1,026 research outputs found
ALDH2-deficiency as genetic epidemiologic and biochemical model for the carcinogenicity of acetaldehyde
Humans are cumulatively exposed to acetaldehyde from various sources including alcoholic beverages, tobacco smoke, foods and beverages. The genetic-epidemiologic and biochemical evidence in ALDH2-deficient humans provides strong evidence for the causal relationship between acetaldehyde-exposure due to alcohol consumption and cancer of the upper digestive tract. The risk assessment has so far relied on thresholds based on animal toxicology with lower one-sided confidence limit of the benchmark dose values (BMDL) typically ranging between 11 and 63 mg/kg bodyweight (bw)/day dependent on species and endpoint. The animal data is problematic for regulatory toxicology for various reasons (lack in study quality, problems in animal models and appropriateness of endpoints - especially cancer - for transfer to humans). In this study, data from genetic epidemiologic and biochemical studies are reviewed. The increase in the daily exposure dose to acetaldehyde in alcohol-consuming ALDH2-deficients vs. ALDH2-actives was about twofold. The acetaldehyde increase due to ALDH2 inactivity was calculated to be 6.7 mu g/kg bw/day for heavy drinkers, which is associated with odds ratios of up to 7 for head and neck as well as oesophageal cancer. Previous animal toxicology based risk assessments may have underestimated the risk of acetaldehyde. Risk assessments of acetaldehyde need to be revised using this updated evidence. (C) 2017 The Authors. Published by Elsevier Inc.Peer reviewe
Absinthism: a fictitious 19th century syndrome with present impact
Absinthe, a bitter spirit containing wormwood (Artemisia absinthium L.), was banned at the beginning of the 20th century as consequence of its supposed unique adverse effects. After nearly century-long prohibition, absinthe has seen a resurgence after recent de-restriction in many European countries. This review provides information on the history of absinthe and one of its constituent, thujone. Medical and toxicological aspects experienced and discovered before the prohibition of absinthe are discussed in detail, along with their impact on the current situation. The only consistent conclusion that can be drawn from those 19th century studies about absinthism is that wormwood oil but not absinthe is a potent agent to cause seizures. Neither can it be concluded that the beverage itself was epileptogenic nor that the so-called absinthism can exactly be distinguished as a distinct syndrome from chronic alcoholism. The theory of a previous gross overestimation of the thujone content of absinthe may have been verified by a number of independent studies. Based on the current available evidence, thujone concentrations of both pre-ban and modern absinthes may not have been able to cause detrimental health effects other than those encountered in common alcoholism. Today, a questionable tendency of absinthe manufacturers can be ascertained that use the ancient theories of absinthism as a targeted marketing strategy to bring absinthe into the spheres of a legal drug-of-abuse. Misleading advertisements of aphrodisiac or psychotropic effects of absinthe try to re-establish absinthe's former reputation. In distinction from commercially manufactured absinthes with limited thujone content, a health risk to consumers is the uncontrolled trade of potentially unsafe herbal products such as absinthe essences that are readily available over the internet
Determination of the biologically active flavour substances thujone and camphor in foods and medicines containing sage (Salvia officinalis L.)
BACKGROUND: The sage plant Salvia officinalis L. is used as ingredient in foods and beverages as well as in herbal medicinal products. A major use is in the form of aqueous infusions as sage tea, which is legal to be sold as either food or medicine. Sage may contain two health relevant substances, thujone and camphor. The aim of this study was to develop and validate an analytical methodology to determine these active principles of sage and give a first overview of their concentrations in a wide variety of sage foods and medicines. RESULTS: A GC/MS procedure was applied for the analysis of α- and β-thujone and camphor with cyclodecanone as internal standard. The precision was between 0.8 and 12.6%, linearity was obtained from 0.1 - 80 mg/L. The recoveries of spiked samples were between 93.7 and 104.0% (average 99.1%). The time of infusion had a considerable influence on the content of analytes found in the teas. During the brewing time, thujone and camphor show an increase up to about 5 min, after which saturation is reached. No effect was found for preparation with or without a lid on the pot used for brewing the infusion. Compared to extracts with ethanol (60% vol), which provide a maximum yield, an average of 30% thujone are recovered in the aqueous tea preparations. The average thujone and camphor contents were 4.4 mg/L and 16.7 mg/L in food tea infusions and 11.3 mg/L and 25.4 mg/L in medicinal tea infusions. CONCLUSIONS: The developed methodology allows the efficient determination of thujone and camphor in a wide variety of sage food and medicine matrices and can be applied to conduct surveys for exposure assessment. The current results suggest that on average between 3 and 6 cups of sage tea could be daily consumed without reaching toxicological thresholds
The Quality of Alcohol Products in Vietnam and Its Implications for Public Health
Four homemade (artisanally manufactured and unrecorded) and seven commercial (industrially manufactured and taxed) alcohol products from Vietnam were collected and chemically analyzed for toxicologically relevant substances. The majority of both types had alcohol contents between 30 and 40% vol. Two homemade samples contained significantly higher concentrations of 45 and 50% vol. In one of these homemade samples the labeled alcoholic strength was exceeded by nearly 20% vol. All other analyzed constituents of the samples (e.g., methanol, acetaldehyde, higher alcohols, esters, metals, anions) were found in concentrations that did not pose a threat to public health. A peculiarity was a homemade sample of alcohol with pickled snakes and scorpions that contained 77% vol of alcohol, allegedly used as traditional Chinese medicine. Based on this small sample, there is insufficient evidence to conclude that alcohol quality, beyond the effects of ethanol, has an influence on health in Vietnam. However, future research with larger samples is needed
Impacts of Irrigated Agriculture on the Near Surface and Planetary Boundary Layer Atmosphere: Results from the Great Plains Irrigation Experiment (GRAINEX)
Modification of natural prairie grasslands into irrigated and rainfed agriculture in the Great Plains produced significant impacts on regional weather and climate including temperatures, precipitation, energy fluxes, and the planetary boundary layer (PBL) atmosphere. The Great Plains Irrigation Experiment (GRAINEX) during the 2018 growing season collected data over irrigated and non-irrigated crop fields to further understand these impacts. The data were collected during two intensive observation periods (IOPs) in early June (IOP 1: 30 May – 13 June of 2018) and late July (IOP 2: 16 July – 30 July of 2018). The data analyzed include latent (LE) and sensible (H) heat fluxes, air temperature, dew point temperature, specific humidity, equivalent temperature (moist enthalpy) which were assessed using ground based sensors, PBL and lower tropospheric development which was assessed using radiosonde data. In addition, near surface soil moisture data were used to model root zone soil moisture utilizing Wang et al. (2017) Exponential Filter Model. Results show increased partitioning of energy into latent heat compared to sensible heat over irrigated areas. It is particularly noticeable during IOP 2 when, on average LE was about ~15 W m-2 higher than H. At the same time, average maximum air temperature decreased by ~2.75 °C from IOP 1 to IOP 2. Implementation of the Wang et. al (2017) Exponential Filter Model indicated periods of notable drying and wetting throughout the site profiles reflective of an increase in water use by plants and rain or irrigation events. Radiosonde data suggest reduced PBL heights at all launch sites from IOP 1 to IOP 2 with larger changes over irrigated areas (up to ~812 meters). Compared to IOP 1, lifting condensation level (LCL) heights were also lower during IOP 2 over irrigated areas. In addition, six one-day case studies were completed to further understand land-atmosphere (L-A) interactions in the context of irrigated and non-irrigated land uses. They further corroborate IOP-wide results.
Advisors: Rezaul Mahmood and Trenton Fran
Ethyl Carbamate in Alcoholic Beverages from Mexico (Tequila, Mezcal, Bacanora, Sotol) and Guatemala (Cuxa): Market Survey and Risk Assessment
Ethyl carbamate (EC) is a recognized genotoxic carcinogen, with widespread occurrence in fermented foods and beverages. No data on its occurrence in alcoholic beverages from Mexico or Central America is available. Samples of agave spirits including tequila, mezcal, bacanora and sotol (n=110), and of the sugarcane spirit cuxa (n=16) were purchased in Mexico and Guatemala, respectively, and analyzed for EC. The incidence of EC contamination was higher in Mexico than in Guatemala, however, concentrations were below international guideline levels (<0.15 mg/L). Risk assessment found the Margin of Exposure (MOE) in line with that of European spirits. It is therefore unlikely that EC plays a role in high rates of liver cirrhosis reported in Mexico
Safety evaluation of topical applications of ethanol on the skin and inside the oral cavity
Ethanol is widely used in all kinds of products with direct exposure to the human skin (e.g. medicinal products like hand disinfectants in occupational settings, cosmetics like hairsprays or mouthwashes, pharmaceutical preparations, and many household products). Contradictory evidence about the safety of such topical applications of the alcohol can be found in the scientific literature, yet an up-to-date risk assessment of ethanol application on the skin and inside the oral cavity is currently lacking
Design and manufacture of static inverter for Brayton power conversion system Final report
Static inverter for Brayton power conversion syste
Gender differences in the impact of population-level alcohol policy interventions: evidence synthesis of systematic reviews
Background: Consistent review-level evidence supports the effectiveness of population-level alcohol policies in reducing alcohol-related harms. Such policies interact with well-established social, cultural and biological differences in how men and women perceive, relate to and use alcohol, and with wider inequalities, in ways which may give rise to gender differences in policy effectiveness. Aims: To examine the extent to which gender-specific data and analyses were considered in, and are available from, systematic reviews of population-level alcohol policy interventions, and where possible, to conduct a narrative synthesis of relevant data. Methods: A prior systematic ‘review of reviews’ of population level alcohol interventions 2002-2012 was updated to May 2014, all gender-relevant data extracted, and the level and quality of gender reporting assessed. A narrative synthesis of extracted findings was conducted. Results: Sixty-three systematic reviews, covering ten policy areas, were included. Five reviews (8%) consistently provided information on baseline participation by gender for each individual study in the review and twenty-nine (46%) reported some gender-specific information on the impact of the policies under consideration. Specific findings include evidence of possible gender differences in the impact of and exposure to alcohol marketing, and a failure to consider potential unintended consequences and harm to others in most reviews. Conclusions: Gender is poorly reported in systematic reviews of population-level interventions to reduce alcohol-related harm, hindering assessment of the intended and unintended effects of such policies on women and men
Unrecorded alcohol consumption in Russia: toxic denaturants and disinfectants pose additional risks
In 2005, 30% of all alcohol consumption in Russia was unrecorded. This paper describes the chemical composition of unrecorded and low cost alcohol, including a toxicological evaluation. Alcohol products (n=22) from both recorded and unrecorded sources were obtained from three Russian cities (Saratov, Lipetsk and Irkutsk) and were chemically analyzed. Unrecorded alcohols included homemade samogons, medicinal alcohols and surrogate alcohols. Analysis included alcoholic strength, levels of volatile compounds (methanol, acetaldehyde, higher alcohols), ethyl carbamate, diethyl phthalate (DEP) and polyhexamethyleneguanidine hydrochloride (PHMG). Single samples showed contamination with DEP (275–1269 mg/l) and PHMG (515 mg/l) above levels of toxicological concern. Our detailed chemical analysis of Russian alcohols showed that the composition of vodka, samogon and medicinal alcohols generally did not raise major public health concerns other than for ethanol. It was shown, however, that concentration levels of DEP and PHMG in some surrogate alcohols make these samples unfit for human consumption as even moderate drinking would exceed acceptable daily intakes
- …
