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Mixtures Specialty Section

Upcoming Webinar

Risk Assessment Specialty Section (RASS)
with the
Mixtures Specialty Section (MixSS)

Jointly Sponsored Webinar

Featuring Graduate and Post-doctoral 2017 MixSS Award Winners


(See Below for Instructions on Webinar Access)

Use of Chemometrics and Multivariate Statistical Analysis to Determine Toxic Constituents Within Various Crude Oils

Joshua Salley, PhD
Ramboll Environ Consulting Firm

The objective of this project is to develop a procedure for estimating human health risk of crude oil exposure from analysis of its compositional profile. We have analyzed eleven crude oils from different geographical locations, including three from the Deepwater Horizon accident, with gas chromatography/mass spectroscopy and 22 total health were outcomes monitored. Partial Least Squares regressions (PLSr) successfully modelled select outcomes adversely affected by the different crude oils, and constituents with the greatest weights determined by their Variable Importance Plot (VIP) were identified via the Agilent Chemstation NIST08 Library Database.

Webinar Presentation

Temporal Trends of Cumulative Risks from Six Phthalates in Biomonitoring Data

Jeanette Reyes, PhD
Oak Ridge Institute for Science and Education (ORISE)
Research Participant, hosted at US EPA, RTP, NC

Phthalates are used in a wide range of consumer goods, resulting in exposures to specific phthalates that vary over time in accordance with changes in product use and how phthalates are utilized. We investigated trends in estimates of daily intake dose and several cumulative risk metrics, including the Hazard Quotient (HQ), Hazard Index (HI), and Maximum Cumulative Ratio (MCR) for six phthalates from 2005 to 2014 using metabolite biomonitoring data collected from spot urine samples under the National Health and Nutrition Examination Survey (NHANES). Over this period, there was a 2.2-fold decrease in the mean HI (0.34 to 0.15) and a 7.2-fold decrease in the percentage of participants with an HI > 1 (5.7% to 0.8%), indicating an overall decrease in combined exposure to these phthalates. Children (aged 6–11 years) had higher mean HI values than either adolescents (aged 12–19 years) or adults (aged 20+ years) during this period. MCR values were generally low and inversely correlated with HI. This indicated that a single phthalate usually drove the hazards for highly exposed individuals. However, the average value of MCR increased 1.2-fold (1.7–2.1) over this period indicating an increasing need to consider exposures to multiple phthalates in this group. (The views expressed in this abstract are those of the authors and do not necessarily reflect the views or policies of the U.S. Environmental Protection Agency.)

Webinar Presentation

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