Findings from a new ECHO PATHWAYS study were published in Environmental International. Co-investigator Dr. Christine Loftus was first author, and mPI Dr. Kaja LeWinn was last author. The paper examined associations between pregnancy exposure to phthalates, compounds found in common plastics, and child neurodevelopment at age 4-6 years old. A novel aspect of the study was demonstration of a new statistical method for analyzing mixtures of chemicals that was developed by Drs. Drew Day and Adam Szpiro, co-investigators on the PATHWAYS study. The team measured 22 phthalate metabolites in third-trimester urine from 1,015 mother-child dyads participating in the diverse CANDLE study and assessed neurodevelopment using child IQ at age 4-6 years old. The results indicted null associations between prenatal phthalate mixtures and language and IQ, adding to a complicated existing literature base suggesting that prenatal and early life phthalate exposure may exert neurotoxicity on developing children. The new statistical method described in this paper, a permutation test extension to weighted quantile sum regression, will be used in future PATHWAYS analyses of complex environmental exposures.
