By Helena Molin Valdes and Dr Arnico Panday
Air pollution has become part of life for people across large parts of Asia. Thick smog chokes cities and their inhabitants as black exhaust from diesel engines clogs the air on daily commutes. In rural areas, views of mountains and valleys are often obscured by a haze that comes from distant urban and industrial sources as well as from local cooking and agricultural fires. Air pollution contributes to climate change, and it also threatens the health and quality of life of those forced to live with it.
Doctors now find themselves on the front lines of two increasingly connected issues: protecting human health and the earth’s climate. This coming May, at the World Health Organization’s 68th World Health Assembly, countries are poised to adopt the first resolution on air pollution and health. This resolution will help mobilize the health sector to coordinate action to reduce the nearly 7 million premature deaths annually due to air pollution, including 2.6 million due to outdoor air pollution and 3.3 million due to indoor pollution in the Asia-Pacific region alone.
To do this there will have to be a concerted global effort to curb emissions of a variety of air pollutants from many different sources. Several of these pollutants have adverse impacts on both health and climate. Because they ‘live’ in the atmosphere for a relatively short time, they are called ‘short-lived climate pollutants’ (SLCPs). Unlike the greenhouse gas carbon dioxide (CO2), which has an atmospheric lifetime of centuries, the concentration of SLCPs in the atmosphere drop rapidly after emissions are cut, leading to a quicker noticeable effect on the climate. In many cases, taking action to reduce SLCPs also reduces carbon dioxide, which is the most critical greenhouse gas in the long-term fight on climate change.
Two major short-lived climate pollutants that cause air pollution are black carbon and methane. More than half of the world’s black carbon and methane emissions are from Asia.
Black carbon is emitted into the atmosphere as tiny particles (‘soot’) that are created during incomplete combustion in sources such as cooking and heating stoves, heavy-duty diesel vehicles, open burning, and brick production. Black carbon is a key component of fine particulate matter (PM 2.5). When inhaled, PM 2.5 penetrates deep into our lungs, increasing the risk of respiratory infections, heart disease, stroke, and lung cancer. Black carbon particles also contribute to climate change by absorbing sunlight and warming the atmosphere. In the Himalayas, black carbon contributes to the melting of glaciers and to changes in monsoon cycles – with implications for water availability and agricultural production.
Reducing human exposure to black carbon from cookstoves alone could cut premature deaths in the Himalayan region by as much as three-quarters of a million people per year, possibly many more. Broaden the focus to include diesel engines, brick production, and other pollution sources and the number goes even higher. The effect on agriculture could be just as dramatic: more than 15 million metric tons of staple crops could be added to the region‘s food supply with the reduction of black carbon and other pollution.
Methane is a very powerful greenhouse gas, especially in the short term, with a warming potential up to 20 times that of carbon dioxide. About 60% of methane emissions are from human sources – primarily agriculture (livestock rearing and rice production), fossil fuel production and distribution, and municipal waste and wastewater treatment. While methane itself does not directly affect health, it reacts in the atmosphere with other gases to create tropospheric ozone. When inhaled, ozone can worsen bronchitis and emphysema, trigger asthma, and permanently damage lung tissue. It also attacks plants, leading to substantial declines in agricultural productivity.
A global resolution on air pollution and health would put health professionals at the forefront of air pollution reduction. Doctors are in the best position to advise patients on steps to reduce their exposure by doing things like wearing appropriate face masks while on the road or near emission sources and encouraging people to stop burning household waste in or near their homes and workplaces. Doctors can teach the public that exposure to air pollution does not only put lungs at risk, but it raises blood pressure. In fact, globally chronic obstructive pulmonary diseases and lung cancer are not the number one air pollution-related killer; heart attack and stroke are responsible for more deaths. Doctors can also convince policy makers of the merits of lower-emitting systems of public transport, improved solid waste collection, clean cooking and heating stoves, and cleaner brick production.
Clinic and hospital administrators can play a leading role in promoting clean air policies by reducing air pollution in their own facilities and vehicles as well as educating patients, policy makers, and other key stakeholders about the health and climate benefits from reducing air pollution. For example, heavy-duty diesel ambulance vehicles can switch to cleaner fuel, clinics can replace kerosene lamps with solar-powered ones, and hospitals can launch awareness campaigns on the health and climate benefits of reduced air pollution.
By doing so healthcare professionals will be supporting a growing coalition of countries and organizations working to reduce short-lived climate pollutants in a way that maximizes benefits to climate, health, and agriculture. The Climate and Clean Air Coalition to Reduce Short-Lived Climate Pollutants is a partnership set up in 2012. Today, the Coalition has more than 100 members representing countries, international organizations, NGOs, and private industry.
The Coalition has launched 11 initiatives, including in the Himalayan region, to address the main sources of air pollution. Specific initiatives focus on urban health, cookstoves, diesel engines, agriculture, municipal solid waste, and brick production. Organizations such as the International Centre for Integrated Mountain Development (ICIMOD) are leading efforts in our region. Given the potential these initiatives have to provide cross-cutting and practical solutions to some of our biggest health, development, and environmental issues, it is expected that more countries and organizations throughout Asia will see the multiple benefits of joining the Coalition.
Ms Helena Molin Valdes <Helena.MolinValdes@unep.org> is Head of the CCAC Secretariat and Dr Arnico Panday <Arnico.Panday@icimod.org> is a Senior Atmospheric Scientist and Programme Coordinator of the Atmosphere Initiative at ICIMOD.