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2.
N Engl J Med ; 382(8): 697-705, 2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-31860793

RESUMO

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.).


Assuntos
Lesão Pulmonar Aguda/patologia , Líquido da Lavagem Broncoalveolar/química , Sistemas Eletrônicos de Liberação de Nicotina , Vaping/efeitos adversos , Vitamina E/análise , Lesão Pulmonar Aguda/etiologia , Adolescente , Adulto , Idoso , Fumar Cigarros , Óleo de Coco/análise , Feminino , Humanos , Limoneno/análise , Masculino , Pessoa de Meia-Idade , Estados Unidos , Adulto Jovem
3.
Artigo em Inglês | MEDLINE | ID: mdl-31766137

RESUMO

As the technology of electronic nicotine delivery systems (ENDS), including e-cigarettes, evolves, assessing metal concentrations in liquids among brands over time becomes challenging. A method for quantification of chromium, nickel, copper, zinc, cadmium, tin, and lead in ENDS liquids using triple quadrupole inductively coupled plasma mass spectrometry was developed. The method's limits of detection (LODs) were 0.031, 0.032, 3.15, 1.27, 0.108, 0.099, 0.066 µg/g for Cr, Ni, Cu, Zn, Cd, Sn, and Pb respectively. Liquids analyzed were from different brands and flavors of refill bottles or single-use, rechargeable, and pod devices from different years. Scanning electron microscopy with energy dispersive spectroscopy further evaluated the device components' compositions. Refill liquids before contacting a device were below lowest reportable levels (LRL) for all metals. Copper and zinc were elevated in liquids from devices containing brass. Cadmium was

4.
MMWR Morb Mortal Wkly Rep ; 68(45): 1040-1041, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31725707

RESUMO

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).


Assuntos
Líquido da Lavagem Broncoalveolar/química , Surtos de Doenças , Lesão Pulmonar/epidemiologia , Vaping/efeitos adversos , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estados Unidos/epidemiologia , Adulto Jovem
5.
J Anal Toxicol ; 2019 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-31588518

RESUMO

Since 2006 the domestic popularity and sales of electronic cigarettes (i.e., electronic nicotine delivery systems or ENDS) have grown rapidly. Although the constituents of the aerosol produced by ENDS have been previously investigated, differences in puff regimens and aerosol trapping schema in published literature often complicate result comparisons and data interpretation. As the ENDS product designs continue to evolve, there is a critical need to develop and validate robust methodologies for laboratory testing, appropriate aerosol generation and trapping media required for accurate determinations of ENDS aerosol metals deliveries. A simple, high metals purity, fluoropolymer trap was developed and validated that meets standard machine puffing regimen (CORESTA Recommended Method 81) specifications and exhibits negligible acid extractable metal backgrounds. Using a standard machine puffing regimen in combination with a fluoropolymer condensation trap, aerosol was generated and collected from select ENDS devices for analysis of chromium, nickel, copper, zinc, cadmium, tin, and lead with triple quadrupole inductively coupled plasma mass spectrometry. Devices tested spanned a range of commercial products, including flavored variants of JUUL pods, refillable tank systems, rechargeable cartridges, and single-use ENDs devices. Results showed that for aerosols generated under a fixed puffing regimen (50 puffs/collection), metal concentrations ranged from below the detection limits (LOD) to 614 ng copper and 339 ng zinc per 10 puffs. Cadmium concentrations were below LOD for all devices tested. Device specific aerosol levels of Sn and Pb ranged from below LOD to low nanogram levels. Cr and Ni were transported in aerosols at levels equivalent to, or slightly higher than in mainstream cigarette smoke using a standard smoking regimen. The generally lower levels of specific metals, Cd and Pb, transmitted in ENDS aerosols compared to mainstream cigarette smoke reflect possible reduction of harm for smokers who substitute the use of ENDS as cessation devices in place of smoking cigarettes.

6.
Artigo em Inglês | MEDLINE | ID: mdl-30018593

RESUMO

Background: Perchlorate, thiocyanate, and nitrate can block iodide transport at the sodium iodide symporter (NIS) and this can subsequently lead to decreased thyroid hormone production and hypothyroidism. NIS inhibitor exposure has been shown to reduce iodide uptake and thyroid hormone levels; therefore we hypothesized that maternal NIS inhibitor exposure will influence both maternal and newborn thyroid function. Methods: Spot urine samples were collected from 185 lactating mothers and evaluated for perchlorate, thiocyanate, and nitrate concentrations. Blood and colostrum samples were collected from the same participants in the first 48 h after delivery. Thyroid hormones and thyroid-related antibodies (TSH, fT3, fT4, anti-TPO, anti-Tg) were analyzed in maternal blood and perchlorate was analyzed in colostrum. Also, spot blood samples were collected from newborns (n = 185) between 48 and 72 postpartum hours for TSH measurement. Correlation analysis was performed to assess the effect of NIS inhibitors on thyroid hormone levels of lactating mothers and their newborns in their first 48 postpartum hours. Results: The medians of maternal urinary perchlorate (4.00 µg/g creatinine), maternal urinary thiocyanate (403 µg/g creatinine), and maternal urinary nitrate (49,117 µg/g creatinine) were determined. Higher concentrations of all three urinary NIS inhibitors (µg/g creatinine) at their 75th percentile levels were significantly correlated with newborn TSH (r = 0.21, p < 0.001). Median colostrum perchlorate level concentration of all 185 participants was 2.30 µg/L. Colostrum perchlorate was not significantly correlated with newborn TSH (p > 0.05); however, there was a significant correlation between colostrum perchlorate level and maternal TSH (r = 0.21, p < 0.01). Similarly, there was a significant positive association between colostrum perchlorate and maternal urinary creatinine adjusted perchlorate (r = 0.32, p < 0.001). Conclusion: NIS inhibitors are ubiquitous in lactating women in Turkey and are associated with increased TSH levels in newborns, thus signifying for the first time that co-exposure to maternal NIS inhibitors can have a negative effect on the newborn thyroid function.

7.
J Chromatogr A ; 1565: 124-129, 2018 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-29945789

RESUMO

Nitrobenzene, a potentially harmful compound found in tobacco smoke, has been largely excluded from prior analysis due to difficulties with quantification. Quantifying harmful compounds in cigarette smoke is useful to compare products, to examine the impact of design parameters on delivery, and to help estimate exposures. A sensitive high-throughput method has been developed for quantifying nitrobenzene in machine-generated mainstream cigarette smoke using isotope dilution gas chromatography-tandem mass spectrometry (ID-GC-MS/MS). This method has sufficient sensitivity to measure vapor phase nitrobenzene concentrations in the low nanogram range, with a 418 pg/cig method limit of detection. Precision estimates from two quality control cigarette products resulted in percent relative standard deviations of 11.5% and 14.9%; product variability estimates from 13 cigarette products resulted in percent relative standard deviations ranging from 2.8% to 16.9%. Nitrobenzene in the machine-generated, mainstream smoke from 15 cigarette products are reported and range from 18 to 38 ng/cig under the Health Canada Intense smoking regimen.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Nitrobenzenos/análise , Poluição por Fumaça de Tabaco/análise , Tabaco/química , Calibragem , Canadá , Íons , Limite de Detecção , Material Particulado/análise , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem , Produtos do Tabaco/análise
8.
J Anal Toxicol ; 42(9): 637-641, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-29750257

RESUMO

A quantitative method for the analysis of aluminum in tobacco products was developed, validated and applied to select samples. Samples were prepared using standard microwave digestion of tobacco from various products. Detection and quantification utilized sector field inductively coupled plasma-mass spectrometry. Method applicability to analyze aluminum in a range of tobacco products was demonstrated with quantitative analyses of smokeless tobacco products, cigarette tobacco, little cigar tobacco and roll-your-own/pipe tobacco. Though these products represent a convenience sampling, we observed that smokeless tobacco products, as a category, had the lowest average aluminum concentrations. Roll-your-own or pipe tobacco and little cigar tobacco had higher median and ranges of aluminum concentrations than cigarette and smokeless tobacco samples.


Assuntos
Alumínio/análise , Poluentes do Solo/análise , Produtos do Tabaco/análise , Produtos do Tabaco/normas , Tabaco/química , Calibragem , Limite de Detecção , Espectrometria de Massas , Controle de Qualidade , Padrões de Referência , Reprodutibilidade dos Testes , Tabaco/crescimento & desenvolvimento , Tabaco sem Fumaça/análise , Tabaco sem Fumaça/normas , Estados Unidos
9.
Anal Chem ; 89(19): 10461-10467, 2017 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-28930436

RESUMO

A new tobacco filler Standard Reference Material (SRM) has been issued by the National Institute of Standards and Technology (NIST) in September 2016 with certified and reference mass fraction values for nicotine, N-nitrosonornicotine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, and volatiles. The constituents have been determined by multiple analytical methods with measurements at NIST and at the Centers for Disease Control and Prevention, and with confirmatory measurements by commercial laboratories. This effort highlights the development of the first SRM for reduced nicotine and reduced tobacco-specific nitrosamines with certified values for composition.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectrometria de Massas em Tandem/métodos , Produtos do Tabaco/análise , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida de Alta Pressão/normas , Congelamento , Cromatografia Gasosa-Espectrometria de Massas/normas , Nicotina/análise , Nicotina/normas , Nitrosaminas/análise , Nitrosaminas/normas , Transição de Fase , Padrões de Referência , Espectrometria de Massas em Tandem/normas , Produtos do Tabaco/normas , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/normas
10.
Environ Res ; 158: 72-81, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28601764

RESUMO

BACKGROUND: At high medicinal doses perchlorate is known to decrease the production of thyroid hormone, a critical factor for fetal development. In a large and uniquely exposed cohort of pregnant women, we recently identified associations between environmental perchlorate exposures and decreased maternal thyroid hormone during pregnancy. Here, we investigate whether perchlorate might be associated with birthweight or preterm birth in the offspring of these women. METHODS: Maternal urinary perchlorate, serum thyroid hormone concentrations, birthweight, gestational age, and urinary nitrate, thiocyanate, and iodide were collected in 1957 mother-infant pairs from San Diego County during 2000-2003, a period when the county's water supply was contaminated with perchlorate. Associations between perchlorate exposure and birth outcomes were examined using linear and logistic regression analyses adjusted for maternal age, weight, race/ethnicity, and other factors. RESULTS: Perchlorate was not associated with birth outcomes in the overall population. However, in analyses confined to male infants, log10 maternal perchlorate concentrations were associated with increasing birthweight (ß=143.1gm, p=0.01), especially among preterm births (ß=829.1g, p<0.001). Perchlorate was associated with male preterm births ≥2500g (odds ratio=3.03, 95% confidence interval=1.09-8.40, p-trend=0.03). Similar associations were not seen in females. CONCLUSIONS: This is the first study to identify associations between perchlorate and increasing birthweight. Further research is needed to explore the differences we identified related to infant sex, preterm birth, and other factors. Given that perchlorate exposure is ubiquitous, and that long-term impacts can follow altered birth outcomes, future research on perchlorate could have widespread public health importance.


Assuntos
Peso ao Nascer/efeitos dos fármacos , Exposição Materna , Percloratos/toxicidade , Nascimento Prematuro/epidemiologia , Poluentes Químicos da Água/toxicidade , Adulto , California/epidemiologia , Estudos de Coortes , Feminino , Humanos , Recém-Nascido , Masculino , Razão de Chances , Percloratos/urina , Gravidez , Nascimento Prematuro/induzido quimicamente , Poluentes Químicos da Água/urina , Adulto Jovem
11.
Tob Regul Sci ; 3(1): 81-94, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28220149

RESUMO

OBJECTIVE: Our objective was to characterize mainstream smoke constituent deliveries from SPECTRUM variable nicotine research cigarettes under 2 machine smoking regimens. SPECTRUM cigarettes are manufactured by the 22nd Century company for the National Institute on Drug Abuse, National Institutes of Health to contain varying (including reduced) levels of nicotine. METHODS: Mainstream smoke constituent deliveries of "tar," nicotine, carbon monoxide, tobacco-specific nitrosamines (N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)), benzo[a]pyrene, aromatic amines, and carbonyls were analyzed in 23 varieties of SPECTRUM cigarettes using ISO 17025 accredited methods. RESULTS: Data are presented as means and standard deviations of 5 replicates for all analytes. CONCLUSIONS: Under the ISO smoking regimen, mean levels of many smoke emissions for SPECTRUM varieties were comparable to the 3R4F research cigarette. Calculated SPECTRUM elasticity ranged from 1.6 to 4.0. Accordingly, under intense machine smoking conditions differences in emissions of SPECTRUM cigarettes were apparent. In addition, NNN increased with smoke nicotine while the same rate of change was not seen for NNK. It is important to monitor levels of chemicals of public health concern and regulatory interest as technologies emerge to reduce levels of nicotine or other targeted chemicals in tobacco products.

12.
J Anal Toxicol ; 41(4): 307-312, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28164228

RESUMO

Chromium is transported in mainstream tobacco smoke at very low concentrations. However, when chromium is deposited too deeply in the lungs for mucociliary clearance, or is in a particle that is too large to pass directly through tissues, it bioaccumulates in the lungs of smokers. It is important to determine the concentrations of chromium that are transported in mainstream smoke. Several reliable studies have resulted in reports of chromium concentrations in smoke particulate that were below limits of detection (LODs) for the instruments and methods employed. In this study, electrothermal vaporization-triple quad-inductively coupled plasma-mass spectrometry (ETV-QQQ-ICP-MS) was chosen for determination of chromium concentrations in mainstream smoke because of the high sensitivity of ETV combined with QQQ-ICP-MS. The smoke from five reference, quality control, and commercial cigarettes was analyzed using ETV-QQQ-ICP-MS with isotope dilution for quantitative determination of chromium. The method LOD was sufficiently low that chromium concentrations in mainstream smoke could indeed be determined. The chromium concentrations in the smoke particulate were between 0.60 and 1.03 ng/cigarette. The range of chromium concentrations was at or below previously reported LODs. Determination of the oxidation state of the chromium transported in mainstream smoke would also be important, in consideration of the fact that both chromium(III) and chromium(VI) oxidation states cause inhalation toxicity, but chromium(VI) is also a carcinogen. It was possible to separate the oxidation states using ETV-QQQ-ICP-MS. However, determination of individual species at the levels found in mainstream smoke particulate matter was not possible with the present method.


Assuntos
Poluentes Atmosféricos/análise , Cromo/análise , Poluição por Fumaça de Tabaco/análise , Limite de Detecção , Espectrometria de Massas , Fumaça/análise , Espectrofotometria Atômica , Produtos do Tabaco/análise , Volatilização
13.
Nicotine Tob Res ; 19(4): 484-492, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27613945

RESUMO

Introduction: Most electronic cigarettes (e-cigarettes) contain a solution of propylene glycol/glycerin and nicotine, as well as flavors. E-cigarettes and their associated e-liquids are available in numerous flavor varieties. A subset of the flavor varieties include coffee, tea, chocolate, and energy drink, which, in beverage form, are commonly recognized sources of caffeine. Recently, some manufacturers have begun marketing e-liquid products as energy enhancers that contain caffeine as an additive. Methods: A Gas Chromatography-Mass Spectrometry (GC-MS) method for the quantitation of caffeine in e-liquids was developed, optimized and validated. The method was then applied to assess caffeine concentrations in 44 flavored e-liquids from cartridges, disposables, and refill solutions. Products chosen were flavors traditionally associated with caffeine (ie, coffee, tea, chocolate, and energy drink), marketed as energy boosters, or labeled as caffeine-containing by the manufacturer. Results: Caffeine was detected in 42% of coffee-flavored products, 66% of tea-flavored products, and 50% of chocolate-flavored e-liquids (limit of detection [LOD] - 0.04 µg/g). Detectable caffeine concentrations ranged from 3.3 µg/g to 703 µg/g. Energy drink-flavored products did not contain detectable concentrations of caffeine. Eleven of 12 products marketed as energy enhancers contained caffeine, though in widely varying concentrations (31.7 µg/g to 9290 µg/g). Conclusions: E-liquid flavors commonly associated with caffeine content like coffee, tea, chocolate, and energy drink often contained caffeine, but at concentrations significantly lower than their dietary counterparts. Estimated daily exposures from all e-cigarette products containing caffeine were much less than ingestion of traditional caffeinated beverages like coffee. Implications: This study presents an optimized and validated method for the measurement of caffeine in e-liquids. The method is applicable to all e-liquid matrices and could potentially be used to ensure regulatory compliance for those geographic regions that forbid caffeine in e-cigarette products. The application of the method shows that caffeine concentrations and estimated total caffeine exposure from e-cigarette products is significantly lower than oral intake from beverages. However, because very little is known about the effects of caffeine inhalation, e-cigarette users should proceed with caution when using caffeine containing e-cigarette products. Further research is necessary to determine associated effects from inhaling caffeine.


Assuntos
Cafeína/análise , Chocolate/análise , Café/química , Sistemas Eletrônicos de Liberação de Nicotina , Bebidas Energéticas/análise , Aromatizantes/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos
14.
Int J Hyg Environ Health ; 220(2 Pt A): 55-63, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27789189

RESUMO

BACKGROUND: General population human biomonitoring programs such as the National Health and Nutrition Examination Survey (NHANES) in the United States suggest that chemical exposures are common. Exposures during childhood may affect health later in life, but biomonitoring data in NHANES among pre-school aged children are limited. METHODS: A convenience group of 122 3-5year old American boys and girls were recruited in 2013 for a pilot study to assess the feasibility of collecting urine from young children and analyzing it for select chemical exposure biomarkers for future NHANES. Children were primarily Hispanic (64.8%); the remainder was divided between non-Hispanic black, and non-Hispanic white and "other." We measured 52 urinary biomarkers: 13 phthalates and one non-phthalate plasticizer, five phenols and four parabens, 10 polycyclic aromatic hydrocarbons (PAHs), and 19 pesticides. For each biomarker, we calculated descriptive statistics. We also calculated the number of biomarkers detected within each child, and performed principal components analysis (PCA). RESULTS: NHANES staff obtained permission to attempt collection of 60mL urine from 3 to 5year olds who participated in the 2013 NHANES health examination; 83% of children successfully provided the target volume. We detected 24 individual biomarkers of pesticides, phenols and parabens, phthalates/non-phthalate plasticizers, and PAHs in 95-100% of children. The median number of biomarkers detected was 37: nine pesticides, five phenols and parabens, 13 phthalates and non-phthalate plasticizers, and 10 PAHs. Biomarkers concentrations appear to be similar to national estimates among 6-11year old children from previous NHANES. PCA suggested high within-class correlations among biomarkers. CONCLUSIONS: These young children successfully adhered to the collection protocol and produced enough urine for the quantification of environmental biomarkers currently being measured in NHANES participants 6 years of age and older. Using the same analytical methods employed for the analysis of samples collected from older NHANES participants, in this sample of pre-school aged children we detected multiple chemicals including plasticizers, combustion products, personal-care product chemicals, and pesticides. Starting with NHANES 2015-2016, the NHANES biomonitoring program will include urinary biomarkers for 3-5year old children to provide exposure data to select chemicals at the national level among this age group.


Assuntos
Poluentes Ambientais/urina , Pré-Escolar , Monitoramento Ambiental , Feminino , Humanos , Masculino , Inquéritos Nutricionais , Parabenos/análise , Praguicidas/urina , Fenóis/urina , Ácidos Ftálicos/urina , Projetos Piloto , Plastificantes/análise , Hidrocarbonetos Policíclicos Aromáticos/urina , Estados Unidos
15.
Anal Bioanal Chem ; 409(5): 1323-1332, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27838756

RESUMO

Polybrominated diphenyl ethers (PBDEs), produced as flame retardants worldwide, have been phased-out in many countries, and chlorinated and non-chlorinated organophosphates and non-PBDE brominated formulations (e.g., Firemaster 550 (FM550)) have entered the consumers' market. Recent studies show that components of organophosphate esters and FM550 are frequently detected in many products common to human environments. Therefore, urinary metabolites of these compounds can be used as human exposure biomarkers. We developed a method to quantify nine compounds in 0.4 mL urine: diphenyl phosphate (DPhP), bis(1,3-dichloro-2-propyl) phosphate (BDCPP), bis-(1-chloro-2-propyl) phosphate, bis-2-chloroethyl phosphate, di-p-cresylphosphate, di-o-cresylphosphate (DoCP), di-n-butyl phosphate, dibenzyl phosphate (DBzP), and 2,3,4,5-tetrabromobenzoic acid. The method relies on an enzymatic hydrolysis of urinary conjugates of the target analytes, automated off-line solid phase extraction, reversed phase high performance liquid chromatography separation, and isotope dilution-electrospray ionization tandem mass spectrometry detection. The method is high-throughput (96 samples/day) with detection limits ranging from 0.05 to 0.16 ng mL-1. Spiked recoveries were 90-113 %, and interday imprecision was 2-8 %. We assessed the suitability of the method by analyzing urine samples collected from a convenience sample of adults (n = 76) and from a group of firefighters (n = 146). DPhP (median, 0.89; range, 0.26-5.6 ng mL-1) and BDCPP (median, 0.69; range, 0.31-6.8 ng mL-1) were detected in all of the non-occupationally exposed adult samples and all of the firefighter samples (DPhP [median, 2.9; range, 0.24-28 ng mL-1], BDCPP [median, 3.4; range, 0.30-44 ng mL-1]); DBzP and DoCP were not detected in any samples.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Hidrocarbonetos Bromados/urina , Organofosfatos/urina , Espectrometria de Massas em Tandem/métodos , Automação , Humanos , Limite de Detecção , Reprodutibilidade dos Testes
16.
PLoS One ; 11(7): e0159126, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27415766

RESUMO

Ammonia in mainstream smoke is present in both the particulate and vapor phases. The presence of ammonia in the cigarette filler material and smoke is of significance because of the potential role ammonia could have in raising the "smoke pH." An increased smoke pH could shift a fraction of total nicotine to free-base nicotine, which is reportedly more rapidly absorbed by the smoker. Methods measuring ammonia in smoke typically employ acid filled impingers to trap the smoke. We developed a fast, reliable method to measure ammonia in mainstream smoke without the use of costly and time consuming impingers to examine differences in ammonia delivery. The method uses both a Cambridge filter pad and a Tedlar bag to capture particulate and vapor phases of the smoke. We quantified ammonia levels in the mainstream smoke of 50 cigarette brands from 5 manufacturers. Ammonia levels ranged from approximately 1µg to 23µg per cigarette for ISO smoking conditions and 38µg to 67µg per cigarette for Canadian intense smoking conditions and statistically significance differences were observed between brands and manufacturers. Our findings suggest that ammonia levels vary by brand and are higher under Canadian intense smoking conditions.


Assuntos
Amônia/análise , Fumaça/análise , Fumar/efeitos adversos , Tabaco/efeitos adversos , Tabaco/química , Canadá , Cromatografia por Troca Iônica/métodos , Humanos , Concentração de Íons de Hidrogênio , Produtos do Tabaco/efeitos adversos , Produtos do Tabaco/análise
17.
Bull Environ Contam Toxicol ; 97(3): 439-45, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27435977

RESUMO

Perchlorate is a chemical pollutant that inhibits iodide uptake and may possibly impair thyroid function. Our previous study found widespread perchlorate exposure in non-pregnant, non-lactating, healthy women residing in Istanbul. The aim of this study is to assess the relative amounts of perchlorate exposure attributable to consumption of municipal water, bottled water and boxed milk available in Istanbul. Only trace levels of perchlorate were found in treated municipal water (58 % detectable, mean = 0.13 µg/L, maximum = 0.75 µg/L) and bottled water (7.4 % detectable, mean = 

Assuntos
Água Potável/química , Exposição Ambiental/análise , Leite/química , Percloratos/análise , Animais , Humanos , Iodetos/metabolismo , Turquia
18.
Environ Res ; 149: 179-188, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27208469

RESUMO

The sodium iodide-symporter (NIS) mediates uptake of iodide into thyroid follicular cells. This key step in thyroid hormone synthesis is inhibited by perchlorate, thiocyanate (SCN) and nitrate (NO3) anions. When these exposures occur during pregnancy the resulting decreases in thyroid hormones may adversely affect neurodevelopment of the human fetus. Our objectives were to describe and examine the relationship of these anions to the serum thyroid indicators, thyroid stimulating hormone (TSH) and free thyroxine (FT4), in third trimester women from the initial Vanguard Study of the National Children's Study (NCS); and to compare urine perchlorate results with those in pregnant women from the National Health and Nutritional Examination Survey (NHANES). Urinary perchlorate, SCN, NO3, and iodine, serum TSH, FT4, and cotinine were measured and a food frequency questionnaire (FFQ) was administered to pregnant women enrolled in the initial Vanguard Study. We used multiple regression models of FT4 and TSH that included perchlorate equivalent concentration (PEC, which estimates combined inhibitory effects of the anions perchlorate, SCN, and NO3 on the NIS). We used multiple regression to model predictors of each urinary anion, using FFQ results, drinking water source, season of year, smoking status, and demographic characteristics. Descriptive statistics were calculated for pregnant women in NHANES 2001-2012. The geometric mean (GM) for urinary perchlorate was 4.04µg/L, for TSH 1.46mIU/L, and the arithmetic mean for FT4 1.11ng/dL in 359 NCS women. In 330 women with completed FFQs, consumption of leafy greens, winter season, and Hispanic ethnicity were significant predictors of higher urinary perchlorate, which differed significantly by study site and primary drinking water source, and bottled water was associated with higher urinary perchlorate compared to filtered tap water. Leafy greens consumption was associated with higher urinary NO3 and higher urinary SCN. There was no association between urinary perchlorate or PEC and TSH or FT4, even for women with urinary iodine <100µg/L. GM urinary perchlorate concentrations in the full sample (n=494) of third trimester NCS women (4.03µg/L) were similar to pregnant women in NHANES (3.58µg/L).


Assuntos
Antitireóideos/farmacologia , Exposição Ambiental , Nitratos/urina , Percloratos/urina , Simportadores/antagonistas & inibidores , Tiocianatos/urina , Tireotropina/sangue , Tiroxina/sangue , Adulto , Feminino , Humanos , Inquéritos Nutricionais , Gravidez , Terceiro Trimestre da Gravidez , Testes de Função Tireóidea , Estados Unidos , Adulto Jovem
19.
Environ Int ; 92-93: 398-404, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27138630

RESUMO

BACKGROUND: N,N-diethyl-m-toluamide (DEET) is a widely used insect repellent in the United States. OBJECTIVES: To assess exposure to DEET in a representative sample of persons 6years and older in the U.S. general population from the 2007-2010 National Health and Nutrition Examination Survey. METHODS: We analyzed 5348 urine samples by using online solid-phase extraction coupled to isotope dilution-high-performance liquid chromatography-tandem mass spectrometry. We used regression models to examine associations of various demographic parameters with urinary concentrations of DEET biomarkers. RESULTS: We detected DEET in ~3% of samples and at concentration ranges (>0.08µg/L-45.1µg/L) much lower than those of 3-(diethylcarbamoyl)benzoic acid (DCBA) (>0.48µg/L-30,400µg/L) and N,N-diethyl-3-hydroxymethylbenzamide (DHMB) (>0.09µg/L-332µg/L). DCBA was the most frequently detected metabolite (~84%). Regardless of survey cycle and the person's race/ethnicity or income, adjusted geometric mean concentrations of DCBA were higher in May-Sep than in Oct-Apr. Furthermore, non-Hispanic whites in the warm season were more likely than in the colder months [adjusted odds ratio (OR)=10.83; 95% confidence interval (CI), 3.28-35.79] and more likely than non-Hispanic blacks (OR=3.45; 95% CI, 1.51-7.87) to have DCBA concentrations above the 95th percentile. CONCLUSIONS: The general U.S. population, including school-age children, is exposed to DEET. However, reliance on DEET as the sole urinary biomarker would likely underestimate the prevalence of exposure. Instead, oxidative metabolites of DEET are the most adequate exposure biomarkers. Differences by season of the year based on demographic variables including race/ethnicity likely reflect different lifestyle uses of DEET-containing products.


Assuntos
DEET/análogos & derivados , DEET/urina , Repelentes de Insetos/urina , Inquéritos Nutricionais , Animais , Biomarcadores/urina , Cromatografia Líquida de Alta Pressão , Grupos de Populações Continentais , Poluentes Ambientais/urina , Feminino , Humanos , Masculino , Extração em Fase Sólida , Estados Unidos
20.
J Expo Sci Environ Epidemiol ; 26(3): 324-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-25805252

RESUMO

Perchlorate (ClO4(-)) is a ubiquitous environmental contaminant with high human exposure potential. Natural perchlorate forms in the atmosphere from where it deposits onto the surface of Earth, whereas synthetic perchlorate is manufactured as an oxidant for industrial, aerospace, and military applications. Perchlorate exposure can potentially cause adverse health effects in humans by interfering with the production of thyroid hormones through competitively blocking iodide uptake. To control and reduce perchlorate exposure, the contributions of different sources of perchlorate exposure need to be quantified. Thus, we demonstrate a novel approach for determining the contribution of different perchlorate exposure sources by quantifying stable and radioactive chlorine isotopes of perchlorate extracted from composite urine samples from two distinct populations: one in Atlanta, USA and one in Taltal, Chile (Atacama region). Urinary perchlorate from the Atlanta region resembles indigenous natural perchlorate from the western USA (δ(37)Cl=+4.1±1.0‰; (36)Cl/Cl=1 811 (±136) × 10(-15)), and urinary perchlorate from the Taltal, Chile region is similar to natural perchlorate in nitrate salt deposits from the Atacama Desert of northern Chile (δ(37)Cl=-11.0±1.0‰; (36)Cl/Cl=254 (±40) × 10(-15)). Neither urinary perchlorate resembled the isotopic pattern found in synthetic perchlorate. These results indicate that natural perchlorate of regional provenance is the dominant exposure source for the two sample populations, and that chlorine isotope ratios provide a robust tool for elucidating perchlorate exposure pathways.


Assuntos
Cloro/química , Exposição Ambiental , Exposição Ocupacional , Percloratos/urina , Humanos
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