Chiang Mai air is generally clean, but this year’s annual smog from mid-February to mid-April has been so bad there have been days when it has had the most poisonous city air in the world.

Due to the continued absence of effective government intervention to tackle the smog a loose group of academics, doctors and students, many from Chiang Mai University (CMU), has been trying to address the problem for the last few years.

Burning in the northern Thai countryside and beyond creates the smog. Dr Poon Thiengburanathum from CMU’s School of Public Policy has been tracking the burning since 2012. He said approximately 60% to 70% of it happens in forested areas while 30% to 40% is in agricultural areas – but over the past seven years, burning has decreased in Thailand but increased in neighboring Shan State in Myanmar, and Laos.

Dr Poon explained that previously most farmers in the mountains were subsistence farmers so they did relatively little burning, but about 15 years ago they started to farm commercially and increased the amount they grew and burned. This coincided with an increase in demand for corn to feed cattle by large industrial food producers such as CP Foods who guaranteed to buy all the corn farmers could produce, so many started growing it.

Unfortunately, the easiest and cheapest way of disposing of the corn waste left after harvest is to burn it.

Due to public pressure, there has been a reduction in the number of new corn farms being set up in northern Thailand, though Dr Poon said there is a possibility that corn production has just shifted into Shan State, which could account for increased burning there.

The smog problem is exacerbated because Chiang Mai lies in a bowl surrounded by mountains and at this time of year there is little wind and a climate inversion that traps smog near the ground under a layer of warmer air.

People exercise on a running track in Chiang Mai in unhealthy PM2.5 levels of 77μg:m3 or 161 on the US AQI scale. Photo: Mark Inkey

Dangerous microbes vs Thai standards

The most dangerous component of the smog is PM2.5 particles. They are carcinogenic particles with a diameter equal to or smaller than 2.5 micrometers (μm or millionths of a meter) that can spread far and bypass the body’s defense systems, penetrating deep into the lungs and then the bloodstream causing many serious, often fatal, respiratory and heart problems.

The World Health Organisation (WHO) says that PM2.5 is dangerous to health even at concentrations as low as 25 micrograms per meter cubed (μg/m3) of air and that average annual and daily levels of PM2.5 above 10μg/m3 and 25μg/m3 respectively are dangerous. Rather than trying to reach these standards the Thai authorities cynically declared without any scientific evidence that average daily and annual levels of up to 25 μg/m3 and 50 μg/m3 were safe.

Usually, the US Air Quality Index (AQI) scale is used to indicate the health risks of different PM2.5 levels, and it has three different dangerous levels of PM2.5 concentrations. Levels above 55μg/m3 are classified as ‘unhealthy’, above 150.5μg/m3 is ‘very unhealthy’ and above 250.5μg/m3 is ‘hazardous’. Much like safe levels for PM2.5 the Thai government has come up with its own AQI scale that minimizes the risks. It has only one dangerous level, which is above 90 μg/m3, this means that people cannot tell the difference between merely dangerous levels and hazardous levels which are considerably more dangerous to health.

This year some areas of Chiang Mai have managed to record PM2.5 rates over 300μg/m3.

Dr Chaicharn Pothirat in his office at Maharaj Hospital sits behind a monitor showing unhealthy PM2.5 levels of 82μg:m3. Photo: Mark Inkey

Dr Chaicharn Pothirat, a CMU professor and pulmonary, critical care and allergy specialist at Maharaj, the main government hospital in Chiang Mai, said northern Thailand has the highest regional rates of lung cancer and people in Chiang Mai die on average four years earlier due to the smog. He has calculated that for every 10μg/m3 rise in PM2.5 levels mortality rates in Chiang Mai rise by 1.6%.

Despite publicizing his findings he said the government has ignored them and still says the health effects of exposure to PM2.5 are “uncertain”.

Levels high even indoors

Worryingly, despite popular perceptions, PM2.5 levels indoors are as high as outdoors unless you seal the room and run an air purifier.

PM2.5 levels throughout Maharaj Hospital are dangerously high yet the only clean sealed rooms are the two operating units and the ICU. Dr Chaicharn is working on getting all the nurses’ stations and one room in each ward sealed and clean, but it is hard because he receives no funding from the government and has to rely on donations solicited from friends.

He has also advised the authorities to build clean sealed rooms for about 20 to 30 people in each of the 205 tambons (municipalities) of the province and a large sealed safe room for at least 1,000 people in central Chiang Mai, so that those with health problems can have a respite from the smog.

This is hard to do because due to increased demand Thailand has nearly no air purifiers on sale and a shortage of N95 facemasks that protect against PM2.5.

Dr Chaicharn blames the unelected Chiang Mai Provincial Governor, Supachai Iamsuwan for that situation. He believes that if Supachai declared a state of emergency the government could save lives by bulk buying air purifiers and masks directly from Chinese manufacturers and rapidly get them to Chiang Mai tax-free by bypassing normal retailers and import channels.

Crisis, what crisis?

Dr Ora-Orn Poocharoen, the director of the School of Public Policy at CMU said a government official had told her they would not declare an emergency because they are worried it would badly affect tourism.

But, even without a state of emergency, the smog has been putting off tourists. Tourist numbers in Chiang Mai normally go up for Songkran, the Thai New Year from 13 to 15 April, but according to La-Iad Bungsrithong, president of the Thai Hotels Association Northern Chapter, numbers are down this year because of the smog.

She explained that the crisis has not really affected the long-haul market because many would have booked before the smog, but some of the Thai and to a slightly lesser extent ASEAN and Chinese tourists who tend to book at the last moment seem to be staying away because of the smog.

Tourist numbers for the whole of March were 5% down on last year and bookings for April are currently 70% to 75% down on last year, though La-Iad still hoped for some more last-minute bookings.

Tourism is a major revenue earner for Chiang Mai – last year 10.9 million tourists visited, and despite the smog, La-Iad expects that figure rise by 10% this year.

There has been a lot of criticism of how the authorities have handled the smog. In Bangkok when PM2.5 levels reached 90 μg/m3 the government took immediate action and shut down all schools. Yet as levels reached double that in Chiang Mai the governor remained silent much to residents’ disgust. They took to social media to register their disapproval and a petition was started on to have him removed for “ineffectiveness in tackling the haze”. Then on April 6, the Legal Research and Development Centre at CMU released a statement calling for him to step down and for the next governor to be democratically elected.

Command center

On April 3, a day after Prime Minister Prayut Chan-o-cha flew up to Chiang Mai and ordered the authorities to solve the problem within a week, the governor’s efforts visibly increased. He set up a command center at the Chiang Mai Conference Centre and asked Dr Paskorn Champrasert, one of the CMU academics working on the smog, to transform one of the large conference rooms into a sealed safe room for at least 1,000 people.

Dr Pasakporn Champrasert shows an air purifier he made to Chiang Mai Governor Supachai Iamsawun. Photo: Mark Inkey

Unfortunately, due to the lack of commercial air purifiers, Dr Paskorn and his students had to design and build their own purifiers using fans and HEPA filters. For the large safe room, they added filters to the air-conditioning units but that was not enough. Dr Paskorn explained that they were unable to lower PM2.5 to safe levels because air was coming in through the roof and there would not be time to seal the roof before the smog cleared. Fortunately, he successfully sealed and purified two small rooms and few people were turning up to use the facilities, as they had not been properly publicized.

Hopefully, the room will be ready by next year and the authorities will not lose interest in the smog problem as soon as it disappears, like in previous years.

Dr Chaicharn said that in May 2018 the CMU group working on the smog tried to arrange a meeting with the prime minister to discuss the smog problem but were told he could only meet them for five minutes. They regarded this as pointless so they sent the PM a letter to which they had no response until smog levels became critical again this year.

According to Dr Ora-Orn, 97% of the government’s budget goes on fighting fires and only 2% of it covers PR, research, monitoring, health and fire prevention technology. More needs to be spent on prevention.

Alternative farm options needed

Dr Poon said that there needs to be a long-term year-round decentralized, inclusive strategy against the smog and the reasons people burn have to be understood so that they can be offered less-polluting alternative solutions.

He believes the best way to stop people burning is to empower them with information about the damaging health effects of smog and access to finance to replace the money they could make from corn that would allow them to explore alternatives such as coffee, livestock or the intensive farming of herbs. They also have to be involved in policy decisions rather than excluded from them as they currently are.

Unsurprisingly, a week after the PM Prayut ordered the smog problem to be solved, air quality remains at dangerous levels despite reports of the number of forest fires in the north being greatly reduced, and the only thing that will clean the air is a change of weather.

For the situation to improve next year the government needs to engage with the problem on multiple levels all year round and focus on preventing fires rather than putting them out.

As Dr Chaicharn put it: “The government should be at the front supported by the social network.”