Thailand — Chai Prakan and Phrao districts of Chiang Mai have been declaredhaze disaster areas and airlines have cancelled most flights because thick smokefrom forest fires and traditional slash-and-burn farming has shrouded northernprovinces and raised fears of increasing levels of harmful dust.
Chiang Mai, along with nearby Chiang Rai, Lampang and Mae Hong Son provinces,has been encountering heavy haze. The smoke also comes from bush fires in theBurmese town of Tachilek opposite Mae Sai district of Chiang Rai, officials said.
“The thick smoke is seen all over the sky,” said Chai Prakan districtchief Chokedee Amornwat.
The disaster zone announcement follows bad weather conditions caused by the hazefor the past two weeks.
The smoke has hindered the visibility of airplane pilots and caused flightdelays and cancellations.
Poor visibility has also blocked an effort to make artificial rain aimed atreducing the amount of dust, which is posing serious health risks to people.
The dust particles, technically called particulate matter (PM-10), have adiameter of not more than 10 microns, around one-seventh the width of a humanhair. The tiny size allows them to easily lodge in lungs and cause respiratoryproblems.
To reduce their exposure to the harmful dust, the Public Health Ministry hasdistributed 130,000 masks to people in eight northern provinces – Chiang Mai,Chiang Rai, Mae Hong Son, Lampang, Lamphun, Phrae, Nan and Phayao.
“The ministry has also given out leaflets telling people how to take careof their health in the face of thick smoke from burning activities,” saidpermanent secretary for public health Prat Boonyawongvirote.
Yesterday, the level of PM-10 dust in Chiang Mai and Lampang was found to bebeyond an acceptable standard. It was measured at 250.9 microgrammes per cubicmetre in Chiang Mai and 154.8 in Lampang, against a health standard of 120 ug/cum, according to the Pollution Control Department.
Chalermsak Vanitsombat, chief of the Natural Park, Wildlife and PlantConservation Department, said forest fires were not only to blame for the airpollution.
“The haze largely comes from weed-burning in farms,” said MrChalermsak, who supervises forest fire control operations.
Mr Chalermsak said his department has no power to stop the farmers and couldonly ask for their cooperation in stopping the burning.
The high price of maize has driven some farmers to encroach on forest and setfire to it to clear land for farming.
Mr Chalermsak said this was a “main cause of thick smoke” in ChiangMai. This has intensified air pollution in the province, where householdbonfires are also common.
The level of humidity in the air is also less than that of last year, causingmore severe fires this year, according to the department.
Officials yesterday started making artificial rain in Chiang Mai. The missionaims to increase humidity in the forest, thus reducing the chance of forestfires.
Meanwhile, Thai Airways International (THAI) cancelled flights between ChiangMai and Mae Hong Son for the second day yesterday due to poor weather conditions.However, Weerapong Kranlert, THAI manager for Chiang Mai airport, said it wascommon practice to do so due to haze in the dry season and mist in the coldseason.
The thick smoke has also caused flight delays between Bangkok and Chiang Rai,but there have been no reports of flight cancellations on this route.
In Chiang Rai, 700 officials and volunteers have been ordered to be on alert forforest fires in areas near the border with Burma. Farmers are also prohibitedfrom burning farm residues. Violators will be fined 2,000 baht, according to theEnvironmental Quality Act.