Singapore studies rising lung cancer among never-smokers as PM2.5 questions grow.
Singapore is examining an emerging lung cancer trend that challenges its traditional association with smoking, while health authorities caution that the impact of periodic haze cannot yet be established.
Lung Cancer Rising Among Never-Smokers
Health Minister Ong Ye Kung said a 2026 modelling study based on Singapore data indicates increasing lung cancer incidence among both male and female never-smokers. He provided the update in response to a parliamentary question from Bishan-Toa Payoh GRC MP Cai Yinzhou, who asked about trends over the past decade and whether long-term PM2.5 exposure could be contributing to the increase.
Lung Cancer Remains Major Killer
Singapore Cancer Registry data covering 2017 to 2021 showed that lung cancer caused about 100 deaths each month, according to AsiaOne. The report also cited the National Cancer Centre Singapore as saying that smoking accounts for roughly half of lung cancer cases, while the other half occur among non-smokers. A separate NCCS study found that 90% of female lung cancer patients were never-smokers, with possible risk factors including secondhand smoke, environmental pollutants, and genetic susceptibility.
PM2.5 Linked to Higher Risk Internationally
Ong said international studies have found an association between long-term exposure to PM2.5 and increased lung cancer risk. PM2.5 consists of very fine airborne particles capable of entering the lungs and bloodstream and is a major pollutant during haze episodes. However, the minister emphasized that the international evidence generally concerns prolonged exposure rather than Singapore’s periodic haze conditions.
Haze Effect Cannot Yet Be Determined
Singapore’s Ministry of Health said the effect of periodic haze exposure on local lung cancer incidence can only be determined when studies establish how environmental factors correlate with disease prevalence. Ong also noted that environmental exposure depends on factors such as where individuals spend their time and what protective measures they take, meaning residential air quality alone cannot capture a person’s full exposure.
Smoking Remains Top Risk Factor
Despite the rising incidence among never-smokers, MOH stressed that smoking remains the leading risk factor for lung cancer. Ong said overall cancer risk can also be reduced through measures including smoking cessation, limiting alcohol consumption, and maintaining a healthy diet. The ministry’s response therefore stops short of attributing Singapore’s increasing never-smoker lung cancer trend to PM2.5 or transboundary haze.
For Singaporeans, the findings highlight an emerging lung cancer trend that requires further research into environmental and other non-smoking risk factors. For Indonesians, the discussion is relevant because transboundary haze was specifically raised as a possible exposure source, although Singapore’s health authorities say current evidence is not sufficient to establish that periodic haze is causing the observed increase.
Sources: Asia One (2026) , MOH GOV SG (2026)
Keywords: Singapore Lung Cancer, Never Smokers Lung Cancer, PM2.5 Exposure, Singapore Haze, Ong Ye Kung, Cancer Risk
