Black carbon refers to particles that strongly bind light and have high concentrations of inorganic carbon. It is released into air during incomplete combustion. In size, it is similar to fine particles. It penetrates efficiently from outdoor air to indoor air.
In the Helsinki Metropolitan area, black carbon emissions are mostly caused by diesel vehicles, small-scale wood burning and marine traffic. Particles including black carbon also come into the Helsinki Metropolitan Area from outside our borders.
Inorganic carbon itself is not particularly detrimental, but the black carbon particulate surface, which is released into air during incomplete combustion, includes organic compounds and metals that are harmful to health. Black carbon also strengthens the greenhouse effect as it binds solar radiation efficiently.
Carbon monoxide causes a lack of oxygen, which is detrimental to people suffering from heart and cardiovascular diseases, lung diseases and anaemia as well as to the elderly, pregnant women and new-borns.
These days, the carbon monoxide concentration is low in the Helsinki Metropolitan Area.
Many evaporating organic compounds have a strong odour and act as irritants. Some of them also in-crease the risk of cancer. For example, the concentration of benzene, which is a cancer risk factor, is high in heavy-traffic areas and sometimes also in residential areas where many of the houses are heated with wood.
In the Helsinki Metropolitan Area, the concentration of benzene is low.
Out of the heavy metals included in the air pollutants, arsenic, cadmium and nickel are carcinogenic. Their concentration may be higher in areas with metal industry. In the Helsinki Metropolitan Area, they have low concentration.
Lead disturbs the development of a child’s central nervous system. Lead concentration of air is quite low, nowadays, as the sales of lead petrol was ended in 1994.
Some sulphur compounds have an unpleasant odour already in small concentrations and thereby they decrease the comfort of the area. In addition to this, they cause:
- symptoms of irritation to eyes, nose and throat
- shortness of breath
- headache and nausea.
Reduced sulphur compounds pollute the air locally near the source of the pollutants.