Association between Lung Function in Adults and Plasma DDT and DDE Levels: Results from the Canadian Health Measures Survey.

BACKGROUND: Although DDT [1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane] has been banned in many countries since the 1970s, it may still pose a risk to human respiratory health. In agriculture, DDT exposures have been associated with asthma and chronic bronchitis. However, little is known about the effect of DDT on lung function. OBJECTIVES: We examined DDT/DDE [1,1-bis-(4-chlorophenyl)-2,2-dichloroethene] concentrations in plasma and associations with lung function FVC (forced vital capacity), FEV₁ (forced expiratory volume in 1 sec), FEV₁/FVC ratio, and FEF_25%-75% (forced expiratory flow between 25% and 75% of FVC). METHODS: We used data on 1,696 participants 20-79 years of age from the Canadian Health Measures Survey (CHMS) and conducted multiple regression analysis to estimate associations between plasma p,p '-DDT/DDE and lung function. RESULTS: Almost all participants (> 99.0%) had detectable concentrations of plasma p,p '-DDE, but only 10.0% had detectable p,p '-DDT. Participants with detectable p,p '-DDT had significantly lower mean FVC (difference = 311 mL; 95% CI: -492, -130; p = 0.003) and FEV₁ (difference = 232 mL; 95% CI: -408,-55;p = 0.015) than those without. A 100-ng/g lipid increase in plasma p,p '-DDE was associated with an 18.8-mL decrease in mean FVC (95% CI: -29, -9) and an 11.8-mL decrease in mean FEV₁ (95% CI: -21, -3). Neither exposure was associated with FEV₁/FVC ratio or FEF_25%-75%. CONCLUSIONS: DDT exposures, which may have occurred decades ago, were still detectable among Canadians. Plasma DDT and DDE were negatively associated with lung function parameters. Additional research on the potential effects of DDT use on lung function is warranted. [ABSTRACT FROM AUTHOR]