A 3-Year Summary of 1-hour and 24-hour Maximum Ozone Concentration
and Number of Exceedances Above the 1-hour AAQC
O 1-hour AAQC is 80 ppb
(A) Number of hours above AAQC
(B) 1-hour max (ppb)
(C) 24-hour max (ppb)
Carbon Monoxide (CO)
Particulate Matter (PM )
A significant decrease in annual concentrations at the
Windsor Downtown site (University Ave) is evident; a
Three sites in Windsor monitored PM . The annual
similar trend is evident across the province. These
means varied from 20 to 32 µg/m which is in the upper
reductions are attributed to reduced emissions from the
range of the measurements recorded in the province.
transportation sector which account for about 66
Overall, the levels were higher at the Wyandotte St., (an
percent of the provincial CO emissions. Annual mean
industrial site,) by about 2 µg/m . The means at that site
carbon monoxide concentrations at this site appear to be
peaked in 1994 and showed a decreasing trend for the
stabilizing at just over 0.2 ppm in the last few years of
remainder of the decade. The other sites show more
the review period. The 1-hour and 8-hour objectives
variability and no obvious temporal pattern.
were not exceeded during this period.
The interim 24 hour objective of 50 µg/m , adopted by
10-year Annual Trend for CO Annual
the Ontario MOE in 1997, was exceeded for 14 percent
Mean (ppm) for Windsor-Downtown
of the samples collected at the Wyandotte St. site,
whereas 7.5 percent of the samples were in non-
conformance at the University Ave. and Wright Ave.
In mid-1996, measurements of PM were taken at the
Windsor West (College St. site) with a TEOM analyzer.
The annual means of the 24-hour measurement varied
from about 24 to over 28 µg/m . Both the annual
means and the number of daily averages greater than the
interim objective of 50 µg/m were higher in 1997 and
1998. Observed maximum hourly averages and 24-hour
and 127 µg/m ,
averages were as high as 349 µg/m
Long range transport of NOx and SO (precursors to
PM ) from the mid-western U.S. contributes to the
PM levels in southwestern Ontario (Ref. 29).