Table 2

Distribution of daily air pollution concentrations, meteorological factors and stroke hospitalisations in Shenzhen

VariablesMeanSDMinP25P50P75Max
Air pollutants
 PM2.5 (μg/m3)30.1166.316.82739.996.1
 NO2 (μg/m3)33.211.111.3253139.584.8
 O3 (μg/m3)56.922.116.938.852.971.9147.8
Meteorological factors
 Temperature (℃)23.55.73.519.025.128.233.0
 Relative humidity (%)74.712.219.069.076.083.099.0
 Air pressure (hPa)1005.66.6986.81000.71005.31010.61027.3
Stroke cases
 All strokes61.215.723.051.059.070.0182.0
 Type
 Intracerebral haemorrhage10.44.21.07.010.013.040.0
 Cerebral infarction47.613.117.039.046.054.0143.0
 Sex
 Male37.910.215.031.037.043.0113.0
 Female23.37.47.018.022.027.077.0
 Age (years)
 <403.72.10.02.04.05.012.0
 40–6430.28.49.024.030.035.090.0
 ≥6527.38.79.021.026.032.0101.0
 Education
 Primary school or below16.95.43.013.016.020.051.0
 Junior high school24.47.97.019.023.029.085.0
 High school or above19.97.65.014.019.024.067.0
  • NO2, nitrogen dioxide; O3, ozone; PM2.5, fine particulate matter.