unhealthy air

Haze is traditionally an atmospheric phenomenon where dust, smoke and other dry particles obscure the clarity of the sky. The World Meteorological Organization manual of codes includes a classification of horizontal obscuration into categories of fog, ice fog, mist, haze , smoke, volcanic ash, dust, sand and snow. Sources for haze particles include farming (sloughing in dry weather), traffic, industry and wildfires.

The term "haze", in meteorological literature, generally is used to denote visibility-reducing aerosols of the wet type. Such aerosols commonly arise from complex chemical reactions that occur as sulfur dioxide gases emitted during combustion are converted into small droplets of sulphuric acid. The reactions are enhanced in the presence of sunlight, high relative humidity, and stagnant air flow. A small component of wet haze aerosols appear to be derived from compounds released by trees, such as terpenes. For all these reasons, wet haze tends to be primarily a warm-season phenomenon. Large areas of haze covering many thousands of kilometers may be produced under favorable conditions each summer.

 Why do the outbreaks happen and when did they start?

The main cause is illegal fires started in peatland and forest on Indonesia's Sumatra island and the Indonesian part of Borneo to quickly and cheaply clear land for palm oil and pulp and paper plantations.

They increased in number as the plantations expanded, in particular due to rising global demand for palm oil, a key ingredient in everyday goods such as shampoo and biscuits.

The outbreaks started in 1997, with what is still regarded as the most serious haze on record.

It followed rapid expansion of plantations in the preceding years, and coincided with an El Nino weather system that made conditions drier than usual in Indonesia.

Who is affected by the haze?

The haze has a devasting impact on daily life every year on Sumatra and the Indonesian part of Borneo

This year, air quality has hit hazardous levels, tens of thousands have contracted respiratory illnesses, many flights have been cancelled and schools closed.

From Indonesia, the smog is blown over Southeast Asia, and fouls the air in neighboring Singapore and Malaysia.

Schools were closed in the Malaysia capital Kuala Lumpur and neighboring states on Tuesday, while dense clouds have shrouded the skyline of financial hub Singapore

How bad is it this year?

More than 2,000 fire “hotspots”, either areas already on fire or very hot and likely to soon go up in flames, were detected by satellites on Sumatra and Indonesian Borneoon Tuesday.

The situation is being exacerbated by an El Nino weather system that has made conditions tinder-dry.

The crisis eased in the past two days, with the haze having been much worse in the past. The most serious recent outbreak was in 2013, when air quality deteriorated to the worst level for years in Singapore and Malaysia.

How Haze Can Affect Your Health

In the 1997 Southeast Asian haze which affected a number of countries in the region, an increase in air pollutants from 50 to 150 μg/m³ is significantly associated with increases of 12% of upper respiratory tract illness, 19% asthma and 26% nasal inflammation.

Depending on how sensitive you are, the severity of the haze and the time of exposure, you may experience the following short-term adverse effects:

• Irritated eyes, watering eyes, and/or conjunctivitis (a type of eye inflammation);
• Running nose, stuffy nose, sneezing, and/or post-nasal drip;
• Throat irritation, dry throat, sore throat and/or coughing;
• Headache, dizziness and/or fatigue;
• Decreased lung function, depressed respiratory immune defenses, chest pain, and/or bronchitis (lung inflammation);
• Diarrhea and/or stomach upset, if drinking water sources are contaminated by dense haze and the water is consumed without further treatment;
• Anxiety, stress and/or depression-like symptoms such as insomnia, feelings of helplessness, loss of interest in daily activities and irritability.

These symptoms are usually mild and will subside when you stay indoor and limit your exposure to haze.

However, in susceptible individuals and those suffering from chronic disease, especially respiratory and heart disease (e.g. coronary artery disease, asthma and chronic obstructive pulmonary disease), their condition may be worsened by haze. They are more likely to experience more severe haze-related effects than healthy people.