol pumps, re-suspension of dust from road side and construction activity, cleaner technology options or alternate fuel for people using traditional fuels (biomass based) for cooking, space heating need to be considered.