Association between urinary concentration of phthalate metabolites and allergic disorders in Korean children: Korean National Environmental Health Survey (KoNEHS) 2015-2017

Abstract

BACKGROUND AND AIM: Phthalates are common industrial chemicals used primarily as plasticizers that make plastic flexible. Children are more prone to these chemicals through various routes of exposure including dermal absorption, inhalation, and ingestion (such as food, water, and dust) than adults and several studies have reported that phthalate exposure may increase the risk of allergic diseases. Therefore, we aimed to examine the association between urinary concentration of phthalate metabolites and allergic disorders in a nationally representative sample of Korean children. METHODS: In this study, we used data on urinary phthalate metabolites, allergic symptoms such as atopic dermatitis (AD), asthma, and allergic rhinitis (AR), and serum total immunoglobin E (IgE) levels from participants aged 3–17 in the Korean National Environmental Health Survey 2015–2017. After adjusted for all covariates, Odds ratio (OR) and their 95% confidence intervals (95% CI) per one ln–unit increase change in the concentration of phthalate metabolites were estimated using logistic regression. RESULTS:Urinary high–molecular–weight phthalate metabolites (HMW) were positively associated with current AD and AR. A significant increase of the OR for high group of IgE levels with increase of urinary mono-(carboxynonyl) phthalate (MCNP) concentrations was found [OR=1.43 (1.06, 1.91)]. Mono–benzyl phthalate, mono–(carboxyoctyl) phthalate, and mono–(2–ethyl–5–oxohexyl) phthalate were positively associated with allergic multimorbidity which means co–occurrence of at least two allergic diseases in one individual. Children with high IgE were more likely to have an AR associated MCNP than those with low IgE or high IgE only (p = 0.007). Specifically, we estimated that 14.7% of total effect of MCNP on AR was mediated by IgE. However, no phthalate metabolites were significantly associated with current asthma. CONCLUSIONS:Our observations revealed that some HMW phthalate metabolites were positively associated with current allergic symptoms and high total IgE levels in children. These results suggested that environmental exposure to phthalates could enhance allergic response in children. KEYWORDS: Atopic dermatitis, Asthma, Allergic rhinitis, Allergic multimorbidity, Total immunogliblin E, Phthalate metabolites