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Biomedical subjects

J W van der Gulden

Publications and source records attributed to J W van der Gulden.

At least 19 recordsLinked to original sources
PubMed2000

Longitudinal changes in bronchial responsiveness associated with swine confinement dust exposure.

STUDY OBJECTIVES: Acute exposure to the air in swine confinement units causes bronchial hyperresponsiveness and inflammation of the airways. This study was performed to assess the longitudinal development of bronchial responsiveness in pig farmers and to establish exposure-response relationships. METHODS: A cohort of 171 pig farmers was followed over a 3-year period. Bronchial responsiveness was assessed by a histamine provocation test. Long-term average exposure to inhalable dust and endotoxin was determined by personal monitoring in summer and winter, using data on farm characteristics and activities. Time-weighted average (TWA) personal exposure to ammonia was measured. Data on farm characteristics were gathered in the same period. RESULTS: Mean increase in responsiveness was 2.52 doubling concentrations of histamine for a 10% decrease in FEV(1) and 1.36 doubling concentrations for a 20% decrease in FEV(1). Long-term average exposure to dust was 2.63 mg/m(3) and to endotoxin was 105 ng/m(3). TWA exposure to ammonia was 1.60 mg/m(3). After adjusting for age and smoking behavior, long-term average exposure to inhalable dust was associated with increases in bronchial responsiveness expressed as steps for provocative concentration causing 10% fall in FEV(1). TWA exposure to ammonia, use of wood shavings as bedding, and automated dry feeding were associated with increases in responsiveness expressed as steps for provocative concentration causing a 20% fall in FEV(1). CONCLUSIONS: Exposure to dust and ammonia in pig farms contributes to chronic inflammation of the airways and should be reduced.

Adult↗
PubMed1999

Organic dust toxic syndrome in swine confinement farming.

BACKGROUND: Pig farmers are exposed to organic dust with pro-inflammatory capacities. This makes it likely that they suffer from organic dust toxic syndrome (ODTS). No studies that included unexposed control populations are available so far. METHODS: The prevalence of ODTS was established by the use of questionnaires in a group of 239 pig farmers and 311 rural controls working in nonagricultural occupations. RESULTS: Pig farmers suffered more often from ODTS than controls (6.4% vs. 2.6%, P < 0.05). Organic dust toxic syndrome was associated with symptoms of atopy (prevalence odds ratio (POR) 3.1, 95% confidence interval (CI) 1.2-8.0) and with the use of wood-shavings as bedding (POR 4.3, 95% CI 1.2-15.6). An inverse association with the number of years worked as pig farmer was found (up to 5 years vs. more than 5 years; POR 5.0, 95% CI 0.8-32.9). CONCLUSIONS: The prevalence of ODTS was elevated among pig farmers when compared to nonfarming, rural controls.

Agricultural Workers' Diseases↗
PubMed1999

Health-based selection for asthma, but not for chronic bronchitis, in pig farmers: an evidence-based hypothesis.

In cross-sectional surveys among pig farmers an elevated prevalence of chronic bronchitis is usually reported, but not of asthma, despite many factors promoting the manifestation of asthma. To investigate this apparent contradiction a postal questionnaire survey was performed among 239 pig farmers and 311 rural controls. Pig farmers reported an elevated prevalence of symptoms of chronic bronchitis (20.2 versus 7.7%, p<0.001), but not of asthma (5.9 versus 5.5% for chest tightness). Among pig farmers the use of disinfectants (prevalence odds ratio (POR) 9.4, 95% confidence interval (CI) 1.6-57.2 for quaternary ammonium compounds) and aspects of the disinfecting procedure were associated with the prevalence of asthma symptoms. Compared with controls, pig farmers reported fewer allergies to common allergens (4.6 versus 14.6%, p<0.001 for pollen) and fewer symptoms of atopy in childhood (9.9 versus 17.2, p<0.05 for one or more of four symptoms). Atopy in childhood was strongly associated with the prevalence of asthma symptoms (POR 4.1, 95% CI 2.2-7.7), but not with chronic bronchitis. Health-based selection of nonasthmatics for pig farming, which tends to mask a work-related hazard for asthma, is offered as an explanation for these results.

Adult↗
PubMed1998

The effects of an ergonomic-educational course. Postural load, perceived physical exertion, and biomechanical errors in nursing.

OBJECTIVES: To evaluate the results of an ergonomic-educational course for nurses we assessed the number and percentage of harmful postures and of ergonomic and biomechanical errors made before and after the course. We also studied the perceived physical exertion. MEANS AND METHODS: In all, 12 nurses who had participated in the course (trainees) and 12 who had not (controls) were recorded on video while performing standardized nursing tasks. The wards from which the two groups of nurses came were comparable, as were the patient populations. The nurses were also comparable in some personal characteristics. The tasks they performed included washing, lifting, and repositioning a patient as well as certain tasks other than patient handling. Video recordings were made once before (1-2 weeks) and twice after the course (after 3 months and after 15 months). The harmful postures, the errors made, and the ratings of perceived exertion were measured by means of the Ovako Working-posture Analysis System (OWAS), a checklist, and Borg scores, respectively. RESULTS: When the first and last measurements of all the above tasks taken as a whole were analyzed the trainees showed a significant improvement in the number and percentage of harmful postures and errors, whereas the controls did not. The same could be concluded for lifting alone. After the course the new work routine did not appear to have caused any extra perceived physical exertion. CONCLUSION: It can be concluded that the course was successful, although it should be carefully investigated as to whether nurses remain capable of working safely in daily practice. The work pressure that nurses experience during their normal duties could prevent them from working safely during everyday work.

Adult↗
PubMed1998

A LISREL analysis of work-related risk factors and health complaints in the nursing profession.

OBJECTIVES: To fit a model which describes the complex interaction between various work-related factors and both musculoskeletal and psychosomatic complaints of nurses simultaneously and to compare the results with those of two LISREL models, in which the health outcome variables are analyzed separately in terms of their correlation with the same set of work-related factors. MATERIALS AND METHODS: Nurses (n=718) working in four Dutch nursing homes completed a questionnaire about work-related factors and musculoskeletal and psychosomatic complaints (response 81%). LISREL was used to describe and analyse the models. RESULTS: The full model had a reasonable overall fit. The strongest (and statistically significant) correlations were found between work postures and musculoskeletal complaints and between psychosocial work demands and psychosomatic complaints. In the two single models, health outcomes showed statistically significant correlations with the same work-related factors as they did in the full model. The full model could be slightly improved when the variable somatized complaints (e.g., dizzyness, headache) was related both to musculoskeletal complaints and to psychosomatic complaints. CONCLUSIONS: Although a model that simultaneously describes more dependent variables appears to provide a better approximation of the complexity of the actual relationship between work-related factors and health effects, the models in which only one health outcome is studied seem to give a proper description of the data at hand. This is an important finding because these single health outcome models resemble the usual analysis strategy by means of standard regression analysis. The adapted version of the full model suggests that musculoskeletal complaints of nurses can partly be understood as non-specific health complaints.

Adult↗
PubMed1998

A simple method to evaluate the reliability of OWAS observations.

Slides showing nurses in different working postures were used to determine the reliability of OWAS observations. Each slide could be looked at for 3 seconds, while a new slide was shown every 30 seconds to resemble the normal practice of observation. Two observers twice scored a series of slides, some of them being identical at both viewings. To reduce effects of recall there was a time interval of 4 weeks or more between the two viewings and the slides were in a different order the second time. Different series were used to evaluate inter- and intra-observer reliability. The OWAS scores of corresponding slides were compared. In almost all comparisons percentages of agreement over 85% and kappa's over 0.6 were found, which is considered as good agreement. The procedure described seems to be a useful and simple technique to determine such reliability.

Humans↗
PubMed1998

Longitudinal changes in lung function associated with aspects of swine-confinement exposure.

Several aspects of swine-confinement farming appear to be leading to adverse respiratory effects. This study was set up in a longitudinal design to study the association between certain characteristics of farms or the way they are run and a decline in lung function. A cohort of 171 pig farmers was observed for 3 years. Lung function was measured. Exposure to farm characteristics was determined at the start of the observation period, using data from standardized farm surveys and from diaries kept by the participants. Mean decline in lung function was 73 mL/year for forced expiratory volume in 1 second (FEV1) and 55 mL/year for forced vital capacity (FVC). A longitudinal decline in FEV1 was significantly associated with the use of quaternary ammonium compounds as disinfectants (an additional 43 mL/year) and also with the use of an automated dry feeding system (an additional 28 mL/year). The association with the use of wood shavings as bedding material was not statistically significant. The impact of these characteristics in a longitudinal study provides stronger evidence for causal inference than that shown in previous cross-sectional designs. This may be useful in promoting preventive measures.

Adult↗
PubMed1998

Endotoxin exposure as a major determinant of lung function decline in pig farmers.

Exposure-response relationships for endotoxin as measured in dust and longitudinal decline in lung function were studied. A cohort of 171 pig farmers was followed over a 3-yr period. Long-term average exposure to dust and endotoxin was determined by personal monitoring in summer and winter, using data on farm characteristics and activities. Mean decline in FEV1 was 73 ml/yr and in FVC 55 ml/ yr. Long-term average exposure to dust was 2.63 mg/m3 (geometric SD [GSD] 1.30), and to endotoxin, 105 ng/m3 (GSD 1.5). Annual decline in FEV1 was significantly associated with endotoxin exposure. An increase in exposure with a factor 2 was associated with an extra decline of FEV1 of 19 ml/yr.

Adult↗
PubMed1997

Metal workers and repairmen at risk for prostate cancer: a review.

BACKGROUND: The objective is to summarize the results of studies of prostate cancer risk among metal workers, mechanics, and repairmen in order to evaluate the magnitude of risk and to investigate the role of specific work-related hazards in the development of this disease. METHODS: Review of literature. RESULTS: In most of the studies reviewed, a slight excess risk of prostate cancer incidence or mortality was observed among metal workers and repairmen. It is as yet unclear, however, whether this excess risk is caused by particular occupational exposures or by risk factors in personal life style (e.g., dietary habits). Hardest evidence is found of a relationship to exist between the use of cutting oils or other metal-work liquids and prostate cancer risk. CONCLUSIONS: It would appear that metal workers, mechanics, and repairmen run a slightly elevated risk of prostate cancer. However, the actual risk factors are still unknown.

Humans↗
PubMed1997

Evaluation of the effects of an ergonomic-educational programme. The assessment of "ergonomic errors" made during the performance of nursing tasks.

OBJECTIVES: The objectives of this study were (i) To establish whether it is possible to assess by means of a check-list in a reliable way errors which violated biomechanical and ergonomical principles during nursing tasks, and (ii) to study the effectiveness of an ergonomic-educational course by using this check-list. MATERIALS AND METHODS: Trainees (n = 12) and a control group of nurses (n = 12) who did not attend the course, performed three nursing activities at three points in time under standardized conditions; once before and twice after the course had ended. Their performances were recorded on video. A check-list was developed to assess the number of ergonomic errors made during the test performances. Two observers completed the check-lists after having watched five videotapes, and one of them did this for a second time 3 weeks later, in order to assess inter- and intra-observer reliability. In addition the tapes of all nurses were scored and analysed on differences in the performance of the two groups at the three points in time. Percentage of agreement and kappa (kappa) was used to express inter- and intra-observer reliability. Student's t-test was used to analyse the differences in mean percentages of errors. RESULTS: The inter- and intra-observer reliability were 92% with kappa of 0.84 and 93% with kappa of 0.86, respectively. Further results showed that the mean percentages of errors made by the control group remained the same at the three measurement times. However, in the trainee group a significant decrease in errors was found. The trainees made fewer errors at all three points in time than the controls did. CONCLUSION: It appears feasible to create a check-list to assess ergonomic errors in a reliable way. Trainees make fewer errors after an ergonomic-educational course. It is necessary, however to evaluate whether trained nurses work more safely in their daily duties than during the study.

Adult↗
PubMed1997

Bronchial hyperresponsiveness and exposure in pig farmers.

OBJECTIVE: To study the effect of exposure on bronchial responsiveness in pig farmers. METHOD: A group of 196 pig farmers were tested for lung function and bronchial responsiveness to histamine in the summer of 1992. To achieve sufficient contrast in respiratory morbidity and exposure, 96 of the farmers were selected because they had chronic respiratory symptoms and the remaining 100 because they were free from any respiratory symptoms. Personal exposure to dust, endotoxins and ammonia was measured during 1 working day in the summer of 1991 and 1 day in the winter of 1992. Data on farm characteristics were gathered in the same period. RESULTS: After adjusting for age and smoking behaviour, mild bronchial responsiveness, defined as PC10 < or = 16 mg/ml, was associated with the use of quaternary ammonium compounds as disinfectant [prevalence odds ratio (POR) 6.7, 95% confidence interval (CI) 1.4-32.8], use of wood-shavings as bedding (POR 13.3, CI 1.3-136.7), use of automated dry feeding (POR 2.8, CI 1.0-7.8), use of pellets as feeding material (POR 4.8, CI 1.1-21.1) and location of air exhaust via pit or roof in the confinement units (POR 2.7, CI 1.2-6.3). The association with the use of disinfectants other than quaternary ammonium compounds was not significant (POR 2.4, CI 0.7-8.4). No associations between bronchial responsiveness and measured exposure to dust, endotoxins or ammonia were discernible. CONCLUSION: Protective measures, designed to prevent airway disease in confinement farming, should be based on information about the operational and other characteristics of farms that are related to high exposure and health effects. Specifically, the use of quaternary ammonium compounds as disinfectant, the use of wood-shavings as bedding and the use of automated dry feeding should be discouraged.

Adult↗
PubMed1996

Respiratory morbidity in relationship to farm characteristics in swine confinement work: possible preventive measures.

Swine confinement farming is associated with an increased risk of respiratory morbidity. Adverse health effects have been shown in association with levels of dust, endotoxins, and ammonia. This study was conducted to evaluate characteristics of confinement farms associated with respiratory morbidity in order to establish priorities for preventive measures. A questionnaire on symptoms and farm characteristics was completed by 1,432 male swine confinement farmers. Of these, 200 with and 200 without chronic respiratory symptoms were randomly selected for lung function testing. A significantly increased risk for chronic respiratory symptoms was shown if farmers used wood-shavings as bedding (prevalent odds ratio [POR]2.2), used disinfectants (POR 1.7), used natural ventilation (POR 2.6), had floor types other than slatted or half-slatted (POR 2.1), or used a mechanical feeding system (POR 1.4). Lung function (FEV1) was significantly lower with increasing numbers of years worked (51 ml/10 years), with smaller numbers of pigs (8.5 ml/100 pigs), and when the air outlet of the ventilation system was via the pit (248 ml). To decrease the risk of respiratory morbidity the following preventive measures are proposed: discouragement of the use of disinfectants and of wood-shavings as bedding, and promotion of the use of mechanical ventilation systems.

Agricultural Workers' Diseases↗
PubMed1996

Work related risk factors for musculoskeletal complaints in the nursing profession: results of a questionnaire survey.

OBJECTIVES: To determine the prevalence of musculoskeletal complaints of the back, arms or neck, and legs among nurses, and to investigate the relation between these complaints and various work related and personal variables. METHODS: A questionnaire survey was carried out in four nursing homes in The Netherlands. RESULTS: The response was 95% and resulted in 846 completed questionnaires. It was found that a large proportion of the subjects regularly had back complaints (36%) but also had arm or neck (30%) and leg complaints (16%). Almost all respondents (89%) considered nursing work as physically strenuous. Most of them complained of working under time pressure (69%), increased work pressure (70%), and having no opportunity to take a break from the work (70%). The physical variables which seem to trouble the subjects most were lifting (65%), working in awkward postures (47%), and stooping (34%). Moreover, 53% of the subjects responded that the ergonomic lay out of the ward was disagreeable. Most of the work related variables under study seemed to be associated with musculoskeletal complaints. For all types of complaints the strongest associations were found with having to lift heavy loads. Apart from physical stress various aspects of work pressure showed strong associations with the occurrence of musculoskeletal complaints. The variables on the ergonomy of the ward showed less clear associations with musculoskeletal complaints than were found for physical stress and work pressure. CONCLUSIONS: From these results it may be concluded that future research of health risks of nursing work should have a wider focus than the relation between physical workload and low back pain.

Adult↗
PubMed1995

Work environment and prostate cancer risk.

A case-referent study of 345 prostate cancer cases and 1,346 referents was carried out in the Netherlands to investigate the relationship between work environment and prostate cancer risk. Cases were selected from the Cancer Registry of the Comprehensive Cancer Centre IKO. Referents (men diagnosed with benign prostate hyperplasia) were recruited with assistance of the pathology laboratories in the IKO region. Questionnaires were mailed to all subjects to obtain information on their work history and occupational exposure. Moreover, workers in farming (n = 323), and in metal work and maintenance (n = 340), were requested to complete short supplements to the questionnaire inquiring in more detail into specific types of exposure. Significantly elevated risks were found for work in food manufacturing and for bookkeepers. Significantly elevated odds ratios (OR) were also observed for jobs held between 1960 and 1970 in administration, in storage, or as farm laborer. In addition, a statistically significant excess risk was found for subjects who reported frequent occupational exposure to cadmium. Cases who worked in farming applied pesticides during significant more days per year than the referents did. A nonsignificantly elevated OR was found for maintenance of tractors and agricultural machinery. Among metal workers, mechanics, and repairmen, nonsignificantly increased ORs were observed with regard to the use of acids, solvents, iron, and steel, and for welding and maintenance of machinery.

Aged↗