title: Correction and comparability of phthalate metabolite measurements of Canadian biomonitoring studies (2007-2012).
abstract: Phthalate metabolites are often measured in biomonitoring studies to evaluate a population's exposure to ubiquitous phthalates. During the course of national biomonitoring studies in Canada, we identified an issue with the accuracy of several commercial phthalate metabolite standards that are commonly used in such studies. The validity of the results from these studies was then questioned. Altogether, three (3) large studies were affected, involving a total of 9302 samples and 105000 individual phthalate metabolite measurements. Data from our previous investigation suggested that the inaccuracies in the commercially-available phthalate metabolite standards were compound- and lot-specific. Therefore, an approach was developed to derive correction factors for each lot of phthalate metabolite standard and was applied to the previously-acquired measurements with the goal of obtaining accurate and comparable data. A statistical analysis was performed to support the approach. It is expected that the corrected phthalate metabolite data from all three Canadian biomonitoring studies are comparable to one another. However, caution is still advised when comparing data obtained from biomonitoring studies for which the calibration standards have not been investigated for their accuracy. Suggestions are made based on quality assurance aspects to improve the validity of phthalate metabolite measurements.
authors: Centre de Toxicologie du Québec (CTQ), Institut National de Santé Publique du Québec (INSPQ), 945 Ave Wolfe, Québec, Québec G1V 5B3, Canada. Electronic address: eric.langlois@inspq.qc.ca.
authors: Éric
authors: É
authors: Langlois
authors: National Biomonitoring Section, Chemicals Surveillance Bureau, Environmental and Radiation Health Sciences Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, 269 Laurier Ave. W., Ottawa, Ontario K1A 0K9, Canada.
authors: Gurusankar
authors: G
authors: Saravanabhavan
authors: Population Studies Division, Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Environmental Health Center, 50 Colombine Dr., Tunney's Pasture, Ottawa, Ontario K1A 0K9, Canada.
authors: Tye E
authors: TE
authors: Arbuckle
authors: Household Survey Methods Division, Statistics Canada, R.H. Coats Building, 100 Tunney's Pasture Driveway, Ottawa, Ontario K1A 0T6, Canada.
authors: Suzelle
authors: S
authors: Giroux
mesh_terms: D002170:Canada; D004784:Environmental Monitoring / Q000379:methods* / Q000592:standards*; D006801:Humans; D010795:Phthalic Acids / Q000737:chemistry / Q000652:urine*; D015203:Reproducibility of Results
chemical_list: D010795:Phthalic Acids; C032279:phthalic acid
keywords: Accuracy; Biomonitoring; Comparability; Correction factor; Phthalate metabolites; Standards