Environmental Engineering Reference
In-Depth Information
In the past three decades, a number of studies have been conducted to
evaluate concentrations of CO and NO
2
in ice skating rinks. In one of the
earliest studies conducted in the U.S., CO concentrations in the range of 12
to 250 ppmv were reported in six rinks (with a median of 100 ppmv). Highest
concentrations were measured during resurfacing activities; when propane-
fueled resurfacers were used, concentrations were in the range of 157 to
304 ppmv, while gasoline-fueled machines were associated with 80 to
170 ppmv. Concentrations of CO measured more recently are much lower,
with breathing zone levels in the range of 10 to 30 ppmv.
Significant recent scientific attention has focused on NO
2
exposures in
ice skating rinks. Short-term exposure concentrations >1 ppmv are com-
monly reported. In a survey study of 332 rinks in nine countries, 7-day NO
2
concentrations averaged 221 and 228 ppbv at breathing height near the ice
surface and spectators' area, respectively, with highest concentrations of 2.68
and 3.18 ppmv. Seven-day average NO
2
concentrations of 360 ppbv in 70
rinks in the northeastern U.S. have been reported.
The World Health Organization (WHO) recommends a 1-hour NO
2
exposure guideline of 213 ppbv. This guideline was exceeded in 40% of the
332 rinks surveyed; 55% of the 70 U.S. rinks surveyed exceeded it.
Concentrations of NO
2
in ice skating rinks depend on a number of
factors. The most important is fuel type. Highest NO
2
concentrations are
associated with propane, followed by gasoline- and diesel-fueled machines,
respectively. Fuel use varies from country to country. Propane-fueled resur-
facers are used in approximately 70 to 75% of rinks in Canada and northern
Europe, 60% in the U.S., and 0% in Japan. In the last case, gasoline-fueled
resurfacers are used exclusively. Increased NO
2
levels have also been asso-
ciated with increased numbers of resurfacing operations, lower ventilation
rates, and smaller rink air volumes.
Compared to other exposure situations in developed countries, human
exposures to CO and NO
2
in ice skating rinks are relatively high. For full-
time employees, individuals who exercise significantly (hockey players and
figure skaters), and those who practice for extended hours, exposures may
be of particular concern. For other users and spectators, exposures are rel-
atively transient.
F. Arena events
A variety of events involving motor vehicle operation are held in indoor
arenas. These include tractor pulls, monster truck shows, and motorcross
(motorcycle) events. Mean instantaneous arena CO concentrations in the
range of 68 to 436 ppmv have been reported for Canadian tractor pulls. Mean
CO concentrations for three different arena competitions (tractor pulls and
monster truck shows) of 79, 106, and 140 ppmv have been reported for U.S.
arenas. Average 5-hour personal exposure concentrations of 38 ppmv and a
peak (3 minutes) of 226 ppmv CO have been reported in Canadian motor-
cross competitions.
