Toxic dust levels above safe limits persisted in the North, the Northeast, Bangkok and surrounding provinces on Thursday, adding to already severe health risks caused by air pollution.
The Ministry of Public Health said that nearly 200,000 people have been admitted to hospitals across the country with pollution-related respiratory problems in the past week.
More than 1.3 million people have fallen sick in the kingdom since the start of the year as a result of air pollution, AFP quoted a ministry official as saying.
Kriangkrai Namthaisong, a doctor at the ministry, urged children and pregnant women to stay indoors.
Anyone going outside should wear a high-quality N95 anti-pollution mask, he added.
Levels of particulate matter 2.5 micrometres or less in diameter (PM2.5) increased in all areas of 17 northern provinces on Thursday morning, according to Pinsak Surasawadi, director-general of the Pollution Control Department (PCD), in his capacity as chairman of the Centre for Air Pollution Mitigation.
In northern Thailand, 17 areas were classified in the orange zone, reflecting levels starting to affect health, and 15 areas in the red zone of serious health impacts. Any PM2.5 concentration exceeding 50 microgrammes per cubic metre (µg/m3) is considered unsafe.
PM2.5 levels ranged between 91 and 136 µg/m3 in Chiang Mai, Chiang Rai, Lamphun, Mae Hong Son, Nan, Tak, Sukhothai, Phitsanulok, Kamphaeng Phet and Uthai Thani, with the highest dust levels in tambon Thani of Muang district in Sukhothai, said Mr Pinsak.
He blamed burning of agricultural waste and sugarcane plantations, coupled with weak winds and poor ventilation, for accumulated dust.
He urged residents to refrain from burning their agricultural waste before the dust situation eased. The smog is expected to cover the upper and lower North until March 14.
PM2.5 levels in many areas in the Northeast still exceeded safe levels. Eleven areas were in the orange zone, while four areas were in the red zone. In Loei, Nong Khai, Nakhon Phanom and Bueng Kan, dust levels were reported at 94-124 µg/m3.
In Bangkok and surrounding provinces, the air quality was at moderate to health risk levels. PM2.5 levels fell slightly in some areas.
Eighty-eight areas were in the orange zone while one area on Kanchanaphisek Road in Bang Khun Thian district was in the red zone, at 109 µg/m3.
The dust situation in Greater Bangkok is expected to improve after Saturday as wind from the South will blow away dust, said the PCD chief.
However, people should take extra caution from March 14-16, as they will be affected by dust that passes over the areas.
People are advised to keep abreast of the air quality via Air4Thai app, said the PCD chief.
Thailand air quality map - IQAir
In the northeastern province of Nakhon Phanom, PM2.5 dust levels were over the safe threshold in four districts on Thursday despite winds blowing away dust above the Mekong River.
Over the past two days, Muang, Ban Phaeng, Tha Uthen and That Phanom districts of Nakhon Phanom were blanketed in smog, with harmful levels of PM2.5 dust measured between 180 and 200 µg/m3.
Burning of agricultural waste along the border, coupled with the hot weather, caused toxic smog to cover the four districts. Although strong winds helped blow away dust in these areas in the morning, PM2.5 levels remained in an unsafe range between 80 and 100 µg/m3.
Authorities advised people to wear masks outdoors and avoid outdoor activities, as they would be at risk of respiratory diseases.
Smog blankets Nakhon Phanom province on Thursday morning despite strong winds that blew away dust particles. (Photo: Pattanapong Sripiachai)
An LUF 60 firefighting robot has been sent to Phetchabun province to help reduce toxic dust levels. (Photo: Sunthorn Kongvarakhom)
In Phetchabun, ultrafine dust levels in many areas in this mountainous tourist province still exceeded the safety level.
According to the PCD’s Air4Thai.com, the PM2.5 level in Muang district of Phetchabun was measured at 88 µg/m3, as of 9am on Thursday.
On the same day, AirVisual app reported the PM2.5 dust level at 161 µg/m3 in Muang district, as of 8am.
Deputy Phetchabun governor Chatchawan Benjarisiwong said provincial authorities have sought for fire extinguisher robot LUF 60 devices from the Disaster Prevention and Mitigation to spray water to reduce dust in the province.
Three LUF 60 devices were expected to be sent to the province, said Mr Chatchawan.
Now, the department has sent one device to spray water to reduce dust in the province, particularly in economic and tourism zones in Muang, Lom Sak, Wichian Buri and Khao Kho districts.