Serum Cadmium and Lead, Current Wheeze, and Lung Function in a Nationwide Study of Adults in the United States

Abstract

Background: Cadmium and lead are hazardous pollutants.

Objective: We examined the relation between serum levels of cadmium and lead and current wheeze, current asthma, and lung function in US adults.

Methods: A cross-sectional study of 13,888 adults aged 20 to 79 years in 2007-2012 National Health and Nutrition Examination Survey (NHANES) was considered. Multivariable logistic or linear regression was used for the analyses of current wheeze, current asthma, and lung function measures (forced expiratory volume in 1 second [FEV₁]% predicted, forced vital capacity [FVC]% predicted, FEV₁/FVC% predicted, and fractional exhaled nitric oxide [FeNO]), which were conducted first in all participants, and then separately in never/former smokers and current smokers.

Results: High levels of serum cadmium were significantly associated with current wheeze in all participants and in current smokers (odds ratio for fourth vs first quartile = 2.84, 95% confidence interval = 2.07-3.90, P_{for linear trend} < .01), as well as with current asthma in current smokers. Serum lead was not significantly associated with current wheeze or current asthma, regardless of smoking status. Serum cadmium was significantly associated with lower FEV₁% predicted, FEV₁/FVC% predicted, and FeNO in all participants and in never/former smokers, and serum lead was significantly associated with lower FEV₁/FVC% predicted in all participants, with similar findings in never/former smokers and in current smokers.

Conclusions: Our findings suggest that exposure to cadmium is associated with an increased risk of wheeze and asthma in US adults who currently smoke. Moreover, our results suggest that exposure to cadmium or lead has negative effects on lung function in nonsmoking US adults.

Keywords: Asthma; Lung functions; Serum cadmium; Serum lead.