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E Tielemans

Publications and source records attributed to E Tielemans.

11 recordsLinked to original sources
PubMed2006

Dermal, inhalation, and internal exposure to 1,6-HDI and its oligomers in car body repair shop workers and industrial spray painters.

OBJECTIVES: To study inhalation and dermal exposure to hexamethylene diisocyanate (HDI) and its oligomers as well as personal protection equipment (PPE) use during task performance in conjunction with urinary hexamethylene diamine (HDA) in car body repair shop workers and industrial spray painters. METHODS: Personal task based inhalation samples (n = 95) were collected from six car body repair shops and five industrial painting companies using impingers with di-n-butylamine (DBA) in toluene. In parallel, dermal exposure was assessed using nitril rubber gloves. Gloves were submerged into DBA in toluene after sampling. Analysis for HDI and its oligomers was performed by LC-MS/MS. Urine samples were collected from 55 workers (n = 291) and analysed for HDA by GC-MS. RESULTS: Inhalation exposure was strongly associated with tasks during which aerosolisation occurs. Dermal exposure occurred during tasks that involve direct handling of paint. In car body repair shops associations were found between detectable dermal exposure and glove use (odds ratio (OR) 0.22, 95% confidence interval (CI) 0.09 to 0.57) and inhalation exposure level (OR 1.34, 95% CI 0.97 to 1.84 for a 10-fold increase). HDA in urine could be demonstrated in 36% and 10% of car body repair shop workers and industrial painting company workers respectively. In car body repair shops, the frequency of detectable HDA was significantly elevated at the end of the working day (OR 2.13, 95% CI 1.07 to 4.22 for 3-6 pm v 0-8 am). In both branches HDA was detected in urine of approximately 25% of the spray painters. In addition HDA was detected in urine of a large proportion of non-spray painters in car body repair shops. CONCLUSION: Although (spray) painting with lacquers containing isocyanate hardeners results in the highest external exposures to HDI and oligomers, workers that do not perform paint related tasks may also receive a considerable internal dose.

Air Pollutants, Occupational↗
PubMed2006

A probabilistic assessment of the impact of interventions on oncology nurses' exposure to antineoplastic agents.

OBJECTIVE: The main goal was to investigate the potential of a probabilistic approach for exposure assessment and use this information to evaluate the impact of a complex of policy actions/interventions on dermal exposure to antineoplastic agents among oncology nurses. The central theme of this study was to make optimal use of existing data, supplemented only with limited additional information from a questionnaire survey. METHODS: A task based exposure model was used to estimate dermal exposure of the hands among oncology nurses in non-academic hospitals in the Netherlands. Monte Carlo simulation was used to integrate information from available (exposure) studies and generate exposure distributions for the total population of oncology nurses in both pre- and post-intervention situation. Graphs and descriptive statistics of the simulated exposure distributions were used to evaluate trends in population exposure. RESULTS: The inventory showed that important intervention occurred in the preparation and administering of antineoplastic agents and in the handling of urine. Hardly any changes were identified in de nursing tasks. The use of gloves seemed to have decreased for a number of tasks. The results of the analysis show that the interventions did not affect the median exposure. However frequencies of occurrence of individuals with very high and very low total dermal exposures decreased substantially in the post-intervention situation. Analysis of the effect of pregnancy showed that pregnancy is very unlikely to influence exposure or any of the key input variables. CONCLUSIONS: The present study shows that the probabilistic approach adds valuable information to deterministic exposure assessment, especially when extrapolating data on a subpopulation to populations of individuals at large. The results show that the identified changes in the past decade in Dutch non-academic hospitals resulted in changes in the exposure distribution of antineoplastic agents among oncology nurses.

Antineoplastic Agents↗
PubMed2000

Paternal occupational exposures and embryo implantation rates after IVF.

OBJECTIVE: To investigate any influence of paternal occupational exposures on implantation rates after IVF. DESIGN: Cohort study of couples who sought IVF treatment. SETTING: University Hospital Utrecht, The Netherlands. PATIENT(S): The study population was composed of 726 couples pursuing IVF treatment. INTERVENTION(S): Only the earliest IVF treatment cycle with ET was selected for the analysis. All couples filled in a generic questionnaire on lifestyle factors and details about their occupation. In addition, more detailed exposure information was obtained for pesticides with use of job-specific questionnaires and a subsequent telephone interview. MAIN OUTCOME MEASURE(S): The implantation rate was defined as the number of gestational sacs seen with ultrasound at 6-7 weeks of pregnancy, divided by the number of embryos replaced. RESULT(S): A significantly reduced implantation rate was seen among couples with male partners working in occupations with presumably high levels of organic solvent exposure. Conversely, paternal pesticide exposure was significantly associated with an increased implantation rate. Paternal exposures to metal dust or fumes and welding fumes were not related to the probability of implantation. CONCLUSION(S): The findings suggested that paternal organic solvent exposure decreased the implantation rate among couples undergoing IVF-ET treatment.

Adult↗
PubMed1999

Occupationally related exposures and reduced semen quality: a case-control study.

OBJECTIVE: To determine whether there is an association between abnormal semen parameters and occupational exposures to organic solvents, metals, and pesticides. DESIGN: Case-control study using three case groups based on different cutoff values for semen parameters and one standard reference group. SETTING: University Hospital Utrecht and University Hospital Rotterdam, the Netherlands. PATIENT(S): Male partners of couples having their first consultation at the two infertility clinics (n = 899). INTERVENTION(S): Men provided at least one semen sample. Occupational exposure was assessed with use of job-specific questionnaires, a job exposure matrix, and measurements of metals and metabolites of solvents in urine. MAIN OUTCOME MEASURE(S): Standard clinical semen analyses were used to define case groups and controls. RESULT(S): An association between aromatic solvents and reduced semen quality was demonstrated, irrespective of the exposure assessment method used. The associations were stronger if the case definition was based on stricter cutoff values for semen parameters. Risk estimates were higher if the analysis was restricted to primary infertile men. Exposure to other pollutants at the workplace was not associated with impaired semen quality. CONCLUSION(S): The findings indicated an association between aromatic solvent exposure and impaired semen parameters.

Adult↗
PubMed1999

Assessment of occupational exposures in a general population: comparison of different methods.

OBJECTIVES: To evaluate the relative merits of job specific questionnaires and various alternative assessment methods of occupational exposures often used in general population studies. METHODS: Subjects were participants in a hospital based case-control study of risk factors for male infertility. Estimates of exposure to organic solvents and chromium, based on job specific questionnaires, generic questionnaires, self reports of exposure, an external job exposure matrix (JEM), and a population specific JEM were compared with passive diffuse dosimeter results and measurements in urine. Urine samples from the end of the shift were analysed for metabolites of toluene, xylene, several glycol ethers, trichloroethylene, and chromium. Passive dosimeter date, metabolites of specific solvents, and urinary chromium concentrations were available for 89, 267, and 156 subjects, respectively. The alternative methods and measurements in urine were compared by means of the Cohen's kappa statistic and by computing the positive predictive value, sensitivity, and specificity of the alternative methods against measurements in urine. RESULTS: Passive dosimeter results indicated that exposure classifications with job specific questionnaire information could discriminate between high and low exposures. The kappa coefficients were < 0.4, so agreement between the various methods and measurements in urine was poor. Sensitivity of the methods ranged from 0.21 to 0.85, whereas specificity ranged from 0.34 to 0.94. Positive predictive values ranged from 0.19 to 0.58, with the highest values for job specific questionnaires. CONCLUSIONS: The results indicate that the implementation of job specific questionnaires in a general population study might be worth the extra expense it entails, bearing in mind the paramount importance of avoiding false positive exposure estimates when exposure prevalence is low.

Case-Control Studies↗
PubMed1998

[Exposure to pseudo-estrogens and the quality of sperm].

Some synthetic chemicals and natural compounds occurring in vegetables or animal food products mimic endogenous hormones, especially oestrogens, or may have a general action of disturbing hormonal status. It is assumed that intrauterine exposure to these compounds may have an adverse effect on development, differentiation and function of the genital organs of the male foetus. In a worldwide discussion a supposed drop in human sperm quality is related to foetal exposure to chemicals with oestrogen activity. Experimental animal evidence suggests that foetal exposure to compounds with oestrogenic activity may influence reproductive capabilities. In addition chemicals such as diethylstilbestrol (DES) in humans and dichlorodiphenyltrichloroethane (DDT) in wildlife influence the reproductive system. There is no conclusive evidence of decreasing semen quality in general.

Abnormalities, Drug-Induced↗
PubMed1998

Individual-based and group-based occupational exposure assessment: some equations to evaluate different strategies.

Basically, two strategies can be considered for the analysis of hazardous pollutants in the work environment: group-based and individual-based strategies. This paper provides existing and recently derived equations for both strategies describing the influence of several factors on attenuation and on the standard error of an estimated linear regression coefficient relating a continuous exposure variable and a continuous health outcome via a simple linear regression model. We applied these equations using exposure variability information from industry-wide surveys over the past decade in order to gain more insight into the effects of various sources of exposure variability on choices among different analysis strategies. In general, for the modeling scenario considered here, there is not a straightforward criterion for choosing an optimal analysis strategy. Researchers have to decide between individual-based strategies generating precise, though biased, estimates or group-based strategies generating less precise but essentially unbiased estimates. For most exposure variability scenarios evaluated, an individual-based strategy yielded substantial attenuation. It is the authors' contention that the choice between individual-based and group-based strategies should be based on validity, rather than on precision, of the estimated exposure-response coefficient.

Air Pollutants, Occupational↗
PubMed1997

Intraindividual variability and redundancy of semen parameters.

We analyzed two databases comprising repeated semen analyses of male patients visiting a fertility clinic in the Netherlands to assess intra- and interindividual variability for several semen parameters. We calculated reliability coefficients to estimate the attenuation of the slope if semen parameters are used to predict the probability of conception in regression models. Reliability was lowest for morphology (Population A: R = 0.48, Population B: R = 0.54), but somewhat better for motility (Population A: R = 0.66, Population B: R = 0.71) and count (Population A: R = 0.79, Population B: R = 0.81). Semen concentration had the largest reliability coefficients (Population A: R = 0.84, Population B: R = 0.84). Stimulations using empirical variance components indicated that using semen parameters as endpoints in case-referent studies might substantially underestimate measures of association. The results showed that most semen parameters were just moderately redundant (range: Kappa = 0.28 to Kappa = 0.45); only agreement between concentration and count was substantial (Population A: Kappa = 0.84, Population B: Kappa = 0.80). Hence, epidemiologic studies focusing on male infertility should take into account a variety of parameters.

Analysis of Variance↗
PubMed1994

Changes in ventilatory function in grain processing and animal feed workers in relation to exposure to organic dust.

OBJECTIVES: The effects of organic dust exposure on the configuration of the maximum expiratory flow volume (MEFV) curve was examined multivariately. METHODS: Data from 390 male workers in the animal feed industry in The Netherlands were analyzed. A multivariate technique called nonlinear canonical correlation analyses was used to study the relationship between a set of organic dust exposure variables and a set of ventilatory function variables. RESULTS: The results indicate an almost independent effect of the overall mean organic dust exposure and the number of years of organic dust exposure on ventilatory function. Increasing mean organic dust exposure was associated with a decrease in both forced expiratory volume in 1 s (FEV1.0) and forced vital capacity (FVC) and decreased flows at high lung volumes only. Increasing number of years of dust exposure was associated with a decrease in FEV1.0 and a decrease in flow at all lung volumes, while the FVC seemed relatively constant. These two distinct patterns of reduction in ventilatory function may represent two different pathological processes. Whereas workers with prolonged exposure showed reduced values for all of the MEFV curve variables, except the FVC, those with only a few years of exposure especially showed a decrease in FVC and peak expiratory flow. The effect of current organic dust exposure was more evident for nonsmokers than for ex-smokers and current smokers. CONCLUSION: The major finding of this study was an independent effect of overall mean organic dust exposure and the number of years of organic dust exposure on the MEFV curve.

Adult↗
PubMedDate not supplied

Exposure to fungicides in fruit growing: re-entry time as a predictor for dermal exposure.

As part of a European Concerted Action on Male Reproduction Capability an exposure assessment survey was conducted among seasonal workers in the fruit growing sector in the Netherlands. Dermal exposure to the fungicides captan and tolylfluanid was measured using cotton gloves (12 persons) and skin pads on several body parts (12 persons). In addition, a set of exposure data was used from a study conducted recently among Dutch fruit growers. For harvesting activities, re-entry time appeared to be an important determinant of dermal exposure to captan and tolyfluanid. Explained variance of regression models was moderate to high (range 0.30-0.87). For captan, calculated half-life times from the most recent exposure survey were lower (glove data: 5 days; pad data: 6 days) compared with half-life times based on the previously conducted study (11 days). Possible explanations for the discrepancy are discussed. For tolylfluanid, estimated half-life times during harvesting were 2 and 3 days, based on pad and glove data, respectively. Prediction of captan exposure during other crop activities appeared to be far more difficult (explained variance equal to 0.06), although the estimated half-life time was comparable with that for harvesting. The data suggest that re-entry time gives useful information to group workers in broad exposure categories. Nonetheless, it was concluded that large studies are needed to evaluate the importance of re-entry time in more detail.

Agricultural Workers' Diseases↗