The Bangkok Metropolitan Administration's (BMA) Health Department on Monday released a report indicating that nearly 40,000 people in the city's two main districts have sought medical treatment for respiratory illnesses at its hospitals since September last year.

Furthermore, the BMA's Environment Department also reported on Monday the unsafe levels of particulate matters in the two districts, and have urged residents to wear a mask outdoors.

"Bangkok's two main districts, Phra Nakhon and Wang Thonglang, have indicated its PM2.5 at 31-54mg per cubic meter of air in the past 24 hours while the safe threshold is at 50mcg," the BMA Environment Department said.

"PM2.5 was at 54mcg at Phra Nakhon district and 52mcg at Wang Thonglang district."

Meanwhile, BMA permanent secretary Silapasuay Raweesaengsoon said the BMA ordered its Taksin Hospital, Charoenkrung Pracharak Hospital and Klang Hospital to open their air pollution clinics to treat people.

From Sept. 27 last year to Jan. 9 this year, 38,803 people sought treatment for illnesses related to smog at hospitals under the supervision of the BMA, the BMA Health Department said.