Delhi — Forget about Beijing; Delhi now has the most air pollution of any city on the planet, according to the World Health Organization. For the past two years, Delhi’s air has had 45 percent more pollution than that of the Chinese capital. In comparison to Beijing’s air, Delhi’s contains higher levels of the toxic particulate PM10 and 15 times more of the toxic particulate PM 2.5 than considered safe by the WHO.
Unfortunately, this poor air quality extends throughout India. There are 23 Indian cities with more than one million inhabitants whose air quality fails to meet WHO standards. Overall, a majority of India’s inhabitants inhale air that is unsafe to breathe.
While many would assume the worst pollution stems from the sputtering engines of the lorries that congest the streets of many Indian cities, it often arises from a seemingly benign but equally ubiquitous source: biomass burning.
Along with fossil fuels, biomass is the main contributor to both gaseous and particulate air pollution in South East Asia. It encompasses a wide array of unprocessed energy sources such as dung, wood and crop residues and serves as the primary energy source of the world’s poor. In fact, 52 percent of the global population relies on biomass fuels.
In India, specifically, 78 percent of the population depends upon biomass as fuel for heating and cooking. Within impoverished rural areas of India, biomass usage is even higher, estimated at 90 percent, according to an Indian national census.
Widely prevalent, the burning of biomass produces considerably more pollution than any other form of fuel on the planet. In comparison to a gas, biomass emits 50 times as many noxious pollutants.
Considering that this fuel is organic, one might wonder how exactly it pollutes so profusely. The answer has less to do with its composition and more to do with how it burns; the biomass stove, or chullah, fails to burn efficiently and leaves a considerable amount of biomass fuel unconsumed. This incomplete process releases a variety of toxic compounds and particulates like carbon-monoxide, poly-aromatic hydrocarbons and formaldehyde.
What makes biomass even more harmful, however, is its use as a cooking fuel. Unlike pollutants from urban traffic that disperse into the local atmosphere, noxious fumes from biomass accumulate within homes.
This form of indoor pollution has become an enormous issue. To convey the magnitude of its health risks, the WHO “asserts ‘the rule of 1000’ which states that a pollutant released indoors is one thousand times more likely to reach peoples lungs than a pollutant released outdoors.”
Not surprisingly, indoor pollution has immense consequences on the poor who rely on biomass fuels to survive. Every year 1.6 million people die from indoor pollution worldwide. According to the WHO, “in developing countries with high mortality rates overall, indoor air pollution ranks fourth in terms of the risk factors that contribute to disease and death.”
India, in particular, bears the burden for 28 percent of these deaths, or around half a million annually and has the highest incidence of disease caused by indoor pollution among developing countries. Women and children under the age of 5 are the most vulnerable.
In order to combat these issues, experts have proposed a variety of interventions. The WHO advocates for the introduction of alternative fuel sources such as liquid petroleum gas and solar power. More fundamentally, it aims to improve stove efficiency and ventilation in areas where alternative fuels are unavailable.
However, a solution requires more than just new fuel sources and efficient stove designs. The Indian Council for Medical Research reported that indoor pollution interventions should not immediately focus on providing alternative energy methods. Rather, they should spread public awareness about the health risks and instruct users how to safely utilize their biomass stoves.
MIT’s Poverty Action Lab learned firsthand about the importance of public awareness in public health interventions. From 2006 to 2010 they conducted an experiment in the Indian town of Orissa in which they provided cleaner, more efficient stoves and hired community members to spread awareness of health hazards.
Yet, as the experiment wore on, community members let their new stoves deteriorate in favor of their traditional ones. The Lab found only a 7.5 percent decrease in carbon-monoxide exposure and negligible health benefits amongst the towns inhabitants.
While posing clear health and environmental risks, biomass has long been a convenient and familiar fuel source to the impoverished. With photos of smog filed cities such as Delhi appearing in the news, it is easy to overlook the pollution hidden within the walls of rural homes.
– Andrew Logan
Sources: ICMR, The Economist, The Poverty Action Lab, TIME Magazine, UNEP, WHO
Photo: India Times