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PubMed1994

Hepatotoxic effects of solvent exposure around permissible limits and alcohol consumption in printers over a 4-year period.

Two field studies were carried out in 1987 and 1991 in order to evaluate the effect of chronic exposure to solvent mixture on liver enzyme patterns. The results in 33 workers who participated in both studies and had complete sets of data are presented. The magnitude of chemical workload was assessed by means of ambient air monitoring and biomonitoring of solvent concentrations. Alanine aminotransferase, aspartate aminotransferase and gamma-glutamyl transpeptidase were used as markers for possible biological effects. No dose-response relationship was found between exposure to complex solvent mixtures in ambient air, reaching and sometimes even exceeding the threshold limit values for mixtures, and liver enzyme activities. Self-reported alcohol intake was the only factor identified as statistically related to increased liver enzyme activity.

Adult↗
PubMed1993

Determination of urinary alkoxyacetic acids by a rapid and simple method for biological monitoring of workers exposed to glycol ethers and their acetates.

In control subjects and workers exposed to glycol ethers and their acetates, we determined the urinary metabolites (three alkoxyacetic acids) by a simple and rapid method. Levels of urinary metabolites were significantly higher in the solvent workers than in the nonexposed subjects. The exposure levels measured by personal monitoring of breathing zone air were far below the threshold limit value. The present results indicate that determination of urinary alkoxyacetic acids by the practical method used here is useful for evaluating excessive exposure to solvents.

Acetates↗
PubMed1989

Experimental human exposure to ethylene glycol monomethyl ether.

The uptake of EGME and the urinary excretion of its major metabolite (MAA) was studied in seven male volunteers during experimental exposure to EGME at rest. The exposure concentration was set at 16 mg/m3, the present Threshold Limit Value. A high retention (0.76) remained unchanged during the 4-h exposure period. In combination with a constant pulmonary ventilation and a fixed exposure concentration this resulted in an uptake rate that showed no significant variation in time. The total amount of EGME inhaled corresponded to a dose of only 0.25 mg/kg. During and up to 120 h after the start of the exposure, MAA was detected in the urine. The elimination half-life was on average 77.1 h. The total amount of MAA excreted was calculated by extrapolation and averaged 85.5% of the inhaled EGME. The pharmacokinetic data are compared with those obtained from other human exposure studies to ethylene glycol ethers (EGEE and EGBE).

Acetates↗
PubMed1995

Assessment of long-term styrene exposure: a comparative study of a logbook method and biological monitoring.

In a recent joint European research project "Biomonitoring of human populations exposed to genotoxic environmental chemicals: biomonitoring of styrene exposed individuals", a logbook method for assessment of long-term styrene exposure was applied in two Danish factories manufacturing glass fibre-reinforced polyester. The method was based on work process identification, assignment of work process concentrations and logbook keeping. Measures of exposure calculated by this method were compared with results from simultaneous measurements of styrene in blood and the metabolites mandelic acid and phenylglyoxylic acid in urine. Correlations were comparable with those obtained by use of personal samplers as published in the literature. Styrene in blood, however, only correlated with logbook concentrations at the time of sampling. Exposures were moderate to low. Mean personal 8-h time-weighted average concentration (8hTWAC) was 76 mg/m3 styrene (SD 54 mg/m3, range 2-230 mg/m3). The Danish 8hTWAC threshold limit value for styrene in air, 105 mg/m3 (25 ppm), was exceeded on 17% of personal days. The summed urinary metabolites, mandelic acid and phenylglyoxylic acid, had a mean personal value of 138 mg/g creatinine (SD 84 mg/g creatinine) on the day of sampling. Blood styrene mean value was 129 micrograms/l (SD 74 micrograms/l, range 66-358 micrograms/l). It is concluded that the logbook method offers a technique for testing whether measurements are performed on representative days and may be recommended as a tool supplementary to biological monitoring in the assessment of long-term exposure.

Adult↗
PubMed1981

Reaction time changes among steel workers exposed to solvent vapors. A longitudinal study.

A longitudinal study was performed to investigate the behavioral changes associated with occupational exposure to organic solvents. An initial simple reaction time (SRT) test was performed on a group of steel workers who were exposed to vapor concentrations of solvents clearly exceeding threshold limit values (TLVs). A second SRT measurement was made six months following the completion of major improvements in the hygiene quality of the work environment which resulted in a reduction of exposure levels to 20% of the TLVs valid at the time. Approximately fifteen months after this measurement, a final SRT test was performed. The workers' performance on the SRT test improved over the three measurements. At the first measurement occasion SRT was found to be related to the degree of exposure, while no such relation could be observed on the following measurement occasions. The results indicate that the workers' central nervous functioning had been negatively affected by solvent exposure and that this effect was at least partially reversible in nature; they thus confirm the importance of changes which enhance the hygienic quality of the work environment.

Adolescent↗
PubMed1994

Determination of 3,4-dimethylhippuric acid as a biological monitoring index for trimethylbenzene exposure in transfer printing workers.

The relationship between exposure to 1,2,4-trimethylbenzene (1,2,4-TMB) and urinary concentration of 3,4-dimethylhippuric acid (3,4-DMHA), one of its metabolites, was studied in workers involved in transfer printing. Airborne TMBs were sampled by an organic vapor monitoring badge and analyzed by capillary gas chromatography. Urinary 3,4-DMHA and creatinine were analyzed under the same conditions of high-performance liquid chromatography. The exposure concentration of 1,2,4-TMB among workers was around 25 ppm, the threshold limit value (TLV). The urinary concentration of 3,4-DMHA was low at the start of each shift and high at the end. Exposure to the TLV (25 ppm) of 1,2,4-TMB results in a urinary 3,4-DMHA concentration of 410 mg/g creatinine (r = 0.897, P < 0.001). Urinary 3,4-DMHA concentration could be used as a biological monitoring index for 1,2,4-TMB exposure.

Adult↗
PubMed1983

Human styrene exposure. V. Development of a model for biological monitoring.

The use of biological indicators to monitor workers' exposure to styrene requires a good understanding of the kinetics of the solvent in the organism. The absorption, distribution and elimination of styrene (STY), as well as the kinetics of formation and excretion of its metabolites (mandelic [MA] and phenylglyoxylic [PGA] acids) are simulated using a mathematical model. The results obtained compare well with experimental data for pulmonary (STY) and urinary (MA and PGA) excretion obtained during controlled human exposures. The model is then used to predict the behaviour of STY, MA and PGA during repeated occupational exposure. It is shown that the results are comparable to the data collected during field surveys in the polyester industry, if the level of physical activity of the workers is taken into account. This latter parameter appears to have a great influence on the urinary excretion of the metabolites. Based on the results obtained, biological limits of exposure are proposed (referenced to a TLV [threshold limit value] of 50 ppm) for MA and MA + PGA excretions in urine collected at the end of the shift (800 and 1000 mg/g creat.) and the next morning (150 and 300 mg/g creat.). Their validity is tested against experimental data obtained under field conditions.

Environmental Exposure↗
PubMed1982

Comparison of renal function and psychomotor performance in workers exposed to elemental mercury.

Renal function and psychomotor performance (eye-hand coordination, arm-hand steadiness) of a group of 43 workers exposed to mercury vapor were examined. Their mean age an average duration of exposure to mercury were 38 and 5 years, respectively. The results were compared with those in a matched group of 47 control workers. Increased proteinuria and albuminuria were found slightly more prevalent in the Hg-exposed group than in the control workers. These results are in agreement with those found during a previous study carrier out in another group of workers also exposed to elemental mercury (Buchet et al. 1980). The scores of the psychomotor tests were less satisfactory in the Hg workers than in the control workers, the arm-hand steadiness test being more discriminative than the eye-hand coordination test. Preclinical changes in psychomotor function can be detected independently of the presence of signs of renal dysfunction. No clear-cut relationships were found between the prevalence of abnormal psychomotor scores and the level of mercury in blood (HgB) or in urine (HgU). Increased prevalences of abnormal psychomotor scores seem however to occur for HgB between 1 and 2 micrograms/100 and for HgU between 50 and 100 micrograms/g creatinine. Therefore, a biologic threshold limit value of 50 micrograms/g creatinine in proposed for urinary mercury to prevent the development of preclinical effects on the central nervous system. A similar critical HgU level based on renal dysfunction prevalences has been suggested in a previous study.

Adult↗
PubMed1994

Lead exposure in starter battery production: investigation of the correlation between air lead and blood lead levels.

The threshold limit value (TLV) for lead (in Germany, the MAK value) is based on a certain blood lead concentration (in Germany BAT value = biological tolerance value for working materials) that is not to be exceeded; thereby a statistically significant association between air lead (PbA) and blood lead (PbB) is assumed. On the basis of a 10-year period of (1982-1991) biological and ambient monitoring of 134 battery factory staff and their workplaces, a PbA/PbB correlation with the regression equation PbB = 62.183 + 21.242 x Log 10 (PbA) (n = 1089, r = 0.274, P < 0.001) was calculated. These results are in line with those of several other investigations. The shape of the regression curve and the wide scattering of values led to the assumption that PbA values above the MAK value (0.1 mg/m3) do not necessarily result in increased PbB values. Similarly, PbA values lower than the MAK value do not guarantee PbB levels below the BAT value in every case. These observations are influenced by numerous confounders and intervening variables. It is concluded that lowering MAK values as a consequence of lowering BAT values is not mandatory.

Air↗
PubMed1993

An evaluation of the significance of mouth and hand contamination for lead absorption in lead-acid battery workers.

The present study was conducted to evaluate the role of ingestion through hand and mouth contamination in the absorption of lead in 25 lead-acid battery workers. Levels of personal exposure to airborne lead ranged from 0.004 to 2.58 mg/m3 [geometric mean 0.098, with 25% of samples exceeding threshold limit values (ACGIH) of 0.15 mg/m3]; the mean (SD) blood lead level was 48.9 (10.8) micrograms/dl. Mean hand lead contents increased 33-fold from preshift levels on Monday mornings (33.5 micrograms/500 ml) to midshift levels on Thursday afternoons (1121 micrograms/500 ml). Mouth lead contents increased 16-fold from 0.021 micrograms/50 ml on Mondays to 0.345 micrograms/50 ml on Thursdays. The typical Malay racial habit of feeding with bare hands and fingers without utensils (closely associated with mouth and hand lead levels on Mondays) explained the bulk of the variance in blood lead levels (40%), with mouth lead on Thursdays (closely associated with poor personal hygiene) explaining a further 10%. Air lead was not a significant explanatory variable. The implementation of a programme of reinforcing hand-washing and mouth-rinsing practices resulted in a reduction of the blood lead level by 11.5% 6 months later. These results indicate that parenteral intake from hand and mouth contamination is an important cause of lead absorption in lead-exposed workers.

Adolescent↗
PubMed1995

External and internal antimony exposure in starter battery production.

In the production of lead batteries two antimony compounds occur: in the casting of grids antimony trioxide (Sb2O3), and in the formation of lead plates stibine (SbH3). Seven workers from the grid-casting area and 14 workers from the formation area were examined with regard to the antimony concentration in blood (Sb-B) and urine (Sb-U). Antimony air concentrations (Sb-A) were measured by means of personal air samplers. Urine samples were collected at the end of the working week, at the beginning (U1) and the end (U2) of the shift, and at the beginning of work following a weekend without Sb exposure (U3). At U2 among the casters, the median Sb-A exposure was 4.5 (1.18-6.6) micrograms Sb/m3 and among the formation workers, 12.4 (0.6-41.5) micrograms Sb/m3. The exposure in both groups is more than 10 times lower than the present threshold limit values. The median Sb-B concentrations in the preshift samples was 2.6 (0.5-3.4) micrograms Sb/l for the casters and 10.1 (0.5-17.9) micrograms Sb/l for the formation workers. The average Sb-U values (U2) were 3.9 (2.8-5.6) micrograms Sb/g creatinine in the casting area and 15.2 (3.5-23.4) micrograms Sb/g creatinine in the forming area. Our investigation indicates that the two antimony compounds show virtually equal pulmonary absorption and renal elimination. The statistically significant correlations between Sb-A/Sb-B and Sb-A/Sb-U form the basis for proposals regarding appropriate biological exposure limits for occupational antimony exposure.

Adult↗
PubMed1993

[Occupational asthma due to isocyanates: current research orientation in occupational hygiene].

The replacement of the HDI monomer by less volatile prepolymers is not accompanied by a decrease of the incidence of occupational asthma in Switzerland. Field measurements show that the prepolymer concentration levels may be high although the monomer is hardly detectable or complies with the norm. Our researches are focused on the improvement of generation and measurement techniques (international quality control), on the characterization of the prepolymers to study their transformation in biological media. Field surveys will be conducted to establish the prepolymer concentration profiles. We recommend for the introduction in Switzerland of threshold limit values for HDI-biuret and isocyanurate.

Air Pollutants, Occupational↗
PubMedDate not supplied

[Medical aspects of the prevention of occupational diseases].

Important tasks of the physician in the field of occupational health are-setting of threshold-limit-values (TLV) as a base for technical and medical measures-planning and carry-out of medical examinations (medical prophylaxis) at the beginning and during work for the purpose of selection and survey.

Humans↗
PubMedDate not supplied

[Air pollution and irritations due to cigarette smoke].

In a nearly airtight climatic chamber of 30 m3 we studied the air pollution due to cigarette smoke as well as resulting irritations and annoyance. When 9 cig/30 m3 have been smoked, acroleine reaches the threshold limit value for industries; when 5 cig/30 m3 have been smoked, the clean air standards for outdoor air are exceeded by acroleine, carbon monoxide, and formaldehyde. The eyes are the most sensitive organ to cigarette smoke, followed by the nose. Annoyance about air quality and the wish to open the door or to leave the room proved to be other susceptible criteria. With 10 cig/30 m3, 9% of the subjects show a "strong" or "very strong" eye irritation, while 78% "wish to leave the room=. The most important of the measured irritants seems to be acroleine.

Acrolein↗
PubMed1991

The dental amalgam issue. A review.

Using an interdisciplinary approach, the current position in the dental amalgam controversy and the potential impact of amalgam mercury on human health are reviewed. Aspects of materials science, corrosion, mercury exposure, toxicology, neurology and immunology are included. New data on mercury exposure from corroded amalgam fillings in vivo are presented. The exposure can reach levels considerably over known threshold limit values. Also, measurements of mercury absorption from intraoral air are presented. The vital importance of avoiding a galvanic amalgam-gold coupling is emphasized. The symptomatology of a disabled patient, who recovered after amalgam removal, has been included. It is concluded that discussion of the dental amalgam issue has suffered from the lack of an interdisciplinary approach. It would be wise to learn from the lesson of acrodynia, and consider amalgam mercury among other possible factors in neurological and immunological diseases of unclear etiology.

Dental Amalgam↗
PubMed1990

New aspects of isocyanate asthma.

Air concentration of isocyanates are associated with the frequency of induced diseases. Asthma, bronchitis and rhinitis, chronic obstructive lung disease, and allergic alveolitis, respectively, were observed in exposed workers. Inhalation challenge tests with isocyanates found some 14% of symptomatic persons immunologically sensitized. At and above current threshold limit values (10 ppb) there is a risk of lung function deterioration also in asymptomatic workers.

Air Pollutants, Occupational↗
PubMed2004

Chlorinated dibenzo-p-dioxins and dibenzofurans in the Baltic herring and sprat of Estonian coastal waters.

BACKGROUND, AIMS AND SCOPE: The concentration of chlorinated dibenzo-p-dioxins and dibenzofurans in many fish from the Baltic requires monitoring, since it approaches or exceeds the European Union threshold limit value of 4 pg TEQ/g wet weight of fish for human consumption. The concentrations, expressed in TEQs, are important for toxicology and regulations, but hide the concentrations of the individual congeners, which are important for other environmental sciences, source allocation, and for the detection of measurement errors. This report evaluates the results of a survey reported earlier only in the terms of the TEQ concentrations. METHODS: Principal Component Analysis (PCA) was used to reduce the dimensions of the data (17 = 7 chlorinated dibenzo-p-dioxin and 10 chlorinated dibenzofuran congeners) to three principal components. This facilitated the interpretation of the congener profiles. Slopes of the congener concentrations as a function of age of the fish were estimated by least squares regression. The results were compared with a large set of data for lake trout from Lake Ontario. RESULTS AND DISCUSSION: The congener profiles of Baltic herring are less scattered than those of sprat. The profiles of herring from the central Baltic differ from those of herring from the Gulf of Riga and both appear to be affected relatively minimally by the age of the fish. The congener profiles of herring from the western Gulf of Finland are similar to those from the central Baltic, those from middle Gulf of Finland are similar to those from the Gulf of Riga. Both seem to be more affected by age of the fish than the profiles of the first two groups. The concentrations of several pentachloro- and hexachloro-dibenzo-p-dioxins and dibenzofurans increase with the age of the fish CONCLUSION: PCA is a good technique for the evaluation of the congener profiles. The resulting loading and score plots provide a good graphic summary of the multidimensional data. Additional analyses are needed to confirm the observed profile patterns. A comparison with the results of a long-term monitoring from another area shows that the age of the fish is a more important factor than the year of capture. RECOMMENDATION AND OUTLOOK: The surveys should continue for a number of years and the results should be presented and evaluated both in terms of the TEQs as well as in terms of weight concentrations. Since the concentrations do not appear to change very much from year to year, it would be better to carry out surveys only every 3-4 years and, instead, stratify the sampling according to age and gender of the fish, and to analyze replicate extracts by replicate measurements. The inclusion of unmarked replicate samples would be a good quality assurance measure. It would be desirable to analyze additional parts of the food chain in order to understand the fate of the compounds in the ecosystem.

Age Factors↗