India has no concentration standards for sulphur and nitrogen dioxide emissions from power plants. It is time for them.

The debate on climate change has rightly focused on mitigating emissions of carbon dioxide. There are other greenhouse gases such as methane and hydrofluorocarbons (HFCs) that certainly have a higher global warming potential, but carbon dioxide by far is the most preponderant. And the most important source of carbon dioxide emissions are coal-based power plants. That is one important reason why US President Barack Obama has proposed a plan for enforcing carbon pollution standards from power plants in the US that would cut carbon dioxide emissions by 30% below 2005 levels by 2030.

In India, carbon dioxide emissions from power plants account for over half of its greenhouse emissions. NTPC Ltd has already come under international scrutiny as being among the top three power-generating companies that are the biggest emitters of carbon dioxide in the world. This may be true, but in its defence, it should be said that measured in terms of carbon intensity (that is, emissions per unit of power generated), NTPC is among the more efficient utilities globally, ranking ahead of Chinese companies.

About two-thirds of our electricity supply comes from such plants, and even with the most aggressive strategy on renewables, nuclear energy, hydel power and natural gas use for power generation, this proportion is unlikely to change dramatically over the next decade. That is why the accelerated deployment of new technologies that reduce carbon dioxide emissions in electricity generation, such as the use of super-critical and ultra-super-critical boilers and turbine-generators that could cut carbon emissions by around 5% becomes critical. India has already entered the 660 megawatts (MW) and 800MW super-critical plant era. Last year, former prime minister Manmohan Singh had announced that from 2017, all new coal-based power plants will be based on this technology.

However, there is a new concern that is emerging and this has to do with emissions of sulphur dioxide from power plants. These are pollutants in the classical sense of the term, but although we have standards for emissions of particulate matter, we have no concentration standards for sulphur dioxide emissions from power plants. The reason for this perhaps is that we have been used to thinking of Indian coal as having a high ash and low sulphur content. This is certainly true (except for coal in north-eastern states such as Assam), but with ever-increasing use of coal and the huge additions to generating capacity every year, even the use of such low-sulphur coal is beginning to have deleterious environmental impacts.

True, progressive ambient air quality standards were promulgated four years back and steps have been taken to clean up cities by, for instance, reducing the sulphur content of diesel and by the use of natural gas in public transportation. But the hotspots are clearly elsewhere and these are not being captured in ground-based monitoring systems that are in place. In a recent publication of the American Chemical Society, scientists at the Argonne National Laboratory and the US National Aeronautics and Space Administration (Nasa) have used data collected from satellite-based remote sensing instruments to assess the situation. The conclusion is, sulphur dioxide emissions increased by 71% between 2005 and 2012, and the increment was highest in Chhattisgarh, Gujarat and Odisha. The researchers also use satellite-based measurement data to establish that overall nitrogen oxide chemistry over Indian power plants has changed significantly in recent years. Here again, unfortunately as in the case of sulphur dioxide, there are no concentration standards for coal-fired power plants. India is the only major coal-based power-generating country not to have such standards, although there are regulations for stack heights. The pollution caused by emissions of sulphur dioxide and oxides of nitrogen is absorbed deep into the respiratory system in the form of secondary fine particulates. This has immediate detrimental health impacts and also triggers the onset of serious chronic ailments.

Preliminary ongoing analysis done by Rohini Pande and Anish Sugathan at Harvard University indicates a positive correlation between the presence of coal-fired power plants and infant mortality rates in a district. Clearly over the last decade, districts where such plants are located have shown relatively less improvements in infant mortality figures. Although this has yet to be studied, these districts will undoubtedly be having higher morbidity rates as well.

Without doubt, there are no quick-fix, short-term alternatives to the use of coal for power generation. But the challenge is to use coal in a way that minimizes environmental damage and increasingly that damage is being reflected in the state of public health. In fact, the environment-growth debate in India does not adequately take into account the fact that both air and water pollution have already emerged as major public health concerns. Environmental health is waiting to emerge as a major discipline in our country. There are increasing concerns around the impact of the use of pesticides on the incidence of breast cancer and other sites of cancer (such as lymphoma, gall bladder). Environmental contaminants in different regions of the country such as arsenic, uranium and fluoride, and heavy metals such as manganese, copper and lead have also been linked to various harmful health outcomes.

India is already the world’s second largest sulphur dioxide-emitting country. The main reason for this has been the phenomenal expansion in coal-fired electricity-generating capacity, an expansion that will continue for quite some time. Given the fact that sulphur dioxide stays long in the atmosphere and can be transported across long distances, it is urgent that concentration standards, from a health perspective at least, be developed and enforced.

The author is a Rajya Sabha MP and a former Union minister.

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