A Non-Targeted Method for Measuring Multiple Chemical Exposures Amoung a Demographically Diverse Population of Pregnant Women in Northern CaliforniaEPA Grant Number: R835643
Title: A Non-Targeted Method for Measuring Multiple Chemical Exposures Amoung a Demographically Diverse Population of Pregnant Women in Northern California
Investigators: Woodruff, Tracey J. , Sirota, Marina , Morello-Frosch, Rachel , Gerona, Roy
Institution: University of California - San Francisco
EPA Project Officer: Klieforth, Barbara I
Project Period: October 1, 2014 through September 30, 2017 (Extended to September 30, 2018)
Project Amount: $900,000
RFA: New Methods in 21st Century Exposure Science (2013) RFA Text | Recipients Lists
Research Category: Human Health , Safer Chemicals , Health
We propose to apply an innovative non-targeted biomonitoring method using liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF/MS) to evaluate everyday exposure to over 700 chemicals classified as Environmental Organic Acids (EOAs) and the extent to which exposures vary amount different racial/ethnic and socio-economic groups of pregnant women. Our new LC-QTOF/MS non-targeted screening methodology has the capacity to directly (without enzymatic hydrolysis) and simultaneously screen for approximately 10-times more EOAs than what is currently being biomonitored in the National Health and Nutrition Examination Survey. We focus on EOAs, which are industrial compounds with at least one ionizable proton, because: 1) their chemical structure facilitates a higher rate of analytical detection; 2) many of their chemical structures are similar to hormones, increasing the potential for endocrine disruption, which can negatively affect fetal development; and 3) many are produced in high quantities and used in a wide range of consumer products, but have not been extensively biomonitored in pregnant women. We will use liquid chromatography tandem mass spectrometry (LC-MS/MS) to confirm the presence and levels of select EOAs identified through our non-targeted screening. Finally, we will assess differences in EOA exposures by race/ethnicity and socio-economic status. We hypothesize that pregnant women are exposed to more EOAs than previously documented, and that EOA exposure varies by race/ethnicity and SES, resulting in disproportionate EOA body-burdens among certain subpopulations.
We will collect blood samples from 200 demographically diverse 2nd trimester pregnant women seeking prenatal care at two clinics at UCSF, San Francisco General Hospital (primarily low-income) and Moffitt-Long Hospital (primarily high-income). The population is about 30% Caucasian, 30% Latino, 10% African-American and 12% Asian. We will use our novel non-targeted biomonitoring method, LC-QTOF/MS, to screen for 729 environmental organic acids in 200 second-trimester maternal serum samples, We will conduct targeted analysis of four selected EOAs from our non-targeted screening using LC-MS/MS to confirm the presence and levels of chemicals identified through the QTOF analysis. Chemicals for the targeted analysis will be selected based on use in everyday consumer products and high production in the US, detected in high frequency in study participants, potential for developmental health risk, and novel exposures. Finally, we will evaluate potential differences in exposure levels by race/ethnicity and SES to six EOAs, four already identified and an additional two which are selected for targeted analysis based on screening data indicating high potential for racial/ethnic and/or SES disparities.
We will have pioneered a screening method for over 700 environmental chemicals, and anticipate identifying chemicals previously unmeasured in biological samples. Further, we will provide novel data on the extent to which pregnant women are potentially exposed to these chemicals, and quantify exposures to six EOAs for which exposure has been poorly characterized in this vulnerable population. Finally, we will enhance understanding of racial/ethnic and economic differences in chemical exposures. Our innovative method of chemical screening will significantly advance biomonitoring science through its efficient approach that broadly characterizes multiple chemical exposures in ways that can help prioritize chemicals for identifying important sources of exposure, risk assessment and exposure education activities, and identify health risks to better protect public health.