Measurements of airborne dioxins and a few of PCB was taken 2007 at Sofienbergparken, Oslo. The study was designed in a way which should allow to identify episodes with and without wood burning. The average dioxin concentration of the 19 samples was 28,2 TE(WHO) fg/m3. The average PCB-7 concentration of the 19 samples was 31,8 pg/m3.

Reducion of dioxins concentrations the last 20 years

The air concentrations of dioxins and PCB measured at Sofienbergparken are in the same range as measured at other urban background stations around the world.

There is a remarkable reduction of the dioxins concentrations from 1989 to 2007 with 3 times lower concentrations today. This reduction is attributed to the ban of leaded gasoline and a general reduction of the major dioxins emissions to air.

Wood burning a source for airborne dioxins

The variability of the dioxins concentration which correlates strongly with reverse temperature, is a strong indication that wood burning for household heating is a source for airborne dioxins.

Traffic related emissions and atmospheric long range transport do not seem to contribute significantly to the dioxins level at the station in sofienbergparken.

In order to reduce the emissions of dioxins from household heating it is essential to use clean firewood only. Burning of newspapers, milk cartons, plastic, and especially impregnated wood must be avoided.

PCB concentration less variable

The PCB concentration is, compared to dioxin concentrations, less variable and do not correlate to any of the measured meteorological parameter. This indicates that the emission sources for PCB are spread and diverse and not as dependent on temperature as for dioxins.

Due to the limited data set and to the short measurement period, a quantification of the different source and an estimation of the strength of the minor sources are not possible. Therefore it is not possible to exclude household heating completely as a source of PCB emissions.