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Biomedical subjects

M Baril

Publications and source records attributed to M Baril.

7 recordsLinked to original sources
PubMed1996

Preliminary study of electrocautery smoke particles produced in vitro and during laparoscopic procedures.

BACKGROUND: The objective of this preliminary study was to describe the particles contained in cautery smoke produced during five laparoscopic procedures and verify the collection method during three laboratory experiments on ex vivo animal tissue. METHODS: A cascade impactor collected the smoke according to particle size, and particle weights were calculated on an electronic microbalance. Electron microscopic analysis and energy dispersive X-ray evaluation were used to determine particle morphology and elemental composition. RESULTS: The particles, distributed according to size on the seven rotating trays of the impactor, had diameters ranging from 0.05 to >25 micro m, with most being 0.1-1 micro m. In vitro experiments yielded more particles, especially larger (>5 micro m) ones, than the surgical procedures, because the cauterized specimens could be placed much closer to the cascade impactor in the laboratory environment, eliminating most obstacles to particle recovery. In the laparoscopic surgery patients, larger particles, because of their physical properties, were more likely to remain trapped in the abdomen or to drop off in the collection apparatus. Uniformly, two populations of particles were demonstrated--either large, irregular fragments (2-25 micro m) rich in carbon and oxygen, suggesting structural cellular components, or small homogeneous spheres (0.1-0.5 micro m) composed of sodium, magnesium, calcium, and potassium salts. CONCLUSIONS: This study demonstrates the presence of breathable aerosols and cell-size fragments in the cautery smoke produced during laparoscopic procedures. Their exact chemical composition and potential adverse effects for patients and personnel are not known.

Cautery↗
PubMed1995

Physico-chemical fate of chromium compounds in the sheep lung model.

Transmission electron microscopy (TEM) equipped with energy-dispersive x-ray analysis (EDX), electron spectroscopy for chemical analysis (ESCA), secondary ion mass spectrometry (SIMS), and laser microprobe for mass analysis (LAMMA) were used to follow the fate of chromium compounds deposited in the sheep tracheal lobe. Four chromium compounds were used: two chromium(VI) compounds (lead chromate and chromium trioxide) and two chromium(III) compounds (chronic oxide and chromium sulfate). Chromium trioxide is very soluble and the other three are slightly soluble. The compositions, concentrations, and sizes of particles were determined in the bronchoalveolar lavages (BAL) at d 2, 3, 5, and 30 after instillation and on the lung samples collected at d 31. The concentrations of particles in the BAL samples separated the chromium compounds in two groups where Cr2O3 and PbCrO4 (as Pb) were higher than Cr2(SO4)3, PbCrO4 (as Cr), and CrO3. The half-life for alveolar clearance of Cr2O3 and Cr2(SO4)3 has been calculated respectively at 11 and 80 d. Prismatic PbCrO4 particles break up in the lung and sustain a high concentration of isometric particles of lead chromate and another lead-containing compound in the BAL. The CrO3 instilled particles react with endogenous compounds or are transformed to insoluble hydroxyl complexes instead of diffusing very rapidly through the alveolar-capillary barrier. The alveolar clearance as measured in the BAL is not different from the control.

Animals↗
PubMed1992

Aerosols characterization in a forested site in Québec, Canada.

Three AERAS low pressure 11 stage cascade impactors with rotatable collecting plates (LPCR) were installed at the Duchesnay forest station near Québec City and four low pressure inertial collectors (LPIC) were installed in the forest. The analysis of the aerosol deposits was performed by static fast atom beam mass spectroscopy (FABMS); SIMS and ESCA analyses were also made. The morphological characterization and the elemental volumetric composition of the aerosols were established by a scanning electron microscope equipped with an X-ray dispersive energy analyser. Micro-weighting of the aluminium substrate before and after the sampling by the AERAS impactor enabled the study of the mass-size-distribution of the aerosols according to their aerodynamic equivalent diameter. Example of the results obtained are presented in relation to air parcels' trajectories. This study has shown that it is possible to characterize the aerosols according to the origin and trajectories of the air mass with which they travel; sources along the tracks have been shown to contribute to the aerosol loading of the air masses.

Aerosols↗
PubMed1992

Toxicological index and the presence in the workplace of chemical hazards for workers who breast-feed infants.

The increasing number of women in the workplace has made it more important than ever to ensure a safe work environment, particularly with respect to mothers who choose to breast-feed their babies. The Quebec Commission de la santé et de la sécurité du travail (CSST) Toxicological Index is fully involved in the provincial program for the protective reassignment of workers who breast-feed infants. The Infotox database provides peer-reviewed information concerning chemicals identified in the workplace that may appear in the mother's milk, possibly to be ingested by the breast-fed infant. Data extracted from the CSST computer system that holds information on 5,500 substances are presented. A total of 153 chemicals (2.7%) are recognized as being involved in some milk transfer. The strength of evidence is assessed with reference to strong or weak association (excretion or detection) in humans or in animals. Such an effect provides a useful basis for administrative decision involving protective reassignment as well as evaluation of work environment. Database users must be well informed about the identification of chemicals in breast milk because this is an essential step for the evaluation of the hazards of transferring chemicals encountered in the workplace from mother to baby. Actually, the main problem is that there are very few data in the scientific literature concerning milk transfer.

Breast Feeding↗
PubMed1990

Computerized product information system: The Toxicological Index.

The Toxicological Index, a division of the Commission de la Santé et de la Sécurité du Travail, was established in 1980 by the Quebec Government. Its main objective, as a database producer, is to provide health and safety related toxicological information to anyone who is involved in risk management in the workplace. In order to meet this requirement, a fully computerized information system was created. It has allowed us to process, over the past 5 years, 250,000 information inquiries, to register 100,000 contaminants, to exchange information with 3,300 product manufacturers and to provide our users with 6,500 fully reviewed toxicological information profiles. The procedure used to assess the information as well as the choices made to achieve our objective in terms of quantity and quality of the information provided are described.

Chemical Phenomena↗
PubMed1979

DDT in northern pike (Esox lucius) from the Richelieu River, Québec, Canada, 1974-75.

Concentrations of DDT, TDE, DDE, and sigma DDT were determined in homogenized whole fish samples of 129 northern pike (Esox lucius). These fish were netted between June 1974 and June 1975 in the first 10 km of the Richelieu River flowing in Canadian territory. Two years after the banning of DDT, sigma DDT levels ranged from 0.2 ppm fresh body weight in two-year-old specimens to 1.5 ppm in a six-year-old pike. Residues increased greatly with age, and significant seasonal variations in the sigma DDT levels were found in five- and six-year-old pike.

Aging↗