Table 1—

Characteristics of study subjects

ShunyiTongxianTotal
Subjects n74251510322528
Sex
 Male3583 (48.3)7381 (48.9)10978 (48.7)
Age group*
 <30 yrs1614 (21.7)3735 (24.7)5349 (23.7)
 30–49 yrs3720 (50.1)7003 (46.4)10723 (47.6)
 >50 yrs2091 (28.2)4365 (28.9)4365 (28.9)
Smoking
 Nonsmokers5199 (70.0)10521 (69.6)15711 (69.7)
 Exsmokers104 (1.4)176 (1.2)280 (1.2)
 Current smokers2122 (28.6)4415 (29.2)6537 (29.0)
Exposure
 Any chemical*600 (8.1)3418 (22.6)4018 (17.8)
 Insecticide*64 (0.9)642 (4.2)706 (3.1)
 Fertiliser*253 (3.4)2992 (19.8)3245 (14.4)
Fuel
 Gas*5547 (74.7)12243 (81.1)17790 (79.0)
 Coal*5986 (80.6)12001 (79.5)17987 (79.8)
 Wood*1401 (18.9)2995 (19.8)4396 (19.5)
 Cornstalk*416 (5.6)3867 (25.6)4283 (19.0)
 Manure*1 (0.0)13 (0.1)14 (0.1)
  • Data are presented as n (%)

  • *: p<0.05 for male versus female prevalence (Chi-squared test)