Air quality in four districts of Lampang, Phrae and Tak has worsened on Wednesday (March 7), with the amount of PM10 particulate matter beyond the standard level of 120 microgramme/cubic metre, the Pollution Control Department (PCD) reported.
The air quality in Chiang Mai's Muang district is not any better either, with the amount of PM10 particulate matter measured on Tuesday at 129 g/cu m and, besides, PM2.5 particulate matter has been present in some spots in the Muang district since early February.
In Lampang, air quality in Muang and Mae Mo districts on Wednesday was measured at 167 g/cu m and 218 g/cu m respectively mainly due to 135 hot spots found in Mae Mo districts whereas the air quality in Muang district of Phrae and Mae Sot district of Tak were measured at 130 g/cu m and 144 g/cu m respectively.
But Lampang ranks top as the province with the highest amount of PM10 beyond the standard level of 120 g/cu m for the northern region.
Smog remains another problem during the dry season although the smog condition has not yet affected aviation activities, said the department.
Meanwhile, Somporn Chanthara, chief of Environment Science Research Centre at Chiang Mai University, urged the PCD to speed up the installation of more monitoring devices to measure the fine particulate matter smaller than 2.5 microns, or PM2.5.
Moreover, the PCD should include PM2.5 in calculation of air quality index to make the calculation more precise, she said.
At the moment, PM10 is the only fine particulate matter used in the PCD's calculation of air quality index, she said.
Source: Thai Public Broadcasting Service (ThaiPBS)