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Biomedical subjects

G Dussault

Publications and source records attributed to G Dussault.

18 recordsLinked to original sources
PubMed2001

Characterization of volatile organic compounds in smoke at municipal structural fires.

The objective of this study was to characterize volatile organic compounds (VOCs) found at municipal structural fires in order to identify sources of long-term health risks to firefighters, which may be contributing factors in heart disease and cancer. Firefighters collected air into evacuated Summa canisters inside burning buildings at nine municipal structural fires under conditions where they judged that at least some firefighters might remove their self-contained breathing apparatus masks. Volatile organic compounds were identified and quantified for 144 target compounds using cryogenic preconcentration and gas chromatography/mass spectral detection (GC/MSD) methodology operating in selected ion monitoring mode. Samples were also analyzed in SCAN mode and examined for the appearance of substances that were not present in the instrument standard calibration mixture. The spectra of municipal structural fires were surprisingly similar and remarkable for their simplicity, which was largely due to the dominating presence of benzene along with toluene and naphthalene. Propene and 1,3-butadiene were found in all of the fires, and styrene and other alkyl-substituted benzene compounds were frequently identified. Similar "fingerprints" of the same 14 substances (propene, benzene, xylenes, 1-butene/2-methylpropene, toluene, propane, 1,2-butadiene, 2-methylbutane, ethylbenzene, naphthalene, styrene, cyclopentene, 1-methylcyclopentene, isopropylbenzene) previously identified at experimental fires burning various solid combustible materials were also found at municipal structural fires, accounting for 76.8% of the total VOCs measured. Statistically significant positive correlations were found between increasing levels of benzene and levels of propene, the xylenes, toluene, 1-butene/2-methylpropene, 1,3-butadiene, and naphthalene. Given the toxicity/carcinogenicity of those VOCs that were found in the highest concentrations, particularly benzene, 1,3-butadiene, and styrene, further investigation of VOC exposures of firefighters is warranted. Benzene, or its metabolic product s-phenylmercapturic acid in urine, was identified as a suitable chemical marker for firefighter exposure to combustion products.

Alkenes↗
PubMed2001

Characterization of volatile organic compounds in smoke at experimental fires.

Significant associations between firefighting and cancer have been reported; however, studies finding toxic products of combustion at municipal fires have been limited by (1) technical difficulties encountered at the scene of working fires, (2) the lack of a coherent sampling strategy, and (3) the absence of verified sampling methods. The objective of the present study was to characterize the presence of volatile organic compound (VOC) combustion products in fire smoke. Air samples from experimental fires burning various materials commonly found at structural fires were collected into evacuated Summa canisters and analyzed for 144 target VOCs using cryogenic preconcentration and gas chromatography/mass spectroscopy (GC/MSD) methodology. The resulting chromatograms were characterized by a small number of predominant peaks, with 14 substances (propene, benzene, xylenes, 1-butene/2-methylpropene, toluene, propane, 1,2-butadiene, 2-methylbutane, ethylbenzene, naphthalene, styrene, cyclopentene, 1-methylcyclopentene, isopropylbenzene) being found in proportionately higher concentrations in all experimental fires and accounting for 65% (SD = +/-12%) by mass of total measured VOCs. Benzene, toluene, 1,3-butadiene, naphthalene, and styrene were found at higher concentrations than most other VOCs and increased with the time of combustion together with increasing levels of carbon monoxide. Benzene was found in the highest concentrations, with peak levels ranging from 0.6 ppm to 65 ppm, while the levels of 1,3-butadiene, styrene, and naphthalene peaked at 0.1, 0.4, and 3 ppm, respectively. This study revealed that there were no new or novel, toxic nonpolar VOCs resulting from the burning of common building materials. This is important in view of the studies that have found associations between firefighting and various forms of cancer.

Beds↗
PubMed2001

Municipal firefighter exposure groups, time spent at fires and use of self-contained-breathing-apparatus.

BACKGROUND: Previous studies have found significant associations between firefighting and cancer. METHODS: Fires, vehicle movement, and firefighter job assignment were determined, and storage and distribution of self-contained-breathing-apparatus (SCBAs) were tracked for 12 months. Time spent at fires and use of SCBAs were calculated. RESULTS: Only 66% of fire department personnel were 1st-line combat firefighters. Number of runs was an unreliable surrogate for time spent at fires. Eight firefighter exposure groups were identified (based on job title, firehall assignment, and time spent at fires), ranging from no exposures to 3,244 min/year/firefighter. SCBAs appear to have been used for approximately 50% of the time at structural fires but for only 6% of the time at all fires. CONCLUSIONS: Failure of previous studies to identify homogeneous exposure groups may have resulted in misclassification and underestimates of health risks. The approach used in this study may be used in epidemiological studies to identify exposure/response relationships.

Adult↗
PubMed1997

Carbon monoxide and water vapor contamination of compressed breathing air for firefighters and divers.

Compressed breathing air, used in self-contained breathing apparatus (SCBA) by firefighters and other categories of workers as well as by recreational and commercial divers, is prepared with the aid of high-pressure compressors operating in the range of 5000 psig. There have been reports of unexplained deaths of SCUBA divers and anecdotal accounts of decreased time to exhaustion in firefighters using SCBAs. Compressed breathing air has been found to contain elevated levels of carbon monoxide (CO) and water vapor that are consistent with carboxyhemoglobin (COHb) poisoning and freezing of the user's regulator on the breathing apparatus. The Coburn-Forster-Kane equation (CFK equation) was used to estimate COHb levels at rest and at maximum exercise when exposed to different levels of CO in contaminated breathing air. The results demonstrated that, at maximum exercise, the COHb ranged from 6.0 to 17% with the use of 1 to 4 SCBA cylinders contaminated by 250 ppm CO. Standard operating procedures have been developed at the Montreal Fire Department to minimize the risk of compressed breathing air contamination. Results of the quality analysis/quality control program indicate that implementation of these procedures has improved the quality of the compressed breathing air. Recommendations are made for improvement of the air testing procedures mandated by the Canadian CAN3 180.1-M85 Standard on Compressed Breathing Air and Systems.

Air Pollutants, Occupational↗
PubMed1984

Dental services in Quebec: issues and changes.

This paper describes the dental care delivery system in the province of Quebec (Canada) and shows that it has failed on two counts: the geographical maldistribution of dental manpower and the lack of development of preventive services. The paper discusses these issues in relation to recent changes which have occurred in the last decade, particularly the recognition of dental hygienists and denturists as legitimate providers of dental care in 1973 and the inception of Denticare in 1974.

Dental Health Services↗
PubMed1983

[Not Available].

Explore the source record for details and available documents.

Canada↗
PubMed1982

Medical theories and professional development. The theory of focal sepsis and dentistry in early twentieth century Britain.

This paper traces the history of the theory of focal infection--which related a number of general conditions to septic foci from which toxic products spread to different parts of the body--and its application to dental diseases in early 20th century Britain. Bad teeth were said to be one of the major sources of infection and a cause of many diseases. The paper focuses on the social and professional context in which the theory emerged and flourished. It shows that in spite of its lack of scientific foundation, the theory of focal sepsis was readily accepted by the dental profession and used to advance its claims for professional recognition. Thus the paper attempts to illustrate the point that the acceptance of a medical theory by health practitioners is as much determined by social and economic factors as by its therapeutic potential or its scientific validity.

Focal Infection, Dental↗
PubMedDate not supplied

Social support received by mothers of chronically ill children.

The main purpose of this study was to describe the characteristics of the social networks and social support of mothers of chronically ill children and adolescents. The data collected also allowed for the identification of the predisposing factors to receiving low social support among the mothers. Receipt of social support was assessed according to six dimensions: source of support, type of support, perceived need for support, satisfaction with the quality and the quantity of support, as well as most valued source of support. Results indicate that mothers wanted more support than they received, particularly in the areas of emotional, appraisal, and informative support. Furthermore, spouses, professionals, and immediate family members were identified by mothers as important sources of support. Discriminant analysis showed that the probability of receiving low support increased if the chronically ill child was an adolescent, the father had a higher level of education, and the family income was middle-low. Results are discussed in terms of the implications for intervention.

Activities of Daily Living↗
PubMedDate not supplied

Negative consequences of acculturation on health behaviour, social support and stress among pregnant Southeast Asian immigrant women in Montreal: an exploratory study.

It is frequently assumed that migrant status constitutes a health risk because migration is inevitably associated with a period of significant adjustment and stress. This paper describes the role of acculturation in understanding the relationship between migration and low birthweight (LBW). Psychosocial and behavioural risk factors for LBW were explored using semi-structured interviews with 17 pregnant Southeast Asian women who represented different levels of acculturation. Findings suggested that acculturation had negative consequences for immigrant women. Higher levels of acculturation were associated with dieting during pregnancy, inadequate social support and stressful life experiences.

Acculturation↗
PubMedDate not supplied

The effect of acculturation on low birthweight in immigrant women.

The interpretation of variations in perinatal morbidity by immigration status has been difficult. Of particular concern is the lack of attention to adaptive capacity. This study explores the effect of acculturation on term low birthweight (LBW) in five ethnic groups representing different immigration experiences. Using Quebec birth certificates (1979-1988), two birth cohorts were defined to control for the effects of repeat pregnancies. Bivariate and logistic regression analyses were used to examine the relationship between acculturation and term LBW. In both birth cohorts the more acculturated women experienced significantly higher rates of term LBW. The odds ratio for term LBW (1.6) was also significantly higher for the more acculturated group but this effect was only observed in the second birth cohort. These findings imply that in addition to other conventional factors, the level of acculturation of the mother should be assessed in perinatal risk identification systems.

Acculturation↗