PETALING JAYA: Inhalable fine particles can penetrate deep into the body and trigger health problems, even when haze levels remain moderate under the Air Pollutant Index (API) system, experts warn.
Public health medicine specialist Datuk Dr Zainal Ariffin Omar said the main health concern was exposure to fine particulate matter such as PM2.5 and PM10, which can penetrate deep into the lungs, and in some cases, enter the bloodstream.
A PM2.5 particle measures 2.5 micrometres (microns) or less in diameter, or about 30 times thinner than a single strand of human hair.
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“This exposure can trigger short-term issues such as eye and throat irritation, coughing and breathing difficulties.
“Children, the elderly, pregnant women and those with existing conditions such as asthma, heart disease and diabetes are particularly vulnerable,” he said.
“Even when API readings remain in the moderate range of 51 to 100, some people could experience symptoms,” he added.
Those who are unusually sensitive should consider limiting prolonged or strenuous outdoor activity, particularly if they experience watery eyes, a runny nose, sneezing, sore throat, persistent coughing, chest tightness or shortness of breath.
“If the API exceeds 100, high-risk groups should avoid prolonged outdoor exertion, while others should limit such activities,” he said, adding that everyone should cease all outdoor activities when readings hit 200 or more.
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“Those who need to be outdoors could consider wearing a properly-fitted N95 respirator, as surgical masks offered less protection against fine particles,” he said.
Other measures include keeping windows and doors closed, using air-conditioning with good filtration or air purifiers, and staying hydrated.
Public healthcare specialist Prof Dr Sharifa Ezat Wan Puteh of Universiti Kebangsaan Malaysia said Malaysians should limit heavy physical activity and outdoor exercise once the API exceeds 100.
“Prolonged exposure to haze could worsen chronic heart and lung conditions, while fine particles could increase the risk of cardiovascular problems, stroke, reduced lung function and inflammation,” she said.
She added that Malaysia was better prepared than during major haze episodes such as those in 1997-98 and 2015, with improved air-quality monitoring, environmental controls and public health guidance.
The 1997 haze crisis saw Sarawak declare an emergency after API readings exceeded 500, while in 2015, 34 locations recorded unhealthy air quality and schools were closed in five states.
However, Dr Sharifa said gaps remained, particularly in controlling illegal burning and pollution from smaller businesses and other local sources.
At the regional level, the Asean Agreement on Transboundary Haze Pollution, which came into force in 2003, provides a framework for cooperation between affected countries.
“Local implementation of air quality and environmental controls still needs to be strengthened,” she said.
