276
7
19
25
Ecotoxicological Issues
@ o
o 0
OD
+ c 2
------~)
26
Figure 2. Generation mechanism of PAR
However, in considering the known reactivity of PAH with atmospheric species
which have their maximum concentrations during summer periods (e.g. photons,
OH', 03), the authors significantly qualified their conclusions:
"In view of what is currently known about PAH reactivity, it is advisable
at present to attempt to use P AH profiles for source identification only
under wintertime conditions."
2
GENERATION OF PAH
Although the specific mechanistic details of PAH formation are not yet known [6,
9], their formation appears to involve stepwise additions to phenyl and phenyl-like
radicals of two-carbon species such as acetylene (27) and four-carbon species such
as diacetylene (28) and vinylacetylene (29). The growth pattern can be
represented in the zig-zag manner of Figure 2 ([8], [9]).
HC=CH
27 ("Ci')
HC=C-C=CH
HC=C-CH=CH2
29 ("C4")
7
19
25
Ecotoxicological Issues
@ o
o 0
OD
+ c 2
------~)
26
Figure 2. Generation mechanism of PAR
However, in considering the known reactivity of PAH with atmospheric species
which have their maximum concentrations during summer periods (e.g. photons,
OH', 03), the authors significantly qualified their conclusions:
"In view of what is currently known about PAH reactivity, it is advisable
at present to attempt to use P AH profiles for source identification only
under wintertime conditions."
2
GENERATION OF PAH
Although the specific mechanistic details of PAH formation are not yet known [6,
9], their formation appears to involve stepwise additions to phenyl and phenyl-like
radicals of two-carbon species such as acetylene (27) and four-carbon species such
as diacetylene (28) and vinylacetylene (29). The growth pattern can be
represented in the zig-zag manner of Figure 2 ([8], [9]).
HC=CH
27 ("Ci')
HC=C-C=CH
HC=C-CH=CH2
29 ("C4")