By Pratch Rujivanarom
Bangkok’s skyline was again obscured by dangerous harmful smog on Wednesday, even as the Royal Rainmaking and Agricultural Aviation Department was carrying out a special mission to address air pollution this week, with levels of particulate matter smaller than 2.5 microns (PM2.5) rising.
The Bangkok’s hourly real-time Air Quality Index (AQI), which is based on US Environmental Protection Agency standards, showed PM2.5 level in Bangkok had reached the level of 156 micrograms per cubic metre of air, posing health hazards for the public, particularly for vulnerable groups such as children, the elderly and sick people.
Meanwhile, the Pollution Control Department (PCD) also disclosed that PM2.5 daily average measurements at every Bangkok air quality monitoring station surpassed both Thailand’s safe standard of 50mg and the WHO’s safe limit of 25mg.
As of Wednesday afternoon, the highest recorded PM2.5 daily average level was in Thonburi district at 96.72mg, higher than Tuesday’s peak of 55.45mg. Levels at the other stations were 71.59mg in Wang Thonglang district, 67.27mg in Pathumwan district and 68.32 in Bang Na.
The director of the Central Region Royal Rainmaking Operation Centre, Rattakorn Warunsukkhasiri, said the rainmaking operation, which began on Monday, had failed due to the unfavourable weather conditions, as the moisture in the air was not high enough for rain clouds to form.
“The cold air from the North is stronger this week, making the humidity reduce to only 30 to 40 per cent and it is impossible to make rain in such weather conditions,” Rattakorn said.
“We have to wait until next week when the cold front will be weakening, so we can try the rainmaking mission again.”
The Meteorological Department also warned that cold air from a high pressure area in the North, which exacerbates air pollution in Bangkok, will last at least until Saturday, but it was predicted that an eastern wind would bring moisture and rain to many parts of Thailand next week.