Dermal and pulmonary absorption of ethanol from alcohol-based hand rub.

BACKGROUND: Ethanol intoxication of healthcare workers (HCWs) using alcohol-based hand rubs (ABHRs) in the workplace is a potentially serious issue. This study quantified the level of ethanol absorption among HCWs after hygienic hand disinfection. METHODS: Eighty-six HCWs from Nancy University Hospital were tested before and after a 4-h shift. Participants used ABHR containing 70% ethanol. Levels of ethanol, acetaldehyde and acetate in blood and urine were determined using gas chromatography. A breathalyzer was used to measure the level of ethanol in expired air. RESULTS: Ethanol [mean concentration 0.076 (standard deviation 0.05) mg/L] was detected in the expired air of 28 HCWs 1-2 min post exposure. Ethanol, acetaldehyde and acetate were undetectable in blood after a 4-h shift, and urine tests were negative in all participants. CONCLUSION: Ethanol exposure from ABHR, particularly inhalation of vapours, resulted in positive breathalyzer readings 1-2 min after exposure. Dermal absorption of ethanol was not detected. Pulmonary absorption was detected but was below toxic levels.

Nickel absorption and distribution from rat small intestine in situ.

The aim of this work was to study the absorption of nickel chloride in rats by means of the intestinal perfusion in situ technique at nickel concentrations of 1, 5, 10, 25, and 100 mg/L. Active transport and facilitated diffusion seem to play an important role in the intestinal absorption of nickel at concentrations < or = 10 mg/L. At higher concentrations, the absorption rate would be limited by saturation of the carriers. The distribution of the absorbed nickel was studied by intestinal perfusion of a 10-mg Ni/L solution for 30 or 60 min. Both in concentration and amount, the jejunum showed the higher values of absorbed nickel, followed by the kidneys and liver. When all of the collected organs (brain, heart, liver, lungs, spleen, kidneys, and testicles) and blood, but not the small intestine, are analyzed following a 60-min perfusion, it was found that 1% of the initial concentration had passed through the intestinal barrier.

Bioavailability and intestinal absorption of aluminum in rats: effects of aluminum compounds and some dietary constituents.

In the present investigation, the deposition of aluminum in intestinal fragment and the appearance in blood were studied in a perfused rat intestine in situ for 1 h with several aluminum forms (16 mM). We observed that aluminum absorption was positively correlated with the theoretic affinity of aluminum and the functional groups of the chelating agent. The absorption of aluminum after ingestion of organic compounds is more important than after ingestion of mineral compounds, with the following order: Al citrate > Al tartrate, Al gluconate, Al lactate > Al glutamate, Al chloride, Al sulfate, Al nitrate. Absorption depends on the nature of the ligands associated with the Al3+ ion in the gastrointestinal fluid. The higher the aluminum retention in intestinal fragment, the lower the absorption and appearance in blood. However, the higher aluminum concentration is always in the jejunal fragment because of the influence of pH variation on this fragment. Another objective of the present study was to determine the influence of several parameters on aluminum citrate absorption: with or without 0.1 mmol dinitrophenol/L, with aluminum concentration from 3.2, 16, 32, and 48, to 64 mmol/L, media containing 0, 3, or 6 mmol Ca/L, with or without phosphorus or glucose. It is concluded that aluminum is absorbed from the gastrointestinal tract by (1) a paracellular energy independent and nonsaturable route, mainly used for high aluminum concentration, which is modified by extracellular calcium, and (2) a transcellular and saturable route, the aluminum level was not modified with enhancement of aluminum quantity in intestinal lumen. This pathway can be similar with calcium transfer through the intestine and is energy dependent because of a decrease of aluminum absorption that follows the removal of glucose and phosphorus.

The effects of aluminum, iron, chromium, and yttrium on rat intestinal smooth muscle in vitro.

The modification of peristaltic activity in the presence of several metal ions has been investigated in the rat intestine by the isolated organ technique. The metals tested modify the intestinal movements: aluminum, chromium, and yttrium cause a decrease of amplitude, while iron showed no effect. By use of microscopic techniques, the presence of yttrium hydroxide was observed in the intestinal tissues. Iron also appears as a precipitate outside of the intestinal serosal, which may explain why iron did not modify the peristaltism. Chromium and aluminum were not apparent to microscope, despite being detected and quantified in the tissues by means of atomic emission spectrometer. We conclude that the trivalent ions of these elements may operate differently on the mechanisms of intestinal contractions: yttrium precipitates in intercellular spaces, iron precipitates outside the intestines, and chromium and aluminum remain in solution and are distributed homogeneously in the smooth intestinal muscle.