What Additional Factors Beyond State-of-the-Art Analytical Methods Are Needed for Optimal Generation and Interpretation of Biomonitoring Data?

Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Environmental Health Perspectives (Impact Factor: 7.98). 10/2009; 117(10):1481-5. DOI: 10.1289/ehp.0901108
Source: PubMed

ABSTRACT The routine use of biomonitoring (i.e., measurement of environmental chemicals, their metabolites, or specific reaction products in human biological specimens) to assess internal exposure (i.e., body burden) has gained importance in exposure assessment.
Selection and validation of biomarkers of exposure are critical factors in interpreting biomonitoring data. Moreover, the strong relation between quality of the analytical methods used for biomonitoring and quality of the resulting data is well understood. However, the relevance of collecting, storing, processing, and transporting the samples to the laboratory to the overall biomonitoring process has received limited attention, especially for organic chemicals.
We present examples to illustrate potential sources of unintended contamination of the biological specimen during collection or processing procedures. The examples also highlight the importance of ensuring that the biological specimen analyzed both represents the sample collected for biomonitoring purposes and reflects the exposure of interest.
Besides using high-quality analytical methods and good laboratory practices for biomonitoring, evaluation of the collection and handling of biological samples should be emphasized, because these procedures can affect the samples integrity and representativeness. Biomonitoring programs would be strengthened with the inclusion of field blanks.

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    • "During pooling, individual urine specimens were thawed, homogenised and aliquoted, after which the pooled sample was well-mixed, divided into smaller aliquots and frozen until analysis. A synthetic urine sample was included as a procedural blank (Calafat and Needham, 2009). No measures of creatinine or specific gravity were available for individual samples. "
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    ABSTRACT: Parabens, benzophenone-3 and triclosan are common ingredients used as preservatives, ultraviolet radiation filters and antimicrobial agents, respectively. Human exposure occurs through consumption of processed food and use of cosmetics and consumer products. The aim of this study was to provide a preliminary characterisation of exposure to selected personal care product chemicals in the general Australian population. De-identified urine specimens stratified by age and sex were obtained from a community-based pathology laboratory and pooled (n=24 pools of 100). Concentrations of free and total (sum of free plus conjugated) species of methyl, ethyl, propyl and butyl paraben, benzophenone-3 and triclosan were quantified using isotope dilution tandem mass spectrometry; with geometric means 232, 33.5, 60.6, 4.32, 61.5 and 87.7ng/mL, respectively. Age was inversely associated with paraben concentration, and females had concentrations approximately two times higher than males. Total paraben and benzophenone-3 concentrations are significantly higher than reported worldwide, and the average triclosan concentration was more than one order of magnitude higher than in many other populations. This study provides the first data on exposure of the general Australian population to a range of common personal care product chemical ingredients, which appears to be prevalent and warrants further investigation.
    Environment International 09/2015; 85:77-83. DOI:10.1016/j.envint.2015.09.001 · 5.56 Impact Factor
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    • "ly introduced into biological media during collection and analysis , contributing to spurious concentrations . In this regard , matrix blanks and special care to awareness of composition of laboratory plastics , machine filters , tubing , and dust levels are very important in controlling for background contamination and interpretation of results ( Calafat et al . , 2009 ; Ye et al . , 2013 ) ."
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    ABSTRACT: Women in the United States have breast milk concentrations of polybrominated diphenyl ethers (PBDEs) that are among the highest in the world, leading to concerns over the potential health implications to breastfeeding infants during critical stages of growth and development. Developing cost effective and sustainable methods for assessing chemical exposures in infants is a high priority to federal agencies and local communities. PBDE data are available in nationally representative serum samples but not in breast milk. As a method to predict PBDE concentrations in U.S. breast milk, we present the development of congener-specific linear regression partitioning models and their application to U.S. serum data. Models were developed from existing paired milk and serum data and applied to 2003-04 NHANES serum data for U.S. women. Highest estimated median U.S. breast milk concentrations were for BDE-47 (30.6 ng/g lipid) and BDE-99 (6.1 ng/g lipid) with the median concentration of Σ7PBDEs estimated at 54.2 ng/g lipid. Predictions of breast milk PBDE concentration were consistent with reported concentrations from 11 similarly timed U.S. studies. When applied to NHANES data, these models provide a sustainable method for estimating population-level concentrations of PBDEs in U.S. breast milk and should improve exposure estimates in breastfeeding infants.
    Environmental Science & Technology 04/2013; 47(9). DOI:10.1021/es305229d · 5.33 Impact Factor
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    • "External contamination can even preclude accurate analyses of phthalate diesters, which are detected in the cleanest laboratory reagents, sampling equipment, and analytical apparatus. Therefore, assessing human exposure to phthalates is routinely done by measuring biomarkers that cannot be formed in the environment (e.g., oxidized metabolites of phthalates) instead of the phthalate diesters themselves (Koch and Calafat 2009). Field blanks have been used to assess potential contamination during collection, processing, and/or transport of environmental samples (National Institute for Occupational Safety and Health 1994) and the importance of using field blanks in biomonitoring studies has been presented (National Research Council 2006; WHO 2011). "
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    ABSTRACT: Background: Biomonitoring studies are conducted to assess internal dose (i.e., body burden) to environmental chemicals. However, because of the ubiquitous presence in the environment of some of these chemicals, such as bisphenol A (BPA), external contamination during handling and analysis of the biospecimens collected for biomonitoring evaluations could compromise the reported concentrations of such chemicals. Objectives: We examined the contamination with the target analytes during analysis of biological specimens in biomonitoring laboratories equipped with state-of-the-art analytical instrumentation. Discussions: We present several case studies using the quantitative determination of BPA and other organic chemicals (i.e., benzophenone-3, triclosan, parabens) in human urine, milk, and serum to identify potential contamination sources when the biomarkers measured are ubiquitous environmental contaminants. Conclusions: Contamination with target analytes during biomonitoring analysis could result from solvents and reagents, the experimental apparatus used, the laboratory environment, and/or even the analyst. For biomonotoring data to be valid—even when obtained from high-quality analytical methods and good laboratory practices—the following practices must be followed to identify and track unintended contamination with the target analytes during analysis of the biological specimens: strict quality control measures including use of laboratory blanks; replicate analyses; engineering controls (e.g., clean rooms, biosafety cabinets) as needed; and homogeneous matrix-based quality control materials within the expected concentration ranges of the study samples.
    Environmental Health Perspectives 03/2013; 121(3):283-6. DOI:10.1289/ehp.1206093 · 7.98 Impact Factor
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