Researcher, CMU Informed Knowledge of Smog Crisis

1 February 2019

Corporate Communication and Alumni Relations Center (CCARC)

In duration of February – March every year, upper northern Thailand always confront with situation of smoke haze due to open burning including forest fires, which caused high air pollutant concentration over standard of ambient air quality, this could cause serious health impacts in long term.

Assistant Professor Dr. Somporn Chantara, Head of Environmental Science Research Center, Faculty of Science, Chiang Mai University mentioned that problem of smoke haze in upper Northern Thailand is caused from 3 main factors those consist of geography of the area, which is a basin surrounded by mountain ranges. The second factor is meteorological conditions since there is calm wind, and high air pressure causing low vertical distribution and air ventilation, therefore air pollutants are trapped in the basin. The main factor is the major source of air pollution in this area, which is open burning.

Biomass burning is a significant source of particulate matters (PM) emission. This activity usually peaks in the dry season, which includes both forest fires and open burning of crop residues for preparation of planting areas. However, vehicle combustion (traffic emission) is the main source of air pollutants in the city. The emission from transportation section is quite constant for the whole year, but open burning is intense in dry season and causes severe air pollution in the area.

Air pollution particularly PM of either, open burning or traffic emission, is a significant worldwide environmental issue and well known to cause harmful effects on human health and environment. PM2.5 (particulate matter with an aerodynamic diameter less than or equal to 2.5 ?m) as well as sub-micron PM are small and cannot be seen by naked eyes.

These fine PMs can penetrate into our respiratory system and cannot be trapped by human protecting system. The smaller sizes of PM can penetrate deeper into lung and blood stream and can be harmful to our health.

PM chemical composition includes carcinogenic compounds. Polycyclic aromatic hydrocarbons (PAHs) are a group of compounds generated from incomplete combustion including biomass burning. They are found as a component of ambient PMs and their concentrations are well correlated meaning that high amount of PM in the air trends to have high amount of carcinogenic-PAHs.

The approach of problem solving of air pollution can be divided in 2 periods; short term and long term. The short term is the self-protection for public. People in the area with bad air quality should wear a mask (N95) for protecting fine PM2.5 particularly when doing outdoor activities. Outdoor exercise must be avoiding during a period of smoke haze with high concentration of air pollutants. Long term problem solution could be planned. The examples are increasing green areas by planting more trees in the city, which can increase humidity and reducing pollution through plant absorption. Applying clean energy and clean technology in transportation, industrial and community sectors to reduce pollutant emission. Providing good public transportation and reducing open burning in both agricultural sector and forest area. Every sector has to collaborate in order to solve problem in long period with sustainably.

Environmental Science Research Center, Faculty of Science, Chiang Mai University is now running a project “Monitoring of Air Quality and Smoke Haze Situation in Upper Northern Thailand for Assessment of Health and Environmental Impacts” funded by Thailand Research Fund (TRF). This project aims to collect ultrafine PM and PM2.5 and analyse their chemical compositions from two major sources (traffic and biomass burning) for health risk assessment and to set up the Smoke Haze Integrated Research Unit to provide information, knowledge and run youth activities concerning smoke haze problem and air quality management. Four sampling stations are selected to represent traffic emission (cities of Chiang Mai and Lampang) and open burning activities (Chiang Dao, Chiang Mai Province and Mae Sarieng District, Mae Hong Son Province). PM2.5 and submicron or ultrafine PM are collected in order to analyze their chemical composition to find out chemical tracers or signatures in relation to emission sources. Moreover, carcinogenic-PAHs will also be analyzed for health risk assessment. The researchers expected that this research project will benefit the local organizations and raise public awareness. Providing information for future problem solving or at least reduce the degree of air pollution in this area in the near future.