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H Kromhout

Publications and source records attributed to H Kromhout.

At least 37 records · Page 2Linked to original sources
PubMed2001

Respiratory effects of exposure to low levels of concrete dust containing crystalline silica.

BACKGROUND: Dusts containing crystalline silica are generated in mining, construction, glass, granite and concrete production industries. The association between exposure to low levels of concrete dust containing crystalline silica and reduction in lung function, was evaluated in a cross-sectional study. METHODS: The study was carried out among 144 concrete workers, from two factories, with exposure assessment of respirable dust and silica by personal samplers. Results of respiratory questionnaires and standardized measurements of lung function were compared with the results in a control population. Multiple linear regression analysis was used in selecting factors that predict (age and standing height standardized residual) lung function. RESULTS: The average concentration of respirable dust in both factories was 0.8 mg/m(3) and 0.06 mg/m(3) for respirable silica. The average silica content of the dust was 9%. The average cumulative dust exposure was 7.0 mg/m(3) year and cumulative silica exposure was 0.6 mg/m(3) year. Significant associations between exposure to concrete dust and a small lung function (FEV(1)/FVC ratio, MMEF) loss were found, independent of smoking habits and of a history of allergy. CONCLUSIONS: Our results indicate that, concrete workers with chronic obstructive pulmonary symptoms and/or work-related lower respiratory symptoms are at risk of having a reduction in lung function (FEV&(1)/FVC ratio) outside the 5th percentile of the external reference population, and therefore, of mild chronic obstructive pulmonary disease, at respirable concrete dust levels below 1 mg/m(3) with a respirable crystalline silica content of 10% (TWA, 8 hr).

Adult↗
PubMed2001

Dermal exposure, handwashing, and hand dermatitis in the rubber manufacturing industry.

Skin diseases, such as hand dermatitis, are thought to be a common problem in the rubber manufacturing industry, as workers are exposed to a wide range of chemicals with known irritant and sensitizing potential. We conducted a cross-sectional survey of a representative sample of rubber manufacturing workers (N = 202), selected from nine different rubber companies. Prevalence of hand dermatitis ("major" and "minor" dermatitis) and skin injuries was assessed on the basis of a diagnosis by a dermatologist. We investigated the possible relations between actual skin exposure, handwashing practices, and hand dermatitis. Prevalence of major hand dermatitis (7%) was comparable with that in the general population; however, minor signs of dermatitis were more common among the surveyed population (28%), as were traumata of the skin (17%). Dermal exposure to cyclohexane-soluble agents at work was related to the occurrence of major hand dermatitis, but not to the occurrence of minor hand dermatitis. Moderate and frequent handwashing especially with industrial surfactants containing scrubbing particles were found to be strongly associated with the occurrence of minor dermatitis [odds ratio = 4.27 (95% confidence interval = 0.90-20.27) and odds ratio = 6.38 (95% confidence interval = 1.33-30.17, respectively)].

Administration, Cutaneous↗
PubMed2001

Occupation, chronic bronchitis, and lung function in young adults. An international study.

We studied the relationship between occupational exposures, chronic bronchitis, and lung function in a general population survey in 14 industrialized countries, including 13,253 men and women aged 20 to 44 yr. We studied associations between occupational group, occupational exposures, bronchitis symptoms (cough and phlegm production for at least 3 mo each year), FEV(1), and nonspecific bronchial responsiveness (NSBR) separately in lifetime nonsmokers, cigarette smokers, and ex-smokers. Occupational exposure to vapors, gas, dust, or fumes, estimated with a job exposure matrix (JEM), was associated with chronic bronchitis among current smokers only (prevalence ratio (PR): 1.2 to 1.7). The interaction of occupational exposure with smoking, however, was not statistically significant (p > 0.1). Self-reported exposure was related to chronic bronchitis in all smoking groups. An increased risk for chronic bronchitis was found in agricultural, textile, paper, wood, chemical, and food processing workers, being more pronounced in smokers. Lung function and NSBR were not clearly related to occupational exposures. Findings were similar for asthmatic and nonasthmatic subjects. In conclusion, occupational exposures contributed to the occurrence of chronic (industrial) bronchitis in young adults. Fixed airflow limitation was not evident, probably due to the relatively young age of this population.

Adult↗
PubMed2001

Temporal, personal and spatial variability in dermal exposure.

A database of dermal exposure measurements (DERMDAT) comprising data from 20 surveys was created. The majority of dermal exposure measurements were from agricultural settings in which workers' exposure to pesticides was investigated. Other data came from studies of workers exposed to polycyclic aromatic hydrocarbons (e.g. coke-oven workers and paving workers) and from studies of subjects exposed to complex mixtures (rubber industry). The database contains approximately 6400 observations. Grouping the workers by job title, factory and body location and excluding groups with more than 25% data below the limit of detection, or with less than two workers with at least two repeats, resulted in 283 groups with 1065 workers and 2716 measurements. Analyses of variability showed median values of the total, within- and between-worker geometric standard deviations of respectively 2.55, 1.98 and 1.47, strikingly similar to what has been published previously for respiratory exposure. Within-worker variability ((w)S(2)y) was in general higher than between-worker variability ((b)S(2)y) in dermal exposure levels. Agricultural groups of re-entry workers showed very little to no between-worker variability, while industrial groups did show some variability in individual mean exposures (range (b)S(2)y=0.15-0.29). When the between-body-location component (bl)S(2)y) was also addressed, it turned out to be the most prominent component (median (b)S(2)y=0.004; median (w)S(2)y=0.12; median (bl)S(2)y=0.34). In agriculture the between-body-location component was smaller than in industry. Day-to-day variability in dermal exposure levels appeared to be significant for specific locations, but not for the average of several body-location. Underlying exposure scenarios (transfer and deposition) also played an important role.

Americas↗
PubMed2001

Simultaneous assessment of occupational exposures from multiple worker groups.

The methods developed by Rappaport et al. [Ann. Occup. Hyg. 39 (1995) 469] and Lyles et al. [J. Agri. Bio. Environ. Stat. 2 (1997a) 64; Ann. Occup. Hyg. 41 (1997b) 63]) for assessing workplace exposures on a group-by-group basis are extended to allow for the simultaneous assessment of data from multiple worker groups within the same industry. These extended methods allow models to be fit simultaneously to data on all groups in a study, even when some of the groups might not contribute adequate information to be modeled separately. We assume that the exposures are log-normally distributed, and that they can be adequately modeled by a mixed effects regression model with parameters for exposure levels and for between- and within-worker variance components. Simultaneously analyzing data from multiple groups is only advantageous when at least one of these variance components can be assumed to be homogeneous across the groups. Here, we advocate testing an assumption of homogeneous within-worker variance components, sigma(2)(w,h), using a likelihood ratio test to choose between a full model (distinct sigma(2)(w,h) for each group) and a reduced model (common sigma(2)(w) across groups). We then develop a procedure, which is conditional on the results of the likelihood ratio test, for testing whether or not each group of workers is overexposed to the contaminant of interest. This modeling and testing procedure was applied to 39 different data sets, each containing data for multiple groups, from a wide variety of industries. For these data, the testing procedure generally resulted in the same conclusion regarding overexposure under both models, even in those data sets where the within-worker variance components appeared to be quite heterogeneous. We also conducted a small simulation study to estimate the significance level of the proposed testing procedure, and found that the significance levels tended to be adequately close to the specified nominal level when a likelihood ratio test with significance level of at least 0.01 was used as a preliminary test. Additionally, we make specific recommendations for designing studies and suggest a method for determining whether engineering and administrative controls or individual-level interventions would be of most benefit to an overexposed group of workers.

Humans↗
PubMed2000

Mutagenic profile of rubber dust and fume exposure in two rubber tire companies.

The aim of this study was to evaluate current mutagenic activity of ambient rubber dust and fume exposure in the mixing and curing departments of two rubber tire companies situated in The Netherlands and Sweden. Salmonella typhimurium strains YG1021, YG1024 and YG1041 were used to study the possible presence of mutagenic nitroarenes and aromatic amines. A large difference in mutagenic activity was found between the two companies. While the rubber tire company situated in The Netherlands revealed overall high mutagenic activity of rubber dust and fumes in the mixing and curing departments, respectively, 430 and 279 rev/m(3) (YG1041), the Swedish company showed almost no mutagenic activity, respectively, 18 and 54 rev/m(3) (YG1041). Further identification of the mutagenic profile showed that mutagenic activity was exclusively observed in S. typhimurium strains with elevated levels of O-acetyltransferase activity (YG1041 and YG1024) in the presence of a metabolic active liver S9 fraction, possibly indicating the presence of indirect mutagenic aromatic amines. These results show that although production processes and lay-out within rubber tire companies are comparable, differences in rubber chemicals used and overall level of control measures (e.g., good housekeeping, cleanliness) are likely to result in substantial differences in mutagenic exposure levels between companies.

Acetyltransferases↗
PubMed2000

Case-cohort analysis of brain cancer and leukemia in electric utility workers using a refined magnetic field job-exposure matrix.

BACKGROUND: The potential association between occupational electric and magnetic field exposure and cancer is well documented in the literature, but there is uncertainty regarding a causal relation. METHODS: Using data from a completed cohort study, we sought to refine the job-exposure matrix in a case-cohort analysis by regrouping jobs into more homogeneous groups, but without making additional measurements. From the original cohort, we selected the 164 men who died of leukemia, 145 men who died of brain cancer, and a random subcohort of 800 men (0.6% of the cohort). Erroneous job assignments were corrected and job groups were subdivided based on differences in work environments or tasks performed. RESULTS: Magnetic field exposure remained unrelated to leukemia mortality and positively associated with brain cancer mortality based on both cumulative and average magnetic field indices. Although not monotonic across the middle intervals, increased risk of brain cancer was found in relation to career exposure, with risk ratios of 1.8 (95% CI = 0.7-4.7) and 2.5 (95% CI = 1.0-6.3) in the uppermost categories for cumulative and average exposure, stronger for exposure 2-10 years past. CONCLUSIONS: Improvements in exposure assignment based only on reassignment of job titles to occupational categories had little impact on the measured associations of magnetic fields with leukemia or brain cancer.

Brain Neoplasms↗
PubMed2000

Postulating a dermal pathway for exposure to anti-neoplastic drugs among hospital workers. Applying a conceptual model to the results of three workplace surveys.

Dermal exposure to anti-neoplastic drugs has been suggested as a potentially important route of exposure of hospital workers. Three small-scale workplace surveys were carried out in several hospitals focusing on contamination by leakage from IV infusion systems; contamination by spilled urine of patients treated with anti-neoplastic drugs and particulate phase anti-neoplastic drugs in the air of outpatient and nursing clinics. A new visual scoring technique using a fluorescent tracer was developed. The method showed a very low limit of detection (0.02 microl of contamination) and a very high inter-observer agreement (ICC=0.99). Evaluation of IV systems and connectors showed distinct differences between the systems. It was estimated that 0.5-250 microg of a drug can become available for contamination during each infusion. Differences in average contamination between nurses were negligible in the experimental set-up. Widespread and frequent contamination due to spillage of contaminated urine was revealed and appeared not to be restricted to the patient's room. Airborne particulate concentrations went undetected for 80% of the measurements. However, in a few cases concentrations up to 2 ng/m(3) of cyclophosphamide were measured predominantly in a room of a patient treated with this anti-neoplastic drug. Based on these results and a recently proposed conceptual model for dermal exposure a most likely exposure scenario was postulated both for nurses involved in administering drugs and nurses caring for treated patients. Estimation of all relevant mass transport rates will be a challenge for the near future.

Air Pollutants, Occupational↗
PubMed2000

Ascertainment of hand dermatitis using a symptom-based questionnaire; applicability in an industrial population.

In this study, the applicability of a symptom-based questionnaire on hand dermatitis was assessed in a population of rubber workers. The questionnaire was previously validated in a study among nurses. 224 subjects employed in 9 different companies completed a questionnaire on skin complaints. Subsequently, 202 workers attended the physical examination of the skin by a dermatologist. The ascertainment of skin complaints according to the questionnaire was compared to the medical evaluation. The 2 different diagnostic tools used for assessing dermatitis resulted in dissimilar estimates of the prevalence of active hand dermatitis, ranging from 6.9% to 38.1% of all workers. Using the medical evaluation as 'gold standard' we observed a moderate sensitivity and specificity (respectively 71.4%; 95% CI: 47.7-95.1 and 76.1%; 95% CI: 70.0-82.2), a low positive predictive value (18.2%; 95% CI: 8.0-28.4) and a high negative predictive value (97.3%; 95% CI: 94.7-99.9) for the classification based on the self-administered questionnaire. When evaluated against 'first symptoms of dermatitis' the sensitivity decreased, while the specificity remained almost the same. The deviant findings between the present and the original validation study of the same questionnaire among nurses hamper its applicability in populations with different occupations. Therefore, if questionnaires are to be used, validity studies have to be carried out to evaluate differences in perception of skin diseases between different (occupational) populations.

Adult↗
PubMed2000

Are the members of a paving crew uniformly exposed to bitumen fume, organic vapor, and benzo(a)pyrene?

The goal of this investigation was to assess if and when a crew of paving workers is uniformly exposed to bitumen fume, organic vapor, and benzo(a)pyrene. Data on paving workers with up to six repeated exposure measurements were extracted from a database of exposure measurements developed within a study of the European asphalt industry (N = 591). The uniformity of exposures to bitumen fume, organic vapor, and benzo(a)pyrene was evaluated while grouping individuals by job title, primary tasks, crew membership, and use of coal tar (discontinued in Western Europe). The estimated ranges within which 95% of individual mean exposures were expected to fall ((BW)R0.95) were used to assess exposure uniformity. Variance components were estimated by constructing mixed-effects models, with grouping variables as fixed effects and worker identity as random effect. The influence of duration of the sampling survey on estimates of exposure variability for a crew was also examined. There was a substantial variability in exposures between paving crews, as well as persons holding the same job or doing the same task, but each crew was uniformly exposed to bitumen fume and benzo(a)pyrene ((BW)R0.95 2 and 1, respectively). Workers within the same crew engaged in paving with coal tar-containing binders were not, however, uniformly exposed to benzo(a)pyrene. Also, organic vapor exposures were not uniform among the members of a paving crew ((BW)R0.95 = 15). Sampling campaigns of up to 7 months had little impact on the estimates of within- and between-worker variability. These findings should assist investigators studying paving operations in optimizing their sampling, exposure assessment, and risk evaluation protocols. The results support the notion that only empirically determined predictors of exposure can yield optimal grouping, unlike a priori grouping strategies based on general descriptors such as jobs title or tasks performed.

Air Pollutants, Occupational↗
PubMed2000

Occupational exposure to carcinogens in the European Union.

OBJECTIVES: To construct a computer assisted information system for the estimation of the numbers of workers exposed to established and suspected human carcinogens in the member states of the European Union (EU). METHODS: A database called CAREX (carcinogen exposure) was designed to provide selected exposure data and documented estimates of the number of workers exposed to carcinogens by country, carcinogen, and industry. CAREX includes data on agents evaluated by the International Agency for Research on Cancer (IARC) (all agents in groups 1 and 2A as of February 1995, and selected agents in group 2B) and on ionising radiation, displayed across the 55 industrial classes. The 1990-3 occupational exposure was estimated in two phases. Firstly, estimates were generated by the CAREX system on the basis of national labour force data and exposure prevalence estimates from two reference countries (Finland and the United States) which had the most comprehensive data available on exposures to these agents. For selected countries, these estimates were then refined by national experts in view of the perceived exposure patterns in their own countries compared with those of the reference countries. RESULTS: About 32 million workers (23% of those employed) in the EU were exposed to agents covered by CAREX. At least 22 million workers were exposed to IARC group 1 carcinogens. The exposed workers had altogether 42 million exposures (1.3 mean exposures for each exposed worker). The most common exposures were solar radiation (9.1 million workers exposed at least 75% of working time), environmental tobacco smoke (7.5 million workers exposed at least 75% of working time), crystalline silica (3.2 million exposed), diesel exhaust (3.0 million), radon (2.7 million), and wood dust (2.6 million). CONCLUSION: These preliminary estimates indicate that in the early 1990s, a substantial proportion of workers in the EU were exposed to carcinogens.

Carcinogens↗
PubMed2000

Performance of population specific job exposure matrices (JEMs): European collaborative analyses on occupational risk factors for chronic obstructive pulmonary disease with job exposure matrices (ECOJEM).

OBJECTIVES: To compare the performance of population specific job exposure matrices (JEMs) and self reported occupational exposure with data on exposure and lung function from three European general populations. METHODS: Self reported occupational exposure (yes or no) and present occupation were recorded in the three general population surveys conducted in France, The Netherlands, and Norway. Analysis was performed on subjects, aged 25-64, who provided good forced expiratory volume in 1 second (FEV1) tracings and whose occupations were performed by at least two people, in the French (6217 men and 5571 women), the Dutch (men from urban (854) and rural (780) areas), and the Norwegian (395 men) surveys. Two population specific JEMs, based on the percentage of subjects who reported themselves exposed in each job, were constructed for each survey and each sex. The first matrix classified jobs into three categories of exposure according to the proportion of subjects who reported themselves exposed in each job (P10-50 JEM, low < 10%, moderate 10-49%, high > or = 50%). For the second matrix, a dichotomous variable was constructed to have the same statistical power as the self reported exposure--that is, the exposure prevalence (p) was the same with both exposure assessment methods (Pp JEM). Relations between occupational exposure, as estimated by the two JEMs and self reported exposure, and age, height, city, and smoking adjusted FEV1 score were compared. RESULTS: Significant associations between occupational exposure estimated by the population specific JEM and lung function were found in the French and the rural Dutch surveys, whereas no significant relation was found with self reported exposure. In populations with few subjects in most jobs, exposure cannot be estimated with sufficient precision by a population specific JEM, which may explain the lack of relation in the Norwegian and the Dutch (urban area) surveys. CONCLUSION: The population specific JEM, which was easy to construct and cost little, seemed to perform better than crude self reported exposures, in populations with sufficient numbers of subjects per job.

Adult↗
PubMed2000

Self reported symptoms and inhibition of acetylcholinesterase activity among Kenyan agricultural workers.

OBJECTIVES: This study was part of the East African pesticides project. The general objective was to assess health hazards posed by handling, storage, and use of pesticides, on agricultural estates and small farms with a view to developing strategies for prevention and control of pesticide poisoning. The aim of this paper is to describe the prevalence of symptoms in this population, to relate levels of inhibition to reported symptoms and evaluate at which levels of inhibition symptoms become increased. METHODS: Complete data were available for 256 exposed subjects and 152 controls from four regions in Kenya. A structured questionnaire on symptoms experienced at the time of interview was given to all subjects and controls. Information was also obtained on sex, age, main occupation, and level of education. Symptoms reported during the high exposure period, were initially clustered in broader symptom categories from reference literature on health effects of pesticides that inhibit cholinesterase (organophosphate and carbamate). Prevalence ratios were estimated for symptoms with changes in cholinesterase activity in serum. RESULTS: Symptom prevalence in exposed subjects was higher during the high exposure period than the low exposure period, although these differences were not significant. Interestingly, a clear and significant change in symptoms prevalence was found in the controls with a higher prevalence in the low exposure period. Analysis of the relation between cholinesterase inhibition and symptoms showed that prevalence ratios were significantly > 1 for respiratory, eye, and central nervous system symptoms for workers with > 30% inhibition. Similar results were found for analyses with the actual level of acetylcholinesterase activity. CONCLUSION: The results suggest the presence of a relation between exposure and acetylcholinesterase inhibition, acetylcholinesterase activity, and respiratory, eye, and central nervous system symptoms. Increased symptom prevalence was found at acetylcholinesterase activities generally considered to be non-adverse.

Acetylcholinesterase↗
PubMed2000

Statistical modelling of the determinants of historical exposure to bitumen and polycyclic aromatic hydrocarbons among paving workers.

INTRODUCTION: An industrial hygiene database has been constructed for the exposure assessment in a study of cancer risk among asphalt workers. AIM: To create models of bitumen and polycyclic aromatic hydrocarbons (PAH) exposure intensity among paving workers. METHODS: Individual exposure measurements from pavers (N = 1581) were collected from 8 countries. Correlation patterns between exposure measures were examined and factors affecting exposure were identified using statistical modelling. RESULTS: Inhalable dust appeared to be a good proxy of bitumen fume exposure. Bitumen fume and vapour levels were not correlated. Benzo(a)pyrene level appeared to be a good indicator of PAH exposure. All exposures steadily declined over the last 20 years. Mastic laying, re-paving, surface dressing, oil gravel paving and asphalt temperature were significant determinants of bitumen exposure. Coal tar use dictated PAH exposure levels. DISCUSSION: Bitumen fume, vapour and PAH have different determinants of exposure. For paving workers, exposure intensity can be assessed on the basis of time period and production characteristics.

Databases, Factual↗