WSH Resources - Our Culture: June 2013

Haze Information: Frequently Asked Questions

What is Haze?

Slash-and-burn farming is a technique that involves cutting down vegetation and burning to clear land for cultivation

It is cheaper than using excavators and bulldozers

The illegal burning of forests to clear land for palm oil plantations has long been a problem in Indonesia - particularly during the dry season in the summer

The traditional practices of slash and burn agriculture generate smoke, which is carried long distances by prevailing winds. The Haze in Indonesia comes largely from extensive wood/peat fires from hot spots in Kalimantan (Borneo, Indonesia) and to a lesser extent Sumatra and Sarawak blown in by the South-Easterly trade winds.

Transboundary smoke haze from land and forest fires during the traditional dry period between June and October has been a recurrent feature in the southern ASEAN region in the past few decades. These annual fires are caused mainly by land clearing and “slash and burn” agricultural practices in Indonesia, particularly Sumatra and Kalimantan. In the northern ASEAN region, agricultural burning activities are common during the traditional dry season between December and March can also cause large scale smoke haze at times. The smoke haze situation is usually exacerbated when it coincides with the El Niño, a climatic phenomenon that often leads to prolonged and drier weather conditions in the region.

What is Haze made up of?
Haze is made up almost entirely of very small particles (less than 10 microns in diameter) produced by wood/peat fires. At the height of the Haze period of April 1998, an independent study was carried out by the Department of Environment Quality, T.N.O, Institute of Environmental Sciences, The Netherlands. It showed that the 97/98 Haze contained:

· very low levels of toxic chemicals, other than relatively inert particles.

· Benzene in very small quantities - below the levels seen in busy urban centres.

· Benzopyrene (polycyclic aromatic hydrocarbons) - well below levels seen in busy urban centres.

· No soot (elemental carbon)

· No heavy metals

· No significant levels of volatile hydrocarbons.

What are the harmful effects of the Haze particles?

Healthy normal individuals will only experience irritation of the eyes and throat. People at risk include: the elderly; people with chronic lung/heart disease and asthmatics. Their conditions could be made worse by the Haze. The elderly with lung/heart disease are most at risk.

When will the Haze stop?

When people stop lighting fires, and when major rains fall in Kalimantan. The North-East trade winds (expected in November) should blow the Haze away from Brunei. However, we may still experience Haze generated locally, if burning in the KB / Seria area persists.

What does PSI mean?

PSI stands for Pollutant Standards Index. It is an index developed by the United States Environmental Protection Agency (US EPA) to provide accurate, timely and easily understandable information about daily levels of air pollution.

The PSI gives an overall estimate of air quality on a given 24 hour day. It is a uniform index based on five pollutants:

· PM₁₀ (the level of small particles of less than 10 microns in the air).

· Sulphur dioxide (SO₂)

· Carbon monoxide (CO)

· Ozone (O₃)

· Nitrogen dioxide (NO₂)

The main pollutant of concern to health during a smoke haze is the fine particulates matter or PM₁₀. The health effect depends on the severity of the smoke haze as described by the PSI reading. At a PSI of 101 and above, the air quality is deemed unhealthy.

See the Haze Index for a guide to PSI values, air quality ratings, general health effects and precautions to take.

If you smoke, should you worry more about the Haze?

Smoking is far worse than the Haze. Smoking 20 cigarettes/day is about the same as an average 24 hour PSI of 24,000 ! This shows how BAD smoking is for our health.

What measures should you take to reduce exposure to Haze?

At Home

· Inspect your house thoroughly and seal any obvious gaps (eg windows and doors).

· Ask air-conditioning personnel to seal any gaps due to a/c piping.

· Keep doors closed during hazy periods.

· Don't use the kitchen / bathroom exhaust fans during hazy conditions.

· Plan your outdoor activities and exercise to coincide with cleaner periods of the day (generally afternoons / early evenings).

· Don't let children play outside during hazy conditions.

· Keep doors/windows OPEN when Haze clears in the evenings.

· Use air filters / purifiers.

· Keep the air purifier in the bedroom at night.

In Your Car:

· Use headlights, NOT side-lights - BE SEEN.

· Restrict your speed.

· Drive defensively - NO overtaking.

· Be extra vigilant of other road users.

· Put air conditioners on re-circulation

Office Workers:

· Wear your mask when travelling between home and office during hazy conditions.

· Ensure your office air conditioning is working efficiently.

· Plan your work, so that your outdoor exposure during hazy periods is minimised.

· Avoid using your bicycle during hazy periods.

· Minimise driving during hazy periods.

Outdoor Workers:

· ALWAYS use your mask during hazy periods - it reduces your exposure by at least 4 times.

· Check that you have been issued with a higher efficiency particulate mask, if you are likely to be spending a long period of work outside in high Haze conditions.

· Plan your work, wherever possible, so that your outdoor exposure during hazy periods is minimised.

· Plan strenuous work activities for late afternoon and early evening.

· Take rest periods in air conditioned environments, where possible.

· Change masks regularly (see manufacturer’s instructions).

· Refrain from smoking.

· Drive safely (see above)

A Note for Managers & Contract Holders…..:

· Use common sense when dealing with staff and contractors to minimise Haze exposure - try and limit time people are exposed.

· Encourage outdoor work when it is less hazy, such as late afternoon, early evening, or even at night.

· Ensure correct PPE is available and worn, especially contractors - replacement masks should be readily available.

· Ask yourself "Is this job really necessary now, or can it wait till the Haze is better?"

· Use the recommended PPE and working guidelines chart as a guide to PPE and work limitations.

Can we conduct cloud seeding in Singapore to disperse the smoke haze?

· Cloud seeding attempts to artificially induce rain by implanting clouds with suitable particles. The seeding particles serve as condensation or ice nuclei to induce formation of more water droplets or ice crystals in the cloud. However, there is still a lack of reliable means to validate the effectiveness of the seeding process.

· Cloud seeding requires existing clouds as it cannot generate rain out of thin and dry air. During the current dry season, cloud seeding is less effective due to the lack of suitable clouds for seeding. The small size of Singapore and the variability of winds also mean that the induced rain, if any, may not fall directly over our island. In any case, the rain will provide only temporary relief as the smoke haze would continue to be blown toward Singapore by the prevailing winds, should the fires in the region continue to persist. For these reasons, we have no plans to conduct cloud seeding, but we will keep the option open.

What is the effect of the haze on my health?

· Haze particles may cause irritation of the eyes, nose, throat in healthy individuals. Such irritation resolves on its own in most cases.

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

· There may be up to 1-3 day time lag between exposure to haze and health effects/ symptoms.

What are the long term effects of the haze?

· Studies have shown that long-term exposure to fine particles (i.e. particulate matter 2.5 (PM2.5); particles smaller than 2.5 micrometers) include (i) cardiovascular effects, such as heart attacks and strokes, (ii) reduced lung development, as well as (iii) the development of chronic respiratory diseases, such as asthma, in children. However, these are the results of long term prolonged exposure, which is not the case here, as we do not get haze throughout the year.

What is MOH’s advice to the public on what to do?

· Please try to minimize exposure by reducing outdoor activities and physical exertion. This means staying indoors, and reducing the length of exposure and strenuous work if you need to be outside.

· Drink plenty of water to stay well hydrated

· Use an N95 mask where appropriate, depending on how healthy you are, the PSI level and the time you need to spend outside.

Should I still follow the daily Health Advisory if the skies look clearer, since these are based on PSI readings from previous hours’?

· While you need not rigidly adhere to the daily Health Advisory, if the situation changes, following the advice for a higher PSI based on previous day’s level would be prudent.

What about children? Children's N95 masks are not available.

· There are no N95 masks approved by the US FDA and HSA for use by young children.

· Young children should therefore minimize prolonged outdoor activity at PSI levels above 100, and avoid outdoor activity if PSI levels reach higher than 200.

Shouldn’t the N95 be properly fitted? How do I learn to fit my N95 mask?

· For best effect, N95 masks need to be fitted properly for each user.

The use of N95 masks to filter out pollutants in the air is not identical to the use of N95 masks for infection control in a healthcare institution during a disease pandemic situation. For use during haze, even if the mask is not perfectly fitted, it can still be useful in filtering out pollutants for those need to wear it.

What are the effects of wearing a N95 mask?

· The use of N95 masks increases effort in breathing. For some people, the use of N95 mask may cause discomfort breathing, tiredness or headache. This may be due to the mask causing increased resistance to breathing, and a reduction in the volume of air breathed. For most people this is not serious.

· However, some elderly people, people with lung or heart conditions, and women in the later stages of pregnancy may already have reduced lung volumes or breathing issues.

· Because of this, elderly people and people with lung or heart problems should stop using a N95 mask if they feel uncomfortable. Those with severe lung or heart problems who have difficulty breathing at rest or on exertion should not wear N95 masks. They should consult their doctor as to whether they should use the N95 mask.

· Women in the 2nd and 3rd trimesters of pregnancy should not use the N95 mask for more than a short duration each time.

· N95 masks are not certified for use in children, so children should try to stay indoors when air quality is poor.

Is the N95 mask an adequate protection against the haze? Does it protect against PM2.5?

· N95 masks are designed to seal to the face of the wearer. This way, most of the air that the wearer breathes in has to go through the filter and not through the gaps between the mask and the wearer’s face. Haze particles are predominantly made up of fine particles that are 2.5 microns or smaller (PM2.5). Studies have shown that N95 masks do provide good protection against the haze as they are at least 95% efficient against fine particles that are about 0.1 – 0.3 microns. It is even more efficient (99.5% efficient) against particles that are 0.75 microns and larger.

Can I reuse my N95 mask?

· You can reuse your N95 mask. It should be changed when it gets soiled or distorted in shape. It should not be shared.

Are surgical masks useful?

· In situations where a N95 is not recommended, those who are healthy and would like to use a surgical mask can do so.

Monitoring Air Quality

· Continuous daily Haze monitoring - data available on-line

Satellite Tracking

· Tracking of weather, satellite images of fire 'hot spots' - data available on-line

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