Mr. Pinsak Suraswadi, Director General of Pollution Control Department (PCD), revealed that it was found that situation of particulate matter with diameter of less than 2.5 microns (PM_2.5) that affects many areas in the northeastern has been accumulated in a high level in some duration of the year. Nong Khai Municipality, a medium-sized city located along the Mekong River should not be accumulated frequently with high PM_2.5. But in the past, high level of PM_2.5 levels had been found frequently and sometimes was higher than neighbouring big cities.

Mr. Pinsak said that PCD cooperated with Suranaree University of Technology with the budget supported from the National Research Office to implement the project namely, “The chemical composition of PM_2.5 in identifying main sources in Nong Khai Municipality”. The objectives of the project were (1) to analyze main chemical composition of PM_2.5 in Nong Khai Municipality area, (2) to assess the proportion of main sources of PM_2.5 in Nong Khai Municipality area and (3) to find factors affecting PM_2.5 accumulation in Nong Khai Municipality area.

Studies were conducted by analysing the characteristics of chemical composition and proportions of main sources of PM_2.5, together with meteorological data, back trajectory data, using satellite images to show hot spots in the area nearby and neighbouring countries and using Positive Matrix Factorization (PMF) model to analyse. The results from the study showed important data that indicated chemical composition, proportion of important sources and factors affecting the accumulation of PM_2.5 in Nong Khai Municipality area. In addition, the exchange of opinions and suggestions on the results of the study between various agencies can lead to solve PM_2.5 problems in Nong Khai Municipality and extend the results to apply in other provinces in the region with similar characteristics, Mr. Pinsak said.