Table 1

Study population stratified by covariates with the weighted proportion in each stratum, the age adjusted geometric mean urine cadmium/creatinine level, and age adjusted forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) ratio for each stratum

VariableNWeighted %Geometric mean (SE) urinary cadmium/creatinine level (μg/g)Mean (SE) FEV1/FVC (%)
From the Third National Health and Nutrition Examination Survey, 1988–94.
Age
    85+2900.70.68 (0.03)72.6 (0.7)
    75–8412124.10.64 (0.03)71.1 (0.4)
    65–7418789.00.69 (0.02)71.1 (0.4)
    45–64376225.00.53 (0.02)75.0 (0.2)
    25–44613544.90.25 (0.01)80.8 (0.2)
    17–24274716.40.11 (0.01)85.3 (0.2)
Race/ethnicity
    White646976.20.30 (0.01)78.3 (0.2)
    Black450910.90.36 (0.01)80.4 (0.2)
    Mexican-American44105.30.31 (0.01)80.7 (0.2)
    Other6367.70.34 (0.02)80.4 (0.4)
Sex
    Male754148.20.26 (0.01)77.4 (0.2)
    Female848351.80.36 (0.01)80.0 (0.2)
Education level (years)
    <12672725.60.37 (0.01)78.5 (0.3)
    12458231.00.33 (0.02)78.5 (0.2)
    ⩾13471543.50.26 (0.01)79.1 (0.2)
Job category
    Agriculture14565.90.27 (0.02)77.9 (0.4)
    Mining/manufacturing373524.30.32 (0.01)78.3 (0.3)
    Transport7765.60.35 (0.02)77.6 (0.5)
    Service588339.10.30 (0.01)79.2 (0.2)
    Unemployed12856.10.34 (0.02)78.6 (0.4)
    Retail288919.10.30 (0.01)79.1 (0.2)
Smoking status
    Current smoker432130.00.46 (0.01)76.5 (0.2)
    Former smoker359223.40.32 (0.01)78.1 (0.3)
    Never smoker811146.60.23 (0.01)80.7 (0.2)
Body mass index (kg/m2)
    <18.53582.50.44 (0.03)78.3 (1.1)
    18.5–24628244.20.30 (0.01)78.4 (0.2)
    25–29541631.60.31 (0.01)78.3 (0.2)
    ⩾30396821.60.31 (0.01)79.2 (0.3)
Years ago quit smoking
    >0–10151610.50.37 (0.01)77.5 (0.4)
    >10–209396.20.33 (0.02)76.8 (0.3)
    >20–305333.40.27 (0.02)74.9 (1.3)
    >30–402361.20.40 (0.05)74.3 (0.7)
    >402100.90.40 (0.06)76.8 (1.2)
    Not applicable1259077.90.31 (0.01)79.0 (0.1)
Pack years of cigarettes
    ⩾605973.80.61 (0.05)73.7 (1.7)
    ⩽30–5911908.50.54 (0.02)77.4 (0.3)
    >0–29588639.60.36 (0.01)78.2 (0.2)
    0835148.00.23 (0.01)80.6 (0.1)
Cotinine level (ng/ml)
    >100341525.40.50 (0.02)76.1 (0.2)
    ⩽15–10010045.60.28 (0.02)78.2 (0.4)
    ⩽0.3–15387622.50.27 (0.02)79.6 (0.2)
    0.05–0.29511431.90.26 (0.01)79.7 (0.2)
    Non-detectable177110.30.22 (0.02)80.1 (0.3)
    Missing8444.30.30 (0.02)79.3 (0.4)
Total16024100.00.31 (0.01)78.7 (1.1)