Sick Building Syndrome: The killer within

People in the UAE spend considerable time indoors — either at home, in the office or in shopping malls. This exposes them to indoor pollutants that have the potential to cause considerable damage to health.

According to the World Health Organisation, exposure to air pollutants happens through inhalation of indoor air and this could lead to Sick Building Syndrome (SBS) and Legionnaires. Several studies confirm the relationship between indoor air quality and the occupants’ health, yet its seriousness is mostly undermined.

A study commissioned by the Environment Agency-Abu Dhabi and conducted by the University of North Carolina reveals that air pollution may have been responsible for more than 850 deaths in 2007 alone, an estimated seven per cent of all UAE fatalities. Of these, outdoor air pollution was responsible for 600 deaths while 250 could be attributed to indoor air pollution. The study suggests that anthropogenic air pollution, particulate matter (PM) in particular, causes considerable public health impact in the UAE. According to a Health Ministry report, 90 per cent of the 150,000 patients treated at Al Ain public health clinics suffered from diseases of the upper respiratory tract, bronchitis, asthma and other forms of respiratory disease.

The dire scenario, however, is not unique to the UAE as one-third of the world’s population suffers from Sick Building Syndrome or SBS. In both developing and developed nations, up to three million people worldwide die each year from air pollution.

Symptoms

Those suffering from SBS experience acute health and comfort effects that appear to be associated with time spent indoors and building condition. Symptoms include headache, eye, nose and throat irritation, skin rashes, dry cough, dry and itchy skin, rashes, dizziness and nausea. This could also lead to difficulty in concentrating, fatigue, aches and pains and sensitivity to odour.

Causes and effects

SBS can be identified through a single or a combination of factors. Some symptoms can be attributed either to known toxic effects of high levels of certain chemicals while others are typical of allergic reactions which could be triggered by allergens found in a building.Trouble usually begins with a poor building design. Then there are other factors such as construction operation, building maintenance and related systems, such as heating, ventilation and air-conditioning systems that might not be working at a desired level. However, the exact mechanism by which a building condition or its indoor air quality causes its occupants to become ill is still largely unknown. But the problem areas can easily be identified with a closer look at various indoor pollutants and factors that usually contribute to SBS.

For instance, volatile organic compounds (VOCs) — chemical compounds that evaporate at ambient temperatures within a building — often irritates the eyes, nose and throat, cause breathing difficulties and even increase the risk of cancer.

Yet another monster is the Carbon monoxide (CO), a colourless and odorless gaseous asphyxiant, often called ‘silent killer’. Once breathed in, it combines with Red Blood Cells (RBCs) and prevents them from carrying oxygen and suffocates the person.

Sulphur dioxide (SO2) — another gas with a strong odour — is also an irritant to the respiratory system. Children, the elderly and those with chronic lung disease and asthmatics are most at risk from these effects.

Nitrogen dioxide (NO2), which is produced from combustion of fuels, can also be fatal if inhaled in high concentrations. Its long-term, low-level exposure can also destroy lung tissue and lead to emphysema and make people more susceptible to respiratory infections. Clearly, even one or a combination of these could be a recipe for disaster.

Similarly, many older buildings contain a significant amount of highly toxic substances posing a risk for heavy metal poisoning. The two most common heavy metals present in buildings are lead and mercury. According to World Health Organization (WHO), lead-based paints are major source of lead poisoning. Mercury is being added to the paint mainly to prevent build-up of mold on walls, as it is an effective anti-fungal agent. However, it can also damage health in a number of ways, from impairing detoxification to causing serious neurological damage and birth defects.

Lead too features in this long list of indoor pollutants. According to estimates, around 70-90 per cent of homes in the UAE still contain asbestos sheets despite a government ban. When high concentrations of asbestos fibres are inhaled over a long time, it can lead to health problems. Inhalation of asbestos fibres into the lungs can also cause malignant lung cancer and mesothelioma. Besides chemicals, biological contaminants such as mold, viruses, bacteria and dust mites are also reported to be the cause of a majority of SBS cases. They can cause illness through infection, allergy, hypersensitivity and toxicity.

But today’s buildings mostly suffer from emission of volatile organic compounds (VOCs) due to extensive use of particle board, which is often used in place of solid wood in modern furniture. Particle board is a major source of VOCs due to the high content of adhesives used in manufacturing them.

The earlier the conclusions are arrived at the better it will be for the inhabitants of the UAE and elsewhere.