Michel P. Guillemin

Impact of thermal proofing of a church on its indoor air quality: The combustion of candles and incense as a source of pollution

Some years ago, a parish in Geneva decided to reduce heating costs by insulating its church to make it more energy efficient. Three years after the last renovations, it was observed that the internal surfaces of the naves had already become dusty compared with the customary frequency of 10–12 years. Dust even deposited on various surfaces during religious services. Our investigation showed that nearly all the dust found inside the church may in fact be soot from incense and candle combustion. Incense appears to be a significant source of polycyclic aromatic hydrocarbons. With a mechanical ventilation system and petrol lamps resembling candles the problem can be resolved.

Human exposure to styrene. IV. Industrial hygiene investigations and biological monitoring in the polyester industry.

SummaryAn industrial hygiene study of 10 glassfiber reinforced polyester plants (including 90 workers) was undertaken to investigate the styrene exposure in this industry and to estimate biological limit values (BLVs) for the urinary metabolites of styrene: mandelic (MA) and phenylglyoxylic acids (PGA). Time weighted average (TWA) styrene exposures were found ranging from 2 to 200 ppm. The urinary elimination of metabolites correlated well with exposure and the BLVs corresponding to an 8-h exposure at 100 ppm were consistent with earlier laboratory findings (end-of-shift sample: MA 1640, PGA 510, MA + PGA 2150; next-morning sample: MA 330, PGA 330, MA + PGA 660 mg/g creat.). Total metabolites (MA + PGA) in the next-morning sample or mandelic acid in the end-of-shift sample are recommended for routine monitoring of exposure to styrene. The study revealed the need for further research on how to reduce styrene exposure in this industry.

Occupational exposure of truck drivers to dust and polynuclear aromatic hydrocarbons : a pilot study in Geneva, Switzerland

SummaryThe exposure to dust and polynuclear aromatic hydrocarbons (PAH) of 15 truck drivers from Geneva, Switzerland, was measured. The drivers were divided between “long-distance” drivers and “local” drivers and between smokers and nonsmokers and were compared with a control group of 6 office workers who were also divided into smokers and nonsmokers. Dust was measured on 1 workday both by a direct-reading instrument and by sampling. The local drivers showed higher exposure to dust (0.3 mg/m3) and PAH than the long-distance drivers (0.1 mg/m3), who showed no difference with the control group. This observation may be due to the fact that the local drivers spend more time in more polluted areas, such as streets with heavy traffic and construction sites, than do the long-distance drivers. Smoking does not influence exposure to dust and PAH of professional truck drivers, as measured in this study, probably because the ventilation rate of the truck cabins is relatively high even during cold days (11–15 r/h). The distribution of dust concentrations was shown in some cases to be quite different from the expected log-normal distribution. The contribution of diesel exhaust to these exposures could not be estimated since no specific tracer was used. However, the relatively low level of dust exposure does not support the hypothesis that present day levels of diesel exhaust particulates play a significant role in the excess occurrence of lung cancer observed in professional truck drivers.

Biological monitoring of exposure to styrene by analysis of combined urinary mandelic and phenylglyoxylic acids

Human volunteers were exposed in an experimental chamber to styrene (4 or 8 hours at 40 to 200 ppm) in order to obtain a quantitative relationship between exposure and urinary elimination of the metabolites mandelic and phenylglyoxylic acids (MA and PGA). For the analysis of PGA a new GC-method was used, based on reductive transformation of the relatively instable PGA into MA, which is stable enough for shipping and handling until final processing. The analysis of the post-exposure elimination shows that spot urine sampled in the morning after exposure and analysed for the sum of MA and PGA is the most reliable index for reflecing a preceding exposure to styrene.

Hydrocarbon Exposure, Hypertension and Kidney-function Tests

SummaryControl and hydrocarbon exposed workers participated in a cross-sectional study about the nephrotoxicity of chronic hydrocarbon exposure. Different markers of glomerular and tubular function as well as the celluria were examined and compared. The results show that the interaction between hypertension and hydrocarbon exposure has an influence on the kidney function. For the clearance the interaction age-exposure seems to play a more important role than age or exposure alone. The most useful markers appear to be the albuminuria, the N-acetyl-beta-d-glucosaminidase activity, the retinol-binding-protein concentration and the creatinine clearance.

Effect of Alcohol on the Kinetics of Styrene and its Metabolites in Volunteers and in Workers

Abstract The reliability of mandelic acid (MA) and phenylglyoxylic acid (PGA) in urine as biological indicators of styrene exposure is impaired by the concurrent intake of ethyl alcohol. This has been verified by controlled experiments in the laboratory and in the field. Six males were exposed to styrene at 50 ppm with four concurrent levels of ethyl alcohol intake from 0 to 1 g per kg of body weight during or following exposure. Blood and urine samples were analyzed for MA, PGA, styrene epoxide (SO), and styrene glycol (SG). The MA/SG ratio in blood was found to be the most promising indicator and could be used as a metabolic “check-index.” An MA/SG ratio less than 30 is proposed as a warning level which is indicative of interference by alcohol intake. Similar studies on seven workers in a polyester plant yielded results in agreement with the controlled laboratory findings. Berode, M.; Droz, P. O.; Boillat, M. A.; Guillemin, M. Effect of alcohol on the kinetics of styrene and its metabolites in volunteer...

A Direct Reading Method for Chlorinated Hydrocarbons in Breath

A direct reading method is described for the measurement of tetrachloroethylene and 1,1,1-trichloroethane in breath for concentrations ranging from 2.5 to 30 ppm. It is based on colorimetric detector tube technology and consists of a two-step procedure: 1) total breath sampling in a bag and 2) analysis of the bags content by detector tubes for the solvent and carbon dioxide. The latter is used to take into account dead space dilution and possible hyper- or hypoventilation. The method is tested in volunteers experimentally exposed to tetrachloroethylene and 1,1,1-trichloroethane and in workers occupationally exposed to tetrachloroethylene. Its results are compared with a reference gas chromatographic method. The agreement between the methods is good, with a systematic proportional error of less than +13% for tetrachloroethylene. Repeated measurements show standard deviations ranging from 6% to 39% of the tested concentrations.

Occupational Health – a very important component of Public Health

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Le nouveau centre de recherche sur l'environnement de l'Institut universitaire de médecine sociale et préventive de Lausanne

The organisation and the services of the new Research Center for Occupational Environment and Chemical Pollutants are described and commented. The advantages of this original structure for the monitoring and the prevention of health hazards on a community level are emphasized.

Occupational Hygiene around the World: Status of Occupational Hygiene in Switzerland

Abstract A summary of the status of occupational hygiene in Switzerland is presented based on the authors experience. Because Switzerland is a very small country and the number of occupational hygienists is also quite small, a survey was not necessary to describe the state of occupational hygiene within the country. As in many other countries, the system for reporting occupational injuries and diseases suffers from strong limitations. This plays a significant role in underestimating the importance of occupational hygiene and the need of its development. The occupational safety and health legal framework is very complicated in Switzerland, which does not favor establishment of a comprehensive and rational approach in this area. Acceptable air contaminants concentrations are legal standards issued periodically by the Swiss National Accident Insurance Organization which is in charge of enforcing the law to prevent and compensate occupational diseases. The role of unions has been quite modest up to now and t...