Seasonal variations of volatile organic compound (VOC) concentrations
were analyzed at two sites in Edmonton, Alberta, Canada, from 1991 to
1993. At the downtown site, maximum values occur in winter and minimum
values in summer. These seasonal changes at the downtown site appear
to be primarily due to meteorology. Seasonal changes cannot be detecte
d at the industrial site owing to the nearby industrial emissions whic
h may be higher in summer. The contribution by hydrocarbon class at th
e two sites to the total lifetime VOC-related cancer risk and ozone ge
neration potential are very different, although the total risk and the
incremental ozone formation potential are similar. Hence, plans for c
ontrolling VOC, to reduce anthropogenically produced O-3 or to reduce
health risks must address the differences in emission species and rate
s at different locations. Copyright (C) 1996 Elsevier Science Ltd