Coming clean on murky air pollution data
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Coming clean on murky air pollution data

During the peak of smog earlier this month, authorities classified the event as 'a temporary problem' that 'doesn't happen every day'. (Bangkok Post file photo)
During the peak of smog earlier this month, authorities classified the event as 'a temporary problem' that 'doesn't happen every day'. (Bangkok Post file photo)

Inescapably, those of us who live in Bangkok are resigned to the fact that pollution is part of our way of life. But the threat of air pollution in recent weeks seems too much to bear. And the state reaction is questionable. Leaving the city, the country's beating economic heart, is not possible for most of us.

Since late January, we have encountered smog that dimmed most of the city. At first, many mistook it for fog, only to learn later what it is and how it poses a threat to health. According to the World Health Organisation, the combined effects of ambient (outdoor) air pollution cause about 3 million premature deaths globally every year, mainly from heart disease, stroke and chronic obstructive pulmonary disease.

The health risks are associated with particulate matter of less than 10 and 2.5 microns in diameter, called PM10 and PM2.5, which is capable of penetrating deep into lung passageways and entering the bloodstream. Human activities are the major sources of outdoor air pollution including fossil fuel combustion from vehicles, power generation, industry and agricultural clearance and waste burning.

Paritta Wangkiat is a columnist, Bangkok Post.

Poor urban planning along with inefficient public transport forces city residents to use private vehicles, which worsens traffic and makes the air filthy. By last month, Department of Land Transport data shows the city had over 9.8 million vehicles, of which about 4.3 million are personal cars and 3.5 million are motorcycles. Surrounding provinces are a hub of industry, with some depending on coal-fired power plants. The industry is a growth engine for the country, but there is no law to force every factory to release real-time pollution data to public. No state agencies mentioned air pollution sources. I understand that it is a complicated issue, but we must confront it.

Greenpeace raised concerns about the possible impact from plants in Map Ta Phut on the air we breathe, especially during this month when the winter wind moves from the south to southwest direction. During the peak of the smog crisis at noon on Feb 8, the Pollution Control Department (PCD) recorded the highest level of PM2.5 concentrations at 95 micrograms per cubic metre (µg/m3) in the Wang Thonglang area -- exceeding the safety level of 50 µg/m3. Other air quality monitoring stations in Bang Na, and on Rama IV, Intara Pitak and Ladprao roads detected PM2.5 concentrations between 72 and 94 µg/m3 in this period.

During the peak of the crisis, the Bangkok Metropolitan Administration came up with a kneejerk solution: spraying water on streets. One senior official was optimistic about a long-term solution, saying we could look forward to clean air in another 10 years when the Bangkok mass transit system is completed! Worse, some authorities said air pollution is "a temporary problem" and that it does not happen every day. I disagree.

When the Pollution Control Department began to measure PM2.5 concentrations in 2010, 24-hour average concentrations were measured at between 16.6 and 77.4 µg/m3 on Bangkok streets, with 11.9% of measurements exceeding the safety level. It is known that PM2.5 is a more serious issue than PM10 since smaller particles can travel more deeply into our lungs and cause more harmful effects. But state agencies still focus on the PM10 measurement on the Thai Air Quality Index (AQI), creating the false belief that the air is not that bad.

In 2016, 24-hour average PM2.5 concentrations on Din Daeng Road alone were measured at between 20 and 103 µg/m3, with 27.6% of measurements exceeding the safety level. The air has long been polluted, with particulate matter concentrations moving up continually, posing a long-term health threat. A pity we have been barely informed of the risk.

Now the best we can do is put on a face mask to protect our health. But being deprived of timely and in-depth pollution information, some people may not realise how serious the problem is.

At public concerns over smog escalate, the PCD presented average PM2.5 concentration measurements on its Facebook page. But the results were still far lower than other international sources such as those from Plume Labs, which recorded Bangkok's highest PM2.5 concentrations at 151 µg/m3 on Feb 10.

The agency claimed the AQI can vary in different countries, depending on their development. It said AQI from other sources "may be inaccurate" or unsuited to the Thai context. Aren't our lungs made similarly, no matter where we are? What we need is transparency in pollutant measurement so we can work out a response. The public must get accurate data. As the rains come, some smog will be washed away. But without long-term efforts, the problem will haunt us.

Paritta Wangkiat


Paritta Wangkiat is a Bangkok Post columnist.

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