Chiang Mai doesn’t have the usual seasonal progression. Our seasons begin when the rains stop in November and the mornings turns chilly. Last year it was so cold that people with old-style, unsealable, Thai houses had to move in with friends whose homes–though unheated–could at least be sealed by closing windows and doors! The cool weather and clear blue skies persist until sometime in March when temperatures rise. And rise. And rise until the afternoons are just plain hot. Since the rains have not started, local Hill Tribes burn off the underbrush to encourage mushroom growth, as you see in the photograph (right). That’s Doi (Mt.) Suthep, our sacred mountain, being burned off. Only this year, as you see, there were only a few burn sites and those were soon extinguished. The forest rangers have been cracking down on fire-starters and Mother Nature has helped with regular rains and, gasp! cloudy skies. The net result is the best hot season in living memory: almost-blue skies and pleasant temperatures. Perhaps the smoke season will soon be a memory…
Underbrush burning is the cause of smoke in Chiang Mai, which us part of the Southeast Asian haze–a fire-related large-scale air pollution problem that occurs every dry season in Brunei, Indonesia, Malaysia, Singapore, the Philippines and Thailand. Its official name is Southeast Asian Transboundary haze and it’s been recorded almost every year since 1972. It’s part of the price we pay for economic development.
Breaking News: Singapore proposed that ASEAN nations put an end to the practice of burning foliage and provided satellites and software for our intrepid rangers, who have been snuffing out fires before they get a hold on the hillsides. Old Asia Hands laughed: nothing would change, they said. But Chiang Mai has had mostly blue skies this season, 50 people have been fined 5,000 baht and the fine money given to informers. Though the level of potentially dangerous airborne particle matter in Chiang Mai rose beyond the safe limit on Saturday, the Disaster Prevention Department sent out more frequent patrols of forestland by fire-watch volunteers, strictly controlling farmlands and highway-side areas and asking for residents’ cooperation to refrain from burning garbage and farm waste.
We’ve still got a ways to go before we have blue skies every day (after all, the indigenous people have practiced slash and burn agriculture for centuries) but–at long last–the authorities are starting to get a handle on it, and that’s good news.
Most of the haze is caused by illegal agricultural fires. The worst, in Indonesia–especially from the provinces of South Sumatra and Riau in Indonesia’s Sumatra island and Kalimantan, where it’s carried out on an industrial scale because burned land sells at a higher price for activities like oil palm and pulpwood production. Burning is cheaper and faster than cutting and clearing, too.
The least bad is the northern Thailand smoke, which comes almost exclusively from Hill Tribes’ burning of underbrush in preparation for the great annual mushroom harvest when the monsoon begins. One reason the locals complain so little about it is that they love mushrooms more than clear skies. The Hill Tribes make 20% of their incomes by harvesting mushrooms. Our local hills produce some of the most exotic edible fungi on earth, and wealthy Bangkokians pay a fortune to have them rushed to them. The most reliable way to ensure that the mushrooms set spores is to burn the underbrush during the dry season. That’s where the smoke comes from.
The health effects of haze are mainly caused by the irritant effects of fine particles on the nose, throat, airways, skin and eyes. The health effects of haze depend on its severity as measured by the Pollutants Standards Index (PSI). There is also individual variation regarding the ability to tolerate air pollution. Most people would at most experience sneezing, running nose, eye irritation, dry throat and dry cough from the pollutants. They are mild and pose no significant danger to the health of the general population.
But people with active medical conditions like asthma, chronic lung disease, bronchitis, chronic sinusitis and allergic skin conditions are more likely to be severely affected and may experience more severe symptoms. Children–with their more rapid metabolisms and the elderly, with their lowered resistance, are more likely to be affected. For some, symptoms may worsen with physical activity.
This documentary, by Chiang Mai filmmaker and photographer Marisa Marchitelli, gives you a sense of Chiang Mai smoke from February through March: