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What are the key air pollutants of concern?

The key air pollutant of concern during the haze period is particulate matter (PM). Short term exposure (i.e. continuous exposure to unhealthy daily average Pollutant Standards Index (PSI) levels over a period of a few days) to these air pollutants can cause respiratory symptoms and aggravate existing heart or lung disease.

Exposure to particulate matter may also cause irritation of the eyes, nose and throat in healthy individuals.

What is the short-term effect of the haze on my health?

Among healthy individuals, short term exposure (i.e. continuous exposure to unhealthy daily average PSI levels over a period of a few days) to high levels of haze particles may cause irritation of the eyes, nose, and throat in healthy individuals. Such irritation resolves on its own in most cases.

Haze particles can sometimes affect the heart and lungs, especially in people who already have chronic heart or lung disease e.g. asthma, chronic obstructive pulmonary disease (COPD), or heart failure.

There may be up to one to three days of time between exposure to haze and health effects/ symptoms.

What are the long-term effects of the haze?

Singapore is not affected by the haze throughout the year. Any exposure is short-term in nature (i.e. continuous exposure to unhealthy daily average PSI levels over a period of a few days) and such exposure may vary from year to year. As international studies are based on long term exposure to air pollution, there is little robust data on the longer-term effects of episodic short-term exposures to haze like the pattern seen in Singapore.

Studies have shown that persons living overseas with continuous exposure over several years to high ambient pollution from fine particles (i.e. particulate matter 2.5 (PM2.5); particles smaller than 2.5 micrometres), may have a higher risk of (i) cardiovascular effects, such as heart attacks, (ii) reduced lung development, as well as (iii) the development of chronic respiratory diseases, such as asthma, in children.

How is the air quality forecasted? Why is the health advisory based on 24-hour PSI forecast?

During haze episodes, the National Environment Agency (NEA) will provide an air quality forecast for the next 24 hours. NEA will look at all relevant factors, including weather conditions, in determining this forward projection.

Which groups of people are more sensitive to haze?

In general, children, elderly, and people with chronic lung disease or heart disease are more sensitive to the health effects of haze, and should adopt the preventive measures in the MOH health advisory when air quality is poor. Individuals are advised to consult their doctor should they develop breathing difficulties. In addition, it is advised that pregnant women reduce exposure to haze for the health of their unborn baby.

What is MOH’s advice to the public?

The public is recommended to adhere to the MOH haze health advisory. In most cases, it is still safe to carry on with outdoor activities. However, do drink plenty of water to stay well hydrated.  Individuals with existing chronic heart and lung conditions should ensure that your medications are on hand and readily available.

Individuals with existing chronic heart and lung conditions should ensure that your medications are on hand and readily available.

Each individual’s reaction to pollutants may vary, and the amount of physical activity or exertion that can be performed differs according to your health status or physical capacity. Should you encounter symptoms or discomfort, please take additional measures to prevent further exposure.

Although the general advice to the public when the forecasted air quality is good or moderate (PSI≤100) is to maintain normal activities, vulnerable persons, especially those with chronic heart and lung conditions who develop symptoms or feel unwell, should seek medical attention promptly.

MOH Health Advisory For The General Public


How will the haze impact patients in nursing homes and subsidised wards with natural ventilation?

The healthcare institutions will institute specific measures to manage particulate matter (PM) levels in indoor spaces, taking reference from NEA’s guidelines on indoor air quality. The healthcare institutions will also monitor patients closely, and ensure ample circulation of clean air indoors.

Where can I get more information on haze?

Please refer to the following websites: