Hans Kromhout

Publications of Hans Kromhout

• Impact of occupational carcinogens on lung cancer risk in a general population.

  Authors: Sara De Matteis, Dario Consonni, Jay H Lubin, Margaret Tucker, Susan Peters, Roel Ch Vermeulen, Hans Kromhout, Pier Alberto Bertazzi, Neil E Caporaso, Angela C Pesatori, Sholom Wacholder, Maria Teresa Landi

  International journal of epidemiology. 03/2012;

  BACKGROUND: Exposure to occupational carcinogens is an important preventable cause of lung cancer. Most of the previous studies were in highly exposed industrial cohorts. Our aim was to quantify lungBACKGROUND: Exposure to occupational carcinogens is an important preventable cause of lung cancer. Most of the previous studies were in highly exposed industrial cohorts. Our aim was to quantify lung cancer burden attributable to occupational carcinogens in a general population. METHODS: We applied a new job-exposure matrix (JEM) to translate lifetime work histories, collected by personal interview and coded into standard job titles, into never, low and high exposure levels for six known/suspected occupational lung carcinogens in the Environment and Genetics in Lung cancer Etiology (EAGLE) population-based case-control study, conducted in Lombardy region, Italy, in 2002-05. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated in men (1537 cases and 1617 controls), by logistic regression adjusted for potential confounders, including smoking and co-exposure to JEM carcinogens. The population attributable fraction (PAF) was estimated as impact measure. RESULTS: Men showed an increased lung cancer risk even at low exposure to asbestos (OR: 1.76; 95% CI: 1.42-2.18), crystalline silica (OR: 1.31; 95% CI: 1.00-1.71) and nickel-chromium (OR: 1.18; 95% CI: 0.90-1.53); risk increased with exposure level. For polycyclic aromatic hydrocarbons, an increased risk (OR: 1.64; 95% CI: 0.99-2.70) was found only for high exposures. The PAFs for any exposure to asbestos, silica and nickel-chromium were 18.1, 5.7 and 7.0%, respectively, equivalent to an overall PAF of 22.5% (95% CI: 14.1-30.0). This corresponds to about 1016 (95% CI: 637-1355) male lung cancer cases/year in Lombardy. CONCLUSIONS: These findings support the substantial role of selected occupational carcinogens on lung cancer burden, even at low exposures, in a general population.

• Transient receptor potential genes, smoking, occupational exposures and cough in adults.

  Authors: Lidwien Am Smit, Manolis Kogevinas, Josep M Anto, Emmanuelle Bouzigon, Juan Ramon Gonzalez, Nicole Le Moual, Hans Kromhout, Anne-Elie Carsin, Isabelle Pin, Deborah Jarvis, Roel Vermeulen, Christer Janson, Joachim Heinrich, Ivo Gut, Mark Lathrop, Miguel A Valverde, Florence Demenais, Francine Kauffmann

  Respiratory research. 03/2012; 13(1):26.

  ABSTRACT: BACKGROUND: Transient receptor potential (TRP) vanilloid and ankyrin cation channels are activated by various noxious chemicals and may play an important role in the pathogenesis of cough.ABSTRACT: BACKGROUND: Transient receptor potential (TRP) vanilloid and ankyrin cation channels are activated by various noxious chemicals and may play an important role in the pathogenesis of cough. The aim was to study the influence of single nucleotide polymorphisms (SNPs) in TRP genes and irritant exposures on cough. METHODS: Nocturnal, usual, and chronic cough, smoking, and job history were obtained by questionnaire in 844 asthmatic and 2046 non-asthmatic adults from the Epidemiological study on the Genetics and Environment of Asthma (EGEA) and the European Community Respiratory Health Survey (ECRHS). Occupational exposures to vapors, gases, dusts, and/or fumes were assessed by a job-exposure matrix. Fifty-eight tagging SNPs in TRPV1, TRPV4, and TRPA1 were tested under an additive model. RESULTS: Statistically significant associations of 6 TRPV1 SNPs with cough symptoms were found in non-asthmatics after correction for multiple comparisons. Results were consistent across the eight countries examined. Haplotype-based association analysis confirmed the single SNP analyses for nocturnal cough (7-SNP haplotype: p-global = 4.8 x 10-6) and usual cough (9-SNP haplotype: p-global = 4.5 x 10-6). Cough symptoms were associated with exposure to irritants such as cigarette smoke and occupational exposures (p < 0.05). Four polymorphisms in TRPV1 further increased the risk of cough symptoms from irritant exposures in asthmatics and non-asthmatics (interaction p < 0.05). CONCLUSIONS: TRPV1 SNPs were associated with cough among subjects without asthma from two independent studies in eight European countries. TRPV1 SNPs may enhance susceptibility to cough in current smokers and in subjects with a history of workplace exposures.

• Respiratory, allergy and eye problems in bagasse-exposed sugar cane workers in Costa Rica.

  Authors: Mireia Gascon, Hans Kromhout, Dick Heederik, Wijnand Eduard, Berna van Wendel de Joode

  Occupational and environmental medicine. 01/2012;

  AimsTo evaluate bagasse (sugar cane fibres) and microbiological exposure among sugar cane refinery workers in Costa Rica and its relationships with respiratory, allergy and eyeAimsTo evaluate bagasse (sugar cane fibres) and microbiological exposure among sugar cane refinery workers in Costa Rica and its relationships with respiratory, allergy and eye problems.MethodsVentilatory lung function and total serum IgE were measured in 104 sugar cane workers in five departments at one refinery before the harvesting season, and repeated for 77 of the workers at the end of the season. Information on the prevalence of respiratory and other symptoms was collected with a standardised questionnaire. During the harvesting season, inhalable dust, endotoxin and mould levels were measured among 74 randomly selected sugar cane workers across departments.ResultsDuring the harvesting season, dust levels were relatively high in some departments, while endotoxin and mould levels were around background levels. Workers' ventilatory lung function differed between departments before, but not during the harvesting season or between seasons. During the harvesting season, the prevalence of wheeze and eye problems almost doubled in workers exposed to bagasse and other types of dust, whereas shortness of breath and rhinitis increased only in bagasse-exposed workers. Reporting wheeze and shortness of breath was positively associated with the number of years working at the refinery, suggesting a long-term health effect.ConclusionIn this refinery, the differences in workers' ventilatory lung function before the harvesting season are unlikely to be explained by bagasse exposure. However, the increase in reported symptoms (wheeze, shortness of breath, eye problems and rhinitis) over the season is likely due to irritation by dust, in particular bagasse, rather than microbiological agents.

• Neurobehavioral and neurodevelopmental effects of pesticide exposures.

  Authors: Leslie London, Cheryl Beseler, Maryse F Bouchard, David C Bellinger, Claudio Colosio, Philippe Grandjean, Raul Harari, Tahira Kootbodien, Hans Kromhout, Francesca Little, Tim Meijster, Angelo Moretto, Diane S Rohlman, Lorann Stallones

  Neurotoxicology. 01/2012;

  The association between pesticide exposure and neurobehavioral and neurodevelopmental effects is an area of increasing concern. This symposium brought together participants to explore the neurotoxicThe association between pesticide exposure and neurobehavioral and neurodevelopmental effects is an area of increasing concern. This symposium brought together participants to explore the neurotoxic effects of pesticides across the lifespan. Endpoints examined included neurobehavioral, affective and neurodevelopmental outcomes among occupational (both adolescent and adult workers) and non-occupational populations (children). The symposium discussion highlighted many challenges for researchers concerned with the prevention of neurotoxic illness due to pesticides and generated a number of directions for further research and policy interventions for the protection of human health, highlighting the importance of examining potential long-term effects across the lifespan arising from early adolescent, childhood or prenatal exposure.

• Comment on: Effects of static magnetic fields on cognition, vital signs, and sensory perception: a meta-analysis.

  Authors: Frank de Vocht, Tobias Stevens, Hans Kromhout

  Journal of magnetic resonance imaging : JMRI. 01/2012; 35(1):235-6; author reply 237.

• Development of an exposure measurement database on five lung carcinogens (ExpoSYN) for quantitative retrospective occupational exposure assessment.

  Authors: Susan Peters, Roel Vermeulen, Ann Olsson, Rainer Van Gelder, Benjamin Kendzia, Raymond Vincent, Barbara Savary, Nick Williams, Torill Woldbæk, Jérôme Lavoué, Domenico Cavallo, Andrea Cattaneo, Dario Mirabelli, Nils Plato, Dirk Dahmann, Joelle Fevotte, Beate Pesch, Thomas Brüning, Kurt Straif, Hans Kromhout

  The Annals of occupational hygiene. 01/2012; 56(1):70-9.

  SYNERGY is a large pooled analysis of case-control studies on the joint effects of occupational carcinogens and smoking in the development of lung cancer. A quantitative job-exposure matrix (JEM)SYNERGY is a large pooled analysis of case-control studies on the joint effects of occupational carcinogens and smoking in the development of lung cancer. A quantitative job-exposure matrix (JEM) will be developed to assign exposures to five major lung carcinogens [asbestos, chromium, nickel, polycyclic aromatic hydrocarbons (PAH), and respirable crystalline silica (RCS)]. We assembled an exposure database, called ExpoSYN, to enable such a quantitative exposure assessment. Existing exposure databases were identified and European and Canadian research institutes were approached to identify pertinent exposure measurement data. Results of individual air measurements were entered anonymized according to a standardized protocol. The ExpoSYN database currently includes 356 551 measurements from 19 countries. In total, 140 666 personal and 215 885 stationary data points were available. Measurements were distributed over the five agents as follows: RCS (42%), asbestos (20%), chromium (16%), nickel (15%), and PAH (7%). The measurement data cover the time period from 1951 to present. However, only a small portion of measurements (1.4%) were performed prior to 1975. The major contributing countries for personal measurements were Germany (32%), UK (22%), France (14%), and Norway and Canada (both 11%). ExpoSYN is a unique occupational exposure database with measurements from 18 European countries and Canada covering a time period of >50 years. This database will be used to develop a country-, job-, and time period-specific quantitative JEM. This JEM will enable data-driven quantitative exposure assessment in a multinational pooled analysis of community-based lung cancer case-control studies.

• Exposure to inhalable dust and endotoxin among Danish livestock farmers: results from the SUS cohort study.

  Authors: Ioannis Basinas, Torben Sigsgaard, Dick Heederik, Hisamitsu Takai, Øyvind Omland, Nils T Andersen, Inge M Wouters, Jakob H Bønløkke, Hans Kromhout, Vivi Schlünssen

  Journal of environmental monitoring : JEM. 12/2011; 14(2):604-14.

  Studies on personal dust and endotoxin concentrations among animal farmers have been either small or limited to a few sectors in their investigations. The present study aimed to provide comparableStudies on personal dust and endotoxin concentrations among animal farmers have been either small or limited to a few sectors in their investigations. The present study aimed to provide comparable information on the levels and variability of exposure to personal dust and endotoxin in different types of animal farmers. 507 personal inhalable dust samples were collected from 327 farmers employed in 54 pig, 26 dairy, 3 poultry, and 3 mink farms in Denmark. Measurements in pig and dairy farmers were full-shift and performed during summer and winter, while poultry and mink farmers were monitored during 4 well-defined production stages. The collected samples were measured for dust gravimetrically and analyzed for endotoxin by the Limulus amebocyte lysate assay. Simple statistics and random-effect analysis were used to describe the levels and the variability in measured dust and endotoxin exposure concentrations. Measured inhalable dust levels had an overall geometric mean of 2.5 mg m(-3) (range <LOD to 47.8) and endotoxin of 988 EU m(-3) (range <LOD to 374,000). The highest dust and endotoxin concentrations were measured among pig and poultry farmers, and were the lowest among dairy and mink farmers, respectively. Exposure among pig and cattle farmers was characterised by a substantial day-to-day variability that increased from the indoor to outdoor working environment. Only mink farmers complied with the Danish occupational exposure limit for total dust (3 mg m(-3)). More than 93% of our measurements exceeded the recently proposed Dutch exposure-limit for endotoxin (90 EU m(-3)). These findings suggest animal farmers to be exposed to high levels of dust and endotoxin consistent with an increased risk of developing respiratory symptoms and diseases. The development of preventive strategies to reduce exposure will require in-depth identification of factors that affect day-to-day variability in exposure.

• Occupational benzene exposure and lymphoma risks: vlaanderen et Al. Respond.

  Authors: Jelle Vlaanderen, Qing Lan, Nat Rothman, Hans Kromhout, Roel Vermeulen

  Environmental health perspectives. 11/2011; 119(11):a468-9.

• Modelling of occupational respirable crystalline silica exposure for quantitative exposure assessment in community-based case-control studies.

  Authors: Susan Peters, Roel Vermeulen, Lützen Portengen, Ann Olsson, Benjamin Kendzia, Raymond Vincent, Barbara Savary, Jérôme Lavoué, Domenico Cavallo, Andrea Cattaneo, Dario Mirabelli, Nils Plato, Joelle Fevotte, Beate Pesch, Thomas Brüning, Kurt Straif, Hans Kromhout

  Journal of environmental monitoring : JEM. 11/2011; 13(11):3262-8.

  We describe an empirical model for exposure to respirable crystalline silica (RCS) to create a quantitative job-exposure matrix (JEM) for community-based studies. Personal measurements of exposure toWe describe an empirical model for exposure to respirable crystalline silica (RCS) to create a quantitative job-exposure matrix (JEM) for community-based studies. Personal measurements of exposure to RCS from Europe and Canada were obtained for exposure modelling. A mixed-effects model was elaborated, with region/country and job titles as random effect terms. The fixed effect terms included year of measurement, measurement strategy (representative or worst-case), sampling duration (minutes) and a priori exposure intensity rating for each job from an independently developed JEM (none, low, high). 23,640 personal RCS exposure measurements, covering a time period from 1976 to 2009, were available for modelling. The model indicated an overall downward time trend in RCS exposure levels of -6% per year. Exposure levels were higher in the UK and Canada, and lower in Northern Europe and Germany. Worst-case sampling was associated with higher reported exposure levels and an increase in sampling duration was associated with lower reported exposure levels. Highest predicted RCS exposure levels in the reference year (1998) were for chimney bricklayers (geometric mean 0.11 mg m(-3)), monument carvers and other stone cutters and carvers (0.10 mg m(-3)). The resulting model enables us to predict time-, job-, and region/country-specific exposure levels of RCS. These predictions will be used in the SYNERGY study, an ongoing pooled multinational community-based case-control study on lung cancer.

• Occupational activities associated with a reported history of malaria among women working in small-scale agriculture in South Africa.

  Authors: Saloshni Naidoo, Leslie London, Alex Burdorf, Rajen N Naidoo, Hans Kromhout

  The American journal of tropical medicine and hygiene. 11/2011; 85(5):805-10.

  Malaria-endemic agricultural communities are at risk for this disease because of crop and agricultural activities. A cross-sectional survey among women in small-scale agriculture on irrigated andMalaria-endemic agricultural communities are at risk for this disease because of crop and agricultural activities. A cross-sectional survey among women in small-scale agriculture on irrigated and dryland areas in Makhatini Flats, KwaZulu-Natal South Africa explored associations with self-reported history of malaria, including demographics, crop production, and specific agricultural activities. Ninety-eight (15.2%) of 644 women reported malaria while working in agriculture. More women working in drylands than women working in irrigation scheme reported disease (18.4% versus 10.9%; P < 0.05). Working self or family-owned farms (prevalence ratio [PR] = 2.6, 95% confidence interval [CI] = 1.3-5.2), spraying pesticides (PR = 2.3; 95% CI = 1.4-3.8), cultivating sugar cane (PR = 1.6, 95% CI = 1.1-2.3), and cultivating cotton and mangoes (PR = 1.7, 95% CI = 1.1-2.6) were positively associated with a history of malaria while working in agriculture. This study suggests that certain agricultural activities and types of crop production may increase the risk for malaria among women working in small-scale agriculture.

• Advanced Reach Tool (ART): development of the mechanistic model.

  Authors: Wouter Fransman, Martie Van Tongeren, John W Cherrie, Martin Tischer, Thomas Schneider, Jody Schinkel, Hans Kromhout, Nick Warren, Henk Goede, Erik Tielemans

  The Annals of occupational hygiene. 11/2011; 55(9):957-79.

  This paper describes the development of the mechanistic model within a collaborative project, referred to as the Advanced REACH Tool (ART) project, to develop a tool to model inhalation exposure forThis paper describes the development of the mechanistic model within a collaborative project, referred to as the Advanced REACH Tool (ART) project, to develop a tool to model inhalation exposure for workers sharing similar operational conditions across different industries and locations in Europe. The ART mechanistic model is based on a conceptual framework that adopts a source receptor approach, which describes the transport of a contaminant from the source to the receptor and defines seven independent principal modifying factors: substance emission potential, activity emission potential, localized controls, segregation, personal enclosure, surface contamination, and dispersion. ART currently differentiates between three different exposure types: vapours, mists, and dust (fumes, fibres, and gases are presently excluded). Various sources were used to assign numerical values to the multipliers to each modifying factor. The evidence used to underpin this assessment procedure was based on chemical and physical laws. In addition, empirical data obtained from literature were used. Where this was not possible, expert elicitation was applied for the assessment procedure. Multipliers for all modifying factors were peer reviewed by leading experts from industry, research institutes, and public authorities across the globe. In addition, several workshops with experts were organized to discuss the proposed exposure multipliers. The mechanistic model is a central part of the ART tool and with advancing knowledge on exposure, determinants will require updates and refinements on a continuous basis, such as the effect of worker behaviour on personal exposure, 'best practice' values that describe the maximum achievable effectiveness of control measures, the intrinsic emission potential of various solid objects (e.g. metal, glass, plastics, etc.), and extending the applicability domain to certain types of exposures (e.g. gas, fume, and fibre exposure).

• Advanced REACH Tool (ART): overview of version 1.0 and research needs.

  Authors: Erik Tielemans, Nick Warren, Wouter Fransman, Martie Van Tongeren, Kevin McNally, Martin Tischer, Peter Ritchie, Hans Kromhout, Jody Schinkel, Thomas Schneider, John W Cherrie

  The Annals of occupational hygiene. 11/2011; 55(9):949-56.

  This paper provides an outline of the Advanced REACH Tool (ART) version 1.0 and a discussion of how it could be further developed. ART is a higher tier exposure assessment tool that combinesThis paper provides an outline of the Advanced REACH Tool (ART) version 1.0 and a discussion of how it could be further developed. ART is a higher tier exposure assessment tool that combines mechanistically modelled inhalation exposure predictions with available exposure data using a Bayesian approach. ART assesses exposure for scenarios across different plants and sites. Estimates are provided for different percentiles of the exposure distribution and confidence intervals around the estimate. It also produces exposure estimates in the absence of data, but uncertainty of the estimates will decrease when results of exposure measurements are included. The tool has been calibrated using a broad range of exposure data and provides estimates for exposure to vapours, mists, and dusts. ART has a robust and stable conceptual basis but will be refined in the future and should therefore be considered an evolving system. High-priority areas for future research are identified in this paper and include the integration of partially analogous measurement series, inclusion of company and site-specific assessments, user decision strategies linked to ART predictions, evaluation of validity and reliability of ART, exploring the possibilities for incorporating the dermal route and integration of ART predictions with tools for modelling internal dose. ART is initially developed in the scope of REACH but is equally useful for exposure assessment in other areas.

• Classification of occupational activities for assessment of inhalation exposure.

  Authors: Hans Marquart, Thomas Schneider, Henk Goede, Martin Tischer, Jody Schinkel, Nick Warren, Wouter Fransman, Suzanne Spaan, Martie Van Tongeren, Hans Kromhout, Erik Tielemans, John W Cherrie

  The Annals of occupational hygiene. 09/2011; 55(9):989-1005.

  There is a large variety of activities in workplaces that can lead to emission of substances. Coding systems based on determinants of emission have so far not been developed. In this paper, a systemThere is a large variety of activities in workplaces that can lead to emission of substances. Coding systems based on determinants of emission have so far not been developed. In this paper, a system of Activity Classes and Activity Subclasses is proposed for categorizing activities involving chemical use. Activity Classes share their so-called 'emission generation mechanisms' and physical state of the product handled and the underlying determinants of emission. A number of (industrial) stakeholders actively participated in testing and fine-tuning the system. With the help of these stakeholders, it was found to be relatively easy to allocate a large number of activities to the Activity Classes and Activity Subclasses. The system facilitates a more structured classification of activities in exposure databases, a structured analysis of the analogy of exposure activities, and a transparent quantification of the activity emission potential in (new) exposure assessment models. The first use of the system is in the Advanced REACH Tool.

• Occupational exposure to organic dust increases lung cancer risk in the general population.

  Authors: Susan Peters, Hans Kromhout, Ann C Olsson, Heinz-Erich Wichmann, Irene Brüske, Dario Consonni, Maria Teresa Landi, Neil Caporaso, Jack Siemiatycki, Lorenzo Richiardi [......] Vladimir Janout, Isabelle Stücker, Rodica Stanescu Dumitru, Simone Benhamou, Bas Bueno-de-Mesquita, Benjamin Kendzia, Beate Pesch, Kurt Straif, Thomas Brüning, Roel Vermeulen

  Thorax. 08/2011; 67(2):111-6.

  Organic dust is a complex mixture of particulate matter from microbial, plant or animal origin. Occupations with exposure to animal products have been associated with an increased lung cancer risk,Organic dust is a complex mixture of particulate matter from microbial, plant or animal origin. Occupations with exposure to animal products have been associated with an increased lung cancer risk, while exposure to microbial components (eg, endotoxin) has been associated with a decreased risk. To date there has not been a comprehensive evaluation of the possible association between occupational organic dust exposure (and its specific constituents) and lung cancer risk in the general population. The SYNERGY project has pooled information on lifetime working and smoking from 13 300 lung cancer cases and 16 273 controls from 11 case-control studies conducted in Europe and Canada. A newly developed general population job-exposure matrix (assigning no, low or high exposure to organic dust, endotoxin, and contact with animals or fresh animal products) was applied to determine level of exposure. ORs for lung cancer were estimated by logistic regression, adjusted for age, sex, study, cigarette pack-years, time since quitting smoking, and ever employment in occupations with established lung cancer risk. Occupational organic dust exposure was associated with increased lung cancer risk. The second to the fourth quartile of cumulative exposure showed significant risk estimates ranging from 1.12 to 1.24 in a dose-dependent manner (p<0.001). This association remained in the highest quartile after restricting analyses to subjects without chronic obstructive pulmonary disease or asthma. No association was observed between lung cancer and exposure to endotoxin or contact with animals or animal products. Occupational exposure to organic dust was associated with increased lung cancer risk in this large pooled case-control study.

• Developing a general population job-exposure matrix in the absence of sufficient exposure monitoring data.

  Authors: Andrea M 't Mannetje, Dave J McLean, Amanda J Eng, Hans Kromhout, Timo Kauppinen, Joelle Fevotte, Neil E Pearce

  The Annals of occupational hygiene. 07/2011; 55(8):879-85.

  In New Zealand, there is a need for a comprehensive and accessible database with national occupational exposure information, such as a general population job-exposure matrix (GPJEM). However, few NewIn New Zealand, there is a need for a comprehensive and accessible database with national occupational exposure information, such as a general population job-exposure matrix (GPJEM). However, few New Zealand-specific exposure data exist that could be used to construct such a GPJEM. Here, we present the methods used to develop a GPJEM for New Zealand (NZJEM), by combining GPJEMs from other countries with New Zealand-specific exposure information, using wood dust as an example to illustrate this process. The assessments of GPJEMs from other countries were made available to a New Zealand expert in occupational wood dust exposure, who then provided a preliminary NZJEM assessment (including the percentage exposed and the level of exposure for each occupation). Where possible, this assessment was based on New Zealand exposure measurements. In the next step, information from a nationwide workplace exposure survey of 3000 members of the New Zealand workforce was used to finalize the NZJEM assessments. The final NZJEM listed 104 of the 956 New Zealand occupational codes as exposed to wood dust. The percentage of workers exposed within an occupation ranged from 5% (e.g. boiler attendants) to 100% (e.g. cabinet makers). The level of exposure ranged from 0.05 mg m(-3) (e.g. electricians) to 3 mg m(-3) (e.g. carpenters). Of these assessments, 23% were mainly based on New Zealand exposure data, 37% on overseas GPJEMs and exposure data, and for 40% the national survey data served as the main source of information for the expert assessment. Combining the NZJEM assessments with national employment statistics indicated that 5.6% of the New Zealand workforce is occupationally exposed to wood dust, corresponding to a total of 97 000 workers (86% male and 14% female). Construction-related occupations included the largest number of exposed workers.

• The impact of saturable metabolism on exposure-response relations in 2 studies of benzene-induced leukemia.

  Authors: Jelle Vlaanderen, Lützen Portengen, Stephen M Rappaport, Deborah C Glass, Hans Kromhout, Roel Vermeulen

  American journal of epidemiology. 07/2011; 174(5):621-9.

  Enzymatic saturation of metabolic pathways is one factor that potentially contributes to the nonlinear exposure-response relations that are frequently reported in occupational epidemiologic studies.Enzymatic saturation of metabolic pathways is one factor that potentially contributes to the nonlinear exposure-response relations that are frequently reported in occupational epidemiologic studies. The authors propose an approach to explore the contribution of saturable metabolism to previously reported exposure-response relations by integrating predictive models of relevant biomarkers of exposure into the epidemiologic analysis. The approach is demonstrated with 2 studies of leukemia in benzene-exposed workers, one conducted in the Australian petroleum industry (1981-1999) and one conducted in a US rubber hydrochloride production factory in Ohio (1940-1996). The studies differed greatly in their magnitudes and durations of exposure. Substitution of biomarker levels for external estimates of benzene exposure reduced the fold difference of the log relative risk of leukemia per unit of cumulative exposure between the 2 studies by 11%-44%. Nevertheless, a considerable difference in the log relative risk per unit of cumulative exposure remained between the 2 studies, suggesting that exposure misclassification, differences in study design, and potential confounding factors also contributed to the heterogeneity in risk estimates.

• Respirable dust and quartz exposure from three South African farms with sandy, sandy loam, and clay soils.

  Authors: Andrew J Swanepoel, Hans Kromhout, Zubair A Jinnah, Lützen Portengen, Kevin Renton, Kerry Gardiner, David Rees

  The Annals of occupational hygiene. 06/2011; 55(6):634-43.

  To quantify personal time-weighted average respirable dust and quartz exposure on a sandy, a sandy loam, and a clay soil farm in the Free State and North West provinces of South Africa and toTo quantify personal time-weighted average respirable dust and quartz exposure on a sandy, a sandy loam, and a clay soil farm in the Free State and North West provinces of South Africa and to ascertain whether soil type is a determinant of exposure to respirable quartz. Three farms, located in the Free State and North West provinces of South Africa, had their soil type confirmed as sandy, sandy loam, and clay; and, from these, a total of 298 respirable dust and respirable quartz measurements were collected between July 2006-November 2009 during periods of major farming operations. Values below the limit of detection (LOD) (22 μg · m(-3)) were estimated using multiple 'imputation'. Non-parametric tests were used to compare quartz exposure from the three different soil types. Exposure to respirable quartz occurred on all three farms with the highest individual concentration measured on the sandy soil farm (626 μg · m(-3)). Fifty-seven, 59, and 81% of the measurements on the sandy soil, sandy loam soil, and clay soil farm, respectively, exceeded the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) of 25 μg · m(-3). Twelve and 13% of respirable quartz concentrations exceeded 100 μg · m(-3) on the sandy soil and sandy loam soil farms, respectively, but none exceeded this level on the clay soil farm. The proportions of measurements >100 μg · m(-3) were not significantly different between the sandy and sandy loam soil farms ('prop.test'; P = 0.65), but both were significantly larger than for the clay soil farm ('prop.test'; P = 0.0001). The percentage of quartz in respirable dust was determined for all three farms using measurements > the limit of detection. Percentages ranged from 0.5 to 94.4% with no significant difference in the median quartz percentages across the three farms (Kruskal-Wallis test; P = 0.91). This study demonstrates that there is significant potential for over-exposure to respirable quartz in farming and even clay soil farming may pose a risk. Soil type may determine whether exposure is >100 μg · m(3), but the job type and the manner in which the task is performed (e.g. mechanical or manual) may be important determinants of exposure. Identifying quartz exposure determinants (e.g. type of job) and modifiers will be of value to focus implementation of controls of particular importance in developing countries.

• Validation of the inhalable dust algorithm of the Advanced REACH Tool using a dataset from the pharmaceutical industry.

  Authors: Patricia E Mc Donnell, Jody M Schinkel, Marie A Coggins, Wouter Fransman, Hans Kromhout, John W Cherrie, Erik L Tielemans

  Journal of environmental monitoring : JEM. 06/2011; 13(6):1597-606.

  As it is often difficult to obtain sufficient numbers of measurements to adequately characterise exposure levels, occupational exposure models may be useful tools in the exposure assessment process.As it is often difficult to obtain sufficient numbers of measurements to adequately characterise exposure levels, occupational exposure models may be useful tools in the exposure assessment process. This study aims to refine and validate the inhalable dust algorithm of the Advanced REACH Tool (ART) to predict airborne exposure of workers in the pharmaceutical industry. The ART was refined to reflect pharmaceutical situations. Largely task based workplace exposure data (n = 192) were collated from a multinational pharmaceutical company with exposure levels ranging from 5 × 10(-5) to 12 mg m(-3). Bias, relative bias and uncertainty around geometric mean exposure estimates were calculated for 16 exposure scenarios. For 12 of the 16 scenarios the ART geometric mean exposure estimates were lower than measured exposure levels with on average, a one-third underestimation of exposure (relative bias -32%). For 75% of the scenarios the exposure estimates were, within the 90% uncertainty factor of 4.4, as reported for the original calibration study, which may indicate more uncertainty in the ART estimates in this industry. While the uncertainty was higher than expected this is likely due to the limited number of measurements per scenario, which were largely derived from single premises.

• Assessment of dermal exposure to bitumen condensate among road paving and mastic crews with an observational method.

  Authors: Michela Agostini, Wouter Fransman, Frank De Vocht, Berna Van Wendel de Joode, Hans Kromhout

  The Annals of occupational hygiene. 05/2011; 55(6):578-90.

  To assess dermal exposure to bitumen condensate among road pavers and indoor mastic workers in multiple crews using a semi-quantitative observational method [DeRmal Exposure Assessment MethodTo assess dermal exposure to bitumen condensate among road pavers and indoor mastic workers in multiple crews using a semi-quantitative observational method [DeRmal Exposure Assessment Method (DREAM)]. Two skilled observers assessed dermal exposure to bitumen condensate among 85 asphalt workers from 12 crews from nine companies active within four European countries using the DREAM methodology, which produces an estimate of exposure expressed in dimensionless DREAM units. Both observers independently evaluated each crew member's job (N = 14 jobs) for road paving and mastic applications. Potential and actual dermal exposures were estimated for hands and for the rest of the body separately, taking into account the effect of protective clothing. To evaluate the reproducibility of the observational method intra-class correlation coefficients (ICCs) were estimated. The exposures in DREAM units were modelled using linear mixed models to estimate average relative scores for each job. Correlations between dermal exposure parameters were evaluated by estimating Pearson correlation coefficients. A total of 170 observations were completed by two observers independently (n = 118 and n = 52 for 59 road pavers and 26 mastic workers, respectively) in 11 days. The mean ICCs (for potential and actual exposure in DREAM units) varied between 0.74 and 0.80 with values for actual units being slightly higher. Geometric mean potential dermal exposure units of mastic workers were higher than for road pavers (factor 3 for hands and factor 4 for rest of the body). Differences for actual dermal exposure units were smaller for hands (factor 2) and larger for actual exposure units of rest of the body (factor 5). Differences in dermal exposure at the hands between jobs within a paving crew were much larger than between jobs within a mastic crew. Within paving crews, a consistent pattern for all exposure units emerged with 'screed man' and 'raker' as the two highest exposed jobs. Within mastic crews, 'driver dumper truck' and 'spreader of mastic' were scored as the two jobs with the highest exposure units. Potential and actual exposure units were highly correlated. Hands were more profoundly exposed than the rest of the body, with transfer from contaminated surface to the hands as the most important route. DREAM observations were reproducible and showed a consistent dermal exposure pattern among the observed crews. The study provided a clear picture of dermal exposure among road pavers and indoor mastic workers, with the mastic workers being considerably more highly exposed. The most important route of exposure appeared to be transferred from contaminated surfaces to the hands.

• AGRICOH: a consortium of agricultural cohorts.

  Authors: Maria E Leon, Laura E Beane Freeman, Jeroen Douwes, Jane A Hoppin, Hans Kromhout, Pierre Lebailly, Karl-Christian Nordby, Marc Schenker, Joachim Schüz, Stephen C Waring [......] John McLaughlin, James A Merchant, Punam Pahwa, Torben Sigsgaard, Leslie Stayner, Catharina Wesseling, Keun-Young Yoo, Shelia H Zahm, Kurt Straif, Aaron Blair

  International journal of environmental research and public health. 05/2011; 8(5):1341-57.

  AGRICOH is a recently formed consortium of agricultural cohort studies involving 22 cohorts from nine countries in five continents: South Africa (1), Canada (3), Costa Rica (2), USA (6), Republic ofAGRICOH is a recently formed consortium of agricultural cohort studies involving 22 cohorts from nine countries in five continents: South Africa (1), Canada (3), Costa Rica (2), USA (6), Republic of Korea (1), New Zealand (2), Denmark (1), France (3) and Norway (3). The aim of AGRICOH, initiated by the US National Cancer Institute (NCI) and coordinated by the International Agency for Research on Cancer (IARC), is to promote and sustain collaboration and pooling of data to investigate the association between a wide range of agricultural exposures and a wide range of health outcomes, with a particular focus on associations that cannot easily be addressed in individual studies because of rare exposures (e.g., use of infrequently applied chemicals) or relatively rare outcomes (e.g., certain types of cancer, neurologic and auto-immune diseases). To facilitate future projects the need for data harmonization of selected variables is required and is underway. Altogether, AGRICOH provides excellent opportunities for studying cancer, respiratory, neurologic, and auto-immune diseases as well as reproductive and allergic disorders, injuries and overall mortality in association with a wide array of exposures, prominent among these the application of pesticides.