Bangkok’s NOx level is in normal range in the past five years, says Pollution Control Department
Atthaphol Charoenchansa, director-general of Pollution Control Department (PCD), said on Friday that the air quality level in Bangkok is in a normal range in the past five years, with the level of Nitrogen Oxide (NOx) at below international standard.
He said in response to Pongprom Yamarat, deputy leader of KLA Party, who posted on facebook earlier that NOx gas in the air of Bangkok and surrounding areas is in critical level. Pongprom also pointed out that the causes for this problem are the use of Euro 1-3 fuel that have been banned globally except for in Thailand, and the lack of rigid legal actions against vehicles and factories emitting black smokes and other pollutions.
“NOx is a pollution gas caused by the combustion of fossil fuel,” said Atthaphol. “The safety standard for NOx level in the air must not exceed 170 parts per billion (ppb) for averaging period of one hour, and not exceed 30 ppb for averaging period of one year.”
“The department’s air quality testing result in Bangkok in the past five years revealed that the level of NOx gas has always been within the safety standard, except for a brief period in 2019 when the air pollution level on Din Daeng Road has exceeded the safety limit for two hours,” he added. “Air quality testing result from January to October 2021 recorded only 122 ppb of NOx in one hour average and 16 ppb for one year average.”
“The PCD has been promoting the use of high-quality fuels to reduce the level of emission. Currently most of the fuels used in Thailand are equivalent to Euro 4 standard, which has sulfur less than 50 ppm (parts per million),” said Atthaphol. “We are planning to upgrade to Euro 5 standard fuels that has sulfur less than 10 ppm by January 2024.”
Atthaphol further added that Thailand is enforcing Euro 4 standard in small vehicles and Euro 3 standard in large vehicles, and is planning to enforce Euro 5 standard in all types of vehicles by January 2024, which will help reduce NOx emission by 60 per cent in large diesel vehicles and by 28 per cent in small diesel vehicles.
“As for black smoke and industrial emissions, the PCD has updated the black smoke emission standard for diesel vehicles from 45 per cent to 30 per cent, as well as increasing the limit on sulfur dioxide and NOx emission among large factories,” he added. “These new regulations should be announced in the Royal Gazette by mid 2022.”