VIENTIANE, March 24 (Xinhua) -- Lao Ministry of Natural Resources and Environment has issued a notice warning residents across the country to stay vigilant against air pollution.
According to the notice issued on Thursday, the pollution had reached dangerous levels in Luang Prabang, Oudomxay, Luang Namtha, Bokeo, Lao capital Vientiane, Khammuan and Savannakhet provinces.
The notice stated that stubble burning and wildfires are causing dangerous levels of air pollution in many regions of Laos, especially in northern Laos' Luang Prabang province.
The concentration of fine dust, known as PM 2.5, which is particulate matter with a diameter of less than 2.5 micrometers, surpasses the safety level.
Data registered on Friday morning showed Luang Prabang's air quality index had reached an unhealthy level, with the PM 2.5 concentration in the city hitting 209 micrograms per cubic meter.
In mid-February, Luang Prabang's authorities reported a landfill fire, causing clouds of smoke in the city of Luang Prabang, some 220 km north of the Lao capital Vientiane, and nearby areas.
The Ministry of Natural Resources and Environment suggested residents in areas affected by air pollution limit outdoor activities and wear a mask outdoors.
Burning all forms of waste during the dry season is strictly prohibited as this contributes to air pollution, according to the notice.
PM 2.5 can lodge in the lungs and enter blood vessels, leading to respiratory and cardiovascular disease.