The researchers conducted a survey on six companies with the offices located at four buildings in Hanoi. The common characteristic of the office buildings is that they are self-contained with a central air-conditioning system. These buildings all bear the current typical modern design. The workers at the buildings all have high education levels and they are young.
Since there have been no official standards on the air quality for the offices in Vietnam, the researchers compared the indicators they found at the buildings in Vietnam with foreign standards. What they have found is that the noise concentration is a bit higher than the allowed level, but it does not seriously affect the workers’ health.
However, the researchers have found other big problems in microbiological factors and volatile compounds, pointing out that these are the factors which most affect the office workers’ health.
The volatile organic compounds (VOCs) include formaldehyde, benzene, toluene, acetone arisen from office equipments such as printers, computers, copiers, furniture cleaners.
In general, in order to clean floors and equipments, people use some kinds of chemicals, but it is the chemicals which cause the environment pollution. Meanwhile, it is a growing tendency that filing cabinets and office furniture are made of industrial wood, adhesives and paints which are the main sources of VOCs.
The experts have also pointed out that the frequent and long lasting exposure to the VOCs would seriously affect workers’ health.
VOCs are the substances capable to dissolve the blood fat easily, thus making it easier to be absorbed through the lungs and gets into the brain, which would cause the central nervous system to decline; causing fatigue, drowsiness and discomfort.
In principle, the VOCs’ influences on human would be different depending on the VOC concentrations. With the VOC concentration of less than 0,2mg/m3, people would not have the sense of discomfort.
Meanwhile, with the VOC concentration at 0.2 - 3.0 mg/m3, this would cause discomfort and irritation, at 3.0 - 25mg/m3 causing headache and contrast mild inflammation, above 25mg/m3 causing neurotoxicity (self, fatigue, confusion, etc.).
The VOC concentrations may vary at different floors of the same buildings. The administrative department always has the VOC concentrations higher than in other departments.
Dr. Phung Van Khoa from the Hanoi Forestry University, especially has given warning about toluene, a volatile organic solvent, now being widely used in industries. Paints, cleansing liquid could be the main sources of toluene at home or office.
Khoa said that one of the most effective solutions to ease the toluene concentrations is Phytoremediation, which means putting the plants which can absorb the pollutants to ease the risks for people.
Khoa and his associates Bui Van Nang, MA, and Nguyen Thi Bich Hao, MA, have found out that three plants Thiet Moc Lan (Dracaena fragrans), Ngu gia bi (Araliaceae), Duong xi thuong (Cyclosorus parasiticus (L.) Farw) have these features.
Within 72 hours, Thiet Moc Lan can absorb 2,7µg/cm2, ngu gia bi 1,20µg/cm2. Especially, the plants can be put in houses as ornamental trees.