Patient numbers at Maharaj Nakhon Chiang Mai Hospital have risen to 1.5 times their normal level as the city’s prolonged air pollution crisis takes its toll, with doctors warning of both immediate and long-term health consequences.
Professor Dr. Arintaya Phrommintikul, director of Maharaj Nakhon Chiang Mai Hospital, confirmed that PM2.5 levels exceeding safety standards are having a measurable impact on public health. Short-term effects include nosebleeds, allergic reactions, nasal irritation, eye inflammation and respiratory problems, with the hospital recording a 1.5-fold increase in patients presenting with these conditions during periods of elevated pollution. Over the longer term, sustained exposure to fine particulate matter can trigger flare-ups of chronic conditions including stroke, coronary artery disease and emphysema, while particles that accumulate in the body may raise cancer risk.
She noted, however, that no research has yet confirmed a direct causal link between the anir pollution and overall patient numbers.
Chiang Mai’s provincial public health officer, Dr. Waranyu Jamnongprasatporn, said surveillance data from this year tells a more nuanced story. Despite the severity of the crisis, recorded cases of chronic obstructive pulmonary disease (COPD) flare-ups stand at 2,181, down 21.3% compared to the three-year median for the same period. Asthma cases number 2,374, a 14.8% decrease, while nosebleed cases total 177, down 39.8%.
Officials attribute the drop partly to protective measures taken among at-risk groups, including mask-wearing, use of clean-air rooms and dust-filtering mosquito nets. A further factor is that this year’s PM2.5 spike arrived later than in previous years. Research from Chiang Mai University’s Faculty of Medicine has found that health impacts typically lag deteriorating air quality by around one week, meaning authorities are continuing to monitor trends closely in the days ahead.
Longer-term conditions are also being tracked. Cumulative cardiovascular and cerebrovascular cases stand at 29,139 — down 19.8% on the three-year comparable period.
The provincial health office has distributed 195,800 masks to patients and vulnerable groups, opened 507 clean-air rooms across hospitals and health centres throughout the province, and established pollution clinics staffed by specialists at five hospitals: Nakornping, Fang, San Sai, San Pa Tong and Chom Thong.
