Is traditionally an atmospheric phenomenon in which dust, smoke and other dry particulates obscure the clarity of the sky. The World Meteorological Organization manual of codes includes a classification of horizontal obscuration into categories of fog,mist, haze, steam fog, smoke, dust, sand, snow and volcanic ash. Sources for haze particles include farming (ploughing in dry weather), traffic, industry and wildfires. Seen from afar (e.g. an approaching airplane) and depending on the direction of view with respect to the Sun, haze may appear brownish or bluish, while mist tends to be bluish grey. Whereas haze often is thought of as a phenomenon of dry air, mist formation is a phenomenon of humid air. However, haze particles may act as condensation nuclei for the subsequent formation of mist droplets; such forms of haze are known as "wet haze".
HOW HAZE HAPPEN ?
Haze often occurs when dust and smoke particles accumulate in relatively dry air. When weather conditions block the dispersal of smoke and other pollutants they concentrate and form a usually low-hanging shroud that impairs visibility and may become a respiratory health threat. Industrial pollution can result in dense haze, which is known as smog.
Haze causes issues in the area of terrestrial photography, where the penetration of large amounts of dense atmosphere may be necessary to image distant subjects. This results in the visual effect of a loss of contrast in the subject, due to the effect of a loss of contrast in the subject, due to the effect of light scattering through the haze particles. For these reasons, sunrise and sunset colors appear subdued on hazy days, and stars may be obscured at night. In some cases, attenuation by haze is so great that, toward sunset, the sun disappears altogether before reaching the horizon.
Haze can be defined as an aerial form of the Tyndall effect therefore unlike other atmospheric effects such as cloud and fog, haze is spectrally selective: shorter (blue) wavelengths are scattered more, and longer (red/infrared) wavelengths are scattered less. For this reason, many super-telephoto lenses often incorporate yellow filters or coatings to enhance image contrast. Infrared (IR) imaging may also be used to penetrate haze over long distances, wit a combination of IR-pass optical filters (such as the Wrattern 89B) and IR-sensitive detector.
Haze is no longer a domestic problem. It has become one of the causes of international disputes among neighboring countries. Haze migrates to adjacent countries and thereby pollutes other countries as well. One of the most recent problems concerned the two neighboring countries Malaysia and Indonesia.
WHY HAZE HITS MALAYSIA TODAY ?
NO AREA RECODS "GOOD" AIR QUALITY ?
PETALING JAYA :The air quality in Indera Mahkota, Pahang, has reached the "unhealthy" level because of peat firs in Pekan, some 50 km away, as haze continues to hit the country,The Department of Environment said that as of 1pm today, the Air Pollutant Index (API) showed that none of the 64 areas which had their readings taken recorded "good" air quality.
In these areas, the air quality was "moderate", while in Indera Mahkota, the air quality had reached "unhealthy" levels, with an API reading of 110.
An API reading of under 50 means the air quality is good, 51-100 (moderate), 101-200 (unhealthy), 201-300 (very unhealthy) and above 300 (hazardous).
According to the DOE's website, "unhealthy" air presents risks to those with heart and lung conditions.
The department said all areas in Peninsular Malaysia's west coast, Sabah and Sarawak were being affected by the haze coming from Sumatera and Kalimantan in Indonesia.
It said the pet fires at Kampung Pulau Manis in Pekan have yet to be fully extinguished.
"Peat fires which have reportedly broken out at Kuala Baram in Miri, Sarawak, have caused a spike in the API reading in Miri," it said.
It said the Asean Specialised Meteorological Centre has, based on satellite images, identified 42 hotspots in Sumatera, three in Kalimantan and four in Pahang.
The department said the National Open Burning Action Plan and National Haze Action Plan has been activated to coordinate the action taken by the relevant government agencies.
"State and local governments and land owners are advised to closely monitor areas which are easily and prone to catching fire such as garbage disposal sites, forests, peat land, fields, and agriculture and industrial land.
"The people are also reminded against open burning or allowing their land or premises to be encroached by irresponsible parties leading to open burning intentionally or otherwise," it said.
Under the Environmental Quality Act 1974, those caught carrying out open burning can be fined up to RM 500,000, jailed up to five years or both.
WHY HAZE IS DANGEROUS ?
What are the key air pollutants of concern?
The key air pollutants of concern include particulate matter (PM), sulphur dioxide, ozone, nitrogen dioxide and also CO (carbon monoxide). Short-term exposure (i.e. continuous exposure to unhealthy daily average 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 and sulphur dioxide may also cause irritation of the eyes, nose and throat in healthy individuals.
In Singapore, the main air pollutant in the event of haze is particulate matter (PM). Singapore experiences haze from time to time, usually caused by forest fires in the region. It can be made worse by dry seasons, changes in wind direction, and when rainfall is low.
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 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 1-3 days of time between exposure to haze and health effects/symptoms.
What are the long-term effects of the haze?
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) carbiovascular effects, such as hearth attacks, (ii) reduced lung development, as well as (iii) the development of chronic respiratory diseases, such as asthma, in children.
What is the revised Pollutant Standard Index? How is it different from PSI reporting last year?
The new, integrated air quality reporting index incorporates PM2.5 in addition to sulphur dioxide (SO2), particulate matter (PM10), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone. Previously, health advisories issued by the Government were based on both 24-hour PSI and 24-hour PM2.5, whichever was worse. Under the new air quality reporting system, the health advisory will be based on the new 24-hour PSI as it now directly takes into account PM2.5.
In general, children, elderly, and people with chronic lung disease, 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.
HOW TO PROTECT YOURSELF FROM HAZE ?
The main pollutants in a haze that have the greatest health impact are those particles that are less than 2.5 micrometer.
Their effects depend very much on the severity of the haze and how long one has been exposed to them.
During a prolonged haze period when the air quality is poor, take the following precautions to protect yourself:
- Pay attention to local air quality updates.
- Recommended precautions you should take will usually be given in the form of advisories based on the latest air condition. So it is recommended that you keep track of the latest air quality update regularly. Here are some websites to check for the following countries:
- Malaysia : Air Pollutant Index
- Singapore : Pollutant Standard Index PM2.5 Reading.
- United States :AIRNow
- Canada: Air Quality Health Index
- Avoid outdoor activities, especially outdoor sports. Children pregnant women, the elderly, and those suffering from chronic illnesses, especially heart and respiratory disease, should remain indoors when haze hits unhealthy levels. Healthy adults should avoid unnecessary outdoor activities. If you must exercise outdoor, avoid exercising in highly congested areas near busy roads and freeways, particularly during rush hours.
- Close all windows, doors and any openings that may allow haze to enter your home and office.Turn on the air conditioner if you have one. Note: If the weather is unusually warm, it can become dangerous if you stay indoor with no fresh air intake and no air conditioner. In this case, seek alternative shelter.
- Use an air purifier to keep the particulate levels low.Choose an air purifier that is suitable for the size and type of your home. Avoid air cleaners that generate ozone as they may generate more air pollutants. If you have multiple rooms, each room may need to be equipped with one air purifier to ensure the air is cleaned efficiently. Regularly replace the filters in the air purifier according to manufacturer's instructions.
- Keep air conditioner in tip-top working condition with regular cleaning and servicing. Fine particles can enter an air-conditioned building through the fresh air intake as well as any openings and gaps.
- If you are staying in a building with a central air conditioning system, install an air cleaning device.This helps to reduce the amount of air contaminants that may be circulating in the building.
- Take your medication regularly if you are suffering from an existing disease, especially heart disease and respiratory disease.If you feel breathless at any point in time, seek medical attention immediately.
- Drink more water and increase the intake of fresh fruits and vegetables.They help the body to flush out toxins absorbed through the skin and lungs, and improve the immune system. Taking more anti-inflammatory fruits and vegetables also help to reduce inflammation that may be triggered by harmful fine particles in the air. Cut down on alcohol and coffee as they promote fluid loss and may leach nutrients from the body.
- Limit or avoid smoking indoor and the use of gas stove, wood fireplace, candles, incense and anything that burns and emits smome.In an enclosed area, smoke, gases and pollutants emitted form burning sources are trapped indoor and can build up to hazardous level if they continue to burn for an extended period of time.
- Avoid driving if visibility is bad.When visibility is severely limited by the haze, avoid driving and use the public transport if you really need to get around. If you cannot avoid driving, do not speed, and drive at a speed that suits the road conditions. Roll up all the windows, turn on the headlight and avoid changing lanes, passing and crossing traffic. Increase your following distance and stay alert.
- Under severe haze condition, wear a respirator if you must go outside. Respirators work better than surgical masks as they seal better and restrict more pollutant air from entering the nose and mouth. They also come with the right filter to remove fine particles found in a haze. If you stayed indoor, but still experience haze-related conditions, it may be necessary to use respirators indoor as well.
@ Jackie San
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