Exposures to Organophosphate Esters and Respiratory Morbidity among School-Aged Children with Asthma

Abstract

Organophosphate esters (OPEs) are an emerging class of chemicals used in a variety of consumer products as flame retardants, plasticizers, and additives. While prior epidemiologic studies suggest that OPEs may impact respiratory health, results remain inconclusive. We examined associations between urinary biomarkers of OPEs and symptoms of respiratory morbidity in a panel study of 147 predominantly Black school-aged children with asthma living in Baltimore City, Maryland. The study consisted of up to four seasonal, week-long, in-home visits where urine samples and self-reported asthma symptoms were collected on days 4 and 7 (n samples = 438). We quantified concentrations of nine urinary OPE biomarkers: bis­(2-chloroethyl) phosphate (BCEtp), bis­(1-chloro-2-propyl) phosphate (BCPP), bis­(1,3-dichloro-2-propyl) phosphate (BDCIPP), di-n-butyl phosphate (DBuP), di-benzyl phosphate (DBzP), di-o-cresylphosphate (DOCP), di-p-cresylphosphate (DPCP), di-(2-propylheptyl) phthalate (DPHP), and 2,3,4,5-tetrabromo benzoic acid (TBBA). We estimated prevalence odds ratios (POR) of respiratory morbidity symptoms using logistic regression with generalized estimating equations to account for our repeated measure design. We assessed BDCIPP and DPHP as continuous (log2) concentrations and dichotomized exposure of BCEtP, DBuP, and DPCP (detect vs non-detect) based on their lower detection frequencies. We adjusted models for season, visit day, age, gender, caregiver education, health insurance type, exposure to household smoking, atopy, and PM2.5. Higher DPHP concentrations were significantly associated with odds of daytime symptoms (POR: 1.26; 95% CI: 1.04–1.53; p = 0.02) where daytime symptoms consisted of trouble breathing due to asthma, reporting bother caused by asthma, and/or limitation in activities due to asthma. DBuP detection was associated with use of rescue medication on the day of sample collection (POR: 2.36; 95% CI: 1.05–5.29; p = 0.04). We also observed several consistent, albeit non-significant (p > 0.05), positive associations for BCEtP and DPCP and respiratory morbidity measures. This is the first study to evaluate the relationship between OPE biomarkers and respiratory morbidity symptoms in children with asthma, and findings suggest that further studies are warranted to confirm whether these associations are causal.

Convenient Self-Heating Instant Food Causes Significant Increasing Human Exposure to Organophosphate Esters

“…Despite this, our research goal was clearly accomplished by demonstrating a significant increase in human exposure to OPEs through SHLBs. Newly published studies have suggested that OPE exposure may contribute to or be associated with thyroid function alterations and thyroid cancer occurrence, increase the odds of daytime asthma symptoms in school-aged children, negatively affect female reproduction, and elevate the risk of type 2 diabetes in older adults . Therefore, the SHLB, which was verified as a non-negligible OPE exposure pathway, should be given particular attention.…”

“…Due to their physical mixing rather than chemical bonding with industrial materials, OPEs can easily leach into the surrounding environment. , Ubiquitous occurrences of OPEs have been identified in air, drinking water, indoor and outdoor dust, , living environments, and global foodstuffs, , all of which are important exposure pathways of humans. Recent studies have indicated potential adverse effects of OPEs on humans, including but not limited to hepatotoxicity, neurotoxicity, endocrine disruption, reproductive toxicity, and developmental toxicity. − The evidence has drawn significant public attention due to both OPEs’ abundant presence and their potential impact on human health.…”