- Email: [email protected]
Human exposure assessment resources on the World Wide Web
Toxicology 198 (2004) 169–176
Human exposure assessment resources on the World Wide Web夽 Dieter Schwela1 , Pertti J. Hakkinen∗ Physical and Chemical Exposure Unit, Institute for Health and Consumer Protection, Joint Research Centre, European Commission, TP 460, I-21020 Ispra (VA), Italy
Abstract Human exposure assessment is frequently noted as a weak link and bottleneck in the risk assessment process. Fortunately, the World Wide Web and Internet are providing access to numerous valuable sources of human exposure assessment-related information, along with opportunities for information exchange. Internet mailing lists are available as potential online help for exposure assessment questions, e.g. RISKANAL has several hundred members from numerous countries. Various Web sites provide opportunities for training, e.g. Web sites offering general human exposure assessment training include two from the US Environmental Protection Agency (EPA) and four from the US National Library of Medicine. Numerous other Web sites offer access to a wide range of exposure assessment information. For example, the (US) Alliance for Chemical Awareness Web site addresses direct and indirect human exposures, occupational exposures and ecological exposure assessments. The US EPA’s Exposure Factors Program Web site provides a focal point for current information and data on exposure factors relevant to the United States. In addition, the International Society of Exposure Analysis Web site provides information about how this society seeks to foster and advance the science of exposure analysis. A major opportunity exists for risk assessors and others to broaden the level of exposure assessment information available via Web sites. Broadening the Web’s exposure information could include human exposure factors-related information about country- or region-specific ranges in body weights, drinking water consumption, etc. along with residential factors-related information on air changeovers per hour in various types of residences. Further, country- or region-specific ranges on how various tasks are performed by various types of consumers could be collected and provided. Noteworthy are that efforts are underway in Europe to develop a multi-country collection of exposure factors and the European Commission is in the early stages of planning and developing a Web-accessible information system (EIS-ChemRisks) to serve as a single gateway to all major European initiatives on human exposure to chemicals contained and released from cleaning products, textiles, toys, etc. © 2004 Elsevier Ireland Ltd. All rights reserved. Keywords: Exposure assessment; Exposure analysis; Risk assessment; Risk analysis; Internet resources; Web sites
夽 Disclaimer: Views expressed are those of the individuals and do not necessarily represent official views of the European Commission. The authors do not necessarily endorse any products or services mentioned in this paper and provided via the Web resources described. They have no editorial control over the ongoing changes in Web site contents. Readers should use caution and apply expert judgment when considering use of the information from Web sites. ∗ Corresponding author. Tel.: +39-0332-78-9249; fax: +39-0332-78-9453. E-mail addresses: [email protected] (D. Schwela), [email protected] (P.J. Hakkinen). 1 Tel.: +39-0332-78-9484.
0300-483X/$ – see front matter © 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.tox.2004.01.025
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D. Schwela, P.J. Hakkinen / Toxicology 198 (2004) 169–176
1. Introduction
2. Internet mailing lists
Human exposure occurs through contact of a physical, chemical or biological agent with a person. The development of a human exposure assessment for an agent can require a wide range of information. This potentially includes information about who and how many people might be exposed, the sources of exposure (i.e. possible natural environmental sources, consumer products, industrial uses, etc.), whether the exposure could occur through breathing air, drinking water, eating food, contact with skin, or any other routes, how often and for how long each type of exposure could occur (i.e. the frequency and duration), consideration of potential exposures to children, prospective parents and/or other subpopulations, and possible exposures to combinations of two or more physical, chemical or biological agents. The above information needs could be extended to certain physical and chemical properties and environmental fate characteristics of the chemical of interest and the identification and review of relevant existing environmental and biological monitoring methods and data, scenarios, assumptions and modelling approaches. Further, the exposure factors of interest for an exposure assessment could include those related to humans (e.g. human body weights, skin surface areas, food and drinking water consumption and activity patterns), products (e.g. the frequency and duration of a task, the amount of product used for a task and the concentration of the chemical of interest in a product) and residences or workplaces (e.g. air changeovers per hour and house and room volumes). Examples and brief descriptions of the types of sources for these data and other information available on the Internet and Web are provided below. Noteworthy is that, barring Internet problems and possible “down times” associated with various Web sites, the access to this information is available at any hour of the day and any day of the week. The following information is organised as follows: (a) Internet mailing lists, (b) Web sites providing training, (c) Web sites offering access to exposure assessment information and (d) the future, e.g. broadening the level of exposure assessment information available via Web sites.
Internet mailing lists are available for information sharing and as potential online help for exposure assessment questions. These types of mailing lists often provide responses to questions within minutes after a question is asked, perhaps from someone located on the other side of the world. RISKANAL is a discussion list focused on risk analysis. The goals of RISKANAL are to provide an opportunity to exchange and disseminate information, ideas and methodologies for risk analysis and risk management; foster understanding and professional collaboration in this field; and encourage application of risk analysis methods. It is affiliated with the Society for Risk Analysis (SRA) and was created by the Columbia-Cascades chapter of the SRA and the Pacific Northwest Laboratory. This list has over 1600 members from over 40 countries and has helped provide feedback for numerous human and environmental exposure assessment and other risk analysis questions. The SRA Web site (http://sra.org) provides additional information about this mailing list, including instructions for joining RISKANAL through http://sra.org/resources riskanal.php. RISKSCI was created and maintained by Dr. Charles Haas of Drexel University. This list is intended to contain discussion of scientific and technical issues surrounding the various aspects of risk assessment, risk management and risk communication. In addition, the policy implications of risk analysis can be discussed. To join this mailing list, the following message should be sent via the Internet to [email protected]: subscribe risksci.
3. Web sites offering general exposure assessment training Many Web sites now offer training related to exposure assessment. Particularly noteworthy are the following sites from the US Environmental Protection Agency (EPA) and the US National Library of Medicine: US EPA’s Office of Pollution Prevention and Toxics (OPPT) has developed several exposure assessment methods, databases and predictive models to help in estimating the fate of chemicals when they are used
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and released to the environment, and how workers, the general public and consumers are exposed to them. The information is published on two Web sites under the headings: • “What is an Exposure Assessment?” (www.epa. gov/opptintr/exposure/docs/exposurep.htm) and • “What is the OPPT’s approach to Exposure Assessment?” (www.epa.gov/opptintr/exposure/ docs/opptexpo.htm), which can be accessed via the OPPT “Exposure Assessment Tools and Models” Web site www.epa.gov/opptintr/exposure/index. htm. US National Library of Medicine’s “Haz-Map®” is an occupational toxicology database, which links hazardous job tasks to occupational diseases and their symptoms. The over 1500 chemical and biological agents in this database are linked to industrial processes and non-occupational activities, with the linkage indicating the potential for exposure to the agent. Further, the over 180 occupational diseases in the database are linked to findings (signs and symptoms of the disease) and hazardous job tasks, with the linkage to a hazardous job task indicating an increased risk for significant exposure and subsequent disease. In this database, acute diseases and infectious diseases are linked to jobs while chronic occupational diseases are linked to both jobs and industries (cancers are not directly linked to jobs, industries or findings). The Web site of Haz-Map® is http://hazmap.nlm.nih.gov/abouthazmap.html. US National Library of Medicine’s “Household Products Database” is based on the Consumer Product Information Database© by DeLima Associates and links over 4000 consumer product brands in the US to health effects indicated in Material Safety Data Sheets (MSDS) provided by the manufacturers. Its Web site is http://hpd.nlm.nih.gov/. Product categories include auto products, “homeinside” products, pesticides, “landscape/yard” products, “personal care/use” products, home maintenance products and products for hobbies and crafts. This database allows scientists and consumers to research products based on chemical ingredients and to research chemical ingredients via a product category or individual product. The database is designed to help answer questions about the chemical ingredients and their levels in specific brands, the products contain-
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ing specific chemical ingredients of interest and the manufacturer of a specific brand. Further, information is provided about how to contact a manufacturer, on the acute and chronic effects of chemical ingredients in a specific brand and what other information is available about a chemical of interest in the toxicology-related databases of the National Library of Medicine: http://hpd.nlm.nih.gov/. US National Library of Medicine’s “ToxTown,” is an “introduction to toxic chemicals and environmental health risks you might encounter in everyday life, in everyday places.” Users can select locations in the “Town” or the “City” to learn about suburban or urban health risks. Clicking on one of the locations gives Web-based information on chemical and environmental concerns one might find in that location. Information includes non-technical descriptions of chemicals, links to select, authoritative information on the impacts on human health and resources on environmental health topics. Its Web site is http://toxtown.nlm.nih.gov/. In addition to the above, the US National Library of Medicine’s Specialized Information Services have developed several exposure assessment-, toxicologyand risk assessment-related tutorials: “Toxicology Tutor Part I—Basic Principles, Part II—Toxicokinetics and Part III—Cellular Toxicology”. Toxicology Tutor is a set of tutorials on toxicology produced by the Toxicology and Environmental Health Information Program of the National Library of Medicine and the US Department of Health and Human Services. It covers the basic principles of toxicology and related topics and is written at the introductory college student level. With respect to exposure assessment, the sections “Risk Assessment” and “Exposure Standards and Guidelines” in Toxicology Tutor I are of relevance. The tutorials can be accessed via http://sis.nlm.nih.gov/Tox/ToxTutor.html and http://sis.nlm.nih.gov/Main/search.html.
4. Web Sites offering access to exposure assessment information Numerous Web sites now offer access to exposure assessment information. Particularly noteworthy are sites from the US EPA and other organisations in the United States.
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4.1. US Agency for Toxic Substances and Disease Registry (ATSDR) The web site of the ATSDR www.atsdr.cdc.gov/ produces “Toxicological Profiles” for hazardous substances found at National Priorities List (NPL) sites. These hazardous substances are ranked based on frequency of occurrence at NPL sites, toxicity and potential for human exposure. Toxicological profiles are developed from a priority list of 275 substances. ATSDR is reformatting its Toxicological Profiles to expand coverage of “the specialized toxicology of children”: www.atsdr.cdc.gov/child/ochchildhlth.html. This Web site provides access to children’s health issues activities within ATDSR. Future Toxicological Profiles will include information on children’s exposure, the alteration of the developmental process by exposure, children’s susceptibility and health. This includes addressing whether there are any known or possible unique exposure pathways for children associated with a particular chemical. 4.2. US Alliance for Chemical Awareness (ACA) ACA’s Web site www.chemicalawareness.org provides support for the US High Production Volume (HPV) Chemical Challenge Program, which collects and publicises an initial set of hazards data about large volume chemicals, based on the “Standard Initial Data Set” (SIDS) endpoints defined under the Organisation for Economic Co-operation and Development’s’ Existing Chemicals program. The US program does not specifically call for the publication of information about chemical use and exposure. However, the ACA believes that such information will be important for future priority setting and risk management, as well as communications with the public about the practical relevance of HPV chemicals hazard data. The ACA’s goal is to provide information to chemical sponsors on how to place the data in the HPV submissions into a risk-based context. The technical component of this effort focuses on providing all the information HPV chemical sponsors and others would need to conduct direct and indirect human exposure, occupational exposure and ecological exposure assessments. The Web site provides frameworks for conducting the assessments, access to information about software and databases for conducting the
assessments and resource and training materials. A related effort for household cleaning product chemicals in Europe is the “Human and Environmental Risk Assessment” project (HERA). The Human and Environmental Risk Assessment (HERA) project (www.heraproject.com) is a European voluntary initiative launched in 1999 by the “Association Internationale de la Savonnerie, de la Détergence et des Produits d’Entretien” (AISE, International Association for Soaps, Detergents and Maintenance Products) representing the formulators and manufacturers of household cleaning products and the European Chemical Industry Council (Cefic, Counsul Europe’en de L’Industrie Chimique), representing the suppliers and manufacturers of the raw materials. Combining hazard with exposure information, HERA’s objective is to provide a common risk assessment framework for the household cleaning products industry and to show how this process will deliver evaluated risk information on the ingredients used in these products in an effective and transparent way. This process is intended to support a risk-based approach to chemicals legislation in the European Union and may serve as a pilot for the application of the same process in other sectors and/or geographical areas. The intended outcome of the HERA process will be the delivery of standardised risk assessment reports based on exposure and hazard assessment. 4.3. European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) ECETOC’s focus includes the manufacture, processing, handling and use of chemicals. ECETOC also co-operates with governmental agencies and other organisations concerned with the effects of chemicals on health and the environment. The Web site (www.ecetoc.org/entry.htm) contains information about ECETOC documents focused on exposure assessment, e.g. ones on the “Exposure Factors Sourcebook for European Populations (with Focus on UK Data),” and the “Assessment of Non-Occupational Exposure to Chemicals. 4.4. European Commission: European Chemicals Bureau (ECB) The ECB’s Existing Chemicals work area conducts data collection, priority setting and risk assessment
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of existing chemicals following Council Regulation (EEC) 793/93. Exposure and risk assessment documents of Existing Chemicals are available in the Existing Chemicals section of the ECB Web site (http://ecb.ei.jrc.it/), along with information about The International Uniform Chemical Information Database (IUCLID), the European Union System for the Evaluation of Substances (EUSES) and The Harmonized Electronic Data Set (HEDSET). The ECB’s New Chemicals work area is responsible for notification of new chemical substances to be placed on the European Market and includes risk assessment guidance and other information for new chemicals, e.g. a set of Technical Guidance Documents (TGDs) has been developed for new and existing chemicals. The TGDs include guidance and resource information on conducting human and environmental exposure assessments, e.g. occupational exposures and exposures associated with the use of consumer products.
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Environment Programme (UNEP), the International Labour Organisation (ILO) and the World Health Organization (WHO). The purpose of IPCS is to establish the scientific basis for safe use of chemicals and to strengthen national capabilities and capacities for chemical safety. IPCS evaluates chemical risks to human health and the environment and develops methodologies for these evaluations. Many of the IPCS documents are available on-line (www.who.int/pcs/index.htm and www.who.int/pcs/ pcs pubs.html). While ordering, instructions are provided for the rest. Risk assessment documents for specific substances are produced by a number of IPCS and WHO programmes and activities. include:
The Web site (www.scorecard.org/) includes information about chemical releases in the United States and provides information about local air pollution. Included are interactive maps that can be accessed by zip code; information on toxic chemicals released by manufacturing facilities and information about the health risks of air pollution. Scorecard ranks and compares pollution in areas across the US and profiles 6800 chemicals, showing locations in which they are used as well as their hazards. Scorecard integrates several hundred scientific and governmental databases to generate the profiles. Scorecard combines exposure estimates of annual average outdoor concentrations of 41 hazardous air pollutants (HAPs) from US EPA’s National-Scale Air Toxics Assessment (NATA) with toxicity data to estimate the health risks posed by chemical pollutants in ambient air. NATA currently provides the only data available for assessing the extent of exposures to hazardous air pollutants across the entire United States.
• Environmental Health Criteria Documents (EHC) http://www.inchem.org/pages/ehc.html, Health and Safety Guides (HSG), http://www.inchem.org/ pages/hsg.html, • Concise International Chemical Assessment Documents (CICAD) http://www.inchem.org/pages/ cicads.html, • Evaluations of the Joint FAO/WHO Expert Committee on Food Additives (JECFA), http://www. inchem.org/pages/jecfa.html, • Evaluations of the Joint FAO/WHO Meeting on Pesticide Residues (JMPR), http://www.inchem.org/ pages/jmpr.html, • WHO Drinking Water Quality Guidelines, http:// www.who.int/water sanitation health/dwq/ guidelines/en/, • WHO Air Quality Guidelines for Europe, http:// www.who.dk/InformationSources/Publications/ Catalogue/20010910 6, • WHO Guidelines for Air Quality, http://www. who.int/phe/air/pheair/en/, • WHO Recommended Classification of Pesticides by Hazard and Guidelines to Classification 2000– 2002, http://www.inchem.org/documents/pds/ pdsother/class.pdf. • Screening Information Data Sets (SIDS) for HPV chemicals, http://www.inchem.org/pages/sids. html.
4.6. International Programme on Chemical Safety (IPCS)
4.7. International Society of Exposure Analysis (ISEA)
The International Programme on Chemical Safety (IPCS) is a joint program of the United Nations
ISEA was established in 1989 to foster and advance the science of exposure analysis related to environ-
4.5. Environmental Defense (ED)
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mental contaminants, both for human populations and ecosystems. The membership of several hundred scientists and others promotes communication among all disciplines involved in exposure analysis, recommends exposure analysis approaches to address substantive or methodological concerns and works to strengthen the impact of exposure assessment on environmental policy. Announcements for upcoming ISEA meeting are available and ISEA members have access through the Web site (www.iseaweb.org/) to current and recent issues of ISEA’s peer-reviewed journal, the Journal of Exposure Analysis and Environmental Epidemiology. 4.8. Organisation for Economic Co-operation and Development (OECD) OECD’s Web site (www.oecd.org/home/) includes access to various types of exposure assessment-related documents, e.g. “Environment Monograph No.70: Occupational and Consumer Exposure Assessments” (www.olis.oecd.org/olis/1993doc.nsf/LinkTo/ocdegd(93)128). In this monograph, the OECD provides guidance for the initial assessment of the occupational and consumer exposure of HPV chemicals. As noted above, information on various compounds based on this guidance can be found in the recent Screening Information Data Set (SIDS) documents at: www.inchem.org/pages/sids.html. Also see: www.chem.unep.ch/irptc/sids/volume10/sids10 intro.pdf. OECD’s efforts also include a “Database on Chemical Risk Assessment Models” Web site (http:// webdomino1.oecd.org/comnet/env/models.nsf) offering models predicting human health or environmental exposure potential and the potential environmental, worker or consumer risks. This searchable database includes information on models (computerised or capable of being computerised) that are used by OECD Member governments and industry to predict health or environmental effects (e.g. QSARs), exposure potential and possible risks. 4.9. RiskWorld RiskWorld, designed and maintained by Tec-Com, is a comprehensive Web site (www.riskworld.com) including news releases on exposure assessment and
other risk assessment-related topics and issues, a virtual library of reports and papers, announcements for various events, calls for papers and listings for grants and fellowships and job openings. RiskWorld also has numerous links to organisations and societies, databases, software, journals, newsletters, papers and reports. 4.10. Society for Risk Analysis (SRA) SRA is a multi-disciplinary international society designed to provide opportunities to exchange information, ideas and methodologies for risk analysis. Risk analysis is broadly defined to include risk assessment, risk characterization, risk communication, risk management and policy relating to risk. SRA’s commitment includes risks to human health and the environment, both built and natural, from physical, chemical and biological agents and from a variety of human activities as well as natural events. SRA’s approximately 2000 members include many exposure assessors. The Society’s RISK newsletter and annual meeting abstracts are available from the Web site and SRA members have access through the Web site to current and recent issues of SRA’s peer-reviewed journal, Risk Analysis: An International Journal (www.sra.org). 4.11. US EPA’s Exposure Assessment Tools and Models Web Site Noted earlier as a link to training materials, this site (www.epa.gov/opptintr/exposure) includes several exposure assessment methods, databases and predictive models to help evaluate consumer, public (“general population”), worker and environmental exposures to chemicals and has a general discussion about the role of exposure assessment and how to appropriately apply models. These models and tools are intended to be used by scientists and engineers familiar with exposure assessment principles. They may be helpful when appropriate monitoring data are not available or need to be supplemented and in considering potential exposure when designing and selecting products and processes and evaluating pollution prevention opportunities.
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4.12. US EPA National Center for Exposure Assessment’s (NCEA) Exposure Factors Program The NCEA Program states at the Web site: http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm? deid = 20563: “The need for the most up-to-date and accurate data on exposure factors used in assessing exposure to contaminants in the environment is of high priority to exposure assessors throughout the US. The completion of the Exposure Factors Handbook has only been the first step in fulfilling this need. Many data needs have been identified and follow-up research is underway to address some of the data gaps. This Web page is intended to provide a focal point where the most current information and data on exposure factors can be found.” For example, this Web site provides access to US EPA’s “Exposure Factors Handbook.” The Exposure Factors Handbook provides a US-focused summary of the available statistical data on various factors used in assessing human exposure. This Handbook is addressed to exposure assessors inside US EPA as well as outside, who need to obtain data on standard factors to calculate human exposure to toxic chemicals. These factors include: drinking water consumption, soil ingestion, inhalation rates, dermal factors including skin area and soil adherence factors, consumption of fruits and vegetables, fish, meats, dairy products, home-grown foods, breast milk intake, human activity factors, consumer product use and residential characteristics. Recommended values are for the general population and also for various segments of the population who may have characteristics different from the general population. The NCEA also developed a “Child-Specific Exposure Factors Handbook,” and access to other EPA-developed exposure assessment guidance and resource documents: see Web site: http://cfpub.epa. gov/ncea/cfm/recordisplay.cfm?deid=12464. 4.13. US EPA’s Guidelines for Exposure Assessment See Web site: www.epa.gov/nceawww1/exposure. htm. “US EPA’s Guidelines for Exposure Assessment, 1992 establish a broad framework for Agency exposure assessments by describing the general concepts of exposure assessment including definitions and associated units and by providing guidance on
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the planning and conducting of an exposure assessment. Guidance is also provided on presenting the results of the exposure assessment and characterising uncertainty.” The document also includes a “General Concepts in Exposure Assessment” section, a “Planning an Exposure Assessment” section offering guidance on screening-level and other types of approaches, a section offering guidance on “Reviewing Exposure Assessments,” and a “Glossary of Terms (US EPA, 1992).” 4.14. US EPA’s Toxics Release Inventory (TRI) Web site The TRI is a publicly accessible toxic chemical database (www.epa.gov/tri) containing information about the use, manufacture, treatment, transport, or release of toxic chemicals into the US environment. It is based on the Emergency Planning and Community Right to Know Act, giving every US citizen the right to know about toxic chemicals that are being released into his community. The Toxics Release Inventory contains information on releases of nearly 650 chemicals and chemical categories from industries including manufacturing, metal and coal mining, electric utilities and commercial hazardous waste treatment, among others.
5. The future—broadening the level of exposure assessment information available via Web Sites Additional information about current Web sites and Internet mailing lists of possible interest o exposure assessors, toxicologists and others is available (Patterson et al., 2002; Wexler et al., 2000) and it should be very apparent from the above examples that the Internet and Web are providing exposure assessors and others around the world with 24 h a day access to numerous valuable sources of information and opportunities for information exchange. As noted in an earlier publication (Hakkinen, 2001), a major opportunity exists for risk assessors and others to broaden the level of exposure assessment information available via Web sites. The exposure information currently available on the Web primarily focuses on the US, largely due to US EPA and other US-focused efforts to have this information available
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on the Web. Broadening the Web’s exposure information could include information about human physical characteristics (e.g. country- or region-specific ranges in body weights, drinking water consumption etc.), the types of residences and workplaces and the exposure factors associated with them (e.g. air changeovers per hour in various types of residences and how various tasks are performed by consumers and workers) and country- and region-specific ranges of climatic conditions. Any non-US exposure-related information could be incorporated into Web sites providing more globally representative information than that currently offered via US EPA efforts. Noteworthy is that efforts are underway by European scientists to develop a European (multi-country) version of the US EPA’s Exposure Factors Handbook and by the European Commission to develop the European information system (EIS-ChemRisks) on risks to human health The Exposure Factors Sourcebook for Europe (ExpoFacts), www.ktl.fi/expofacts/ will be a Web-based resource compiled from extensive national and international data that is both published and unpublished. The goal for EIS-ChemRisks (contact the authors or see http://ihcp.jrc.it/ for updates on status) is to sys-
tematically collect, store and assess information on human exposure to chemicals released from consumer products, along with providing a single web-based gateway to all major European initiatives on human exposure to chemicals contained and released from products. It is expected that many additional exposure assessment-related Web sites will be created in the future by regulatory agencies, professional societies and other organisations. These would provide further valuable information for use around the world and for specific locations and other localised needs.
References Hakkinen, P.J., 2001. Global toxicology and risk analysis: roles of the Internet and World Wide Web. Toxicology 160, 59–63. Patterson, J., Hakkinen, P.J., Wullenweber, A.E., 2002. Human health risk assessment: selected Internet and World Wide Web resources. Toxicology 173, 123–143. US EPA’s, 1992. Guidelines for Exposure Assessment. Federal Register, Vol. 57, pp. 22888–22938. Wexler, P., Hakkinen, P.J., Stoss, F.W., 2000. Internet and Other Digital Resources. In: Wexler, P., Hakkinen, P.J. Kennedy, G. Jr., Stoss, F.W. (Eds.), Information Resources in Toxicology, Academic Press, San Diego, pp. 287–332
Human exposure assessment resources on the World Wide Web夽 Dieter Schwela1 , Pertti J. Hakkinen∗ Physical and Chemical Exposure Unit, Institute for Health and Consumer Protection, Joint Research Centre, European Commission, TP 460, I-21020 Ispra (VA), Italy
Abstract Human exposure assessment is frequently noted as a weak link and bottleneck in the risk assessment process. Fortunately, the World Wide Web and Internet are providing access to numerous valuable sources of human exposure assessment-related information, along with opportunities for information exchange. Internet mailing lists are available as potential online help for exposure assessment questions, e.g. RISKANAL has several hundred members from numerous countries. Various Web sites provide opportunities for training, e.g. Web sites offering general human exposure assessment training include two from the US Environmental Protection Agency (EPA) and four from the US National Library of Medicine. Numerous other Web sites offer access to a wide range of exposure assessment information. For example, the (US) Alliance for Chemical Awareness Web site addresses direct and indirect human exposures, occupational exposures and ecological exposure assessments. The US EPA’s Exposure Factors Program Web site provides a focal point for current information and data on exposure factors relevant to the United States. In addition, the International Society of Exposure Analysis Web site provides information about how this society seeks to foster and advance the science of exposure analysis. A major opportunity exists for risk assessors and others to broaden the level of exposure assessment information available via Web sites. Broadening the Web’s exposure information could include human exposure factors-related information about country- or region-specific ranges in body weights, drinking water consumption, etc. along with residential factors-related information on air changeovers per hour in various types of residences. Further, country- or region-specific ranges on how various tasks are performed by various types of consumers could be collected and provided. Noteworthy are that efforts are underway in Europe to develop a multi-country collection of exposure factors and the European Commission is in the early stages of planning and developing a Web-accessible information system (EIS-ChemRisks) to serve as a single gateway to all major European initiatives on human exposure to chemicals contained and released from cleaning products, textiles, toys, etc. © 2004 Elsevier Ireland Ltd. All rights reserved. Keywords: Exposure assessment; Exposure analysis; Risk assessment; Risk analysis; Internet resources; Web sites
夽 Disclaimer: Views expressed are those of the individuals and do not necessarily represent official views of the European Commission. The authors do not necessarily endorse any products or services mentioned in this paper and provided via the Web resources described. They have no editorial control over the ongoing changes in Web site contents. Readers should use caution and apply expert judgment when considering use of the information from Web sites. ∗ Corresponding author. Tel.: +39-0332-78-9249; fax: +39-0332-78-9453. E-mail addresses: [email protected] (D. Schwela), [email protected] (P.J. Hakkinen). 1 Tel.: +39-0332-78-9484.
0300-483X/$ – see front matter © 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.tox.2004.01.025
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D. Schwela, P.J. Hakkinen / Toxicology 198 (2004) 169–176
1. Introduction
2. Internet mailing lists
Human exposure occurs through contact of a physical, chemical or biological agent with a person. The development of a human exposure assessment for an agent can require a wide range of information. This potentially includes information about who and how many people might be exposed, the sources of exposure (i.e. possible natural environmental sources, consumer products, industrial uses, etc.), whether the exposure could occur through breathing air, drinking water, eating food, contact with skin, or any other routes, how often and for how long each type of exposure could occur (i.e. the frequency and duration), consideration of potential exposures to children, prospective parents and/or other subpopulations, and possible exposures to combinations of two or more physical, chemical or biological agents. The above information needs could be extended to certain physical and chemical properties and environmental fate characteristics of the chemical of interest and the identification and review of relevant existing environmental and biological monitoring methods and data, scenarios, assumptions and modelling approaches. Further, the exposure factors of interest for an exposure assessment could include those related to humans (e.g. human body weights, skin surface areas, food and drinking water consumption and activity patterns), products (e.g. the frequency and duration of a task, the amount of product used for a task and the concentration of the chemical of interest in a product) and residences or workplaces (e.g. air changeovers per hour and house and room volumes). Examples and brief descriptions of the types of sources for these data and other information available on the Internet and Web are provided below. Noteworthy is that, barring Internet problems and possible “down times” associated with various Web sites, the access to this information is available at any hour of the day and any day of the week. The following information is organised as follows: (a) Internet mailing lists, (b) Web sites providing training, (c) Web sites offering access to exposure assessment information and (d) the future, e.g. broadening the level of exposure assessment information available via Web sites.
Internet mailing lists are available for information sharing and as potential online help for exposure assessment questions. These types of mailing lists often provide responses to questions within minutes after a question is asked, perhaps from someone located on the other side of the world. RISKANAL is a discussion list focused on risk analysis. The goals of RISKANAL are to provide an opportunity to exchange and disseminate information, ideas and methodologies for risk analysis and risk management; foster understanding and professional collaboration in this field; and encourage application of risk analysis methods. It is affiliated with the Society for Risk Analysis (SRA) and was created by the Columbia-Cascades chapter of the SRA and the Pacific Northwest Laboratory. This list has over 1600 members from over 40 countries and has helped provide feedback for numerous human and environmental exposure assessment and other risk analysis questions. The SRA Web site (http://sra.org) provides additional information about this mailing list, including instructions for joining RISKANAL through http://sra.org/resources riskanal.php. RISKSCI was created and maintained by Dr. Charles Haas of Drexel University. This list is intended to contain discussion of scientific and technical issues surrounding the various aspects of risk assessment, risk management and risk communication. In addition, the policy implications of risk analysis can be discussed. To join this mailing list, the following message should be sent via the Internet to [email protected]: subscribe risksci.
3. Web sites offering general exposure assessment training Many Web sites now offer training related to exposure assessment. Particularly noteworthy are the following sites from the US Environmental Protection Agency (EPA) and the US National Library of Medicine: US EPA’s Office of Pollution Prevention and Toxics (OPPT) has developed several exposure assessment methods, databases and predictive models to help in estimating the fate of chemicals when they are used
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and released to the environment, and how workers, the general public and consumers are exposed to them. The information is published on two Web sites under the headings: • “What is an Exposure Assessment?” (www.epa. gov/opptintr/exposure/docs/exposurep.htm) and • “What is the OPPT’s approach to Exposure Assessment?” (www.epa.gov/opptintr/exposure/ docs/opptexpo.htm), which can be accessed via the OPPT “Exposure Assessment Tools and Models” Web site www.epa.gov/opptintr/exposure/index. htm. US National Library of Medicine’s “Haz-Map®” is an occupational toxicology database, which links hazardous job tasks to occupational diseases and their symptoms. The over 1500 chemical and biological agents in this database are linked to industrial processes and non-occupational activities, with the linkage indicating the potential for exposure to the agent. Further, the over 180 occupational diseases in the database are linked to findings (signs and symptoms of the disease) and hazardous job tasks, with the linkage to a hazardous job task indicating an increased risk for significant exposure and subsequent disease. In this database, acute diseases and infectious diseases are linked to jobs while chronic occupational diseases are linked to both jobs and industries (cancers are not directly linked to jobs, industries or findings). The Web site of Haz-Map® is http://hazmap.nlm.nih.gov/abouthazmap.html. US National Library of Medicine’s “Household Products Database” is based on the Consumer Product Information Database© by DeLima Associates and links over 4000 consumer product brands in the US to health effects indicated in Material Safety Data Sheets (MSDS) provided by the manufacturers. Its Web site is http://hpd.nlm.nih.gov/. Product categories include auto products, “homeinside” products, pesticides, “landscape/yard” products, “personal care/use” products, home maintenance products and products for hobbies and crafts. This database allows scientists and consumers to research products based on chemical ingredients and to research chemical ingredients via a product category or individual product. The database is designed to help answer questions about the chemical ingredients and their levels in specific brands, the products contain-
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ing specific chemical ingredients of interest and the manufacturer of a specific brand. Further, information is provided about how to contact a manufacturer, on the acute and chronic effects of chemical ingredients in a specific brand and what other information is available about a chemical of interest in the toxicology-related databases of the National Library of Medicine: http://hpd.nlm.nih.gov/. US National Library of Medicine’s “ToxTown,” is an “introduction to toxic chemicals and environmental health risks you might encounter in everyday life, in everyday places.” Users can select locations in the “Town” or the “City” to learn about suburban or urban health risks. Clicking on one of the locations gives Web-based information on chemical and environmental concerns one might find in that location. Information includes non-technical descriptions of chemicals, links to select, authoritative information on the impacts on human health and resources on environmental health topics. Its Web site is http://toxtown.nlm.nih.gov/. In addition to the above, the US National Library of Medicine’s Specialized Information Services have developed several exposure assessment-, toxicologyand risk assessment-related tutorials: “Toxicology Tutor Part I—Basic Principles, Part II—Toxicokinetics and Part III—Cellular Toxicology”. Toxicology Tutor is a set of tutorials on toxicology produced by the Toxicology and Environmental Health Information Program of the National Library of Medicine and the US Department of Health and Human Services. It covers the basic principles of toxicology and related topics and is written at the introductory college student level. With respect to exposure assessment, the sections “Risk Assessment” and “Exposure Standards and Guidelines” in Toxicology Tutor I are of relevance. The tutorials can be accessed via http://sis.nlm.nih.gov/Tox/ToxTutor.html and http://sis.nlm.nih.gov/Main/search.html.
4. Web Sites offering access to exposure assessment information Numerous Web sites now offer access to exposure assessment information. Particularly noteworthy are sites from the US EPA and other organisations in the United States.
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4.1. US Agency for Toxic Substances and Disease Registry (ATSDR) The web site of the ATSDR www.atsdr.cdc.gov/ produces “Toxicological Profiles” for hazardous substances found at National Priorities List (NPL) sites. These hazardous substances are ranked based on frequency of occurrence at NPL sites, toxicity and potential for human exposure. Toxicological profiles are developed from a priority list of 275 substances. ATSDR is reformatting its Toxicological Profiles to expand coverage of “the specialized toxicology of children”: www.atsdr.cdc.gov/child/ochchildhlth.html. This Web site provides access to children’s health issues activities within ATDSR. Future Toxicological Profiles will include information on children’s exposure, the alteration of the developmental process by exposure, children’s susceptibility and health. This includes addressing whether there are any known or possible unique exposure pathways for children associated with a particular chemical. 4.2. US Alliance for Chemical Awareness (ACA) ACA’s Web site www.chemicalawareness.org provides support for the US High Production Volume (HPV) Chemical Challenge Program, which collects and publicises an initial set of hazards data about large volume chemicals, based on the “Standard Initial Data Set” (SIDS) endpoints defined under the Organisation for Economic Co-operation and Development’s’ Existing Chemicals program. The US program does not specifically call for the publication of information about chemical use and exposure. However, the ACA believes that such information will be important for future priority setting and risk management, as well as communications with the public about the practical relevance of HPV chemicals hazard data. The ACA’s goal is to provide information to chemical sponsors on how to place the data in the HPV submissions into a risk-based context. The technical component of this effort focuses on providing all the information HPV chemical sponsors and others would need to conduct direct and indirect human exposure, occupational exposure and ecological exposure assessments. The Web site provides frameworks for conducting the assessments, access to information about software and databases for conducting the
assessments and resource and training materials. A related effort for household cleaning product chemicals in Europe is the “Human and Environmental Risk Assessment” project (HERA). The Human and Environmental Risk Assessment (HERA) project (www.heraproject.com) is a European voluntary initiative launched in 1999 by the “Association Internationale de la Savonnerie, de la Détergence et des Produits d’Entretien” (AISE, International Association for Soaps, Detergents and Maintenance Products) representing the formulators and manufacturers of household cleaning products and the European Chemical Industry Council (Cefic, Counsul Europe’en de L’Industrie Chimique), representing the suppliers and manufacturers of the raw materials. Combining hazard with exposure information, HERA’s objective is to provide a common risk assessment framework for the household cleaning products industry and to show how this process will deliver evaluated risk information on the ingredients used in these products in an effective and transparent way. This process is intended to support a risk-based approach to chemicals legislation in the European Union and may serve as a pilot for the application of the same process in other sectors and/or geographical areas. The intended outcome of the HERA process will be the delivery of standardised risk assessment reports based on exposure and hazard assessment. 4.3. European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) ECETOC’s focus includes the manufacture, processing, handling and use of chemicals. ECETOC also co-operates with governmental agencies and other organisations concerned with the effects of chemicals on health and the environment. The Web site (www.ecetoc.org/entry.htm) contains information about ECETOC documents focused on exposure assessment, e.g. ones on the “Exposure Factors Sourcebook for European Populations (with Focus on UK Data),” and the “Assessment of Non-Occupational Exposure to Chemicals. 4.4. European Commission: European Chemicals Bureau (ECB) The ECB’s Existing Chemicals work area conducts data collection, priority setting and risk assessment
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of existing chemicals following Council Regulation (EEC) 793/93. Exposure and risk assessment documents of Existing Chemicals are available in the Existing Chemicals section of the ECB Web site (http://ecb.ei.jrc.it/), along with information about The International Uniform Chemical Information Database (IUCLID), the European Union System for the Evaluation of Substances (EUSES) and The Harmonized Electronic Data Set (HEDSET). The ECB’s New Chemicals work area is responsible for notification of new chemical substances to be placed on the European Market and includes risk assessment guidance and other information for new chemicals, e.g. a set of Technical Guidance Documents (TGDs) has been developed for new and existing chemicals. The TGDs include guidance and resource information on conducting human and environmental exposure assessments, e.g. occupational exposures and exposures associated with the use of consumer products.
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Environment Programme (UNEP), the International Labour Organisation (ILO) and the World Health Organization (WHO). The purpose of IPCS is to establish the scientific basis for safe use of chemicals and to strengthen national capabilities and capacities for chemical safety. IPCS evaluates chemical risks to human health and the environment and develops methodologies for these evaluations. Many of the IPCS documents are available on-line (www.who.int/pcs/index.htm and www.who.int/pcs/ pcs pubs.html). While ordering, instructions are provided for the rest. Risk assessment documents for specific substances are produced by a number of IPCS and WHO programmes and activities. include:
The Web site (www.scorecard.org/) includes information about chemical releases in the United States and provides information about local air pollution. Included are interactive maps that can be accessed by zip code; information on toxic chemicals released by manufacturing facilities and information about the health risks of air pollution. Scorecard ranks and compares pollution in areas across the US and profiles 6800 chemicals, showing locations in which they are used as well as their hazards. Scorecard integrates several hundred scientific and governmental databases to generate the profiles. Scorecard combines exposure estimates of annual average outdoor concentrations of 41 hazardous air pollutants (HAPs) from US EPA’s National-Scale Air Toxics Assessment (NATA) with toxicity data to estimate the health risks posed by chemical pollutants in ambient air. NATA currently provides the only data available for assessing the extent of exposures to hazardous air pollutants across the entire United States.
• Environmental Health Criteria Documents (EHC) http://www.inchem.org/pages/ehc.html, Health and Safety Guides (HSG), http://www.inchem.org/ pages/hsg.html, • Concise International Chemical Assessment Documents (CICAD) http://www.inchem.org/pages/ cicads.html, • Evaluations of the Joint FAO/WHO Expert Committee on Food Additives (JECFA), http://www. inchem.org/pages/jecfa.html, • Evaluations of the Joint FAO/WHO Meeting on Pesticide Residues (JMPR), http://www.inchem.org/ pages/jmpr.html, • WHO Drinking Water Quality Guidelines, http:// www.who.int/water sanitation health/dwq/ guidelines/en/, • WHO Air Quality Guidelines for Europe, http:// www.who.dk/InformationSources/Publications/ Catalogue/20010910 6, • WHO Guidelines for Air Quality, http://www. who.int/phe/air/pheair/en/, • WHO Recommended Classification of Pesticides by Hazard and Guidelines to Classification 2000– 2002, http://www.inchem.org/documents/pds/ pdsother/class.pdf. • Screening Information Data Sets (SIDS) for HPV chemicals, http://www.inchem.org/pages/sids. html.
4.6. International Programme on Chemical Safety (IPCS)
4.7. International Society of Exposure Analysis (ISEA)
The International Programme on Chemical Safety (IPCS) is a joint program of the United Nations
ISEA was established in 1989 to foster and advance the science of exposure analysis related to environ-
4.5. Environmental Defense (ED)
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mental contaminants, both for human populations and ecosystems. The membership of several hundred scientists and others promotes communication among all disciplines involved in exposure analysis, recommends exposure analysis approaches to address substantive or methodological concerns and works to strengthen the impact of exposure assessment on environmental policy. Announcements for upcoming ISEA meeting are available and ISEA members have access through the Web site (www.iseaweb.org/) to current and recent issues of ISEA’s peer-reviewed journal, the Journal of Exposure Analysis and Environmental Epidemiology. 4.8. Organisation for Economic Co-operation and Development (OECD) OECD’s Web site (www.oecd.org/home/) includes access to various types of exposure assessment-related documents, e.g. “Environment Monograph No.70: Occupational and Consumer Exposure Assessments” (www.olis.oecd.org/olis/1993doc.nsf/LinkTo/ocdegd(93)128). In this monograph, the OECD provides guidance for the initial assessment of the occupational and consumer exposure of HPV chemicals. As noted above, information on various compounds based on this guidance can be found in the recent Screening Information Data Set (SIDS) documents at: www.inchem.org/pages/sids.html. Also see: www.chem.unep.ch/irptc/sids/volume10/sids10 intro.pdf. OECD’s efforts also include a “Database on Chemical Risk Assessment Models” Web site (http:// webdomino1.oecd.org/comnet/env/models.nsf) offering models predicting human health or environmental exposure potential and the potential environmental, worker or consumer risks. This searchable database includes information on models (computerised or capable of being computerised) that are used by OECD Member governments and industry to predict health or environmental effects (e.g. QSARs), exposure potential and possible risks. 4.9. RiskWorld RiskWorld, designed and maintained by Tec-Com, is a comprehensive Web site (www.riskworld.com) including news releases on exposure assessment and
other risk assessment-related topics and issues, a virtual library of reports and papers, announcements for various events, calls for papers and listings for grants and fellowships and job openings. RiskWorld also has numerous links to organisations and societies, databases, software, journals, newsletters, papers and reports. 4.10. Society for Risk Analysis (SRA) SRA is a multi-disciplinary international society designed to provide opportunities to exchange information, ideas and methodologies for risk analysis. Risk analysis is broadly defined to include risk assessment, risk characterization, risk communication, risk management and policy relating to risk. SRA’s commitment includes risks to human health and the environment, both built and natural, from physical, chemical and biological agents and from a variety of human activities as well as natural events. SRA’s approximately 2000 members include many exposure assessors. The Society’s RISK newsletter and annual meeting abstracts are available from the Web site and SRA members have access through the Web site to current and recent issues of SRA’s peer-reviewed journal, Risk Analysis: An International Journal (www.sra.org). 4.11. US EPA’s Exposure Assessment Tools and Models Web Site Noted earlier as a link to training materials, this site (www.epa.gov/opptintr/exposure) includes several exposure assessment methods, databases and predictive models to help evaluate consumer, public (“general population”), worker and environmental exposures to chemicals and has a general discussion about the role of exposure assessment and how to appropriately apply models. These models and tools are intended to be used by scientists and engineers familiar with exposure assessment principles. They may be helpful when appropriate monitoring data are not available or need to be supplemented and in considering potential exposure when designing and selecting products and processes and evaluating pollution prevention opportunities.
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4.12. US EPA National Center for Exposure Assessment’s (NCEA) Exposure Factors Program The NCEA Program states at the Web site: http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm? deid = 20563: “The need for the most up-to-date and accurate data on exposure factors used in assessing exposure to contaminants in the environment is of high priority to exposure assessors throughout the US. The completion of the Exposure Factors Handbook has only been the first step in fulfilling this need. Many data needs have been identified and follow-up research is underway to address some of the data gaps. This Web page is intended to provide a focal point where the most current information and data on exposure factors can be found.” For example, this Web site provides access to US EPA’s “Exposure Factors Handbook.” The Exposure Factors Handbook provides a US-focused summary of the available statistical data on various factors used in assessing human exposure. This Handbook is addressed to exposure assessors inside US EPA as well as outside, who need to obtain data on standard factors to calculate human exposure to toxic chemicals. These factors include: drinking water consumption, soil ingestion, inhalation rates, dermal factors including skin area and soil adherence factors, consumption of fruits and vegetables, fish, meats, dairy products, home-grown foods, breast milk intake, human activity factors, consumer product use and residential characteristics. Recommended values are for the general population and also for various segments of the population who may have characteristics different from the general population. The NCEA also developed a “Child-Specific Exposure Factors Handbook,” and access to other EPA-developed exposure assessment guidance and resource documents: see Web site: http://cfpub.epa. gov/ncea/cfm/recordisplay.cfm?deid=12464. 4.13. US EPA’s Guidelines for Exposure Assessment See Web site: www.epa.gov/nceawww1/exposure. htm. “US EPA’s Guidelines for Exposure Assessment, 1992 establish a broad framework for Agency exposure assessments by describing the general concepts of exposure assessment including definitions and associated units and by providing guidance on
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the planning and conducting of an exposure assessment. Guidance is also provided on presenting the results of the exposure assessment and characterising uncertainty.” The document also includes a “General Concepts in Exposure Assessment” section, a “Planning an Exposure Assessment” section offering guidance on screening-level and other types of approaches, a section offering guidance on “Reviewing Exposure Assessments,” and a “Glossary of Terms (US EPA, 1992).” 4.14. US EPA’s Toxics Release Inventory (TRI) Web site The TRI is a publicly accessible toxic chemical database (www.epa.gov/tri) containing information about the use, manufacture, treatment, transport, or release of toxic chemicals into the US environment. It is based on the Emergency Planning and Community Right to Know Act, giving every US citizen the right to know about toxic chemicals that are being released into his community. The Toxics Release Inventory contains information on releases of nearly 650 chemicals and chemical categories from industries including manufacturing, metal and coal mining, electric utilities and commercial hazardous waste treatment, among others.
5. The future—broadening the level of exposure assessment information available via Web Sites Additional information about current Web sites and Internet mailing lists of possible interest o exposure assessors, toxicologists and others is available (Patterson et al., 2002; Wexler et al., 2000) and it should be very apparent from the above examples that the Internet and Web are providing exposure assessors and others around the world with 24 h a day access to numerous valuable sources of information and opportunities for information exchange. As noted in an earlier publication (Hakkinen, 2001), a major opportunity exists for risk assessors and others to broaden the level of exposure assessment information available via Web sites. The exposure information currently available on the Web primarily focuses on the US, largely due to US EPA and other US-focused efforts to have this information available
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on the Web. Broadening the Web’s exposure information could include information about human physical characteristics (e.g. country- or region-specific ranges in body weights, drinking water consumption etc.), the types of residences and workplaces and the exposure factors associated with them (e.g. air changeovers per hour in various types of residences and how various tasks are performed by consumers and workers) and country- and region-specific ranges of climatic conditions. Any non-US exposure-related information could be incorporated into Web sites providing more globally representative information than that currently offered via US EPA efforts. Noteworthy is that efforts are underway by European scientists to develop a European (multi-country) version of the US EPA’s Exposure Factors Handbook and by the European Commission to develop the European information system (EIS-ChemRisks) on risks to human health The Exposure Factors Sourcebook for Europe (ExpoFacts), www.ktl.fi/expofacts/ will be a Web-based resource compiled from extensive national and international data that is both published and unpublished. The goal for EIS-ChemRisks (contact the authors or see http://ihcp.jrc.it/ for updates on status) is to sys-
tematically collect, store and assess information on human exposure to chemicals released from consumer products, along with providing a single web-based gateway to all major European initiatives on human exposure to chemicals contained and released from products. It is expected that many additional exposure assessment-related Web sites will be created in the future by regulatory agencies, professional societies and other organisations. These would provide further valuable information for use around the world and for specific locations and other localised needs.
References Hakkinen, P.J., 2001. Global toxicology and risk analysis: roles of the Internet and World Wide Web. Toxicology 160, 59–63. Patterson, J., Hakkinen, P.J., Wullenweber, A.E., 2002. Human health risk assessment: selected Internet and World Wide Web resources. Toxicology 173, 123–143. US EPA’s, 1992. Guidelines for Exposure Assessment. Federal Register, Vol. 57, pp. 22888–22938. Wexler, P., Hakkinen, P.J., Stoss, F.W., 2000. Internet and Other Digital Resources. In: Wexler, P., Hakkinen, P.J. Kennedy, G. Jr., Stoss, F.W. (Eds.), Information Resources in Toxicology, Academic Press, San Diego, pp. 287–332