PETALING JAYA: Long-term exposure to haze could raise the risk of serious health problems, including lung cancer, cardiovascular disease and poor lung development in children, health experts warned.
Dr John Chan Kok Meng, consultant cardiothoracic surgeon at CVSKL Hospital, said numerous studies had found a strong association between prolonged exposure to fine particles in polluted air, particularly PM2.5 and PM10, and lung cancer.
“The risk of lung cancer increases with prolonged exposure to these pollutants. Studies in Europe and the UK have also found an association between exposure to polluted air and poorer lung growth in children,” he said.
“This could affect their lung health later in life as they reach adulthood and beyond. It is probably best to avoid outdoor activities on days when air quality is recorded as poor or very poor,” he added.
Public health expert Prof Dr Sharifa Ezat Wan Puteh of Universiti Kebangsaan Malaysia said there was evidence linking long-term haze exposure to cardiovascular diseases such as atherosclerosis, coronary artery disease and ischaemic stroke.
“Persistent haze elevates inflammatory proteins and markers in the blood, such as C-reactive protein (CRP), IL-6 and T -alpha. Chronic inflammation and oxidative stress may also contribute to lung carcinogenesis, even among non-smokers,” she said.
She said long-term exposure could cause progressive airway inflammation, reduced lung function, chronic bronchitis, chronic obstructive pulmonary disease, worsening asthma and higher rates of respiratory infections.
“The risk increases by 5% to 30%, depending on the pollutant concentration and duration of exposure,” she said.
She added that human and animal studies had also found a biologically plausible association between air pollution and an increased risk of spontaneous abortion through inflammatory, oxidative and vascular mechanisms.
“Pregnant individuals are particularly susceptible. Reduced placental vascularisation may contribute to adverse pregnancy outcomes, so preventive measures such as minimising exposure are recommended,” she said.
On precautionary measures, Sharifa Ezat said the ultimate solution was to reduce sources of open burning, while cloud seeding could be considered to promote rainfall.
She said schools should be closed and outdoor activities limited at high-risk locations when the Air Pollutant Index (API) reached 100 or above.
According to the Health Ministry’s haze advisory for workplaces, long-term exposure to fine particles could contribute to diabetes, spontaneous abortion, underweight infants, birth defects and infant deaths.
It also increases the risk of cardiovascular-related deaths and could reduce life expectancy by several months to a few years.
The advisory said haze particles could accelerate the thickening of arteries and promote the development of vascular diseases.
“A large number of particles in haze are below 2.5 micrometres in diameter. These ultra-small particles remain in the air longer and can be carried over long distances, increasing the chances of being inhaled by animals and humans,” the ministry said.
