Article pubs.acs.org/est
High Exposure to Organophosphate Flame Retardants in Infants: Associations with Baby Products Kate Hoffman,† Craig M. Butt,† Albert Chen,† Alexander T. Limkakeng, Jr.,‡ and Heather M. Stapleton*,† †
Nicholas School of the Environment, Duke University, Durham, North Carolina 90328, United States Division of Emergency Medicine, Duke University, Durham, North Carolina 90328, United States
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ABSTRACT: Infant products containing polyurethane foam are commonly treated with organophosphate flame retardants (PFRs), including tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) and triphenyl phosphate (TPHP). Infants may have greater exposure due to greater contact with these products, yet little is known about levels of exposure or the factors contributing to higher exposure. We recruited children age 2−18 months from North Carolina to investigate PFR exposure (n = 43; recruited 2014−2015). Parents provided information on potential sources and modifiers of exposure, and reported whether they owned common infant products. We measured five PFR metabolites in urine samples collected from children. TDCIPP and TPHP metabolites (bis(1,3dichloro-2-propyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP)) were most commonly detected (>93% detect). Other metabolites were detected infrequently (16 products had BDCIPP levels that were 6.8 times those with 90% of samples), and we recently reported that urine samples from toddlers have higher levels of PFR metabolites than those from their mothers.10,17−23 Pooled samples from Australia also demonstrate widespread exposure and suggest that levels decrease with age.23 Although these samples clearly suggest that infants may have higher levels of exposure to PFRs than adults,23 the levels of exposure experienced by individual infants have not been measured. The primary objective of this study was to measure levels of exposure to several PFRs, particularly TDCIPP and TPHP, in children age 2−18 months. Additionally, we sought to measure potential sources of exposure (e.g., infant products and time in various microenvironments) and behaviors that may be related to higher levels of exposure. Received: July 23, 2015 Revised: October 23, 2015 Accepted: November 9, 2015
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DOI: 10.1021/acs.est.5b03577 Environ. Sci. Technol. XXXX, XXX, XXX−XXX
Article
Environmental Science & Technology
Figure 1. Structure of parent PFRs and metabolites.
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MATERIALS AND METHODS Study Population. Infants (2−18 months of age) were recruited from the Durham, North Carolina area between September 2014 and March 2015 (three participants lived more than 50 miles from Durham). Two methods of recruitment were used: (1) infants obtaining care at the Duke University Emergency Department (ER) were invited to participate if a urine sample was ordered as part of their clinical evaluation (n = 5); and (2) infants were recruited from the general community using flyers posted in public locations and on social media (n = 38). Children provided a urine sample and their parents completed a survey about the child and their home environment. Parents gave informed consent before participation in any aspect of the study and all procedures were carried out in accordance with a human subjects research protocol approved by the Duke University Institutional Review Board. Questionnaire. Parents completed a questionnaire about their child and their home environment. Information collected about the child included demographic data (e.g., sex; age; race/ ethnicity; and height and weight at the most recent doctor visit); time activity data (e.g., time in the home and day care
attendance); and behavior and habit data (e.g., hand washing frequency and achievement of developmental milestones). Additional information about the family and their home was also obtained (e.g., family size, income, year of home construction). Parents were also shown pictures of common infant products and were asked to indicate whether their family owned the product or a similar version. For products that parents reported owning, they were also asked if they had purchased a flame retardant free version of the product. These products included a breastfeeding pillow, bassinette, crib, sleep positioner, stroller, highchair, car seat, baby carrier, play yard, swing, jumper, seat/chair, bouncer, activity mat, walker, changing pad, nursery glider/rocker, teething toys, and bath toys. Purchasing a flame retardant free product was uncommon (
