Lung cancer, PM2.5 deaths surge in the North

>> CHIANG MAI: People in northern Thailand, particularly in Chiang Mai and Lampang, face high mortality rates due to lung cancer. The Faculty of Medicine at Chiang Mai University has identified elevated levels of PM2.5 particles in the air as being one of the leading causes.

Assoc Prof Chalerm Liewsisakul from Chiang Mai University’s (CMU) Faculty of Medicine said PM2.5 pollution in the northern region has worsened over the past decade, leading to a surge in patients suffering from lung diseases.

One study shows the ratio of people who died of lung cancer per 100,000 people in the North increased from 20.3 in 2010 to 30.7 in 2019. That compares with figures for Bangkok of 14.9 in 2010 to 22.6 in 2019; the Northeast, 10.2 in 2010 to 17 in 2019; and the South, 9.5 in 2010 to 16.8 in 2019.

Comparative data from 2010 to 2021 shows the northern provinces, especially Chiang Mai and Lampang, have the highest death rates from lung cancer. This highlights the urgent need for targeted interventions to address air pollution and its health consequences in these areas, he said.

“In addition, the incidence of lung cancer among young individuals in the northern region surpasses that of other areas. This correlation is likely attributed to PM2.5 pollution, a link supported by global research indicating the heightened cancer risk, particularly lung cancer, associated with prolonged exposure to PM2.5 particles,” he said.

He referred to a study by the Faculty of Medicine focusing on emphysema patients in Chiang Dao, an area notorious for elevated PM2.5 levels. Through cell analysis obtained from cheek scrapings of emphysema patients, the research showed significant cellular changes during periods of high PM2.5 compared to low PM2.5 periods. These alterations suggest genetic abnormalities that could lead to cancer cells in the future, he said.

Additionally, a surge in respiratory ailments, ranging from nosebleeds to persistent coughs, has been observed during periods of heightened PM2.5 levels, particularly in March. Severe conditions such as emphysema exacerbations, coronary heart disease, and strokes are notably prevalent during these pollution peaks, emphasising the acute health risks associated with elevated PM2.5.

According to research by CMU’s Faculty of Medicine, analysing deaths in Chiang Mai in relation to PM2.5 levels revealed a concerning correlation: for every 10 microgrammes per cubic metre (μg/m³) increase in daily average PM2.5 concentration, there is a corresponding 1.6% rise in Chiang Mai’s mortality rate over the subsequent six days.

The faculty’s lab also found the cause of the death of Prof Rawiwan Olarnratmanee, a former dean of Chiang Mai University’s Faculty of Architecture. Test results indicated the cancer cells found in her lungs bore genetic mutations attributable to PM2.5 exposure. Her husband, Jittrakorn Olarnratmanee, said she had been diagnosed with late-stage lung cancer in February, succumbing to the illness on April 3. She was one of four lecturers at the university who have died of lung cancer since 2022.

Maharaj Nakorn Chiang Mai Hospital said 30,339 patients had sought treatment for pollution-linked diseases from Jan 1-March 15, twice the number for the same time last year.

IQAir.com yesterday reported the province had returned to its place at the top of cities in the world with the worst air quality, with the Air Quality Index (AQI) hitting 237 at 8.52am.