Persistent organic pollutants (POPs) p,p'-dichlorodiphenyltrichloroethane (DDT), p,p'-dichlorodiphenyldichloroethylene (DDE), dieldrin, and hexabromobenzene (HBB) are capable of transplacental and lactational transfer, and may pose a particular health risk to the developing fetus. Serum is the traditional biological matrix for assessing exposure to POPs, but has many limitations. Chief among those are the invasive nature of, and expense associated with collection, storage and analysis. Dried blood spots (DBS) are a commonly employed method to measure pharmaceutical and tobacco derivatives in newborns and test for genetic abnormalities such as phenylketonuria. We propose here that DBS can be used to accurately and precisely quantify DDT, DDE, dieldrin, and HBB in newborns. DBS are a relatively non-invasive, cheaper, and more practical alternative to serum for assessing exposure to such toxicants. Employing DBS as a matrix for assessing in utero exposure also provides an opportunity for retrospective biomonitoring as well as in assessing multigenerational effects. In order to validate DBS as an exposure matrix, whole blood and DBS samples were collected from a subset (n=52) of the Michigan PBB cohort. GC-MS/MS analysis was used to quantify DDT, DDT, dieldrin, and HBB in both serum and DBS. Method detection limits for DBS were determined to be 0.082, 0.2, 0.312, and 1.93 ng/spot for DDE, dieldrin, DDT, and HBB, respectively. It was found that DBS can be used to accurately and precisely quantify DDT, DDE, and dieldrin (100 ± 20% and <15% RSD). A Bland-Altman assessment for agreement for DDE showed bias for DDE at ± 2SD, and DBS was observed to be higher in value at the latter portion of the Bland-Altman plot. However, serum DDE and quantitated DBS DDE were found to have a high degree of correlation, which demonstrates the potential of this method; correlation coefficient and associated p-value of 0.95 (p-value <0.0001). Based on an estimated costs assessment, DBS is approximately 85 times less expensive than serum using a sample population of 500. Our findings serve to highlight the potential and relevance of DBS as an exposure matrix for POPs such as DDT, DDE, dieldrin, and HBB.
Table of Contents
Materials and Methods 7
Tables and Figures 20
About this Master's Thesis
|Committee Chair / Thesis Advisor
|Validation and Characterization of Dried Blood Spots as an Exposure Matrix for Measuring Persistent Organic Pollutants ()
|2018-08-28 10:21:18 -0400