Ms. Preeyaporn Suwanaged, Director General of the Pollution Control Department (PCD), revealed that PM_2.5 can be caused by various things depended on activities in each area. For Bangkok, its vicinity and major cities, the main cause of PM_2.5 emissions is heavy traffic and congestion. The study of pollution emissions from various sources in Bangkok and its vicinity, it was found that PM_2.5 came from road transport sector at 51%, industrial sector at 21%, households at 10%, open burning at 6%, and others at 12%. The majority of PM_2.5 emissions from road transport sector came from trucks and pickup trucks, which emit up to 44%. In addition, vehicles with more than 20 years old were the group of the highest PM_2.5 emission rate because there is no technology to control or reduce the amount of particulate matter. According to the vehicle registration statistics of the Department of Land Transport, diesel vehicles are the highest proportion of vehicles that have been used for more than 20 years.

Ms. Preeyaporn said that to prevent and solve the PM_2.5 problem in large cities, the measure of annual vehicle inspections for diesel vehicles that are used over 20 years should be increased from once a year to twice a year or every 6 months. Thus, this vehicle should be more treated and kept maintenance in order to prevent, control, and reduce PM_2.5 that affects overall air quality.

To have prudent and complete information, PCD would like to invite the public to comment and share opinions on increasing frequency of annual vehicle inspections for diesel vehicles that are used over 20 years to be twice a year. This condition will be used in considering measures to prevent and solve PM_2.5 problem from used vehicles. For more information, please visit https://forms.gle/Dz7pToCKmEA5gqM27 and contact 02-2982280 from now until July 2, 2024, Ms. Preeyaporn said.