Clearing the Air on Health Impacts of Pollution

The World Health Organization (WHO) highlights the health threat posed by air pollution, especially in Asia, which bears 65% of global deaths. At the Clean Air Forum in Singapore delegates were told the pollutant posing the greatest risk is identified as particulate matter – fine particles that deposit in airways and can lead to increased acute morbidity, mortality, and decreased lung growth and function. Action has been urged to clean up the air, especially from industry, transportation and energy production. And diesel is seen as a significant contributor, too.  Read more

Report from Ken Hickson at the CleanEnviro Summit Singapore:

Asia’s booming cities are experiencing mounting problems of air pollution and this is being borne out with the region having more than its share of deaths from environmental pollution, according to World Health Organisation (WHO).

While Singapore’s air might to amongst the cleanest in Asia,  attention is now turning to the very fine particles – less than 2.5 micrometres in diameter  and labelled PM2.5 – which are believed to pose the largest health risks, increasingly accounting for cardiovascular and respiratory illnesses.

The Clean Air Forum jointly presented at the CleanEnviro Summit by the Singapore Institute of International Affairs (SIIA) and the National Environment Agency (NEA) set out to provide “innovative solutions to improve air quality among Asia’s growing cities”, but also drew sobering attention to the health and environmental impacts of indoor and outdoor pollution.

In a keynote address to the Forum, Nasir Hassan, PhD, Regional Adviser on Environmental Health for the World Health Organization (WHO) pointed out that globally 3 million children under the age of five die every year due to environment-related diseases, with half of them – 1.5 million – from acute respiratory infections.

While outdoor air pollution is the most obvious problem and is identified as the cause of 800,000 deaths a year, nearly 50% of pneumonia deaths among children under five are due to particulate matter inhaled from indoor air pollution.

Asia is carrying an “uneven burden” from environmental pollution, says Dr Hassan, as 65% of the world total of deaths and lost life-years occur in Asia.

He drew particular attention to the single most studied and the most important health-damaging pollutant: particulate matter (PM), which includes black carbon. Fine particles deposit in airways and can lead to increased acute respiratory morbidity (pneumonia, asthma), increased mortality (from all causes) and well as decreased lung growth and function.

While particles less than 10 micrometres in diameter (PM10) pose certain health concern, particles less than 2.5 micrometres in diameter (PM2.5) and referred to as “fine” particles, are believed to pose the largest health risks. Because of their small size (less than one-seventh the average width of a human hair), fine particles can lodge deeply into the lungs. Exposure to PM2.5 increases the risk of cardiovascular and respiratory illnesses, and reduces life expectancy.

As some of the largest contributors to urban outdoor air pollution are industry, power generation, and transport, the WHO points to improvements in urban planning and public transport, stronger emissions controls for motor vehicles and regulations for industry  which have been shown to improve air quality and health.

May Ajero, the Programme Manager for Clean Air Initiative for Asian Cities Centre, told the Clean Air Forum that the Centre’s mission is to promote better air quality and liveable cities by translating knowledge to policies and actions that reduce air pollution and greenhouse gas emissions from transport, energy and other sectors.

“We need to put air pollution back on the agenda,” she said, “as it is a major issue with severe impacts on public health and contributes to climate change”.

While Asia has measures in place to help bring down pollution, Ms Ajero believes there are still plenty of opportunities to bring down pollution further, identifying diesel exhaust as a major problem as it has been identified as a cause of lung cancer.

She drew attention to a report last month (June) by the International Agency For Research On Cancer (IARC) which has for more than two decades classified diesel engine exhaust as a “probable” carcinogen — a cancer-causing agent — but until recently there was no clear evidence linking it to higher cancer rates.

This winter, however, two studies in the United States were published based on research involving more than 12,000 mine workers done by the National Cancer Institute and the National Institute for Occupational Safety and Health, known as the Diesel Exhaust in Miners Study, or DEMS.

According to a CNN report – referenced by Ms Ajero – industry groups and clean-air advocates alike say recent improvements in diesel engines are dramatic, but older engines are still in widespread use. Dr. Christopher Wild, the IARC director said while the United States and Europe already have “stringent” guidelines on diesel fumes, but there is “relatively little information about diesel exhaust in developing countries.” Other scientists warn that cancer takes years or even decades to develop, meaning that people exposed to fumes in the past are still at risk.

The Clean Air Forum also saw the launch of a new initiative by SIIA to further draw attention to the problems of air pollution. It has established the Clean City Air Coalition, a partnership of various stakeholders to raise awareness of the impacts of air pollution to inform policy makers and private corporations as well as change behaviours of individuals and the broader society.

Nicholas Fang, Director of SIIA and one of moderators at the Clean Air Forum, felt that more needs to be done to raise public awareness of this issue, especially pertaining to sources of pollutants such as PM2.5 and NOX (Nitrous Oxides). In 2011, the annual PM2.5 level remained the same as the year before (2010) while the annual PM10 level increased slightly, with both exceeding the WHO’s Air Quality Guidelines.

In working towards raising awareness, the SIIA has been writing commentaries on the clean city air issue for local media and also has ambitious plans to ramp up online initiatives to reach out to the general population.

Source: www.wpro.who.int/topics/air_pollution/,  www.cleanairinitiative.org and www.siiaonline.org

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