Table 2—

Pollutant distribution across census classes

UrbanTownVillageHamletp-value
Subjects n241252612
Primary particles μg·m−314.79±0.1611.70±0.1411.26±0.1811.12±0.29<0.0001
Secondary particles μg·m−37.46±0.087.72±0.267.96±0.227.12±0.350.082
NO2 μg·m−320.29±0.3811.85±0.8212.93±0.589.96±0.94<0.0001
SO2 μg·m−33.99±0.162.86±0.482.71±0.132.14±0.12<0.0001
Number of ozone days >120 μg·m−314.25±0.2215.98±0.8617.33±0.6116.44±1.27<0.0001
AOT40 μg·m−3·h−111859.13±190.2413602.18±498.9813673.59±735.6013746.80±1056.48<0.0001
  • Data are presented as mean±sem, unless otherwise stated. AOT40 represents accumulated ozone dose, being the sum of the differences between the hourly mean and 40 ppb ozone concentrations for daylight hours exceeding this limit. These results are shown in the supplementary material.