Bad air days are no laughing matter
We shouldn't fool ourselves. In the coming weeks, whenever the air quality standard in Bangkok and other cities is declared safe and healthy, it can still be unsafe and deadly.
Why? The Pollution Control Department (PCD) has set a pretty low standard for Thailand's ambient air quality. As a result, we have unknowingly been living with the prospect of having a shorter life span year after year as we commute through the streets of Bangkok day after day.
Surasak Glahan is Deputy Editorial Pages Editor, Bangkok Post.
Yes, we had been pretty much complacent until late last month when greater Bangkok started to be covered with hazardous fine dust particles called PM2.5 -- particulate matter with a diameter of up to 2.5 microgrammes per cubic metre (µg/m³) or less.
Since then, the PCD has shared data from its selective monitoring stations in the city which show that PM2.5 levels have exceeded its acceptable standard of 50 µg/m³ for the daily average.
As of press time yesterday, the 24-hour average levels of PM2.5 in several Bangkok areas went down lower than in previous days. But they were still within the range of 51-90 µg/m³, which is described by the PCD as "starting to have a health impact".
Air quality in other areas showed an improvement yesterday, with PM2.5 concentrations in the range of 37-50 µg/m³, which is considered "fair air quality".
But what is accepted here may not be tolerated elsewhere. The World Health Organisation (WHO) guidelines recommend 25 µg/m³ as the acceptable threshold for the daily average. The United States Environmental Protection Agency has adopted the the level of 35 µg/m³ for American people. Australia's environment agency sticks to the WHO's recommendation of 25 µg/m³.
That means whenever air quality in Bangkok is described as "good" by the PCD once PM2.5 concentration is in the range of 26-37 µg/m³, it would still be considered "poor" under the Australian standard.
The majority of PM2.5 originates primarily from sources of combustion, motor vehicles, power plant emissions and bush fires. With a size about one-third the width of a human hair, PM2.5 can easily penetrate into our bodies and can cause damage to our respiratory and cardiovascular systems.
As if being in the poor state of health isn't life threatening enough, the PCD this week insisted that as long as the PM2.5 levels in certain areas have not been higher than 90 µg/m³ for three consecutive days, it will not be treated as an emergency.
Once the PCD declares it to be an air pollution crisis, it will give the government a reason to come up with drastic measures such as the suspension of classrooms and outdoor activities.
But do we have to wait until the situation becomes that bad?
The government and other relevant state agencies have done a disservice to potentially affected people by advising us not to panic and by coming up with measures such as spraying water into the air, which is not useful because it will only suppress larger dust particles, not PM2.5.
The fact is that Thailand's low air quality standard has already made us complacent about the state of our health.
Without the government alerting us that the current air pollution might pose a risk to our health, we would not have become so vigilant.
To be fair, tackling air pollution is not a matter for government and state agencies alone. It needs collaboration from all of us -- individuals and companies -- to do our part.
But we need a full understanding of the situation and how bad it really is.
We still have to ask ourselves whether we want to keep the Thai acceptable standard of PM2.5 at 50 µg/m³ or whether we should aim for a cleaner level. Aiming higher would force state agencies, the private sector and individuals to be more vigilant and do more to improve air quality.
It is promising that the PCD yesterday said it may consider setting the crisis threshold at 70 µg/m³, instead of using the 90 µg/m³ level. This is a good start.
But we should not fool ourselves that this air pollution crisis will be over soon.
Even when the PM2.5 levels become lower than 50 µg/m³, accumulative and long-term exposure to it can cause adverse health effects.
The WHO guidelines recommend an annual average of 10 µg/m³ for PM2.5 in a given area as the acceptable level. The US adopts sets its annual average standard at 12 µg/m³. But Thailand aims much lower, setting it at 25 µg/m³.
According to the PCD report, the annual PM2.5 average in Bangkok during 2011-2017 had been in a range of 25-34 µg/m³, mostly exceeding the poor standard it has set for Thai people.
That is worrying for those who expose themselves daily to the deadly dust, such as street sweepers, bus drivers and conductors, street vendors, motorcycle taxi drivers and traffic policemen. The majority of them are low-income earners who would find it hard to look after their families and themselves if they are diagnosed with respiratory and cardiovascular diseases.
So it would be best if the government, the PCD and other state agencies start to tell us exactly how bad the PM2.5 situation is in certain areas for the entire year.
We should be aware of exactly how close the prospect of our death really is.
Deputy Op-ed Editor
Surasak Glahan is deputy op-ed pages editor, Bangkok Post.