Methodology for collecting, storing, and analyzing human milk for volatile organic compounds

US Centers for Disease Control and Prevention, Division of Laboratory Sciences, National Center for Environmental Health, Atlanta, GA 30341, USA.
Journal of Environmental Monitoring (Impact Factor: 2.18). 03/2010; 12(6):1265-73. DOI: 10.1039/b927022a
Source: PubMed


Biomonitoring, or the measurement of environmental chemicals in human tissues and fluids, is used to supplement-and in some cases replace-more traditional exposure assessments which measure chemicals in environmental media. Volatile organic compounds (VOCs) in physiological fluids are biomarkers of exposure that present numerous challenges for sample collection and analysis. To date, a thorough evaluation of methods for collection and analysis of breast milk samples for volatiles has not been conducted. In this paper, we describe the development and validation of methods for collecting, storing, and analyzing 36 volatile organic compounds (VOCs) in breast milk to assess VOC exposure of lactating women and nursing infants. Volatile analyte loss was minimized by collecting and storing samples in containers with small headspace volume resulting in recovery >or=70% for all 10 VOCs detected in most breast milk samples. Potential contamination by chloroform, benzene, toluene, ethylbenzene, xylenes, and methyl-tert-butyl ether was minimized by using specially treated sample collection materials. Method detection limits in the low parts per trillion range were achieved by using solid-phase microextraction headspace sampling, gas chromatography, and selective ion monitoring mass spectrometry. We used this method to analyze 3 mL aliquots of breast milk collected from 12 women and found that 10 of the 36 VOCs were detectable in most samples (median values follow): m/p-xylene, 0.539 ng mL(-1); toluene, 0.464 ng mL(-1); 1,4-dichlorobenzene, 0.170 ng mL(-1); tetrachloroethylene, 0.165 ng mL(-1); o-xylene, 0.159 ng mL(-1); ethylbenzene, 0.0149 ng mL(-1); styrene, 0.129 ng mL(-1); benzene, 0.080 ng mL(-1); chloroform, 0.030 ng mL(-1); and methyl-tert-butyl ether, 0.016 ng mL(-1).

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Available from: Benjamin C Blount, Dec 11, 2014
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    • "Urinary mercapturic and mandelic acid metabolites will be included in future NHANES assessments (Alwis et al. 2012). A few studies have measured styrene in human saliva and breast milk (Blount et al. 2010; Sanchez et al. 2012). Other chemicals. "
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    ABSTRACT: Exposure to chemicals that cause rodent mammary gland tumors is common, but few studies have evaluated potential breast cancer risks in humans. The goal of this paper is to facilitate measurement of biomarkers of exposure to potential breast carcinogens in breast cancer studies and biomonitoring. We conducted a structured literature search to identify measurement methods for exposure biomarkers for 102 chemicals that cause rodent mammary tumors. To evaluate concordance, we compared human and animal evidence for agents identified as plausibly linked to breast cancer in major reviews. To facilitate future application of exposure biomarkers, we compiled information about relevant cohort studies. Exposure biomarkers have been developed for nearly three-quarters of these rodent mammary carcinogens. Methods have been published for 73 of the chemicals. Some of the others could be measured with modified versions of existing methods for related chemicals. Exposure to 62 has been measured in humans, 45 in a non-occupationally exposed population. US CDC has measured 23 in the US population. Seventy-five of the rodent mammary carcinogens fall into 17 groups, based on exposure potential, carcinogenicity, and structural similarity. Carcinogenicity in humans and rodents is generally consistent, although comparisons are limited because few agents have been studied in humans. We identified 44 cohort studies that have recorded breast cancer incidence and stored biological samples, with a total of over 3.5 million enrolled women. Exposure measurement methods and cohort study resources are available to expand biomonitoring and epidemiology related to breast cancer etiology and prevention.
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    • "Other studies have looked for specific organic compounds in the headspace above milk using SPME with GCMS (four VOCs [171], monocyclic aromatic amines [172], phthalate esters [173], and benzene and alkylbenzenes [17] [174]). A broader study, also using the SPME method, attempted to quantify 36 different VOCs [175] and identified 10 compounds whose median concentration across 12 samples was above the 'lowest recordable level'. Buettner has analysed the volatiles from milk and in one study identified 45 odour-active consituents, using olfactory GC in combination with GC-MS [176]. "
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    ABSTRACT: A compendium of all the volatile organic compounds (VOCs) emanating from the human body (the volatolome) is for the first time reported. 1840 VOCs have been assigned from breath (872), saliva (359), blood (154), milk (256), skin secretions (532) urine (279), and faeces (381) in apparently healthy individuals. Compounds were assigned CAS registry numbers and named according to a common convention where possible. The compounds have been grouped into tables according to their chemical class or functionality to permit easy comparison. Some clear differences are observed, for instance, a lack of esters in urine with a high number in faeces. Careful use of the database is needed. The numbers may not be a true reflection of the actual VOCs present from each bodily excretion. The lack of a compound could be due to the techniques used or reflect the intensity of effort e.g. there are few publications on VOCs from blood compared to a large number on VOCs in breath. The large number of volatiles reported from skin is partly due to the methodologies used, e.g. collecting excretions on glass beads and then heating to desorb VOCs. All compounds have been included as reported (unless there was a clear discrepancy between name and chemical structure), but there may be some mistaken assignations arising from the original publications, particularly for isomers. It is the authors' intention that this database will not only be a useful database of VOCs listed in the literature, but will stimulate further study of VOCs from healthy individuals. Establishing a list of volatiles emanating from healthy individuals and increased understanding of VOC metabolic pathways is an important step for differentiating between diseases using VOCs.
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    ABSTRACT: Potential chronic health risks for children and prospective parents exposed to ethylbenzene were evaluated in response to the Voluntary Children's Chemical Evaluation Program. Ethylbenzene exposure was found to be predominately via inhalation with recent data demonstrating continuing decreases in releases and both outdoor and indoor concentrations over the past several decades. The proportion of ethylbenzene in ambient air that is attributable to the ethylbenzene/styrene chain of commerce appears to be relatively very small, less than 0.1% based on recent relative emission estimates. Toxicity reference values were derived from the available data, with physiologically based pharmacokinetic models and benchmark dose methods used to assess dose–response relationships. An inhalation non-cancer reference concentration or RfC of 0.3 parts per million (ppm) was derived based on ototoxicity. Similarly, an oral non-cancer reference dose or RfD of 0.5 mg/kg body weight/day was derived based on liver effects. For the cancer assessment, emphasis was placed upon mode of action information. Three of four rodent tumor types were determined not to be relevant to human health. A cancer reference value of 0.48 ppm was derived based on mouse lung tumors. The risk characterization for ethylbenzene indicated that even the most highly exposed children and prospective parents are not at risk for non-cancer or cancer effects of ethylbenzene.
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