Documents skin absorption 35 results

Objectives This study investigated the facial skin complaints of office workers before and after the static electric fields of a visual display unit were reduced.Methods On the basis of a screening survey of 4556 office workers in 11 companies, 120 of 227 subjects reporting facial skin complaints were randomly selected to this double blind intervention study. Antistatic measures were used to reduce the static electric fields of the visual display unit in the intervention group but not in the control group, which worked with a visual display unit resembling that of the intervention group. Electric fields, dust concentration, health complaints, and psychological behavior tests were recorded before and after the intervention.Results The intervention group reported statistically significantly fewer facial skin complaints than the control group. In the intervention group, among those with an office dust concentration of >58 g/m3, a median reduction of 1.5 skin index points (scale 0-8) was achieved, whereas there was no change in the control group. In the regression model "group category" was still a significant variable after control for background factors. In addition, further linear regression analyses indicated that several static electric field parameters were predictors of the skin complaint reduction.Conclusions This field trial indicates that removing static electric fields from visual display units can probably help reduce the facial skin complaints of workers in offices with high dust concentrations.

"Objectives The aims were to study the toxicokinetics of 5-hydroxy-N-methyl-2-pyrrolidone (5-HNMP) in blood and urine after exposure to N-methyl-2-pyrrolidone (NMP) and to study the suitability of 5-HNMP as a biomarker for assessing NMP exposure.Methods Six male volunteers were exposed for 8 hours to NMP concentrations of 0, 10, 25, and 50 mg/m3. Blood and urine were sampled before, during, and up to 40 hours after exposure. Aliquots of urine and plasma were purified, derivatized, and analyzed for 5-HNMP on a gas chromatograph/mass spectrometer in the electron impact mode.Results The mean plasma concentration [P-(5-HNMP)] after 8-hour NMP exposure to 10, 25, and 50 mg/m3 was 8.0, 19.6, and 44.4 mmol/l, respectively. The mean urinary concentration [U-(5-HNMP)] for the 2 last hours of exposure was 17.7, 57.3, and 117.3 mmol/mol creatinine, respectively. The maximal P-(5-HNMP)and U-(5-HNMP) concentrations occurred 1 hour and 0-2 hours, respectively, after the exposure. The half-times of P-(5-HNMP) and U-(5-HNMP) were 6.3 and 7.3 hours, respectively. The 5-HNMP urinary concentrations were 58% of the calculated retained dose. There was a close correlation (r) between P-(5-HNMP) (r=0.98) and U-(5-HNMP) (r=0.97) with NMP exposure.Conclusion 5-HNMP is an excellent biomarker for assessing exposure to NMP. Its plasma and urinary half-times (6-7 hours), the minimal risk for contamination during sampling in occupational settings, and the close correlation of P-(5-HNMP) and U-(5-HNMP) with NMP exposure makes 5-HNMP suitable for monitoring exposure to NMP. 5-HNMP in plasma is recommended."

A richly detailed analysis of the many research issues surrounding the role of selenium as both an essential and a toxic element. The book opens with an analysis of what is known about the distribution of this ubiquitous element in the environment, including the natural presence of selenium in the food chain. Since food constitutes the main route of exposure for the general population, the book provides especially extensive coverage of levels typically found in different foods and the factors that can account for unusually high or low concentrations. Other sections cover the metabolism of selenium, discuss diseases in farm animals linked to either excessive or deficient intake, and summarize the results of experimental work on the physiological responses to toxicity and deficiency. Particular attention is given to the evaluation of past studies claiming a carcinogenic effect and more recent studies suggesting a protective effect against certain cancers in experimental animals.

"Une nouvelle révolution industrielle s'amorce autour des nanotechnologies. L'engouement, maintenant planétaire, se traduit par des investissements annuels de plusieurs milliards de dollars en recherche et développement (R-D). Dans un contexte où les technologies actuelles permettent de manipuler la matière et de synthétiser des produits à l'échelle atomique, les nanoparticules démontrent des propriétés totalement différentes des produits de même composition mais de plus forte taille. L'ère des nanomatériaux et des nanotechnologies nous promet des développements et des percées scientifiques majeures qui affecteront de façon permanente le quotidien de chacun dans un avenir rapproché. Plusieurs de ces produits sont déjà utilisés et de nombreux organismes estiment un marché mondial annuel de l'ordre de 1 000 milliards de dollars américains dès 2015. Bienvenue dans le nanomonde où tout se passe à l'échelle du nanomètre (nm), soit le milliardième de mètre (10-9 m).
Les nanotechnologies couvrent un large domaine multidisciplinaire où les activités de recherche et d'implantation industrielle se sont développées extrêmement rapidement au niveau mondial au cours de la dernière décennie. Des physiciens, chimistes, biologistes, ingénieurs, électroniciens et divers spécialistes des matériaux, de procédés et d'applications travaillent conjointement sur des objets de dimensions nanométriques. Les nanoparticules peuvent être produites par toute une série de procédés chimiques, physiques ou biologiques parmi lesquels certains sont totalement nouveaux et innovateurs alors que d'autres existent depuis fort longtemps.
En effet, de nouvelles technologies permettent de construire des matériaux, atome par atome, ce qui leur confère souvent des propriétés fort différentes des matériaux usuels. Les nanoparticules et les nanotechnologies ne représentent pas uniquement une autre étape vers la miniaturisation. À cette échelle, le comportement des particules est dominé par les effets quantiques. Celles-ci peuvent être confinées dans une petite structure, présenter de grandes fractions surfaciques et démontrer toute une série de phénomènes et de propriétés uniques, non rencontrés chez les matériaux de plus grande taille. … "

An expert assessment of both the beneficial and toxic effects to human health posed by the use of fluorine and fluorides. Conclusions and recommendations are based on a critical analysis of well over 400 clinical and laboratory investigations. The introductory sections consider methods for the measurement of fluorides in inorganic and organic materials, sources and magnitude of exposure, and effects on health as determined through a large number of laboratory investigations. The most extensive section is devoted to a critical review of data on beneficial and toxic effects in humans. Beneficial effects of fluoride in drinking water, salt, milk, tablets, and topical applications are considered in terms of the preventive effects on dental caries and their use in the treatment of osteoporosis. Toxic effects reviewed include various forms of fluorosis, effects on renal function, hypersensitivity and dermatological reactions, and carcinogenic and teratogenic risks. On the basis of this review, the report confirms the beneficial effects of fluoride in the prevention of caries, while noting that long-term exposure to high quantities may damage enamel and bone; very high doses cause acute toxic effects and may be lethal

"Over the past decade, the primary focus of nanotoxicology and nanoenvironmental health and safety efforts has been largely on inhalation exposure to engineered nanomaterials, at the production stage, and much less on considering risks along the life cycle of nano-enabled products. Dermal exposure to nanomaterials and its health impact has been studied to a much lesser extent, and mostly in the context of intentional exposure to nano-enabled products such as in nanomedicine, cosmetics and personal care products. How concerning is dermal exposure to such nanoparticles in the context of occupational exposures? When and how should we measure it?

In the first of a series of two papers (Larese Filon et al., 2016), we focused our attention on identifying conditions or situations, i.e. a combination of nanoparticle physico-chemical properties, skin barrier integrity, and occupations with high prevalence of skin disease, which deserve further investigation. This second paper focuses on the broad question of dermal exposure assessment to nanoparticles and attempts to give an overview of the mechanisms of occupational dermal exposure to nanoparticles and nano-enabled products and explores feasibility and adequacy of various methods of quantifying dermal exposure to NOAA. We provide here a conceptual framework for screening, prioritization, and assessment of dermal exposure to NOAA in occupational settings, and integrate it into a proposed framework for risk assessment."

"The paper reviews and critically assesses the evidence on the relevance of various skin uptake pathways for engineered nanoparticles, nano-objects, their agglomerates and aggregates (NOAA). It focuses especially in occupational settings, in the context of nanotoxicology, risk assessment, occupational medicine, medical/epidemiological surveillance efforts, and the development of relevant exposure assessment strategies.
Skin uptake of nanoparticles is presented in the context of local and systemic health effects, especially contact dermatitis, skin barrier integrity, physico-chemical properties of NOAA, and predisposing risk factors, such as stratum corneum disruption due to occupational co-exposure to chemicals, and the presence of occupational skin diseases. Attention should be given to: (1) Metal NOAA, since the potential release of ions may induce local skin effects (e.g. irritation and contact dermatitis) and absorption of toxic or sensitizing metals; (2) NOAA with metal catalytic residue, since potential release of ions may also induce local skin effects and absorption of toxic metals; (3) rigid NOAA smaller than 45 nm that can penetrate and permeate the skin; (4) non rigid or flexible NOAA, where due to their flexibility liposomes and micelles can penetrate and permeate the intact skin; (5) impaired skin condition of exposed workers.
Furthermore, we outline possible situations where health surveillance could be appropriate where there is NOAA occupational skin exposures, e.g. when working with nanoparticles made of sensitizer metals, NOAA containing sensitizer impurities, and/or in occupations with a high prevalence of disrupted skin barrier integrity. The paper furthermore recommends a stepwise approach to evaluate risk related to NOAA to be applied in occupational exposure and risk assessment, and discusses implications related to health surveillance, labelling, and risk communication."

"This study examines a method for estimating the dermal absorption of benzene contained in hydrocarbon liquids that contact the skin. This method applies to crude oil, gasoline, organic solvents, penetrants, and oils. The flux of benzene through occluded skin as a function of the ercent vol/vol benzene in the liquid is derived by fitting a curve to experimental data; thefunction is supralinear at benzene concentrations ? 5% vol/vol. When a liquid other than pure benzene is on nonoccluded skin, benzene may preferentially evaporate from the liquid, which thereby decreases the benzene flux. We present a time-averaging method here for estimating the reduced dermal flux during evaporation. Example calculations are presented for benzeneat 2% vol/vol in gasoline, and for benzene at 0.1% vol/vol in a less volatile liquid. We also discuss other factors affecting dermal absorption."