Baby care products: possible sources of infant phthalate exposure.
OBJECTIVE
Phthalates are man-made chemicals found in personal care and other products. Recent studies suggest that some phthalates can alter human male reproductive development, but sources of infant exposure have not been well characterized. We investigated the relationship between phthalate metabolite concentrations in infant urine and maternal reported use of dermally applied infant care products.


METHODS
We measured 9 phthalate metabolites in 163 infants who were born in 2000-2005. An infant was considered to have been exposed to any infant care product that the mother reported using on her infant within 24 hours of urine collection. Results of multiple linear regression analyses are reported as the ratio of metabolite concentrations (with 95% confidence intervals) in exposed and unexposed infants. We standardized concentrations by forming z scores and examined combined exposure to multiple metabolites.


RESULTS
In most (81%) infants, > or = 7 phthalate metabolites were above the limit of detection. Exposure to lotion was predictive of monoethyl phthalate and monomethyl phthalate concentrations, powder of monoisobutyl phthalate, and shampoo of monomethyl phthalate. Z scores increased with number of products used. Most associations were stronger in younger infants.


CONCLUSIONS
Phthalate exposure is widespread and variable in infants. Infant exposure to lotion, powder, and shampoo were significantly associated with increased urinary concentrations of monoethyl phthalate, monomethyl phthalate, and monoisobutyl phthalate, and associations increased with the number of products used. This association was strongest in young infants, who may be more vulnerable to developmental and reproductive toxicity of phthalates given their immature metabolic system capability and increased dosage per unit body surface area.
Sathyanarayana
Sheela
S
Department of Occupational and Environmental Health Sciences, Division of General Pediatrics, Child Health Institute, University of Washington, Building 296200, NE 74th St, Seattle, WA 98115-8160, USA. sathyana@u.washington.edu
Karr
Catherine J
CJ
Lozano
Paula
P
Brown
Elizabeth
E
Calafat
Antonia M
AM
Liu
Fan
F
Swan
Shanna H
SH
D002675:Child, Preschool; D003358:Cosmetics / Q000737:chemistry*; D004781:Environmental Exposure / Q000032:analysis*; D005260:Female; D006801:Humans; D007223:Infant; D007224:Infant Care; D016014:Linear Models; D008297:Male; D010795:Phthalic Acids / Q000378:metabolism / Q000652:urine*; D010968:Plasticizers / Q000378:metabolism*; D011208:Powders / Q000737:chemistry
D003358:Cosmetics; D010795:Phthalic Acids; D010968:Plasticizers; D011208:Powders; C517284:monomethyl phthalate