Environmental Engineering Reference
In-Depth Information
because they are not volatile and thus there should be no potential for them to undergo
atmospheric transport. However, it was not long before it was found that they are glob-
ally distributed and are present in Arctic air and Arctic biota. Exactly how their long-range
transport is achieved is the subject of much debate and we will carefully avoid the details.
It is now believed to be made up of two parts. There is the atmospheric component from
volatile precursors that then degrade in the atmosphere to the acids. The PFAS found in
caribou have taken this route. On the other hand, ocean biota seem to be accumulating their
PFAS largely from long-range ocean transport but possibly with an atmospherically depos-
ited contribution when the ice melts (see
Figure 8.7
).
Figure 8.7
Transport pathways for fluorinated compounds
In animals, PFAS do not partition into fatty tissues, as do organochlorine and other organ-
ohaline substances, but accumulate in the blood, kidneys and liver, where they remain for
a very long time (especially in the liver). Little is known about the toxicity of these sub-
Search WWH ::
Custom Search