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Hans Kromhout - One of the best experts on this subject based on the ideXlab platform.
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conceptual model for assessment of inhalation exposure defining modifying factors
Annals of Occupational Hygiene, 2008Co-Authors: Erik Tielemans, Nick Warren, Hans Kromhout, Thomas Schneider, Henk Goede, Martin Tischer, Martie Van Tongeren, Joop J Van Hemmen, John W CherrieAbstract:The present paper proposes a source-receptor model to schematically describe inhalation exposure to help understand the complex processes leading to inhalation of hazardous substances. The model considers a stepwise transfer of a contaminant from the source to the receptor. The conceptual model is constructed using three components, i.e. (i) the source, (ii) various transmission compartments and (iii) the receptor, and describes the contaminant's emission and its pattern of transport. Based on this conceptual model, a list of nine mutually independent principal modifying factors (MFs) is proposed: activity emission potential, substance emission potential, localized control, separation, segregation, dilution, worker behavior, surface contamination and respiratory protection. These MFs describe the exposure process at a high level of abstraction so that the model can be generically applicable. A list of exposure determinants underlying each of these principal MFs is proposed to describe the exposure process at a more detailed level. The presented conceptual model is developed in conjunction with an activity taxonomy as described in a separate paper. The proposed conceptual model and MFs should be seen as 'building blocks' for development of higher tier exposure models. © The Author 2008. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.
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a database of exposures in the rubber manufacturing industry design and quality control
Annals of Occupational Hygiene, 2005Co-Authors: Frank De Vocht, Roel Vermeulen, Kurt Straif, Neonila Szeszeniadabrowska, Lars Hagmar, Tom Sorahan, Igor Burstyn, Hans KromhoutAbstract:The concerted action EXASRUB was initiated to create a database management system for information on Occupational Hygiene measurements that could be used to develop exposure models in the European rubber manufacturing industry. Quality of coding was assessed by calculating percentages of agreement and Cohen's kappa statistics (kappa) for an intra- and inter-centre recoding of randomly selected subsets of the measurements. In a 6-month period, 59 609 measurements from 523 surveys in 333 factories from as early as 1956 to 2003 were coded. The database consists primarily of measurements of N-nitrosamines (36%), rubber dust (23%), solvents (14%) and rubber fumes (10%). Coding of epidemiologically relevant information was done consistently with inter-centre kappa between 0.86 and 1.00. For Occupational Hygiene information, values of kappa were estimated to be between 0.67 and 1.00. The proposed method resulted in a large quantity of exposure measurements with auxiliary information of varying completeness and quality. Analyses showed that coding of epidemiologically relevant information in such a multi-centre, multi-country study was coded consistently. Larger errors however, occurred in coding of Occupational Hygiene information. This was primarily caused by lack of information in the primary records of measurements, emphasizing the importance of having a universal system in place to collect and store measurement information by Occupational hygienists for future use.
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use of qualitative and quantitative fluorescence techniques to assess dermal exposure
Annals of Occupational Hygiene, 2000Co-Authors: John W Cherrie, D H Brouwer, Martin Roff, Roel Vermeulen, Hans KromhoutAbstract:Fluorescent tracers provide a way of simultaneously assessing the mass of a contaminant hazardous substance on the surface of the skin of a worker and the area of skin exposed. These parameters, along with the duration of exposure and the estimated contaminant concentration in the skin contamination layer, can be used to calculate the likely uptake through the skin. Repeated assessment of the mass of tracer on a surface within a room or on the surface of the skin can also allow the net transfer of contaminant to that compartment to be estimated. Qualitative evaluation of transfer processes using fluorescent tracers can help identify important secondary sources of exposure. (C) 2000 British Occupational Hygiene Society. Fluorescent tracers provide a way of simultaneously assessing the mass of a contaminant hazardous substance on the surface of the skin of a worker and the area of skin exposed. These parameters, along with the duration of exposure and the estimated contaminant concentration in the skin contamination layer, can be used to calculate the likely uptake through the skin. Repeated assessment of the mass of tracer on a surface within a room or on the surface of the skin can also allow the net transfer of contaminant to that compartment to be estimated. Qualitative evaluation of transfer processes using fluorescent tracers can help identify important secondary sources of exposure. Chemicals/CAS: Fluorescent Dyes
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identification of dermal exposure pathways in the rubber manufacturing industry
Annals of Occupational Hygiene, 2000Co-Authors: Roel Vermeulen, J M C Heideman, R P Bos, Hans KromhoutAbstract:Current existing dermal exposure assessment strategies are predominantly based on regulatory protocols. In order to develop effective and efficient strategies more data driven approaches are needed. In a recently developed conceptual model for dermal exposure, compartments, barriers and mass transport processes relevant for dermal exposure were described. We systematically applied this conceptual model to the rubber manufacturing industry to assess dermal exposure to cyclohexane soluble matter (CSM) and used quantitative data to design an exposure assessment strategy. Identification of the spatial distribution of the dermal contamination showed high CSM surface concentrations for the upper body. Moreover, because of the high correlation between dermal exposure at the wrist and calculated total body exposure (r=0.89, P,0.01) an exposure assessment strategy based on only one pad sampler was employed to estimate CSM surface concentrations in the skin contaminant layer. Qualitative and quantitative evaluation of the relevant compartments and related mass transport processes demonstrated the importance of deposition of airborne contaminants and direct transfer of contaminants from sources and surfaces to the skin contaminant layer. Interestingly, the importance of the different exposure pathways varied considerably between production functions.The use of a model driven exposure assessment strategy in the rubber manufacturing industry revealed relevant skin regions, compartments and mass transport processes and enabled development of an effective and efficient strategy for dermal exposure assessment and hazard control in this particular Occupational setting. ≈ 2000 British Occupational Hygiene Society. Published by Elsevier Science Ltd. All rights reserved.
George Havenith - One of the best experts on this subject based on the ideXlab platform.
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The Eects of Wind and Human Movement on the Heat and Vapour Transfer Properties of Clothing
2015Co-Authors: K. C. Parsons, Hans Nilsson, George Havenith, Jacques MalchaireAbstract:(1999) Clothing evaporative heat resistance: proposal for improved representation in standards and models. Annals of Occupational Hygiene, in press] to provide a practical suggestion for improving existing clothing models so that they can account for the eects of wind and human movement. The proposed method is presented and described in the form of a BASIC computer program. Analytical methods (for example ISO 7933) for the assessment of the thermal strain caused by human exposure to hot environments require a mathematical quantification of the thermal properties of clothing. These eects are usually considered in terms of ‘dry ’ thermal insulation and vapour resistance. This simple ‘model ’ of clothing can account for the insulation properties of clothing which reduce heat loss (or gain) between the body and the environment and, for example, the resistance to the transfer of evaporated sweat from the skin, which is important for cooling the body in a hot environment. When a clothed person is exposed to wind, however, and when the person is active, there is a potentially significant limitation in the simple model of clothing presented above. Heat and mass transfer can take place between the microclimate (within clothing and next to the skin surface) and the external environment. The method described in this paper ‘corrects ’ static values of clothing properties to provide dynami
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heat balance when wearing protective clothing
Annals of Occupational Hygiene, 1999Co-Authors: George HavenithAbstract:This issue of the Annals of Occupational Hygiene is dedicated to the topic of heat stress evaluation. For this evaluation, several evaluation programs and international standards are available. In order to understand the reasoning and underlying theory behind these programs and standards, a basic knowledge of heat exchange processes between workers and their environment is needed. This paper provides an overview of the relevant heat exchange processes, and defines the relevant parameters (air and radiant temperature, humidity, wind speed, metabolic heat production and clothing insulation). Further it presents in more detail the relation between clothing material properties and properties of clothing ensembles made from those materials. The eAects of clothing design, clothing fit, and clothing air permeability are discussed, and finally an overview of methods for the determination of clothing heat and vapour resistance is given. # 1999 British Occupational Hygiene Society. Published by Elsevier Science Ltd. All rights reserved.
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clothing convective heat exchange proposal for improved prediction in standards and models
Annals of Occupational Hygiene, 1999Co-Authors: Ingvar Holmer, George Havenith, Hakan Nilsson, Ken ParsonsAbstract:Convection is an important determinant for both sensible and evaporative heat exchange. Heat transfer by convection for normal boundary conditions is readily described by simple power functions. Clothing aAects convection in various ways and existing characterisation of clothing by its static insulation values produces inaccurate prediction of sensible heat exchange, eventually leading to erroneous risk assessment. The present paper reviews various methods for evaluation of clothing convective (sensible) heat exchange. Based on available data, two equations are proposed for determination of the reduction of the total insulation values obtained under static, still wind conditions as a consequence of wind and walking eAects. The equations apply from 0 to 1.84 clo, from 0.2 to 3 m/s and for walking speeds up to 1.2 m/s. The equations are incorporated in ISO 7933 to provide a more realistic and accurate prediction of sensible heat transfer through clothing. # 1999 British Occupational Hygiene Society. Published by Elsevier Science Ltd. All rights reserved.
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The effects of wind and human movement on the heat and vapour transfer properties of clothing.
The Annals of occupational hygiene, 1999Co-Authors: K. Parsons, Ingvar Holmér, Hans Nilsson, George Havenith, Jacques MalchaireAbstract:This paper integrates the research presented in the papers in this special issue of Holmér et al. and Havenith et al. [Holmér, I., Nilsson, H., Havenith, G., Parsons, K. C. (1999) Clothing convective heat exchange: proposal for improved prediction in standards and models. Annals of Occupational Hygiene, in press; Havenith, G., Holmér, I., den Hartog, E. and Parsons, K. C. (1999) Clothing evaporative heat resistance: proposal for improved representation in standards and models. Annals of Occupational Hygiene, in press] to provide a practical suggestion for improving existing clothing models so that they can account for the effects of wind and human movement. The proposed method is presented and described in the form of a BASIC computer program. Analytical methods (for example ISO 7933) for the assessment of the thermal strain caused by human exposure to hot environments require a mathematical quantification of the thermal properties of clothing. These effects are usually considered in terms of 'dry' thermal insulation and vapour resistance. This simple 'model' of clothing can account for the insulation properties of clothing which reduce heat loss (or gain) between the body and the environment and, for example, the resistance to the transfer of evaporated sweat from the skin, which is important for cooling the body in a hot environment. When a clothed person is exposed to wind, however, and when the person is active, there is a potentially significant limitation in the simple model of clothing presented above. Heat and mass transfer can take place between the microclimate (within clothing and next to the skin surface) and the external environment. The method described in this paper 'corrects' static values of clothing properties to provide dynamic values that take account of wind and human movement. It therefore allows a more complete representation of the effects of clothing on the heat strain of workers.
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The eects of wind and human movement on the heat and vapour transfer properties of clothing. Annals of Occupational Hygiene 347–352
1999Co-Authors: K. C. Parsons, Hans Nilsson, George Havenith, Jacques MalchaireAbstract:(1999) Clothing evaporative heat resistance: proposal for improved representation in standards and models. Annals of Occupational Hygiene, in press] to provide a practical suggestion for improving existing clothing models so that they can account for the eects of wind and human movement. The proposed method is presented and described in the form of a BASIC computer program. Analytical methods (for example ISO 7933) for the assessment of the thermal strain caused by human exposure to hot environments require a mathematical quantification of the thermal properties of clothing. These eects are usually considered in terms of ‘dry ’ thermal insulation and vapour resistance. This simple ‘model ’ of clothing can account for the insulation properties of clothing which reduce heat loss (or gain) between the body and the environment and, for example, the resistance to the transfer of evaporated sweat from the skin, which is important for cooling the body in a hot environment. When a clothed person is exposed to wind, however, and when the person is active, there is a potentially significant limitation in the simple model of clothing presented above. Heat and mass transfer can take place between the microclimate (within clothing and next to the skin surface) and the external environment. The method described in this paper ‘corrects ’ static values of clothing properties to provide dynami
Claudia R Binder - One of the best experts on this subject based on the ideXlab platform.
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dermal exposure assessment to pesticides in farming systems in developing countries comparison of models
International Journal of Environmental Research and Public Health, 2015Co-Authors: Camilo Lesmes Fabian, Claudia R BinderAbstract:In the field of Occupational Hygiene, researchers have been working on developing appropriate methods to estimate human exposure to pesticides in order to assess the risk and therefore to take the due decisions to improve the pesticide management process and reduce the health risks. This paper evaluates dermal exposure models to find the most appropriate. Eight models (i.e., COSHH, DERM, DREAM, EASE, PHED, RISKOFDERM, STOFFENMANAGER and PFAM) were evaluated according to a multi-criteria analysis and from these results five models (i.e., DERM, DREAM, PHED, RISKOFDERM and PFAM) were selected for the assessment of dermal exposure in the case study of the potato farming system in the Andean highlands of Vereda La Hoya, Colombia. The results show that the models provide different dermal exposure estimations which are not comparable. However, because of the simplicity of the algorithm and the specificity of the determinants, the DERM, DREAM and PFAM models were found to be the most appropriate although their estimations might be more accurate if specific determinants are included for the case studies in developing countries.
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dermal exposure assessment of pesticide use the case of sprayers in potato farms in the colombian highlands
Science of The Total Environment, 2012Co-Authors: Camilo Lesmesfabian, Claudia R Binder, Glenda Garciasantos, Fanny Leuenberger, David NuyttensAbstract:Quantifying dermal exposure to pesticides in farming systems in developing countries is of special interest for the estimation of potential health risks, especially when there is a lack of Occupational Hygiene regulations. In this paper we present the results of a dermal exposure assessment for the potato farming system in the highlands of Colombia, where farmers apply pesticides with hand pressure sprayers without any personal protective equipment. The fractioning of the pesticide, in terms of potential and actual dermal exposure, was determined via the whole-body dosimetry methodology, using the tracer uranine as pesticide surrogate, and luminescence spectrometry as analytical method. We assessed the three activities involved in pesticide management: preparation, application, and cleaning; analyzed three types of nozzles: one with a standard discharge and two modified by farmers to increase the discharge; and derived the protection factor given by work clothing. Our results suggest that to reduce the health risk, three aspects have to be considered: (i) avoiding the modification of nozzles, which affects the droplet size spectrum and increases the level of dermal exposure; (ii) using adequate work clothing made of thick fabrics, especially on the upper body parts; and (iii) cleaning properly the tank sprayer before the application activity.
B Crook - One of the best experts on this subject based on the ideXlab platform.
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Occupational exposure to metalworking fluid mist and sump fluid contaminants
Annals of Occupational Hygiene, 2003Co-Authors: A T Simpson, Martin Stear, John A Groves, Mark Piney, S D Bradley, S Stagg, B CrookAbstract:: This paper summarizes the analytical and Occupational Hygiene findings from a recent survey of Occupational exposure to metalworking fluids (MWFs) in the engineering industry. The aim of the survey was to link MWF mist exposure measurements with particular engineering processes and controls, and utilize the data obtained to develop exposure standards. At the same time the opportunity was taken to assess fluid management and control, including bacterial and fines contamination in the machine sumps. In general, Occupational exposure to mineral oil MWF mist was controlled to 1 x 10(6) CFU/ml, and endotoxin levels of >100 000 EU/ml were not uncommon. The median values were 109 000 CFU/ml and 8039 EU/ml, respectively. Mists could potentially contain extensive contamination from bacteria and endotoxin. Analysis of the data suggests that sumps operating under typical conditions for machining (a temperature of 20 degrees C, a pH of 9 and a fluid strength below 10%), also appear to provide optimum conditions for the proliferation of bacteria. Low levels of benzo[a]pyrene (median 0.03 micro g/g) were found in the mineral oils, and low levels of N-nitrosodiethanolamine (median 0.4 micro g/ml) were found in the water-mix MWFs. The results of this work will contribute to guidance from the HSE, setting out accepted industry good practice, including guide values for MWF mist and sump fluid contaminants, with significant emphasis on sump fluid management (maintenance and monitoring), as well as control issues.
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Occupational Exposure to Metalworking Fluid Mist and Sump Fluid Contamination,” Ann
2003Co-Authors: A T Simpson, Martin Stear, John A Groves, Mark Piney, S D Bradley, S Stagg, B CrookAbstract:This paper summarizes the analytical and Occupational Hygiene findings from a recent survey of Occupational exposure to metalworking fluids (MWFs) in the engineering industry. The aim of the survey was to link MWF mist exposure measurements with particular engineering processes and controls, and utilize the data obtained to develop exposure standards. At the same time the opportunity was taken to assess fluid management and control, including bacterial and fines contamination in the machine sumps. In general, Occupational exposure to mineral oil MWF mist was controlled to <3 mg/m3 (8 h time-weighted average) and to <1 mg/m3 for water-mix MWF mist (in terms of the concentrate). These exposure values do not neces-sarily represent best practice, but are believed to be achievable and representative of industry as a whole. Gravimetric analysis of the total inhalable particulate was found to be a good predictor of mineral oil MWF mist but not for water-mix MWF mist. Grinding and drilling operations produced higher exposures than turning and milling for water-mix fluids. There were insufficient data to compare machining operations for mineral oil MWFs. On the whole, fluid management was found to be poor, with most sites failing to meet industry good practice or Health & Safety Executive (HSE) standards. Some of the operating procedures utilized wer
Jacques Malchaire - One of the best experts on this subject based on the ideXlab platform.
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The Eects of Wind and Human Movement on the Heat and Vapour Transfer Properties of Clothing
2015Co-Authors: K. C. Parsons, Hans Nilsson, George Havenith, Jacques MalchaireAbstract:(1999) Clothing evaporative heat resistance: proposal for improved representation in standards and models. Annals of Occupational Hygiene, in press] to provide a practical suggestion for improving existing clothing models so that they can account for the eects of wind and human movement. The proposed method is presented and described in the form of a BASIC computer program. Analytical methods (for example ISO 7933) for the assessment of the thermal strain caused by human exposure to hot environments require a mathematical quantification of the thermal properties of clothing. These eects are usually considered in terms of ‘dry ’ thermal insulation and vapour resistance. This simple ‘model ’ of clothing can account for the insulation properties of clothing which reduce heat loss (or gain) between the body and the environment and, for example, the resistance to the transfer of evaporated sweat from the skin, which is important for cooling the body in a hot environment. When a clothed person is exposed to wind, however, and when the person is active, there is a potentially significant limitation in the simple model of clothing presented above. Heat and mass transfer can take place between the microclimate (within clothing and next to the skin surface) and the external environment. The method described in this paper ‘corrects ’ static values of clothing properties to provide dynami
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The effects of wind and human movement on the heat and vapour transfer properties of clothing.
The Annals of occupational hygiene, 1999Co-Authors: K. Parsons, Ingvar Holmér, Hans Nilsson, George Havenith, Jacques MalchaireAbstract:This paper integrates the research presented in the papers in this special issue of Holmér et al. and Havenith et al. [Holmér, I., Nilsson, H., Havenith, G., Parsons, K. C. (1999) Clothing convective heat exchange: proposal for improved prediction in standards and models. Annals of Occupational Hygiene, in press; Havenith, G., Holmér, I., den Hartog, E. and Parsons, K. C. (1999) Clothing evaporative heat resistance: proposal for improved representation in standards and models. Annals of Occupational Hygiene, in press] to provide a practical suggestion for improving existing clothing models so that they can account for the effects of wind and human movement. The proposed method is presented and described in the form of a BASIC computer program. Analytical methods (for example ISO 7933) for the assessment of the thermal strain caused by human exposure to hot environments require a mathematical quantification of the thermal properties of clothing. These effects are usually considered in terms of 'dry' thermal insulation and vapour resistance. This simple 'model' of clothing can account for the insulation properties of clothing which reduce heat loss (or gain) between the body and the environment and, for example, the resistance to the transfer of evaporated sweat from the skin, which is important for cooling the body in a hot environment. When a clothed person is exposed to wind, however, and when the person is active, there is a potentially significant limitation in the simple model of clothing presented above. Heat and mass transfer can take place between the microclimate (within clothing and next to the skin surface) and the external environment. The method described in this paper 'corrects' static values of clothing properties to provide dynamic values that take account of wind and human movement. It therefore allows a more complete representation of the effects of clothing on the heat strain of workers.
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The eects of wind and human movement on the heat and vapour transfer properties of clothing. Annals of Occupational Hygiene 347–352
1999Co-Authors: K. C. Parsons, Hans Nilsson, George Havenith, Jacques MalchaireAbstract:(1999) Clothing evaporative heat resistance: proposal for improved representation in standards and models. Annals of Occupational Hygiene, in press] to provide a practical suggestion for improving existing clothing models so that they can account for the eects of wind and human movement. The proposed method is presented and described in the form of a BASIC computer program. Analytical methods (for example ISO 7933) for the assessment of the thermal strain caused by human exposure to hot environments require a mathematical quantification of the thermal properties of clothing. These eects are usually considered in terms of ‘dry ’ thermal insulation and vapour resistance. This simple ‘model ’ of clothing can account for the insulation properties of clothing which reduce heat loss (or gain) between the body and the environment and, for example, the resistance to the transfer of evaporated sweat from the skin, which is important for cooling the body in a hot environment. When a clothed person is exposed to wind, however, and when the person is active, there is a potentially significant limitation in the simple model of clothing presented above. Heat and mass transfer can take place between the microclimate (within clothing and next to the skin surface) and the external environment. The method described in this paper ‘corrects ’ static values of clothing properties to provide dynami
