Phthalate Exposure and Respiratory Diseases Among Adults and Children: the US NHANES 2007-2016

Abstract

Background/Aim: Phthalates are used as plasticizers in many consumer products. Although they have associations with multiple adverse health outcomes, studies on phthalate exposure and respiratory outcomes are limited. The objective of our study was to examine the association between phthalate exposure and respiratory diseases in the US population. Methods: Using data from the National Health and Nutrition Examination Survey (NHANES) 2007-2016, we analyzed the data on twelve urinary metabolites and current respiratory diseases (asthma, bronchitis, and emphysema) among adults (≥ 20 years of age) and children and adolescents (6-19 years of age). The logistic regression was conducted to estimate the odds ratios (ORs) per one log10 unit increase in the concentration of urinary phthalate metabolites, and age, gender, race, waist/height ratio, urinary creatinine, serum cotinine level, and poverty index ratio were included in the model for adjustment. Analyses were conducted separately on children and adults to investigate the difference by age. Results: In adults, mono-benzyl phthalate (MBzP) was positively associated with asthma and chronic bronchitis (OR 1.34; 95% CI 1.11-1.61 and OR 1.39; 95% CI 1.02-1.91). Mono-(3-carboxypropyl) phthalate and mono-(carboxynonyl) phthalate also showed the significant associations with chronic bronchitis (OR 1.38; 95% CI 1.04-1.84 and OR 1.44; 95% 1.03-2.02). Although there was a trend with elevated risk between low-molecular-weight phthalates and emphysema, it was not significant (OR 1.26; 95% CI 0.98-1.62 for mono-ethyl phthalate, and OR 1.28; 95% CI 0.80-2.04 for mono-isobutyl phthalate). In children and adolescents, no evidence of associations between phthalates and asthma was found. Conclusion: Our cross-sectional study advocates for the positive associations of high-molecular -weight phthalate metabolites with respiratory diseases among adults. However, in children, the evidence of such association was absent, for which further analysis and research are recommended.