Biomedical subjects

J van Hemmen

Publications and source records attributed to J van Hemmen.

6 recordsLinked to original sources

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↗

PubMed2001

Assessing reasonable worst-case full-shift exposure levels from data of variable quality.

Exposure assessors involved in regulatory risk assessments often need to estimate a reasonable worst-case full-shift exposure level from very limited exposure information. Full-shift exposure data of very high quality are rare. A full-shift value can also be calculated from (short term) task-based values, either derived from measured data or from models. The most simple option is to use the task based exposure levels as the full-shift value. A second option is to calculate a time-weighted average (TWA), using (reasonable worst case) estimates of the duration and the exposure level of the relevant tasks. The third option is to use a Monte Carlo analysis with estimated input distributions for exposure level and duration of exposure. If an estimated distribution of respiratory volume is also included, this leads to a distribution of inhaled amounts. The 90th percentile of such a distribution is generally substantially lower than the fixed point estimates calculated using high end values for each parameter. This technique can thus prevent unnecessary conservative estimates in risk assessment. The output distribution can also be used as valuable input to the risk management process, because it provides information on probabilities of exposure levels, that can influence the cost-benefit analysis of the risk management process. Finally, the sensitivity analysis of Monte Carlo simulation can give guidance for further studies to increase the accuracy of the exposure assessment.

Europe↗

PubMed2000

Hand wash and manual skin wipes.

Hand wash and skin wipes are major techniques that have been used for dermal exposure sampling. Both techniques remove chemicals either deposited on or transferred to the skin contaminant layer by a combination of chemical and mechanical actions. The paper overviews identified methods and techniques, with emphasis on sampling parameters and sampling efficiency. It is concluded that identified sampling protocols, including sampling techniques, deviate at possible key issues, which hampers comparisons of study results. It is recommended to conduct sampling efficiency studies prior to field sampling, under conditions that are quite similar to conditions of exposure regarding exposure process, levels of skin loading, and time of residence of the compound on the skin. Harmonization of sampling protocols will be a first step in creating a database for better understanding the influence of sampling parameters on the performance of removal techniques to assess dermal exposure.

Bias↗

PubMed1999

Dermal route in systemic exposure.

To evaluate risk from dermal exposure, the amount of material on the skin must first be measured. The potential for dermal uptake must then be assessed for the potential health effects from systemic exposure. No standard methods exist for studying these processes, and published data are not comparable because of the different techniques used. Future validated methodology should provide a sound scientific basis for risk assessment. Methods for measuring skin and surface contamination will require development of reference contaminated surfaces and skin as part of quality control procedures. Biological monitoring is a valuable tool in the assessment of dermal absorption, in contributing to the validation of in vitro techniques, and in risk assessment and management. It will be necessary to conduct detailed investigations to support risk assessment for dermal exposure. Ultimately, predictive models will be established for exposure and for dermal absorption to support a generic approach and allow risk assessment strategies appropriate to actual workplace situations.

Environmental Monitoring↗

PubMed1987

Influence of occupational low-level lead exposure on renal parameters.

The influence of lead exposure on renal function was examined. In 155 lead workers and 126 control workers, lead in blood (PbB) and zinc protoporphyrin in blood (ZPP) were measured as indicators of exposure to lead; various proteins in urine were measured as parameters of renal functions. Regression and matched-pair analyses suggest that tubular parameters may be more influenced by lead exposure than glomerular parameters. Changes in renal function parameters may already occur at PbB levels below 3 mumol/liter (600 micrograms/liter). The excretion of N-acetyl-beta-D-glucosaminidase appears to be the most consistent and sensitive parameter of an early effect on the tubular function.

Adult↗

PubMed1987

Renal function of workers with low-level cadmium exposure.

The influence of occupational exposure to cadmium on renal function was examined in 27 male cadmium workers from plants with second-degree usage of cadmium. The levels of cadmium in the blood and urine and various protein concentrations in the urine and serum were determined. The urinary levels of beta 2-microglobulin, retinol-binding protein, and N-acetyl-beta-D-glucosaminidase were statistically significantly increased in workers with urinary cadmium levels above 50 nmol/l. SDS-PAGE electrophoresis with silver staining is probably a sensitive indicator of the early effects of cadmium on protein excretion. The currently recommended biological exposure limits may have to be lowered.

Cadmium↗