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Newborn screening is the largest population-based genetic screening effort in the United States. The detection of treatable, inherited congenital disorders is a major public health responsibility. The Centers for Disease Control and Prevention's (CDC's) Newborn Screening Quality Assurance Program helps newborn screening laboratories ensure that testing accurately detects these disorders, does not delay diagnosis, minimizes false-positive reports, and sustains high-quality performance. For over 30 years, the CDC's Newborn Screening Quality Assurance Program has performed this essential public health service, ensuring the quality and accuracy of screening tests for more than 4 million infants born each year in the United States and millions more worldwide. The Program has grown from 1 disorder in 1978 for 31 participants to more than 50 disorders for 459 participants in 2009. This report reviews the Program's milestones and services to the newborn screening community. Copyright © 2010 by Elsevier Inc. [ABSTRACT FROM AUTHOR]

Objectives: Developing an expanded representation of the total testing process that includes contemporary elements of laboratory practice can be useful to understanding and optimizing testing workflows across clinical laboratory and patient care settings., Methods: Published literature and meeting reports were used by the coauthors to inform the development of the expanded representation of the total testing process and relevant examples describing its uses., Results: A visual representation of the total testing process was developed and contextualized to patient care scenarios using a number of examples covering the detection of blood culture contamination, use of next-generation sequencing, and pharmacogenetic testing., Conclusions: The expanded representation of the total testing process can serve as a model and framework to document and improve the use of clinical testing within the broader context of health care delivery. This representation recognizes increased engagement among clinical laboratory professionals with patients and other health care providers as essential to making informed decisions. The increasing use of data is highlighted as important to ensuring quality, appropriate test utilization, and sustaining an efficient workflow across clinical laboratory and patient care settings. Maintaining a properly resourced and competent workforce is also featured as an essential component to the testing process., (© American Society for Clinical Pathology, 2023.)

Access to laboratory test results through patient portals is a health equity issue for patients with limited English proficiency (LEP), particularly for Spanish-speaking patients, the largest minority group in the USA. Gaps ranging from linguistic, cultural, and socioeconomic disparities to lack of systematic approaches (e.g., implementation of specific support protocols, policies) are among the identified factors that limit LEP patients' access to patient portals. This paper summarizes initiatives healthcare providers, laboratory professionals, and portal developers can use to address disparities that affect >26 million LEPs while improving their health equity., (Published by Oxford University Press on behalf of American Association for Clinical Chemistry 2023.)

Introduction: Cotinine is a widely used biomarker for classifying cigarette smoking status. However, cotinine does not differentiate between the use of combustible and noncombustible tobacco products. The increasing use of noncombustible tobacco drives the need for a complementary biomarker for distinguishing cigarette smokers from users of noncombustible tobacco products., Aims and Methods: We evaluated the urinary acrylonitrile metabolite, 2CyEMA, as a biomarker of exposure to cigarette smoke in the US population-representative data from the National Health and Nutritional Examination Survey (NHANES). Smoking status was categorized based on the recent tobacco use questionnaire. The receiver operating characteristic (ROC) curve analysis was performed to identify optimal cutoff concentrations by maximizing Youden's J index. The area under the curve (AUC) was used to compare 2CyEMA effectiveness with respect to serum cotinine., Results: The overall cutoff concentration for the classification of cigarette smokers from nonsmokers was 7.32 ng/ml with high sensitivity and specificity (≥0.925). When stratified by demographic variables, the cutoff concentrations varied among subgroups based on age, sex, and race/Hispanic origin. Non-Hispanic Blacks had the highest cutoff concentration (15.3 ng/ml), and Hispanics had the lowest (4.63 ng/ml). Females had higher cutoff concentrations (8.80 ng/ml) compared to males (6.10 ng/ml). Among different age groups, the cutoff concentrations varied between 4.63 ng/ml (21-39 years old) and 10.6 ng/ml (for ≥60 years old). We also explored the creatinine adjusted cutoff values., Conclusions: 2CyEMA is an effective biomarker for distinguishing cigarette smokers from nonsmokers (users of noncombustible tobacco products or nonusers)., Implications: Distinguishes smokers from noncombustible tobacco product users., (Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco 2021.)

Background: 2-Hydroxyethyl mercapturic acid (2HEMA, N-acetyl-S-(2-hydroxyethyl)-L-cysteine) is a urinary metabolite of several volatile organic compounds including acrylonitrile and ethylene oxide, which are found in cigarette smoke., Methods: We measured 2HEMA concentrations in urine specimens collected during the National Health and Nutrition Examination Survey (2011-2016) from eligible participants aged >12 years ( N  = 7,416). We developed two multiple linear regression models to characterize the association between cigarette smoking and 2HEMA concentrations wherein the dependent variable was 2HEMA concentrations among participants who exclusively smoked cigarettes at the time of specimen collection and the independent variables included sex, age, race/ethnicity, creatinine, diet, and either cigarettes smoked per day (CPD) or serum cotinine., Results: We detected 2HEMA in 85% of samples tested among exclusive cigarette smokers, and only 40% of specimens from non-smokers. When compared to exclusive cigarette smokers who smoked 1-9 CPD, smoking 10-19 CPD was associated with 36% higher 2HEMA ( p <  0.0001) and smoking >19 CPD was associated with 61% higher 2HEMA ( p <  0.0001). Additionally, 2HEMA was positively associated with serum cotinine., Conclusions: This study demonstrates that cigarette smoking intensity is associated with higher urinary 2HEMA concentrations and is likely a major source of acrylonitrile and/or ethylene oxide exposure.

Hairdressers are exposed to volatile organic compounds (VOCs), many of which have been linked to acute and chronic health effects. Those hairdressers serving an ethnic clientele may potentially experience disproportionate exposures from frequent use of products containing VOCs or different VOC concentrations contained in products which are marketed to the specific needs of their clientele. However, no biomonitoring studies have investigated occupational exposures in this population. In the present pilot study, we sought to characterize concentrations and exposure determinants for 28 VOC biomarkers in post-shift urine samples among 23 hairdressers primarily serving an ethnic clientele. VOC biomarker concentrations among hairdressers of color were compared to concentrations among a comparison group of 17 office workers and a representative sample of women participating in the U.S. National Health and Nutrition Examination Survey. VOC biomarkers were detected in all hairdressers with higher concentrations observed among hairdressers serving a predominantly Black versus Latino clientele, and among hairdressers overall versus office workers and women in the U.S. general population. Median biomarker concentrations for acrolein,1,3-butadiene, and xylene in hairdressers were more than twice as high as those observed among office workers. Median concentrations for 1-bromopropane, acrolein and 1,3-butadiene were more than four times higher among all hairdressers compared to those reported among women in the U.S. general population. Select salon services (e.g., sister locs, flat ironing, permanent hair coloring, permanent waves or texturizing, Brazilian blowout or keratin treatment, etc.) were also associated with higher VOC biomarker concentrations among hairdressers. This pilot study represents the first biomonitoring analysis to characterize VOC exposures among women hairdressers of color and to provide evidence that this occupational population may experience elevated VOC exposures compared to women in the U.S. general population. Results from our study represent an important first step in elucidating occupational VOC exposures in this understudied occupational group. Larger studies among a racially and ethnically diverse cohort of hairdressers are warranted to confirm our findings and inform future exposure interventions in this understudied occupational population., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Benzene is a known genotoxic carcinogen linked to many hematological abnormalities. S-phenylmercapturic acid (PHMA, N-acetyl-S-(phenyl)-L-cysteine, CAS# 4775-80-8) is a urinary metabolite of benzene and is used as a biomarker to assess benzene exposure. Pre-S-phenylmercapturic acid (pre-PHMA) is a PHMA precursor that dehydrates to PHMA at acidic pH. Published analytical methods that measure urinary PHMA adjust urine samples to a wide range of pH values using several types of acid, potentially leading to highly variable results depending on the concentration of pre-PHMA in a sample. Information is lacking on the variation in sample preparation among laboratories regularly measuring PHMA and the effect of those differences on PHMA quantitation in human urine samples. To investigate the differences in PHMA quantitation, we conducted an inter-laboratory comparison that included the analysis of 50 anonymous human urine samples (25 self-identified smokers and 25 self-identified non-smokers), quality control samples and commercially available reference samples in five laboratories using different analytical methods. Observed urinary PHMA concentrations were proportionally higher at lower pH, and results for anonymous urine samples varied widely among the methods. The method with the neutral preparation pH yielded results about 60% lower than the method using the most acidic conditions. Samples spiked with PHMA showed little variation, suggesting that the variability in results in human urine samples across methods is driven by the acid-mediated conversion of pre-PHMA to PHMA., (Published by Oxford University Press. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Biomarkers of tobacco exposure are known to be associated with disease risk but previous studies are limited in number and restricted to certain regions. We conducted a nested case-control study examining baseline levels and subsequent lung cancer incidence among current male exclusive cigarette smokers in the Golestan Cohort Study in Iran. We calculated geometric mean biomarker concentrations for 28 matched cases and 52 controls for the correlation of biomarker levels among controls and for adjusted odds' ratios (ORs) for lung cancer incidence by biomarker concentration, accounting for demographic characteristics, smoking quantity and duration, and opium use. Lung cancer cases had higher average levels of most biomarkers including total nicotine equivalents (TNE-2), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and 3-hydroxyfluorene (3-FLU). Many biomarkers correlated highly with one another including TNE-2 with NNAL and N-Acetyl-S-(2-cyanoethyl)-L-cysteine (2CYEMA), and N-Acetyl-S-(4-hydroxy-2-buten-1-yl)-L-cysteine (t4HBEMA) with N-Acetyl-S-(3-hydroxypropyl-1-methyl)-L-cysteine (3HMPMA) and N-Acetyl-S-(4-hydroxy-2-methyl-2-buten-1-yl)-L-cysteine (4HMBEMA). Lung cancer risk increased with concentration for several biomarkers, including TNE-2 (OR = 2.22, 95% CI = 1.03, 4.78) and NNN (OR = 2.44, 95% CI = 1.13, 5.27), and estimates were significant after further adjustment for demographic and smoking characteristics for 2CYEMA (OR = 2.17, 95% CI = 1.03, 4.55), N-Acetyl-S-(2-carbamoylethyl)-L-cysteine (2CAEMA) (OR = 2.14, 95% CI = 1.01, 4.55), and N-Acetyl-S-(2-hydroxypropyl)-L-cysteine (2HPMA) (OR = 2.85, 95% CI = 1.04, 7.81). Estimates were not significant with adjustment for opium use. Concentrations of many biomarkers were higher at the baseline for participants who subsequently developed lung cancer than among the matched controls. Odds of lung cancer were higher for several biomarkers including with adjustment for smoking exposure for some but not with adjustment for opium use.

1,3-Butadiene is a volatile organic compound with a gasoline-like odour that is primarily used as a monomer in the production of synthetic rubber. The International Agency for Research on Cancer has classified 1,3-butadiene as a human carcinogen. We assessed 1,3-butadiene exposure in the U.S. population by measuring its urinary metabolites N -acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (34HBMA), N -acetyl-S-(1-hydroxymethyl-2-propenyl)-L-cysteine (1HMPeMA), N -acetyl-S-(2-hydroxy-3-butenyl)-L-cysteine (2HBeMA), and N -acetyl-S-(4-hydroxy-2-buten-1-yl)-L-cysteine (4HBeMA). Urine samples from the 2011 to 2016 National Health and Nutrition Examination Survey were analysed for 1,3-butadiene metabolites using ultrahigh-performance liquid chromatography/tandem mass spectrometry. 34HBMA and 4HBeMA were detected in >96% of the samples; 1HMPeMA and 2HBeMA were detected in 0.66% and 9.84% of the samples, respectively. We used sample-weighted linear regression models to examine the influence of smoking status (using a combination of self-reporting and serum-cotinine data), demographic variables, and diet on biomarker levels. The median 4HBeMA among exclusive smokers (31.5 µg/g creatinine) was higher than in non-users (4.11 µg/g creatinine). Similarly, the median 34HBMA among exclusive smokers (391 µg/g creatinine) was higher than in non-users (296 µg/g creatinine). Furthermore, smoking 1-10, 11-20, and >20 cigarettes per day (CPD) was associated with 475%, 849%, and 1143% higher 4HBeMA ( p  < 0.0001), respectively. Additionally, smoking 1-10, 11-20, and >20 CPD was associated with 33%, 44%, and 102% higher 34HBMA ( p  < 0.0001). These results provide significant baseline data for 1,3-butadiene exposure in the U.S. population, and demonstrate that tobacco smoke is a major exposure source.

Increased interest in volatile organic compound (VOC) exposure has led to an increased need for consistent, systematic, and informative naming of VOC metabolites. As analytical methods have expanded to include many metabolites in a single assay, the number of acronyms in use for a single metabolite has expanded in an unplanned and inconsistent manner due to a lack of guidance or group consensus. Even though the measurement of VOC metabolites is a well-established means to investigate exposure to VOCs, a formal attempt to harmonize acronyms amongst investigators has not been published. The aim of this work is to establish a system of acronym naming that provides consistency in current acronym usage and a foundation for creating acronyms for future VOC metabolites., (Published by Elsevier GmbH.)

A method to achieve accurate measurement of unmetabolized volatile organic compounds (VOCs) in urine was developed and characterized. The method incorporates a novel preanalytical approach of adding isotopically labeled internal standard (ISTD) analogues directly to the collection container at the point of collection to compensate for analyte loss to the headspace and the collection container surfaces. Using this approach, 45 toxic VOCs ranging in water solubility and boiling point were evaluated and analyzed by headspace solid-phase microextraction/gas chromatography-mass spectrometry. Results show that urine VOCs could be equally lost to the container headspace as to the container surface suggesting similarity of these two regions as partition phases. Surface adsorption loss was found to trend with compound water solubility. In particular, with no headspace, more nonpolar VOCs experienced substantial losses (e.g., 48% for hexane) in a standard 120 mL urine cup at concentrations in the low- and sub-ppb range. The most polar VOCs evaluated (e.g., tetrahydrofuran) showed no significant loss. Other commonly practiced methods for urine sample collection and analysis such as aliquoting, specimen freezing, and use of surrogate ISTD were found to significantly bias results. With this method, we achieved errors ranging from -8.0 to 4.8% of spiked urine specimens. Paired urine and blood specimens from cigarette smokers were compared to assess this method., Competing Interests: The authors declare no competing financial interest., (Not subject to U.S. Copyright. Published 2021 by American Chemical Society.)

Aldehydes are known carcinogens and irritants that can negatively impact health. They are present in tobacco smoke, the environment, and food. The prevalence of aldehyde exposure and potential health impact warrants a population-wide study of serum aldehydes as exposure biomarkers. We analyzed 12 aldehydes in sera collected from 1843 participants aged 12 years or older in the 2013-2014 National Health and Nutrition Examination Survey. Several aldehydes were detected at high rates, such as isopentanaldehyde (99.2%) and propanaldehyde (88.3%). We used multiple linear regression models to examine the impact of tobacco smoke and dietary variables on serum concentrations of isopentanaldehyde and propanaldehyde. Although 12 serum aldehydes were analyzed and compared to tobacco smoke exposure, only isopentanaldehyde and propanaldehyde showed any significant association with tobacco smoke exposure. Survey participants who smoked 1-10 cigarettes per day (CPD) had 168% higher serum isopentanaldehyde and 28% higher propanaldehyde compared with nonusers. Study participants who smoked 11-20 CPD had higher serum isopentanaldehyde (323%) and propanaldehyde (70%). Similarly, study participants who smoked >20 CPD had 399% higher serum isopentanaldehyde and 110% higher serum propanaldehyde than nonexposed nonusers. The method could not, however, differentiate between nonexposed nonusers and nonusers exposed to secondhand smoke for either of these two aldehydes. No dietary variables were consistently predictive of serum isopentanaldehyde and propanaldehyde concentrations. This report defines baseline concentrations of serum aldehydes in the U.S. population and provides a foundation for future research into the potential health effects of aldehydes. In addition, this study suggests that tobacco smoke is a significant source of exposure to some aldehydes such as isopentanaldehyde and propanaldehyde.

Methylcarbamoyl mercapturic acid (MCAMA, N-acetyl-S-(N-methylcarbamoyl)-L-cysteine) is a urinary metabolite of N,N-dimethylformamide and methyl isocyanate, which are volatile organic compounds that are harmful to humans. N,N-dimethylformamide exposure causes liver damage, and methyl isocyanate inhalation damages the lining of the respiratory tract, which can increase risk of chronic obstructive pulmonary disease and asthma. This study characterizes urinary MCAMA levels in the US population and explores associations of MCAMA concentrations with select demographic and environmental factors. We used liquid chromatography tandem mass spectrometry to measure MCAMA in urine collected from study participants ≥ 12 years old (N = 8272) as part of the National Health and Nutrition Examination Survey 2005-2006 and 2011-2016. We produced multiple regression models with MCAMA concentrations as the dependent variable and sex, age, fasting time, race/ethnicity, diet, and cigarette smoking as independent variables. Cigarette smokers and nonsmokers had median urinary MCAMA concentrations of 517 μg/g creatinine and 127 μg/g creatinine, respectively. Sample-weighted multiple regression analysis showed that MCAMA was positively associated with serum cotinine (p < 0.0001). Compared to non-exposed participants (serum cotinine ≤ 0.015 ng/mL), presumptive exposure to second-hand tobacco smoke (serum cotinine > 0.015-≤ 10 ng/mL and 0 cigarettes smoked per day) was associated with 20% higher MCAMA (p < 0.0001). Additionally, smoking 1-10 cigarettes per day was associated with 261% higher MCAMA (p < 0.0001), smoking 11-20 cigarettes per day was associated with 357% higher MCAMA (p < 0.0001), and smoking > 20 cigarettes per day was associated with 416% higher MCAMA (p < 0.0001). These findings underscore the strong association of tobacco smoke exposure with urinary MCAMA biomarker levels.

Microbial volatile organic compounds (MVOCs) are primary and secondary metabolites of fungal and bacterial growth. Changes in environmental conditions (e.g., humidity, light, oxygen, and carbon dioxide) influence microbial growth in indoor environments. Prolonged human exposure to MVOCs has been directly associated with sick building syndrome (SBS), respiratory irritation, and asthma-like symptoms. However, no method exists for assessing MVOC exposure by quantifying them in human serum. We developed a novel, high-throughput automated method for quantifying seven MVOCs (3-methylfuran, 2-hexanone, 2-heptanone, 3-octanone, 1-octen-3-ol, 2-ethyl-1-hexanol, and geosmin) in human serum. The method quantifies the target analytes using solid-phase microextraction gas chromatography-tandem mass spectrometry at low parts-per-billion levels. Limits of detection ranged from 0.076 to 2.77 μg/L. This method provides excellent linearity over the concentration range for the analytes, with coefficients of determination >0.992. Recovery in human serum was between 84.5% and 113%, and analyte precision ranged from 0.38% to 8.78%. The intra-day and inter-day reproducibility showed coefficients of variation ≤11% and ≤8%, respectively. Accurate and precise quantification of MVOCs is necessary for detecting and quantifying harmful human exposures in environments with active microbial growth. The method is well suited for high-throughput analysis to aid investigations of unhealthy exposures to microbial emissions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

Background: Acrylonitrile is a possible human carcinogen that is used in polymers and formed in tobacco smoke. We assessed acrylonitrile exposure in the US population by measuring its urinary metabolites N-acetyl-S-(4-hydroxy-2-methyl-2-buten-1-yl)-L-cysteine (2CYEMA) and N-acetyl-S-(1-cyano-2-hydroxyethyl)-L-cysteine (1CYHEMA) in participants from the 2011-2016 National Health and Nutrition Examination Survey., Objective: To assessed acrylonitrile exposure using population-based biomonitoring data of the US civilian, non-institutionalized population., Methods: Laboratory data for 8057 participants were reported for 2CYEMA and 1CYHEMA using ultrahigh-performance liquid chromatography/tandem mass spectrometry. Exclusive tobacco smokers were distinguished from non-users using a combination of self-reporting and serum cotinine data. We used multiple linear regression models to fit 2CYEMA concentrations with sex, age, race/Hispanic origin, and tobacco user group as predictor variables., Results: The median 2CYEMA level was higher for exclusive cigarette smokers (145 µg/g creatinine) than for non-users (1.38 µg/g creatinine). Compared to unexposed individuals (serum cotinine ≤0.015 ng/ml) and controlling for confounders, presumptive second-hand tobacco smoke exposure (serum cotinine >0.015 to ≤10 ng/ml and 0 cigarettes per day, CPD) was significantly associated with 36% higher 2CYEMA levels (p < 0.0001). Smoking 1-10 CPD was significantly associated with 6720% higher 2CYEMA levels (p < 0.0001)., Significance: We show that tobacco smoke is an important source of acrylonitrile exposure in the US population and provide important biomonitoring data on acrylonitrile exposure.

Aim: Xylenes are aromatic hydrocarbons used for industrial applications such as the production of petrochemicals and plastics. Acute xylene exposures can negatively impact health through neurotoxicity and irritation of respiratory and dermal tissues. We quantified urinary biomarkers of xylene exposure [2-methylhippuric acid (2MHA) and a mixture of 3- and 4-methylhippuric acids (34MH)] in a representative sample of the U.S. population. Methods: Spot urine obtained during the National Health and Nutrition Examination Survey 2005-2006 and 2011-2016 was analysed using ultra-high-performance liquid chromatography/tandem mass spectrometry. Exclusive smokers were distinguished from non-users using a combination of self-report and serum cotinine data. Results: The median 2MHA and 34MH levels were higher for exclusive smokers (100 µg/g and 748 µg/g creatinine, respectively) than for non-users (27.4 µg/g and 168 µg/g creatinine, respectively). Participants who smoked cigarettes had significantly higher 2MHA and 34MH levels ( p  < 0.0001) than unexposed participants. Smoking 1-10, 11-20, and >20 cigarettes per day (CPD) was significantly associated with 181%, 339% and 393% higher 2MHA levels, respectively. For 34MH, smoking 1-10, 11-20, and >20 CPD was significantly associated with 201%, 398%, and 471% higher 34MH levels, respectively. Conclusion: We confirm that tobacco smoke is a significant source of xylene exposure as measured by urinary 2MHA and 34MH levels.

Background: Marijuana smoke contains some of the same toxicants present in tobacco smoke. Marijuana smoking is prevalent among HIV+ individuals, but few studies have characterized smoke-related toxicants or associated health outcomes in exclusive marijuana users., Methods: This longitudinal study included 245 participants over age 40 (76% HIV+). 33 plasma and 28 urine metabolites of nicotine, ∆-9-trans-tetrahydrocannabinol, polycyclic aromatic hydrocarbons, and volatile organic compounds were assayed by liquid or gas chromatography/mass spectrometry. Exposures and health outcomes were assessed from surveys and medical records., Findings: At baseline, 18% of participants were marijuana-only smokers, 20% tobacco-only smokers, and 24% dual marijuana-tobacco smokers (median (IQR) age 53 (47-60) years, 78% male, 54% white race). Marijuana smoking was independently associated with elevated plasma naphthalenes, 2-hydroxyfluorene sulfate, 4-vinylphenol sulfate, and o-cresol sulfate (p< 0·05) and urine acrylonitrile and acrylamide metabolites ( p< 0·05), but levels were lower than those associated with tobacco smoking. Acrolein metabolite N-Acetyl-S-(3-hydroxypropyl)-l-cysteine (3HPMA) was significantly elevated in plasma and urine in tobacco-only and dual but not marijuana-only smokers, and correlated with nicotine metabolites ( p< 0·05). The highest tertile of 3HPMA was associated with increased cardiovascular disease diagnoses independent of tobacco smoking, traditional risk factors, and HIV status (odds ratio [95% CI] 3·34 [1·31-8·57]; p   =  0·012)., Interpretation: Smoke-related toxicants, including acrylonitrile and acrylamide metabolites, are detectable in exclusive marijuana smokers, but exposures are lower compared with tobacco or dual smokers. Acrolein exposure is increased by tobacco smoking but not exclusive marijuana smoking in HIV+ and HIV- adults, and contributes to cardiovascular disease in tobacco smokers., Funding: U.S. NIH., Competing Interests: DL, VM, SC, HU, BG, SM, SW and DG report grants from the NIH during the conduct of the study. All other authors have nothing to disclose., (© 2020 The Authors.)

Terpenes are a class of volatile organic hydrocarbons commonly produced by vegetation and released into the atmosphere. These compounds are responsible for the scents of pine forests, citrus fruits, and some flowers. Human terpene exposure can come from inhalation, diet, smoking, and more recently, using e-cigarettes. Terpenes are present in tobacco smoke and are used as flavor chemicals in e-liquids. The health effects of terpenes are not widely known, though several studies have suggested that they may prove useful in future medical applications. We have developed a novel, high-throughput method of quantifying seven terpenes (α-pinene, β-pinene, β-myrcene, 3-carene, limonene, β-caryophyllene, and α-humulene) in human serum to aid human-exposure investigations. This method employs headspace sampling using solid-phase microextraction (SPME) coupled to gas chromatography-tandem mass spectrometry to detect and quantify five monoterpenes and two sesquiterpenes in the low parts-per-trillion to low parts-per-billion range. The intraday and interday variability (percent error) of the method are ≤2 and ≤11%, respectively. In addition, this method showed excellent recovery in human serum (between 80 and 120% for all analytes). The assay precision ranges between 4.0 and 11%. Limits of detection ranged between 0.032 and 0.162 μg/L. Using serum cotinine values to classify tobacco use showed that smokers have higher serum concentrations of six terpenes compared to nonusers. Terpene concentrations were 14-78% higher in smokers than nonusers. Our method can provide essential biomonitoring data to establish baseline exposure levels for terpenes in humans.

Rationale: Over 2700 e-cigarette, or vaping, product use-associated lung injury (EVALI) cases were reported to the Centers for Disease Control and Prevention (CDC) during August 2019-February 2020. Bronchoalveolar lavage (BAL) fluid samples from 51 EVALI and 99 non-EVALI cases were analyzed for toxicants including petroleum distillates. We describe a novel method to measure petroleum distillates in BAL fluid using gas chromatography-mass spectrometry (GC/MS)., Methods: n-Hexane, n-heptane, n-octane, methylcyclopentane, and cyclohexane were measured in BAL fluid specimens by headspace solid-phase microextraction/GC/MS. We created and characterized BAL fluid pools from non-EVALI individuals to determine assay accuracy, precision, linearity, limits of detection (LODs), and analytical specificity. All measurements were conducted in accordance with the rigorous method validation procedures of CDC's Division of Laboratory Sciences., Results: Matrix validation experiments showed that calibration curves in BAL fluid and saline had similar slopes, with differences less than 5%. Assay precision ranged from 1.98% to 18%. In addition, the LODs for the five analytes ranged from 0.05 to 0.10 μg/L, and their linearity was confirmed with R 2 values >0.99. The analysis of selected petroleum distillates in BAL fluid analysis was shown to be comparable with their analysis in blood in which the 95th percentiles are below detection., Conclusions: We developed and validated a method to quantify petroleum distillates in BAL fluid specimens using GC/MS. The assay provided precise and accurate analyses of EVALI and non-EVALI BAL fluid specimens in support of CDC's EVALI response. This method is applicable to the determination of a broad range of volatile organic compounds in BAL fluid specimens., (Published 2020. This article is a U.S. Government work and is in the public domain in the USA.)

Rationale: Over 2800 e-cigarette, or vaping, product use-associated lung injury (EVALI) cases were reported to the Centers for Disease Control and Prevention (CDC) during August 2019 to February 2020. Bronchoalveolar lavage (BAL) fluid samples from 51 EVALI and 99 non-EVALI cases were analyzed for toxicants including terpenes. We describe a novel method to measure selected terpenes in BAL fluid by gas chromatography/tandem mass spectrometry (GC/MS/MS)., Methods: α-Pinene, β-pinene, β-myrcene, 3-carene, and limonene were measured in BAL fluid specimens by headspace solid-phase microextraction/gas chromatography/tandem mass spectrometry. We created and characterized BAL fluid pools from non-EVALI individuals to determine assay accuracy, precision, linearity, limits of detection, and analytical specificity. All measurements were conducted in accordance with the CDC's Division of Laboratory Sciences rigorous method validation procedures., Results: Matrix validation experiments showed that calibration curves in BAL fluid and saline had similar slopes, with differences of less than 7%. The assay precision ranged from 2.52% to 5.30%. In addition, the limits of detection for the five analytes ranged from 1.80 to 16.8 ng/L, and the linearity was confirmed with R 2 values >0.99., Conclusions: We developed and validated a method to quantify selected terpenes in BAL fluid specimens using GC/MS/MS. The assay provided accurate and precise analyses of EVALI and non-EVALI BAL fluid specimens in support of CDC's EVALI response. This method is applicable to the determination of a broad range of terpenes in BAL fluid specimens., (Published 2020. This article is a U.S. Government work and is in the public domain in the USA.)

Newborn screening (NBS) laboratories cannot accurately compare mass spectrometry-derived results and cutoff values due to differences in testing methodologies. The objective of this study was to assess harmonization of laboratory proficiency test (PT) results using quality control (QC) data. Newborn Screening Quality Assurance Program (NSQAP) QC and PT data reported from 302 laboratories in 2019 were used to compare results among laboratories. QC materials were provided as dried blood spot cards which included a base pool and the base pool enriched with specific concentrations of metabolites in a linear range. QC data reported by laboratories were regressed on QC data reported by the Centers for Disease Control and Prevention (CDC), and laboratory's regression parameters were used to harmonize their PT result. In general, harmonization tended to reduce overall variation in PT data across laboratories. The metabolites glutarylcarnitine (C5DC), tyrosine, and phenylalanine were displayed to highlight inter- and intra-method variability in NBS results. Several limitations were identified using retrospective data for harmonization, and future studies will address these limitations to further assess feasibility of using NSQAP QC data to harmonize PT data. Harmonizing NBS data using common QC materials appears promising to aid result comparison between laboratories., Competing Interests: Conflicts of InterestThe authors declare no conflict of interest., (© 2020 by the authors.)

Cannabis use through smoking, vaping, or ingestion is increasing, but only limited studies have investigated the resulting exposure to harmful chemicals. N-acetyl-S-(2-cyanoethyl)-L-cysteine (2CYEMA), a urinary metabolite of acrylonitrile, a possible carcinogen, is elevated in the urine of past-30-day cannabis users compared to non-cannabis users. Five frequent and five occasional cannabis users smoked and vaped cannabis on separate days; one also consumed cannabis orally. Urine samples were collected before and up to 72 h post dose and urinary 2CYEMA was quantified. We compared 2CYEMA pre-exposure levels, maximum concentration, time at maximum concentration for occasional versus frequent users following different exposure routes, and measured half-life of elimination. Smoking cannabis joints rapidly (within 10 min) increased 2CYEMA in the urine of occasional cannabis users, but not in frequent users. Urine 2CYEMA did not consistently increase following vaping or ingestion in either study group. Cigarette smokers had high pre-exposure concentrations of 2CYEMA. Following cannabis smoking, the half-lives of 2CYEMA ranged from 2.5 to 9.0 h. 2CYEMA is an effective biomarker of cannabis smoke exposure, including smoke from a single cannabis joint, however, not from vaping or when consumed orally. When using 2CYEMA to evaluate exposure in cannabis users, investigators should collect the details about tobacco smoking, route of consumption, and time since last use as possible covariates.

Hookah smoking has become common in the USA, especially among young adults. This study measured biomarkers of exposure to known tobacco product toxicants in a population-based sample of exclusive, established hookah users. Urinary biomarker data from 1753 adults in Wave 1 of the Population Assessment of Tobacco and Health (PATH) Study were used to compare geometric mean concentrations of biomarkers of exposure in exclusive, established past 30-day hookah users to never users of tobacco. Geometric mean ratios were calculated comparing hookah user groups with never users adjusting for age, sex, race/ethnicity, education, past 30-day marijuana use, secondhand smoke exposure and creatinine. Past 30-day hookah users ( n = 98) had 10.6 times the urinary cotinine level of never tobacco users. Compared to never tobacco users, past 30-day hookah users had 2.3 times the level of the carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a metabolite of the tobacco-specific nitrosamine (TSNA) 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), 1.3 times higher polycyclic aromatic hydrocarbons (PAHs) 3-hydroxyfluorene and 1-hydroxypyrene, 1.8 times higher levels of acrylonitrile, 1.3 times higher levels of acrylamide, and 1.2 times higher levels of acrolein exposure. These data indicate that hookah use is a significant source of exposure to nicotine, carcinogens, and respiratory toxicants.

Adenosine deaminase severe combined immunodeficiency (ADA-SCID) is an autosomal recessive disorder in which a lack of ADA enzyme prevents the maturation of T- and B-cells; early intervention is crucial for restoring immune function in affected neonates. ADA is responsible for purine metabolism and-in its absence-adenosine, deoxyadenosine, and S-adenosylhomocysteine build up and can be detected in the blood. Preparing dried blood spot (DBS) quality control (QC) materials for these analytes is challenging because enrichments are quickly metabolized by the endogenous ADA in normal donor blood. Adding an inhibitor, erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA), has been previously reported to minimize enzyme activity, although this adds additional cost and complexity. We describe an alternative method using unnatural L-enantiomer nucleosides (L-adenosine and 2'-deoxy-L-adenosine) which eliminates the need for enzyme inhibition. We also present a novel method for characterization of the materials using liquid chromatography mass spectrometry to quantify the analytes of interest.

Volatile organic compounds (VOCs) are ubiquitous in the environment. In the United States (U.S.), tobacco smoke is the major non-occupational source of exposure to many harmful VOCs. Exposure to VOCs can be assessed by measuring their urinary metabolites (VOCMs). The Population Assessment of Tobacco and Health (PATH) Study is a U.S. national longitudinal study of tobacco use in the adult and youth civilian non-institutionalized population. We measured 20 VOCMs in urine specimens from a subsample of adults in Wave 1 (W1) (2013-2014) to characterize VOC exposures among tobacco product users and non-users. We calculated weighted geometric means (GMs) and percentiles of each VOCM for exclusive combustible product users (smokers), exclusive electronic cigarette (e-cigarette) users, exclusive smokeless product users, and tobacco product never users. We produced linear regression models for six VOCMs with sex, age, race, and tobacco user group as predictor variables. Creatinine-ratioed levels of VOCMs from exposure to acrolein, crotonaldehyde, isoprene, acrylonitrile, and 1,3-butadiene were significantly higher in smokers than in never users. Small differences of VOCM levels among exclusive e-cigarette users and smokeless users were observed when compared to never users. Smokers showed higher VOCM concentrations than e-cigarette, smokeless, and never users. Urinary VOC metabolites are useful biomarkers of exposure to harmful VOCs.

Background: The FDA is considering a mandated reduction in the nicotine content of cigarettes. Clinical trials have been limited by non-study cigarette use (noncompliance), which could mask compensation. The goal of this study was to assess whether compensation occurs when smokers provided with very low nicotine cigarettes cannot access normal nicotine cigarettes., Methods: In a within-subjects, crossover design, current smokers ( n = 16) were confined to a hotel for two 4-night hotel stays during which they were only able to access the research cigarettes provided. The hotel stays offered normal nicotine cigarettes or very low nicotine content (VLNC) cigarettes, in an unblinded design, available for "purchase" via a study bank., Results: In the context of complete compliance with the study cigarettes ( n = 16), there was not a significant increase during the VLNC condition for cigarettes smoked per day, expired carbon monoxide, or N-acetyl-S-(cyanoethyl)-l-cysteine (cyanoethyl-MA, metabolite of acrylonitrile). There was a significant nicotine × time interaction on urine N-acetyl-S-(3-hydroxypropyl)-l-cysteine (hydroxypropyl-MA, metabolite of acrolein), driven by an increase in the VLNC condition during the first 24 hours. By the end of the VLNC condition, there was no evidence of compensation across any measure of smoking or smoke exposure., Conclusions: Among current smokers who exclusively used VLNC cigarettes for 4 days, there was no significant compensatory smoking behavior., Impact: These data, combined with the larger body of work, suggest that a mandated reduction in nicotine content is unlikely to result in an increase in smoking behavior to obtain more nicotine., (©2020 American Association for Cancer Research.)

Background: There is little information on human exposure to carcinogens and other toxicants related to opiate use, alone or in combination with tobacco., Methods: Among male participants of the Golestan Cohort Study in Northeast Iran, we studied 28 never users of either opiates or tobacco, 33 exclusive cigarette smokers, 23 exclusive users of smoked opiates, and 30 opiate users who also smoked cigarettes (dual users; 21 smoked opiates and 9 ingested them). We quantified urinary concentrations of 39 exposure biomarkers, including tobacco alkaloids, tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons (PAH), and volatile organic compounds (VOC), and used decomposition to parse out the share of the biomarker concentrations explained by opiate use and nicotine dose., Results: Dual users had the highest concentrations of all biomarkers, but exclusive cigarette smokers and exclusive opiate users had substantially higher concentrations of PAH and VOC biomarkers than never users of either product. Decomposition analysis showed that opiate use contributed a larger part of the PAH concentrations than nicotine dose, and the sum of 2- and 3-hydroxyphenanthrene (∑ 2,3 -phe) resulted almost completely from opiate use. Concentrations of most VOC biomarkers were explained by both nicotine dose and opiate use. Two acrylamide metabolites, a 1,3-butadiene metabolite and a dimethylformamide metabolite, were more strongly explained by opiate use. Acrylamide metabolites and ∑ 2,3 -phe were significantly higher in opiate smokers than opiate eaters; other biomarkers did not vary by the route of opiate intake., Conclusions: Both cigarette smokers and opiate users (by smoking or ingestion) were exposed to many toxicants and carcinogens., Impact: This high exposure, particularly among dual opiate and cigarette users, can have a substantial global public health impact., (©2020 American Association for Cancer Research.)

Background: The causative agents for the current national outbreak of electronic-cigarette, or vaping, product use-associated lung injury (EVALI) have not been established. Detection of toxicants in bronchoalveolar-lavage (BAL) fluid from patients with EVALI can provide direct information on exposure within the lung., Methods: BAL fluids were collected from 51 patients with EVALI in 16 states and from 99 healthy participants who were part of an ongoing study of smoking involving nonsmokers, exclusive users of e-cigarettes or vaping products, and exclusive cigarette smokers that was initiated in 2015. Using the BAL fluid, we performed isotope dilution mass spectrometry to measure several priority toxicants: vitamin E acetate, plant oils, medium-chain triglyceride oil, coconut oil, petroleum distillates, and diluent terpenes., Results: State and local health departments assigned EVALI case status as confirmed for 25 patients and as probable for 26 patients. Vitamin E acetate was identified in BAL fluid obtained from 48 of 51 case patients (94%) in 16 states but not in such fluid obtained from the healthy comparator group. No other priority toxicants were found in BAL fluid from the case patients or the comparator group, except for coconut oil and limonene, which were found in 1 patient each. Among the case patients for whom laboratory or epidemiologic data were available, 47 of 50 (94%) had detectable tetrahydrocannabinol (THC) or its metabolites in BAL fluid or had reported vaping THC products in the 90 days before the onset of illness. Nicotine or its metabolites were detected in 30 of 47 of the case patients (64%)., Conclusions: Vitamin E acetate was associated with EVALI in a convenience sample of 51 patients in 16 states across the United States. (Funded by the National Cancer Institute and others.)., (Copyright © 2019 Massachusetts Medical Society.)

Isoprene is the 2-methyl analog of 1,3-butadiene and is a possible human carcinogen (IARC Group 2B). We assessed isoprene exposure in the general US population by measuring its urinary metabolite, N -acetyl- S -(4-hydroxy-2-methyl-2-buten-1-yl)-l-cysteine (IPM3) in participants (≥3 year old) from the 2015-2016 National Health and Nutrition Examination Survey. Spot urine samples were analyzed for IPM3 using ultrahigh-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry. Exclusive tobacco smokers were distinguished from non-users using a combination of self-reporting and serum cotinine data. IPM3 was detected in 80.2% of samples. The median IPM3 level was higher for exclusive cigarette smokers (39.8 μg/g creatinine) than for non-users (3.05 μg/g creatinine). Sample weighted regression analysis, controlling for creatinine, sex, age, race, body mass index, and diet, showed that IPM3 was positively and significantly associated with serum cotinine. Smoking 1-10 cigarettes per day (CPD, 0.5 pack) was significantly associated with an IPM3 increase of 596% ( p < .0001), and smoking >20 CPD (>1 pack) was significantly associated with an IPM3 increase of 1640% ( p < .0001), controlling for confounding variables. Drinking beer/ale at median and 90th percentile levels (compared to zero consumption) was associated ( p < 0.05) with 0 and 2.9% increase in IPM3 in non-users, respectively. We conclude that tobacco smoke is a major source of isoprene exposure in the US population. This study provides important public health biomonitoring data on isoprene exposure in the general US population.

Disinfection is critical for maintaining a safe water supply, but the use of chlorine or chloramine leads to exposure to disinfection byproducts (DBPs), including trihalomethanes (THMs), which have been associated with adverse reproductive outcomes and bladder cancer. The U.S. Environmental Protection Agency revised the DBP regulations starting in 1998 to further limit levels of THMs in household water. We analyzed data from the National Health and Nutrition Examination Survey (NHANES) collected between 2001 and 2012 (with 2 years per cycle) using models with and without water-related predictors to examine the utility of including these measures. Median blood chloroform levels (25th-75th percentiles) were 16.2 (9.13-31.2) ng/L in 2001-2002 and 5.97 (2.92-12.3) ng/L in 2011-2012. Median blood bromodichloromethane (BDCM) levels (25th-75th percentiles) were 2.22 (1.06-4.61) ng/L in 2001-2002 and 1.18 (

Background: Methyl tertiary-butyl ether (MTBE) was used as a gasoline additive in the United States during 1995-2006. Because of concerns about potential exposure and health effects, some U.S. states began banning MTBE use in 2002, leading to a nationwide phaseout in 2006., Objectives: We investigated the change in blood MTBE that occurred during the years in which MTBE was being phased out of gasoline., Methods: We used data from the National Health and Nutrition Examination Survey (NHANES) from 2001-2012 to assess the change in blood MTBE over this period. We fit sample-weighted multivariate linear regression models to 12,597 human blood MTBE concentrations from the NHANES 2001-2002 to 2011-2012 survey cycles., Results: The unweighted proportion of the individuals with MTBE blood levels above the limit of detection (LOD) of 1.4   ng / L was 93.9% for 2001-2002. This portion dropped to 25.4% for the period 2011-2012. Weighted blood MTBE median levels (ng/L) (25th and 75th percentiles) decreased from 25.8   ( 6.08 ,   68.1 )   ng / L for the period from 2001-2002 to 4.57   ( 1.44 ,   19.1 )   ng / L for the period from 2005-2006. For the entire postban period (2007-2012), MTBE median levels were below the detection limit of 1.4   ng / L ., Discussion: These decreases in blood MTBE coincided with multiple statewide bans that began in 2002 and a nationwide ban in 2006. The multivariate log-linear regression model for the NHANES 2003-2004 data showed significantly higher blood MTBE concentrations in the group who pumped gasoline less than 7 h before questionnaire administration compared to those who pumped gasoline more than 12 h before questionnaire administration ( p = 0.032 ). This study is the first large-scale, national-level confirmation of substantial decrease in blood MTBE levels in the general population following the phaseout of the use of MTBE as a fuel additive. https://doi.org/10.1289/EHP5572.

CDC, the Food and Drug Administration (FDA), state and local health departments, and multiple public health and clinical partners are investigating a national outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI). Based on data collected as of October 15, 2019, 86% of 867 EVALI patients reported using tetrahydrocannabinol (THC)-containing products in the 3 months preceding symptom onset (1). Analyses of THC-containing product samples by FDA and state public health laboratories have identified potentially harmful constituents in these products, such as vitamin E acetate, medium chain triglyceride oil (MCT oil), and other lipids (2,3) (personal communication, D.T. Heitkemper, FDA Forensic Chemistry Center, November 2019). Vitamin E acetate, in particular, might be used as an additive in the production of e-cigarette, or vaping, products; it also can be used as a thickening agent in THC products (4). Inhalation of vitamin E acetate might impair lung function (5-7).

We report on the development of an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for simultaneously measuring eight biomarkers of volatile organic compound (VOC) exposure, with potential application to e-cigarette aerosol biomonitoring. Phenylmercapturic acid (PMA) and trans, trans-muconic acid (tt-MA) are metabolites of benzene; 2-aminothiazoline-4-carboxylic acid (ATCA) is a metabolite of cyanide; N-2-furoylglycine (N2FG) is a metabolite of furfural and furfuryl alcohol; 5-hydroxymethylfuroic acid (HMFA), 5-hydroxymethyl-2-furoylglycine (HMFG), and 2,5-furandicarboxylic acid (FDCA) are metabolites of 5-hydroxymethylfurfural; and 5-hydroxy-N-methylpyrrolidone (5HMP) is a metabolite of N-methyl-2-pyrrolidone. A pentafluorophenyl-modified silica column was used for chromatographic separation. The overall run time for the method is about 6 min per sample injection. The method has low to sub-nanograms per milliliter sensitivity, linearity over 3 orders of magnitude, and precision and accuracy within 15%. The method was used to measure human urine samples. Results showed that people with known benzene exposure (daily cigarette smokers) had higher levels of tt-MA and PMA compared with non-smokers. The method is advantageous for high-throughput analysis of selected VOC metabolites in large-scale, population-based studies such as the National Health and Nutrition Examination Survey (NHANES). Quantifying these urinary biomarkers is important to public health efforts to understand human exposure to VOCs from various sources, including tobacco products and electronic nicotine delivery systems., (Published by Elsevier B.V.)

Multiple ion transition summation of isotopologues (MITSI) is an adaptable and easy-to-implement methodology for improving analytical sensitivity, especially for halogenated compounds and otherwise abundant isotopologues. This novel application of signal summing was applied to measure and quantitate the two most abundant ion transitions of two isotopologues of N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine (1DCV), a urinary metabolite of trichloroethylene (TCE). Because 1DCV is dichlorinated, only approximately half of the total potential signal is quantifiable when the monoisotopic ion transition (i.e., m/z 256 → 127 for 35 Cl 2 ) is monitored. By summing the intensity of a separate and high-abundance 1DCV isotopologue ion transition (i.e., m/z 258 → 129 to include 35 Cl and 37 Cl), overall signal intensity increased by over 70%. This summation technique improved the analytical sensitivity and limit of detection (LOD) by factors of 2.3 and 2.9, respectively, compared to monitoring the two transitions separately, without summation. Separation and detection were performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in negative-ion mode with scheduled selected reaction monitoring. This approach was verified for accuracy and precision using two quality control materials. In addition, we derived a modified signal summation equation to calculate predicted signal enhancements specific to the MITSI approach. Graphical Abstract .

Background: Electronic cigarette (e-cigarette) conventions regularly bring together thousands of users around the world. In these environments, secondhand exposures to high concentrations of e-cigarette emissions are prevalent. Some biomarkers for tobacco smoke exposure may be used to characterize secondhand e-cigarette exposures in such an environment., Methods: Participants who did not use any tobacco product attended four separate e-cigarette events for approximately six hours. Urine and saliva samples were collected from participants prior to the event, immediately after the event, 4-h after the event, and the next morning (first void). Urine samples from 34 participants were analyzed for cotinine, trans-3'-hydroxycotinine, S-(3-hydroxypropyl)-N-acetylcysteine (3-HPMA), S-carboxyethyl-N-acetylcysteine (CEMA), select tobacco-specific nitrosamines (TSNAs), and 8-isoprostane. Saliva samples were analyzed for cotinine and trans-3'-hydroxycotinine., Results: Data from 28 of 34 participants were used in the data analysis. Creatinine-adjusted urinary cotinine concentrations increased up to 13-fold and peaked 4-h after completed exposure (range of adjusted geometric means [AGMs] = 0.352-2.31 μg/g creatinine). Salivary cotinine concentrations were also the highest 4-h after completed exposure (range of AGMs = 0.0373-0.167 ng/mL). Salivary cotinine and creatinine-corrected concentrations of urinary cotinine, trans-3'-hydroxycotinine, CEMA, and 3-HPMA varied significantly across sampling times. Urinary and salivary cotinine, urinary trans-3'-hydroxycotinine, and urinary 3-HPMA concentrations also varied significantly across events., Conclusion: Secondhand e-cigarette exposures lasting six hours resulted in significant changes in exposure biomarker concentrations of both nicotine and acrolein but did not change exposure to tobacco-specific nitrosamines. Additional research is needed to understand the relationship between biomarker concentrations and environmental concentrations of toxicants in e-cigarette emissions., (Published by Elsevier GmbH.)

Ethylbenzene and styrene are air toxicants with widespread nonoccupational exposure sources, including tobacco smoke and diet. Ethylbenzene and styrene (EB/S) exposure was quantified from their common metabolites measured in spot urine samples obtained from participants (≥6 years old) in the 2005-2006 and 2011-2012 cycles of the National Health and Nutrition Examination Survey (NHANES; N = 4690). EB/S metabolites mandelic acid (MA) and phenylglyoxylic acid (PGA) were measured using ultra-high performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). MA and PGA were detected in 98.9% and 90.6% of tested urine specimens, respectively. Exclusive smokers had 2-fold and 1.6-fold higher median urinary MA and PGA, respectively, compared with non-users. Sampleweighted regression analysis among exclusive smokers showed that smoking 0.5 pack cigarettes per day significantly increased MA (+97.9 μg/L) and PGA (+69.3 μg/L), controlling for potential confounders. In comparison, exposure from the median daily dietary intake of grain products increased MA by 1.95 μg/L and was not associated with statistically significant changes in urinary PGA levels. Conversely, consuming vegetables and fruit was associated with decreased MA and PGA. These results confirm tobacco smoke as a major source of ethylbenzene and styrene exposure for the general U.S. population., (Published by Elsevier Inc.)

Nitromethane is a known toxicant and suspected human carcinogen. Exposure to nitromethane in a representative sample of the civilian, noninstitutionalized population in the United States ≥12 years old was assessed using 2007-2012 National Health and Nutritional Examination Survey (NHANES) data. Nitromethane was detected in all 8000 human blood samples collected, of which 6730 were used for analyses reported here. Sample-weighted median blood nitromethane was higher among exclusive combusted tobacco users (exclusive smokers; 774 ng/L) than nonusers of tobacco products (625 ng/L). In stratified sample-weighted regression analysis, smoking 0.5 pack of cigarettes per day was associated with a statistically significant increase in blood nitromethane by 150 ng/L, and secondhand smoke exposure (serum cotinine >0.05 ng/mL and <10 ng/mL) was statistically significant with a 31.1 ng/L increase in blood nitromethane. Certain dietary sources were associated with small but statistically significant increases in blood nitromethane. At median consumption levels, blood nitromethane was associated with an increase of 7.55 ng/L (meat/poultry), 9.32 ng/L (grain products), and 14.5 ng/L (vegetables). This is the first assessment of the magnitude and relative source apportionment of nitromethane exposure in the U.S. population.

Sources of human aldehyde exposure include food additives, combustion of organic matter (tobacco smoke), water disinfection byproducts via ozonation, and endogenous processes. Aldehydes are potentially carcinogenic and mutagenic, and chronic human aldehyde exposure has raised concerns about potential deleterious health effects. To aid investigations of human aldehyde exposure, we developed a novel method to measure 19 aldehydes released from Schiff base protein adducts in serum using controlled acid hydrolysis, solid-phase microextraction (SPME), gas chromatography (GC), and high-resolution mass spectrometry (HRMS). Aldehydes are released from Schiff base protein adducts through acid hydrolysis, and are quantified in trace amounts (μg/L) using stable isotope dilution. Detection limits range from 0.1 to 50 μg/L, with calibration curves spanning 3 orders of magnitude. The analysis of fortified quality control material over a three-month period showed excellent precision and long-term stability (3-22% CV) for samples stored at -70 °C. The intraday precision is also excellent (CV, 1-10%). The method accuracy ranges from 89 to 108% for all measured aldehydes, except acrolein and crotonaldehyde, two aldehydes present in tobacco smoke; their analysis by this method is not considered robust due in part to their reactivity in vivo. However, results strongly suggest that propanal, butanal, isobutanal, and isopentanal levels in smokers are higher than levels in nonsmokers, and thus may be useful as biomarkers of tobacco smoke exposure. This method will facilitate large epidemiological studies involving aldehyde biomonitoring to examine nonoccupational environmental exposures.

Introduction: Crotonaldehyde is an α,β-unsaturated carbonyl compound that is a potent eye, respiratory, and skin irritant. Crotonaldehyde is a major constituent of tobacco smoke and its exposure can be quantified using its urinary metabolite N-acetyl-S-(3-hydroxypropyl-1-methyl)-L-cysteine (HPMM). A large-scale biomonitoring study is needed to determine HPMM levels, as a measure of crotonaldehyde exposure, in the general U.S., Materials and Methods: Urine samples were obtained as part of the National Health and Nutrition Examination Survey 2005-2006 and 2011-2012 from participants who were at least six-years-old (N = 4692). Samples were analyzed for HPMM using ultra performance liquid chromatography - tandem mass spectrometry. Exclusive tobacco smokers were distinguished from non- tobacco users through a combination of self-reporting and serum cotinine data., Results: Detection rate of HPMM among eligible samples was 99.9%. Sample-weighted, median urinary HPMM levels for smokers and non-users were 1.61 and 0.313 mg/g creatinine, respectively. Multivariable regression analysis among smokers showed that HPMM was positively associated with serum cotinine, after controlling for survey year, urinary creatinine, age, sex, race, poverty level, body mass index, pre-exam fasting time, and food intake. Other significant predictors of urinary HPMM include sex (female > male), age (children > non-user adults), race (non-Hispanic Blacks < non-Hispanic Whites)., Conclusions: This study characterizes U.S. population exposure to crotonaldehyde and confirms that tobacco smoke is a major exposure source. Urinary HPMM levels were significantly higher among exclusive combusted tobacco users compared to non-users, and serum cotinine and cigarettes per day were significant predictors of increased urinary HPMM. This study also found that sex, age, ethnicity, pre-exam fasting time, and fruit consumption are related to urinary HPMM levels., (Published by Elsevier Inc.)

This work describes a quantitative high-throughput analytical method for the simultaneous measurement of small aliphatic nitrogenous biomarkers, i.e., 1,6-hexamethylenediamine (HDA), isophoronediamine (IPDA), β-methylamino-l-alanine (BMAA), and trimethylamine N-oxide (TMAO), in human urine. Urinary aliphatic diamines, HDA and IPDA, are potential biomarkers of environmental exposure to their corresponding diisocyanates. Urinary BMAA forms as a result of human exposure to blue-green algae contaminated food. And, TMAO is excreted in urine due to the consumption of carnitine- and choline-rich diets. These urinary biomarkers represent classes of small aliphatic nitrogen-containing compounds (N-compounds) that have a high aqueous solubility, low logP, and/or high basic pK a . Because of the highly polar characteristics, analysis of these compounds in complex sample matrices is often challenging. We report on the development of ion-pairing chemistry based ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) method for the simultaneous measurement of these biomarkers in human urine. Chromatographic separation was optimized using heptafluorobutyric acid-(HFBA-) based mobile phase and a reversed-phase C18 column. All four analytes were baseline separated within 2.6 min with an overall run time of 5 min per sample injection. Sample preparation involved 4 h of acid hydrolysis followed by automated solid phase extraction (SPE) performed using strong cation exchange sorbent bed with 7 N ammonia solution in methanol as eluent. Limits of detection ranged from 0.05 ng/mL to 1.60 ng/mL. The inter-day and intra-day accuracy were within 10%, and reproducibility within 15%. The method is accurate, fast, and well-suited for biomonitoring studies within targeted groups, as well as larger population-based studies such as the U. S. National Health and Nutrition Examination Survey (NHANES)., (Published by Elsevier B.V.)

Studies of exposure to petroleum (crude oil/fuel) often involve monitoring benzene, toluene, ethylbenzene, xylenes (BTEX), and styrene (BTEXS) because of their toxicity and gas-phase prevalence, where exposure is typically by inhalation. However, BTEXS levels in the general U.S. population are primarily from exposure to tobacco smoke, where smokers have blood levels on average up to eight times higher than nonsmokers. This work describes a method using partition theory and artificial neural network (ANN) pattern recognition to classify exposure source based on relative BTEXS and 2,5-dimethylfuran blood levels. A method using surrogate signatures to train the ANN was validated by comparing blood levels among cigarette smokers from the National Health and Nutrition Examination Survey (NHANES) with BTEXS and 2,5-dimethylfuran signatures derived from the smoke of machine-smoked cigarettes. Classification agreement for an ANN model trained with relative VOC levels was up to 99.8% for nonsmokers and 100.0% for smokers. As such, because there is limited blood level data on individuals exposed to crude oil/fuel, only surrogate signatures derived from crude oil and fuel were used for training the ANN. For the 2007-2008 NHANES data, the ANN model assigned 7 out of 1998 specimens (0.35%) and for the 2013-2014 NHANES data 12 out of 2906 specimens (0.41%) to the crude oil/fuel signature category.

Objective: Prior to initial distribution of Glucose-6-phosphate dehydrogenase (G6PD) proficiency testing (PT) materials, we evaluated G6PD enzyme stability in dried blood spots (DBS) under various temperature and humidity environments to develop storage and usage guidelines for our new materials., Design & Methods: We prepared fresh G6PD-normal DBS materials and conducted stability evaluations of daily use and short and long-term storage under various temperature and humidity environments., Results: G6PD DBS PT materials retained 92% of initial activity after 30days of use at 4°C. Materials stored at -20°C and 4°C with desiccant for 30days retained 95% and 90% of initial activity, respectively. When stored for one year at -20°C or six months at 4°C specimens retained >90% of initial activity. Specimens stored at 37°C with desiccant lost 10% activity in three days. At the end of 30days, specimens stored under 'Extreme'-humidity >50% without desiccant- conditions at 37°C assayed below the NSQAP cut off for G6PD. Humidity exacerbated loss of enzyme activity with increasing temperature and time duration., Conclusion: Data suggest that G6PD PT materials can be stored at 4°C and used for up to one month and can be stored at -20°C for one year and yield >90% enzyme activity. Exposure to warm temperatures, especially with elevated humidity, should be avoided. Desiccant should always be used to mitigate humidity effects., (Published by Elsevier Inc.)

The importance of hemoglobin A 2 (HbA 2 ) as an indicator of the presence of β-thalassemia was established many years ago. However, clinical application of recommended HbA 2 cut off values is often hampered due to poor equivalence of HbA 2 results among methods and laboratories. Thus, the IFCC standardization program for HbA 2 was initiated in 2004 with the goal of achieving a complete reference system for this measurand. HbA 2 standardization efforts are still in progress, including the development of a higher-order HbA 2 reference measurement procedure and the preparation of a certified reference material in collaboration with the IRMM. Here, we review the past, present and future of HbA 2 standardization and describe the current status of HbA 2 testing., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Objectives: The goal of this study was to include the quantitation of hexacosanoyl lysophosphatidylcholine, a biomarker for X-linked adrenoleukodystrophy and other peroxisomal disorders, in the routine extraction and analysis procedure used to quantitate amino acids, acylcarnitines, and succinylacetone during newborn screening. Criteria for the method included use of a single punch from a dried blood spot, one simple extraction of the punch, no high-performance liquid chromatography, and utilizing tandem mass spectrometry to quantitate the analytes., Design and Methods: Dried blood spot punches were extracted with a methanolic solution of stable-isotope labeled internal standards, formic acid, and hydrazine, followed by flow injection analysis-electrospray ionization-tandem mass spectrometry., Results: Quantitation of amino acids, acylcarnitines, and hexacosanoyl lysophosphatidylcholine using this combined method was similar to results obtained using two separate methods., Conclusions: A single dried blood spot punch extracted by a rapid (45min), simple procedure can be analyzed with high throughput (2min per sample) to quantitate amino acids, acylcarnitines, succinylacetone, and hexacosanoyl lysophosphatidylcholine., (Published by Elsevier Inc.)

Guanidinoacetate methyltransferase (GAMT) deficiency is an autosomal recessive genetic disorder which results in global developmental delay and intellectual disability. There is evidence that early treatment prevents intellectual disability and seizures. GAMT deficiency is now being discussed as a potential addition to the U.S. Recommended Uniform Screening Panel (RUSP); the availability of suitable screening methods must be considered. A neonatal screening derivatized method to quantify creatine (CRE) and guanidinoacetic acid (GAA) in dried blood spots by tandem mass spectrometry (MS/MS) has been described. Its key feature is the ability to detect CRE and GAA in the same extract generated from neonatal DBS during amino acids (AA) and acylcarnitines (AC) analysis. More laboratories are adopting non-derivatized MS/MS screening methods. We describe an improved, non-derivatized DBS extraction and MS/MS analytical method (AAAC-GAMT) which incorporates quantitation of CRE and GAA into routine analysis of amino acids, acylcarnitines, and succinylacetone. The non-derivatized AAAC-GAMT method performs comparably to the stand-alone GAMT and non-derivatized AAAC screening methods, evidencing its potential suitability for high-throughput GAMT neonatal screening., Competing Interests: Conflicts of Interest: The authors declare no conflict of interest.

Dried blood spots (DBS) have been used in newborn screening (NBS) tests for over 50 years. The Newborn Screening Quality Assurance Program (NSQAP) at the Centers for Disease Control and Prevention (CDC) conducted studies to assess the individual impacts of hematocrit and total-spot volume on characteristics of DBS samples. Per-punch serum volumes decreased 27%, RBC volumes more than doubled, absorption times increased over 300%, and spot diameters decreased marginally between the hematocrits of 40% to 65%. Per-punch serum and RBC volumes decreased logarithmically with lowering total-spot volumes. Patient hematocrit is an uncontrollable variable and inevitably affects the resulting punch from a DBS sample. It may be possible, though, to identify samples that fall outside of an acceptable range by noting certain physical characteristics of the DBS., Competing Interests: Conflicts of Interest The authors declare no conflict of interest.