3 janvier 2017

Air pollution

Indoor air pollution is a complex system to describe, mostly due to the many pollution sources and chemical species involved.

Indoor air pollutants can be sorted in a few families :

Volatil organic compound (VOC) includes many chemical species. Their toxicity depends on their chemical structures.

CH2O

Oxydants are compounds that chemically reacts with other atmospheric pollutants in the air and on indoor surfaces. Oxydants, like ozone or nitrogen dioxide, can be toxic by themselves but also form compounds with higher toxicity by reacting with VOCs.

NO2

Particulate matter are very small solid or liquid aggregates. Their size ranges from few nanometers to few microns.
By inspiring, particulate matter enters the respiratory system and can damage it with inflammatory reactions. They can also cause more dammage while crossing the blood-air barrier. Their toxicity also depends on the chemical composition.

 

Carbon dioxide (CO2) is the first indoor pollutant but is not really harmful since it’s expired by humans continuously. However, at high concentrations, it can cause losses of focus, lower efficiency at work. It happens in confined environments where ventilation system is not enough to renew indoor air.

CO2

Carbone monoxide (CO) is a pollutant emitted by combustion systems (car engines, gas boiler, etc). It is very hazardous since it crosses bloor-air barrier and replace dioxygen in blood (O2).

CO