1 DR. TEAL: I know that, I'm talking about pollution PAH's from 



2 combustion. 



3 DR. BOEHM: I don't recall what studies, there have been some 



4 studies, but the direct analysis I have seen of plant waxes, show that 



5 to be a very, very minor element. 



6 DR. TEAL: Yes, but if you degraded the plant waxes, which they 



7 do, and were left with the others--it's a wild idea. 



8 DR. BOEHM: Well, it's not such a wild idea. It's not clear how, 



9 the plant waxes certainly degrade. It really depends on what the 



10 physical form of what the plant wax is, if it's available for 



11 degradation. 



12 The plant waxes seem to be on the coarser particles here. The 



13 anthropogenics seem to be on the finer particles. They seem to be the 



14 same particles and I don't have a lot of data where people have taken 



15 sediments and done that size fractionation in this environment. 



16 There are data from other environments where the size 



17 fractionations have revealed different compositions of different 



18 particles. 



19 So, if you look at the mixture I think you'll find the PAH's and 



20 the plant wax. I think if you look at the coarser materials, the PAH's, 



21 for the most part, drop out, if you look at the plant wax. 



22 That certainly may be true of certain plants as far as a screen 



23 for PAH's, as a generality explaining some of this distribution, I don't 



24 know. 



25 DR. TEAL: You expect the combustion products to be associated 



26 with the fine-silt particles in any case, they tend to be more 



27 concentrated there. I was just wondering if there was any direct 



28 evidence of the filtering of some of this out by living leaves. 



29 Then, of course, there would be a reason for them to be co- 



30 distributed. 



31 DR. BOEHM: I think I see the study. I think the leaves from New 



32 York or from Boston, I'm not sure. 



33 (Laughter) 



85 



