Thailand –Officials are using a new technique to boost air humidity as dry weather has put the brakes on attempts to make artificial rain to ease the choking haze in northern provinces.
The technique involves the use of the “formula 3” chemical which is used in the cloud-seeding process to build up moisture and small drops of water, which is preferable to making artificial rain, said Song Klinprathum, chief of the Royal Rainmaking and Agricultural Aviation’s operation centre in the upper North yesterday.
His centre is also planning to follow the King’s advice to have a plane fly and sprinkle more concentrated chemicals to enhance rain-making efforts.
Artificial rain is one of the ways to reduce haze, which has put northern residents at risk of respiratory problems, but little has been made over the past three days because, according to rain-making expert Kitti Thupsi, the humidity level has been as low as 40%.
The air quality in many northern provinces has been a grave concern as levels of particulate matter (PM10), or fine dust less than 10 micrometres in diameter, are still above the safety limit of 120 microgrammes per cubic metre.
Chiang Mai, which has enjoyed improved air quality only for a few days, suffered dangerous levels of PM10 again yesterday with a record 200.72 ug/cu m at the Chiang Mai provincial hall, the Pollution Control Department said.
Banpot Khanthasen, director of the natural resources and environment office in Chiang Mai, said there were a total of 1,007 PM10 hotspots in Chiang Mai between Jan 1 and Feb 28, a sharp rise from the same period last year during which only 159 hot spots were found.
He attributed the rising number of hotspots, where forest fires and farmland burn off have taken place, to the prolonged dry spell.
Chiang Rai was still top for the worst air quality with up to 305.6 ug/cu m of PM10 measured in front of a public health office in Mae Sai district yesterday.
The PM10 levels elsewhere are 243.13 ug/cu m in Phayao’s Kwan Phayao learning centre, 202 ug/cu m in Phrae, 168.88 ug/cu m in Mae Hong Son, 165.25 ug/cu m in Nan municipality and 136.04 ug/ cu m in Lamphun.