Standards/Criteria
TABLE 3
Standards (Michigan) / Guidelines (Ontario) for Sulphur Dioxide
Michigan (U.S. EPA NAAQS)
Pollutant
Primary Standard (Health Related)
Secondary Standard
3
3
Annual Arithmetic Mean
80 µg/m  (0.03 ppm)
3-hour
1300 µg/m
SO
23
(0.50 ppm)
3
Not to be
24-hour
365 µg/m
(0.14 ppm)
exceeded more
Not to be exceeded more than
than once per
once per year
year
Ontario (MOE)
Pollutant
Criteria
Annual Arithmetic Mean
20 ppb (0.02 ppm)
SO
23
1-hour Average
250 ppb (0.250 ppm)
24-hour Average
100 ppb (0.10 ppm)
Nitrogen Dioxide (NO )
Effects
2
and Nitrogen Oxides (NOx)
contributes to the formation of  fine particulate
NO
2
aerosols.  Individuals suffering from pre-existing
Nitrogen dioxide is a reddish-brown gas with a strong
respiratory illness, the elderly, and children react to
odor created from combustion sources principally the
short-term exposures (e.g. less than three hours) to
burning of  fossil fuels.  Nitrogen Oxides (NOx) form
low levels of  NO .  (Ref. 6)
2
when nitrogen and oxygen combine.  ‘Nitrogen oxides
Long-term exposures to NO  may lead to increased
2
(NOx)’ is a term used to describe NO, NO , and other
susceptibility to respiratory infection and may cause
2
oxides of  nitrogen.  NOx plays an indispensable role in
irreversible alterations in lung structure, particularly
the formation of  ground level ozone.
in young children. (Ref. 7)
NOx (typically a mixture of NO and NO ) reacts in
Sources
2
the air to form ground-level ozone and fine particle
• Sources of NOx emissions are those related to high-
pollution, which are both associated with adverse
temperature combustion processes such as electrical
health effects.  (Ref. 8)
utilities, refuse and sludge incinerators, and automobiles.
Standards/Criteria
TABLE 4
Standards (Michigan) / Criteria (Ontario) for Nitrogen Dioxide
Michigan (U.S. EPA NAAQS)
 Pollutant
Primary (Health Related)
Secondary
Annual Arithmetic Mean
0.053 ppm (53 ppb)
Same as Primary
 NO
2
3
(100µg/m )
Ontario (MOE)
 Pollutant
Criteria
1-hour
200 ppb
 NO
2
24-hour average
100 ppb
9