Sources of indoor air pollutants related to ventilation
As in many workplaces people spend most of their time indoors which is why it of most importance that the air that enters the building is as clean of pollutants as practically applicable. Properly working ventilation systems in a building could protect occupants from outdoor pollutants as well as from their effects on people’s health.
One of the sources of indoor air pollutants related to ventilation is outdoor air. When outdoor air is used for indoor air ventilation it can be a source of indoor air pollution as outdoor air contains such pollutants as particulate matter, particulates of biological origin (e.g. microorganisms and pollen) and various gasses (e.g. nitric oxides and ozone). Air pollutants enter the workplace area through natural ventilation directly as there is no means for reduction of pollutants in outdoor air before it enters the building.
It is a big risk of indoor air pollution in residential buildings where mechanical air ventilation is not installed. Due to this outdoor particles enter the area without any obstacles and cumulate indoors leading to asthma and other health problems in occupants of the building.
Other sources of potential outdoor pollutants can be exhaust gases, cooling towers (Legionella risk), evaporative cooling systems, garbage collection points, biomass-burning stoves and boilers.
In old buildings we can come across other sources of air pollution, i.e. wet surface on air ventilation and handling systems. Wet surfaces are suitable media for microbial growth. And it becomes a major source of pollution. It can cause significant health effect in building occupants although the effects of this pollution cannot be identified promptly.
When mechanical ventilation systems are installed in the building it can reduce the concentration of pollutants in outdoor air entering the system. However, poor maintenance of air ventilation system is also identified as a risk factor. Some materials used in air ventilation system installments can emit volatile organic compounds when surfaces of the system become dirty. Thus increasing the concentration of dust and volatile organic compounds in indoor air.
Another source of pollution can be considered the air filters used for a long period of time which become loaded with dust. As a result, it can react with the chemicals in the air from outdoors and form new chemical combinations that can enter the ventilation system through filters.
As a result it can be concluded that the air ventilation systems have to be properly maintained, cleaned, repaired, and filters replaced as per technical and manufacturer’s requirements. May be most people don’t even fill how indoor air affects them however by time the effects become more obvious. That’s why the most effective way of risk reduction is to be proactive, i.e. identify and assess the risks properly and implement all the necessary mitigation measures on a timely basis.
EVENAIR’s team of professionals are always ready to assist, consult, implement the necessary work and help to reduce the risks from outdoor air pollutants related to ventilation systems.
