Martie Van Tongeren - Academia.edu (original) (raw)

Papers by Martie Van Tongeren

Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 2014

Occupational exposure to extremely low-frequency magnetic fields (ELF) is a suspected risk factor... more Occupational exposure to extremely low-frequency magnetic fields (ELF) is a suspected risk factor for brain tumors, however the literature is inconsistent. Few studies have assessed whether ELF in different time windows of exposure may be associated with specific histologic types of brain tumors. This study examines the association between ELF and brain tumors in the large-scale INTEROCC study. Cases of adult primary glioma and meningioma were recruited in seven countries (Australia, Canada, France, Germany, Israel, New Zealand, and the United Kingdom) between 2000 and 2004. Estimates of mean workday ELF exposure based on a job exposure matrix were assigned. Estimates of cumulative exposure, average exposure, maximum exposure, and exposure duration were calculated for the lifetime, and 1 to 4, 5 to 9, and 10+ years before the diagnosis/reference date. There were 3,761 included brain tumor cases (1,939 glioma and 1,822 meningioma) and 5,404 population controls. There was no associati...

European Journal of Epidemiology, 2007

The very rapid worldwide increase in mobile phone use in the last decade has generated considerab... more The very rapid worldwide increase in mobile phone use in the last decade has generated considerable interest in the possible health effects of exposure to radio frequency (RF) fields. A multinational case-control study, INTERPHONE, was set-up to investigate whether mobile phone use increases the risk of cancer and, more specifi-Baruch Modan is deceased.

Occupational and environmental medicine, Jan 14, 2015

We examined the mortality of a historic cohort of workers in Great Britain with measured blood le... more We examined the mortality of a historic cohort of workers in Great Britain with measured blood lead levels (BLLs). SMRs were calculated with the population of Great Britain as the external comparator. Trends in mortality with mean and maximum BLLs and assessed lead exposure were examined using Cox regression. Mean follow-up length among the 9122 study participants was 29.2 years and 3466 deaths occurred. For all causes and all malignant neoplasms, the SMRs were statistically significantly raised. For disease groups of a priori interest, the SMR was significantly raised for lung cancer but not for stomach, brain, kidney, bladder or oesophageal cancers. The SMR was not increased for non-malignant kidney disease but was borderline significantly increased for circulatory diseases, for ischaemic heart disease (IHD) and cerebrovascular disease (CVD). No significant trends with exposure were observed for the cancers of interest, but for circulatory diseases and IHD, there was a statistical...

Occupational and environmental medicine, 2014

Exposure to electromagnetic fields (EMF) has become ubiquitous in modern life and concern has inc... more Exposure to electromagnetic fields (EMF) has become ubiquitous in modern life and concern has increased regarding possible associated health effects. To date, assessment of occupational exposure has relied on job-exposure matrices, with exposure estimates for very broad occupational categories. To move EMF research forward, a new approach was necessary. A source-based strategy, incorporating detailed information on tasks, equipment used and work organisation could allow a more individualised exposure assessment. Information on occupational histories and sources of EMF was collected as part of the INTERPHONE-INTEROCC study, providing an opportunity to assess occupational EMF exposure by assigning exposure to each source used. A source-exposure matrix (SEM) was developed based on measurements identified in the literature and estimates obtained through experts' elicitation, for sources without available measurements. This paper focuses on the SEM development methodology to ensure t...

Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 2014

Occupational exposure to extremely low-frequency magnetic fields (ELF) is a suspected risk factor... more Occupational exposure to extremely low-frequency magnetic fields (ELF) is a suspected risk factor for brain tumors, however the literature is inconsistent. Few studies have assessed whether ELF in different time windows of exposure may be associated with specific histologic types of brain tumors. This study examines the association between ELF and brain tumors in the large-scale INTEROCC study. Cases of adult primary glioma and meningioma were recruited in seven countries (Australia, Canada, France, Germany, Israel, New Zealand, and the United Kingdom) between 2000 and 2004. Estimates of mean workday ELF exposure based on a job exposure matrix were assigned. Estimates of cumulative exposure, average exposure, maximum exposure, and exposure duration were calculated for the lifetime, and 1 to 4, 5 to 9, and 10+ years before the diagnosis/reference date. There were 3,761 included brain tumor cases (1,939 glioma and 1,822 meningioma) and 5,404 population controls. There was no associati...

Environ. Sci.: Processes Impacts, 2014

Several methods exist to estimate dermal exposure and it is unclear how comparable they are. Thes... more Several methods exist to estimate dermal exposure and it is unclear how comparable they are. These methods fall into three main categories: (i) removal techniques (such as wiping or rinsing); (ii) interception techniques (such as gloves, patches, or coveralls); and (iii) fluorescent tracer techniques. Controlled experiments were conducted to compare two removal methods for exposure to particulate, and a removal method with an interception method for exposure to liquids. Volunteers' hands were exposed to three liquid solutions (glycerol-water solutions of different concentrations) and three particulates (Epsom salts, calcium acetate and zinc oxide) in simulated exposure scenarios. Both hands were exposed and a different sampling method was used on each to allow comparison of methods. Cotton glove samplers and a cotton wipe sampling method were compared for exposure to liquids. For exposure to powders a cotton wipe sampling method was compared to rinsing the hands in deionised water. Wipe and rinse methods generally yielded similar results for Epsom salts and zinc oxide (geometric mean [GM] ratios of wipe-to-rinse measurements of 0.6 and 1.4, respectively) but they did not for calcium acetate (GM wipe-to-rinse ratio of 4.6). For glycerol solutions measurements from the glove samplers were consistently higher than wipe samples. At lower levels of exposure the relative difference between the two methods was greater than at higher levels. At a hand loading level of 24,000 μg cm(-2) (as measured by wiping) the glove-to-wipe ratio was 1.4 and at a hand loading of 0.09 μg cm(-2) the ratio was 42.0. Wipe and rinse methods may be directly comparable but the relationship between glove and wipe sampling methods appears to be complex. Further research is necessary to enable conversion of exposure measurements from one metric to another, so as to facilitate more reliable risk assessment.

European Radiology, 2015

Recent studies have consistently shown that amongst staff working with MRI, transient symptoms di... more Recent studies have consistently shown that amongst staff working with MRI, transient symptoms directly attributable to the MRI system including dizziness, nausea, tinnitus, and concentration problems are reported. This study assessed symptom prevalence and incidence in radiographers and other staff working with MRI in healthcare in the UK. One hundred and four volunteer staff from eight sites completed a questionnaire and kept a diary to obtain information on subjective symptoms and work practices, and wore a magnetic field dosimeter during one to three randomly selected working days. Incidence of MRI-related symptoms was obtained for all shifts and prevalence of MRI-related and reference symptoms was associated to explanatory factors using ordinal regression. Incident symptoms related to working with MRI were reported in 4 % of shifts. Prevalence of MRI-related, but not reference symptoms were associated with number of hours per week working with MRI, shift length, and stress, but not with magnetic field strength (1.5 and 3 T) or measured magnetic field exposure. Reporting of prevalent symptoms was associated with longer duration of working in MRI departments, but not with measured field strength of exposure. Other factors related to organisation and stress seem to contribute to increased reporting of MRI-related symptoms. • Routine work with MRI is associated with increased reporting of transient symptoms • No link to the strength of the magnetic field was demonstrated. • Organisational factors and stress additionally contribute to reporting of MRI-related symptoms.

The Annals of occupational hygiene, 2014

This paper describes a Bayesian model for the assessment of inhalation exposures in an occupation... more This paper describes a Bayesian model for the assessment of inhalation exposures in an occupational setting; the methodology underpins a freely available web-based application for exposure assessment, the Advanced REACH Tool (ART). The ART is a higher tier exposure tool that combines disparate sources of information within a Bayesian statistical framework. The information is obtained from expert knowledge expressed in a calibrated mechanistic model of exposure assessment, data on inter- and intra-individual variability in exposures from the literature, and context-specific exposure measurements. The ART provides central estimates and credible intervals for different percentiles of the exposure distribution, for full-shift and long-term average exposures. The ART can produce exposure estimates in the absence of measurements, but the precision of the estimates improves as more data become available. The methodology presented in this paper is able to utilize partially analogous data, a...

Occupational and environmental medicine, 2014

We report on the first ever analysis of a UK cohort of workers with blood lead level measurements... more We report on the first ever analysis of a UK cohort of workers with blood lead level measurements that was assembled in the late 1970s. As an alternative to mean and maximum blood lead levels, we carried out an exposure assessment that assigned workers to high, medium or low exposure to lead. We additionally assessed whether workers would be exposed to an important level of relevant co-carcinogens. 3466 deaths were observed among 7770 men and 1352 women. The SMRs for all causes (109, 95% CI 105-112) and all malignant neoplasms (113,107-120) were significantly raised. SMRs for oesophageal, stomach, bladder, brain and kidney cancer and non-malignant kidney disease were not raised, but were raised for lung cancer (142,129-157). The SMR for circulatory diseases (105,99-100) was of borderline significance. No trends were observed for mean or maximum blood lead level or assessed lead exposure for any of the cancers of a priori interest, but a significant association was found for circulat...

The Annals of occupational hygiene, 2014

The task of grinding sandstone with a 5-inch angle grinder is a major source of exposure to respi... more The task of grinding sandstone with a 5-inch angle grinder is a major source of exposure to respirable crystalline silica (RCS), known to cause diseases such as silicosis and lung cancer among workers who work with these materials. A shroud may be a suitable engineering control for this task. The objectives of this study were to evaluate the effectiveness of four commercially available shrouds at reducing respirable dust and RCS levels during the task of grinding sandstone using tools and accessories typical of restoration stone work. The task of grinding sandstone with a 5-inch angle grinder, equipped with different grinding wheels, was carried out over three trials at a restoration stone masonry site. Photometric and RCS data were collected when a 5-inch grinder, equipped with different grinding wheels, was used to grind sandstone with and without a shroud. A total of 24 short duration samples were collected for each no shroud and with shroud combination. Worker feedback on the pr...

British journal of cancer, Jan 19, 2012

Journal of Exposure Science and Environmental Epidemiology, 2014

Contact between contaminated hands and the mouth or the area around the mouth (the perioral area)... more Contact between contaminated hands and the mouth or the area around the mouth (the perioral area) can result in inadvertent ingestion exposure. Exposure by this route is known to occur among children, but adults may also be exposed. Observations of 48 workers were carried out in 8 UK worksites to study hand- and object-to-mouth behavior. Each subject was observed in real-time for ~60 min during normal work activities. Each contact was recorded along with information about time of contact, glove use, respirator use, task and object type. Subjects were interviewed to gather information about smoking, nail biting and risk perception. The effects of factors (glove use, respirator use, smoking, nail biting, risk perception, work sector and task group) on contact frequency were assessed using non-parametric tests and Poisson regression models. Several determinants of contact frequency were identified, including time spent "between" work tasks, glove and respirator use, smoking and nail biting. Hand-to-mouth contact frequencies were particularly high while workers were "between" work tasks (23.6 contacts per hour, compared with the average contact frequency of 6.3 per hour). The factors that were related to contact frequency differed between object- and hand-to-mouth contacts, suggesting that these should be considered separately. These findings could be used for developing exposure models, to inform measurements of inadvertent ingestion among adults and to identify control strategies.Journal of Exposure Science and Environmental Epidemiology advance online publication, 5 November 2014; doi:10.1038/jes.2014.71.

Retrospective exposure assessment remains a problematic aspect of population-based case-control s... more Retrospective exposure assessment remains a problematic aspect of population-based case-control studies. Different methods have been developed, including case-by-case expert assessment and job-exposure matrices (JEM). The present analyses compare exposure prevalence and risk estimates derived by different exposure assessment methods. In the context of a case-control study conducted in seven European countries, exposure was estimated for asbestos, diesel motor emissions (DME) and crystalline silica, using three different assessment methods. First, experts assigned exposures to all reported jobs on a case-by-case basis. Second, a population-specific JEM (PSJEM) was developed using the expert assessments of controls only, and re-applied to all study subjects. Third, an independent general population JEM (GPJEM) was created by occupational exposure experts not involved in the original study, and applied to study subjects. Results from these methods were compared. There was poor to fair agreement in assigned exposure between expert assessment and the GPJEM (kappas: asbestos 0.17; DME 0.48; silica 0.38). Exposure prevalence was significantly heterogeneous (p<0.01) between countries for all three agents and assessment methods. For asbestos and DME, significant country heterogeneity in risk estimates was observed when using expert assessment. When applying the GPJEM, the heterogeneity in risk estimates for asbestos and, to some extent, silica diminished. It has been previously advocated that the expert assessment approach to assign exposures based on detailed questionnaire responses provides more accurate exposure estimates than JEM-based results. However, current results demonstrated little, if any, advantage of case-by-case assessment when compared to a JEM approach.

Toxicology Letters, 2008

The REACH process requires a Tiered exposure assessment to effectively cope with the broad range ... more The REACH process requires a Tiered exposure assessment to effectively cope with the broad range of Exposure Scenarios. Currently, a higher Tier model generating realistic exposure estimates is missing. A new advanced exposure assessment tool is under development.

Occupational and Environmental Medicine, 2011

Occupational and Environmental Medicine, 2009

The aim was to develop a new up-to-date and comprehensive job exposure matrix (JEM) for estimatin... more The aim was to develop a new up-to-date and comprehensive job exposure matrix (JEM) for estimating exposure to potential endocrine disruptors in epidemiological research. Chemicals with endocrine disrupting properties were identified from the literature and classified into 10 chemical groups: polycyclic aromatic hydrocarbons (PAHs), polychlorinated organic compounds, pesticides, phthalates, organic solvents, bisphenol A, alkylphenolic compounds, brominated flame retardants, metals and a miscellaneous group. Most chemical groups were divided into three to six subgroups. Focusing on the years 1996-2006, three experts scored the probability of exposure to each chemical group and subgroup for 353 job titles as "unlikely" (0), "possible" (1) or "probable" (2). Job titles with positive exposure probability scores were provided with exposure scenarios that described the reasoning behind the scores. Exposure to any chemical group was unlikely for 238 job titles (67%), whereas 102 (29%) job titles were classified as possibly (17%) or probably (12%) exposed to one or several endocrine disruptors. The remaining 13 job titles provided too little information to classify exposure. PAHs, pesticides, phthalates, organic solvents, alkylphenolic compounds and metals were often linked to a job title in the JEM. The remaining chemical groups were found to involve very few occupations. Despite some important limitations, this JEM could be a valuable tool for exposure assessment in studies on the health risks of endocrine disruptors, especially when task specific information is incorporated. The documented exposure scenarios are meant to facilitate further adjustments to the JEM to allow more widespread use.

Occupational and Environmental Medicine, 1998

Objectives-To examine the relation between exposure to acid anhydrides and the risk of developing... more Objectives-To examine the relation between exposure to acid anhydrides and the risk of developing immediate skin prick test responses to acid anhydride human serum albumin (AA-HSA) conjugates or work related respiratory symptoms; to assess whether these relations are modified by atopy or smoking. Methods-A cohort of 506 workers exposed to phthalic (PA), maleic (MA), and trimellitic anhydride (TMA) was defined. Workers completed questionnaires relating to employment history, respiratory symptoms, and smoking habits. Skin prick tests were done with AA-HSA conjugates and common inhalant allergens. Exposure to acid anhydrides was measured at the time of the survey and a retrospective exposure assessment was done. Results-Information was obtained from 401 (79%) workers. Thirty four (8.8%) had new work related respiratory symptoms that occurred for the first time while working with acid anhydrides and 12 (3.2%) were sensitised, with an immediate skin prick test reaction to AA-HSA conjugates. Sensitisation to acid anhydrides was associated with work related respiratory symptoms and with smoking at the time of exposure to acid anhydride. When all subjects were included and all three acid anhydrides were taken into account there was no consistent evidence for an exposure-response relation, but with the analysis restricted to a factory where only TMA was in use there was an increased prevalence of sensitisation to acid anhydrides and work related respiratory symptoms with increasing full shift exposure. This relation was apparent within the current occupational exposure standard of 40 µg.m −3 and was not modified significantly by smoking or atopy.

Occupational and Environmental Medicine, 1998

Objectives-To estimate past exposure to phthalic (PA), trimellitic (TMA) and maleic anhydride (MA... more Objectives-To estimate past exposure to phthalic (PA), trimellitic (TMA) and maleic anhydride (MA) in three alkyd resin and one cushioned flooring factory to estimate exposure-response relations in a retrospective cohort study. Methods-Personal exposure measurements were carried out in 1992 and quantitative and qualitative information on past exposure and production processes were collected. Job titles were ranked by decreasing exposure and amalgamated into job categories and exposure groups. Multiplication factors for back calculating past exposure levels were estimated with past exposure data, or if no such data were available these factors were estimated by a panel of occupational hygienists. Exposure levels were back calculated starting with the exposure levels in 1992. Results-High exposures to PA were estimated to have occurred among workers operating the PA melting pots in factory 1 (estimated exposure in 1960-9 was 2480 µg.m -3 ). Highest concentrations of TMA were estimated to have occurred among the ink mixers in factory 2 from 1979 to 1986 (554 µg.m -3 ). Exposure in most other job titles was thought to be fairly constant over time for PA, TMA, and MA. Conclusions-Exposure to acid anhydride at these factories has fallen during the period covered by the study. However, it is estimated that in only one job in factory 2 did past exposure to acid anhydride exceed the current occupational exposure standard. Accuracy of the estimated exposure is limited by a paucity of reliable past exposure data. (Occup Environ Med 1998;55:692-696)

Nanotoxicology, 2014

Substantial limitations and uncertainties hinder the exposure assessment of engineered nanomateri... more Substantial limitations and uncertainties hinder the exposure assessment of engineered nanomaterials (ENMs). The present deficit of reliable measurements and models will inevitably lead in the near term to qualitative and uncertain exposure estimations, which may fail to support adequate risk assessment and management. Therefore it is necessary to complement the current toolset with user-friendly methods for near-term nanosafety evaluation. This paper proposes an approach for relative exposure screening of ENMs. For the first time, an exposure model explicitly implements quantitative weight of evidence (WoE) methods and utilizes expert judgment for filling data gaps in the available evidence-base. Application of the framework is illustrated for screening of exposure scenarios for nanoscale titanium dioxide, carbon nanotubes and fullerenes, but it is applicable to other nanomaterials as well. The results show that the WoE-based model overestimates exposure for scenarios where expert judgment was substantially used to fill data gaps, which suggests its conservative nature. In order to test how variations in input data influence the obtained results, probabilistic Monte Carlo sensitivity analysis was applied to demonstrate that the model performs in stable manner. © Informa UK, Ltd. This provisional PDF corresponds to the article as it appeared upon acceptance. Fully formatted PDF and full text (HTML) versions will be made available soon.

Journal of Nanoparticle Research, 2012

ABSTRACT The aim of this paper is to describe the process and challenges in building exposure sce... more ABSTRACT The aim of this paper is to describe the process and challenges in building exposure scenarios for engineered nanomaterials (ENM), using an exposure scenario format similar to that used for the European Chemicals regulation (REACH). Over 60 exposure scenarios were developed based on information from publicly available sources (literature, books, and reports), publicly available exposure estimation models, occupational sampling campaign data from partnering institutions, and industrial partners regarding their own facilities. The primary focus was on carbon-based nanomaterials, nano-silver (nano-Ag) and nano-titanium dioxide (nano-TiO2), and included occupational and consumer uses of these materials with consideration of the associated environmental release. The process of building exposure scenarios illustrated the availability and limitations of existing information and exposure assessment tools for characterizing exposure to ENM, particularly as it relates to risk assessment. This article describes the gaps in the information reviewed, recommends future areas of ENM exposure research, and proposes types of information that should, at a minimum, be included when reporting the results of such research, so that the information is useful in a wider context.

Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 2014

Occupational exposure to extremely low-frequency magnetic fields (ELF) is a suspected risk factor... more Occupational exposure to extremely low-frequency magnetic fields (ELF) is a suspected risk factor for brain tumors, however the literature is inconsistent. Few studies have assessed whether ELF in different time windows of exposure may be associated with specific histologic types of brain tumors. This study examines the association between ELF and brain tumors in the large-scale INTEROCC study. Cases of adult primary glioma and meningioma were recruited in seven countries (Australia, Canada, France, Germany, Israel, New Zealand, and the United Kingdom) between 2000 and 2004. Estimates of mean workday ELF exposure based on a job exposure matrix were assigned. Estimates of cumulative exposure, average exposure, maximum exposure, and exposure duration were calculated for the lifetime, and 1 to 4, 5 to 9, and 10+ years before the diagnosis/reference date. There were 3,761 included brain tumor cases (1,939 glioma and 1,822 meningioma) and 5,404 population controls. There was no associati...

European Journal of Epidemiology, 2007

The very rapid worldwide increase in mobile phone use in the last decade has generated considerab... more The very rapid worldwide increase in mobile phone use in the last decade has generated considerable interest in the possible health effects of exposure to radio frequency (RF) fields. A multinational case-control study, INTERPHONE, was set-up to investigate whether mobile phone use increases the risk of cancer and, more specifi-Baruch Modan is deceased.

Occupational and environmental medicine, Jan 14, 2015

We examined the mortality of a historic cohort of workers in Great Britain with measured blood le... more We examined the mortality of a historic cohort of workers in Great Britain with measured blood lead levels (BLLs). SMRs were calculated with the population of Great Britain as the external comparator. Trends in mortality with mean and maximum BLLs and assessed lead exposure were examined using Cox regression. Mean follow-up length among the 9122 study participants was 29.2 years and 3466 deaths occurred. For all causes and all malignant neoplasms, the SMRs were statistically significantly raised. For disease groups of a priori interest, the SMR was significantly raised for lung cancer but not for stomach, brain, kidney, bladder or oesophageal cancers. The SMR was not increased for non-malignant kidney disease but was borderline significantly increased for circulatory diseases, for ischaemic heart disease (IHD) and cerebrovascular disease (CVD). No significant trends with exposure were observed for the cancers of interest, but for circulatory diseases and IHD, there was a statistical...

Occupational and environmental medicine, 2014

Exposure to electromagnetic fields (EMF) has become ubiquitous in modern life and concern has inc... more Exposure to electromagnetic fields (EMF) has become ubiquitous in modern life and concern has increased regarding possible associated health effects. To date, assessment of occupational exposure has relied on job-exposure matrices, with exposure estimates for very broad occupational categories. To move EMF research forward, a new approach was necessary. A source-based strategy, incorporating detailed information on tasks, equipment used and work organisation could allow a more individualised exposure assessment. Information on occupational histories and sources of EMF was collected as part of the INTERPHONE-INTEROCC study, providing an opportunity to assess occupational EMF exposure by assigning exposure to each source used. A source-exposure matrix (SEM) was developed based on measurements identified in the literature and estimates obtained through experts' elicitation, for sources without available measurements. This paper focuses on the SEM development methodology to ensure t...

Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 2014

Occupational exposure to extremely low-frequency magnetic fields (ELF) is a suspected risk factor... more Occupational exposure to extremely low-frequency magnetic fields (ELF) is a suspected risk factor for brain tumors, however the literature is inconsistent. Few studies have assessed whether ELF in different time windows of exposure may be associated with specific histologic types of brain tumors. This study examines the association between ELF and brain tumors in the large-scale INTEROCC study. Cases of adult primary glioma and meningioma were recruited in seven countries (Australia, Canada, France, Germany, Israel, New Zealand, and the United Kingdom) between 2000 and 2004. Estimates of mean workday ELF exposure based on a job exposure matrix were assigned. Estimates of cumulative exposure, average exposure, maximum exposure, and exposure duration were calculated for the lifetime, and 1 to 4, 5 to 9, and 10+ years before the diagnosis/reference date. There were 3,761 included brain tumor cases (1,939 glioma and 1,822 meningioma) and 5,404 population controls. There was no associati...

Environ. Sci.: Processes Impacts, 2014

Several methods exist to estimate dermal exposure and it is unclear how comparable they are. Thes... more Several methods exist to estimate dermal exposure and it is unclear how comparable they are. These methods fall into three main categories: (i) removal techniques (such as wiping or rinsing); (ii) interception techniques (such as gloves, patches, or coveralls); and (iii) fluorescent tracer techniques. Controlled experiments were conducted to compare two removal methods for exposure to particulate, and a removal method with an interception method for exposure to liquids. Volunteers' hands were exposed to three liquid solutions (glycerol-water solutions of different concentrations) and three particulates (Epsom salts, calcium acetate and zinc oxide) in simulated exposure scenarios. Both hands were exposed and a different sampling method was used on each to allow comparison of methods. Cotton glove samplers and a cotton wipe sampling method were compared for exposure to liquids. For exposure to powders a cotton wipe sampling method was compared to rinsing the hands in deionised water. Wipe and rinse methods generally yielded similar results for Epsom salts and zinc oxide (geometric mean [GM] ratios of wipe-to-rinse measurements of 0.6 and 1.4, respectively) but they did not for calcium acetate (GM wipe-to-rinse ratio of 4.6). For glycerol solutions measurements from the glove samplers were consistently higher than wipe samples. At lower levels of exposure the relative difference between the two methods was greater than at higher levels. At a hand loading level of 24,000 μg cm(-2) (as measured by wiping) the glove-to-wipe ratio was 1.4 and at a hand loading of 0.09 μg cm(-2) the ratio was 42.0. Wipe and rinse methods may be directly comparable but the relationship between glove and wipe sampling methods appears to be complex. Further research is necessary to enable conversion of exposure measurements from one metric to another, so as to facilitate more reliable risk assessment.

European Radiology, 2015

Recent studies have consistently shown that amongst staff working with MRI, transient symptoms di... more Recent studies have consistently shown that amongst staff working with MRI, transient symptoms directly attributable to the MRI system including dizziness, nausea, tinnitus, and concentration problems are reported. This study assessed symptom prevalence and incidence in radiographers and other staff working with MRI in healthcare in the UK. One hundred and four volunteer staff from eight sites completed a questionnaire and kept a diary to obtain information on subjective symptoms and work practices, and wore a magnetic field dosimeter during one to three randomly selected working days. Incidence of MRI-related symptoms was obtained for all shifts and prevalence of MRI-related and reference symptoms was associated to explanatory factors using ordinal regression. Incident symptoms related to working with MRI were reported in 4 % of shifts. Prevalence of MRI-related, but not reference symptoms were associated with number of hours per week working with MRI, shift length, and stress, but not with magnetic field strength (1.5 and 3 T) or measured magnetic field exposure. Reporting of prevalent symptoms was associated with longer duration of working in MRI departments, but not with measured field strength of exposure. Other factors related to organisation and stress seem to contribute to increased reporting of MRI-related symptoms. • Routine work with MRI is associated with increased reporting of transient symptoms • No link to the strength of the magnetic field was demonstrated. • Organisational factors and stress additionally contribute to reporting of MRI-related symptoms.

The Annals of occupational hygiene, 2014

This paper describes a Bayesian model for the assessment of inhalation exposures in an occupation... more This paper describes a Bayesian model for the assessment of inhalation exposures in an occupational setting; the methodology underpins a freely available web-based application for exposure assessment, the Advanced REACH Tool (ART). The ART is a higher tier exposure tool that combines disparate sources of information within a Bayesian statistical framework. The information is obtained from expert knowledge expressed in a calibrated mechanistic model of exposure assessment, data on inter- and intra-individual variability in exposures from the literature, and context-specific exposure measurements. The ART provides central estimates and credible intervals for different percentiles of the exposure distribution, for full-shift and long-term average exposures. The ART can produce exposure estimates in the absence of measurements, but the precision of the estimates improves as more data become available. The methodology presented in this paper is able to utilize partially analogous data, a...

Occupational and environmental medicine, 2014

We report on the first ever analysis of a UK cohort of workers with blood lead level measurements... more We report on the first ever analysis of a UK cohort of workers with blood lead level measurements that was assembled in the late 1970s. As an alternative to mean and maximum blood lead levels, we carried out an exposure assessment that assigned workers to high, medium or low exposure to lead. We additionally assessed whether workers would be exposed to an important level of relevant co-carcinogens. 3466 deaths were observed among 7770 men and 1352 women. The SMRs for all causes (109, 95% CI 105-112) and all malignant neoplasms (113,107-120) were significantly raised. SMRs for oesophageal, stomach, bladder, brain and kidney cancer and non-malignant kidney disease were not raised, but were raised for lung cancer (142,129-157). The SMR for circulatory diseases (105,99-100) was of borderline significance. No trends were observed for mean or maximum blood lead level or assessed lead exposure for any of the cancers of a priori interest, but a significant association was found for circulat...

The Annals of occupational hygiene, 2014

The task of grinding sandstone with a 5-inch angle grinder is a major source of exposure to respi... more The task of grinding sandstone with a 5-inch angle grinder is a major source of exposure to respirable crystalline silica (RCS), known to cause diseases such as silicosis and lung cancer among workers who work with these materials. A shroud may be a suitable engineering control for this task. The objectives of this study were to evaluate the effectiveness of four commercially available shrouds at reducing respirable dust and RCS levels during the task of grinding sandstone using tools and accessories typical of restoration stone work. The task of grinding sandstone with a 5-inch angle grinder, equipped with different grinding wheels, was carried out over three trials at a restoration stone masonry site. Photometric and RCS data were collected when a 5-inch grinder, equipped with different grinding wheels, was used to grind sandstone with and without a shroud. A total of 24 short duration samples were collected for each no shroud and with shroud combination. Worker feedback on the pr...

British journal of cancer, Jan 19, 2012

Journal of Exposure Science and Environmental Epidemiology, 2014

Contact between contaminated hands and the mouth or the area around the mouth (the perioral area)... more Contact between contaminated hands and the mouth or the area around the mouth (the perioral area) can result in inadvertent ingestion exposure. Exposure by this route is known to occur among children, but adults may also be exposed. Observations of 48 workers were carried out in 8 UK worksites to study hand- and object-to-mouth behavior. Each subject was observed in real-time for ~60 min during normal work activities. Each contact was recorded along with information about time of contact, glove use, respirator use, task and object type. Subjects were interviewed to gather information about smoking, nail biting and risk perception. The effects of factors (glove use, respirator use, smoking, nail biting, risk perception, work sector and task group) on contact frequency were assessed using non-parametric tests and Poisson regression models. Several determinants of contact frequency were identified, including time spent "between" work tasks, glove and respirator use, smoking and nail biting. Hand-to-mouth contact frequencies were particularly high while workers were "between" work tasks (23.6 contacts per hour, compared with the average contact frequency of 6.3 per hour). The factors that were related to contact frequency differed between object- and hand-to-mouth contacts, suggesting that these should be considered separately. These findings could be used for developing exposure models, to inform measurements of inadvertent ingestion among adults and to identify control strategies.Journal of Exposure Science and Environmental Epidemiology advance online publication, 5 November 2014; doi:10.1038/jes.2014.71.

Retrospective exposure assessment remains a problematic aspect of population-based case-control s... more Retrospective exposure assessment remains a problematic aspect of population-based case-control studies. Different methods have been developed, including case-by-case expert assessment and job-exposure matrices (JEM). The present analyses compare exposure prevalence and risk estimates derived by different exposure assessment methods. In the context of a case-control study conducted in seven European countries, exposure was estimated for asbestos, diesel motor emissions (DME) and crystalline silica, using three different assessment methods. First, experts assigned exposures to all reported jobs on a case-by-case basis. Second, a population-specific JEM (PSJEM) was developed using the expert assessments of controls only, and re-applied to all study subjects. Third, an independent general population JEM (GPJEM) was created by occupational exposure experts not involved in the original study, and applied to study subjects. Results from these methods were compared. There was poor to fair agreement in assigned exposure between expert assessment and the GPJEM (kappas: asbestos 0.17; DME 0.48; silica 0.38). Exposure prevalence was significantly heterogeneous (p<0.01) between countries for all three agents and assessment methods. For asbestos and DME, significant country heterogeneity in risk estimates was observed when using expert assessment. When applying the GPJEM, the heterogeneity in risk estimates for asbestos and, to some extent, silica diminished. It has been previously advocated that the expert assessment approach to assign exposures based on detailed questionnaire responses provides more accurate exposure estimates than JEM-based results. However, current results demonstrated little, if any, advantage of case-by-case assessment when compared to a JEM approach.

Toxicology Letters, 2008

The REACH process requires a Tiered exposure assessment to effectively cope with the broad range ... more The REACH process requires a Tiered exposure assessment to effectively cope with the broad range of Exposure Scenarios. Currently, a higher Tier model generating realistic exposure estimates is missing. A new advanced exposure assessment tool is under development.

Occupational and Environmental Medicine, 2011

Occupational and Environmental Medicine, 2009

The aim was to develop a new up-to-date and comprehensive job exposure matrix (JEM) for estimatin... more The aim was to develop a new up-to-date and comprehensive job exposure matrix (JEM) for estimating exposure to potential endocrine disruptors in epidemiological research. Chemicals with endocrine disrupting properties were identified from the literature and classified into 10 chemical groups: polycyclic aromatic hydrocarbons (PAHs), polychlorinated organic compounds, pesticides, phthalates, organic solvents, bisphenol A, alkylphenolic compounds, brominated flame retardants, metals and a miscellaneous group. Most chemical groups were divided into three to six subgroups. Focusing on the years 1996-2006, three experts scored the probability of exposure to each chemical group and subgroup for 353 job titles as "unlikely" (0), "possible" (1) or "probable" (2). Job titles with positive exposure probability scores were provided with exposure scenarios that described the reasoning behind the scores. Exposure to any chemical group was unlikely for 238 job titles (67%), whereas 102 (29%) job titles were classified as possibly (17%) or probably (12%) exposed to one or several endocrine disruptors. The remaining 13 job titles provided too little information to classify exposure. PAHs, pesticides, phthalates, organic solvents, alkylphenolic compounds and metals were often linked to a job title in the JEM. The remaining chemical groups were found to involve very few occupations. Despite some important limitations, this JEM could be a valuable tool for exposure assessment in studies on the health risks of endocrine disruptors, especially when task specific information is incorporated. The documented exposure scenarios are meant to facilitate further adjustments to the JEM to allow more widespread use.

Occupational and Environmental Medicine, 1998

Objectives-To examine the relation between exposure to acid anhydrides and the risk of developing... more Objectives-To examine the relation between exposure to acid anhydrides and the risk of developing immediate skin prick test responses to acid anhydride human serum albumin (AA-HSA) conjugates or work related respiratory symptoms; to assess whether these relations are modified by atopy or smoking. Methods-A cohort of 506 workers exposed to phthalic (PA), maleic (MA), and trimellitic anhydride (TMA) was defined. Workers completed questionnaires relating to employment history, respiratory symptoms, and smoking habits. Skin prick tests were done with AA-HSA conjugates and common inhalant allergens. Exposure to acid anhydrides was measured at the time of the survey and a retrospective exposure assessment was done. Results-Information was obtained from 401 (79%) workers. Thirty four (8.8%) had new work related respiratory symptoms that occurred for the first time while working with acid anhydrides and 12 (3.2%) were sensitised, with an immediate skin prick test reaction to AA-HSA conjugates. Sensitisation to acid anhydrides was associated with work related respiratory symptoms and with smoking at the time of exposure to acid anhydride. When all subjects were included and all three acid anhydrides were taken into account there was no consistent evidence for an exposure-response relation, but with the analysis restricted to a factory where only TMA was in use there was an increased prevalence of sensitisation to acid anhydrides and work related respiratory symptoms with increasing full shift exposure. This relation was apparent within the current occupational exposure standard of 40 µg.m −3 and was not modified significantly by smoking or atopy.

Occupational and Environmental Medicine, 1998

Objectives-To estimate past exposure to phthalic (PA), trimellitic (TMA) and maleic anhydride (MA... more Objectives-To estimate past exposure to phthalic (PA), trimellitic (TMA) and maleic anhydride (MA) in three alkyd resin and one cushioned flooring factory to estimate exposure-response relations in a retrospective cohort study. Methods-Personal exposure measurements were carried out in 1992 and quantitative and qualitative information on past exposure and production processes were collected. Job titles were ranked by decreasing exposure and amalgamated into job categories and exposure groups. Multiplication factors for back calculating past exposure levels were estimated with past exposure data, or if no such data were available these factors were estimated by a panel of occupational hygienists. Exposure levels were back calculated starting with the exposure levels in 1992. Results-High exposures to PA were estimated to have occurred among workers operating the PA melting pots in factory 1 (estimated exposure in 1960-9 was 2480 µg.m -3 ). Highest concentrations of TMA were estimated to have occurred among the ink mixers in factory 2 from 1979 to 1986 (554 µg.m -3 ). Exposure in most other job titles was thought to be fairly constant over time for PA, TMA, and MA. Conclusions-Exposure to acid anhydride at these factories has fallen during the period covered by the study. However, it is estimated that in only one job in factory 2 did past exposure to acid anhydride exceed the current occupational exposure standard. Accuracy of the estimated exposure is limited by a paucity of reliable past exposure data. (Occup Environ Med 1998;55:692-696)

Nanotoxicology, 2014

Substantial limitations and uncertainties hinder the exposure assessment of engineered nanomateri... more Substantial limitations and uncertainties hinder the exposure assessment of engineered nanomaterials (ENMs). The present deficit of reliable measurements and models will inevitably lead in the near term to qualitative and uncertain exposure estimations, which may fail to support adequate risk assessment and management. Therefore it is necessary to complement the current toolset with user-friendly methods for near-term nanosafety evaluation. This paper proposes an approach for relative exposure screening of ENMs. For the first time, an exposure model explicitly implements quantitative weight of evidence (WoE) methods and utilizes expert judgment for filling data gaps in the available evidence-base. Application of the framework is illustrated for screening of exposure scenarios for nanoscale titanium dioxide, carbon nanotubes and fullerenes, but it is applicable to other nanomaterials as well. The results show that the WoE-based model overestimates exposure for scenarios where expert judgment was substantially used to fill data gaps, which suggests its conservative nature. In order to test how variations in input data influence the obtained results, probabilistic Monte Carlo sensitivity analysis was applied to demonstrate that the model performs in stable manner. © Informa UK, Ltd. This provisional PDF corresponds to the article as it appeared upon acceptance. Fully formatted PDF and full text (HTML) versions will be made available soon.

Journal of Nanoparticle Research, 2012

ABSTRACT The aim of this paper is to describe the process and challenges in building exposure sce... more ABSTRACT The aim of this paper is to describe the process and challenges in building exposure scenarios for engineered nanomaterials (ENM), using an exposure scenario format similar to that used for the European Chemicals regulation (REACH). Over 60 exposure scenarios were developed based on information from publicly available sources (literature, books, and reports), publicly available exposure estimation models, occupational sampling campaign data from partnering institutions, and industrial partners regarding their own facilities. The primary focus was on carbon-based nanomaterials, nano-silver (nano-Ag) and nano-titanium dioxide (nano-TiO2), and included occupational and consumer uses of these materials with consideration of the associated environmental release. The process of building exposure scenarios illustrated the availability and limitations of existing information and exposure assessment tools for characterizing exposure to ENM, particularly as it relates to risk assessment. This article describes the gaps in the information reviewed, recommends future areas of ENM exposure research, and proposes types of information that should, at a minimum, be included when reporting the results of such research, so that the information is useful in a wider context.