Abstract PS-320 Table 1
Pollutants and
Croup incidence
Areas with traffic load >1.500
motor vehicles/ hour
Areas with traffic load <300
motor vehicles/ hour
P*
SO2 (mg/m3)0.148 ± 0.1040.000 ± 0.000<0.01
NO2 (mg/m3)0.045 ± 0.0160.009 ± 0.008<0.01
Particulate matter (mg/m3)0.274 ± 0.0820.190 ± 0.079<0.05
CO (mg/m3)3.317 ± 0.7162.275 ± 0.411<0.01
Annual incidence of croup
in children
(cases per 1000 child population)
10.781.08<0.01
  • * non-parametric Mann-Whitney test and Wald-Wolfowitz Runs Test