Health Risk Assessment Data Research Articles

Health risk factor modification predicts incidence of diabetes in an employee population: results of an 8-year longitudinal cohort study.

To understand risk factor modification effect on Type 2 diabetes incidence in a workforce population. Annual health risk assessment data (N = 3125) in years 1 through 4 were used to predict diabetes development in years 5 through 8. Employees who reduced their body mass index from 30 or more to less than 30 decreased their chances of developing diabetes (odds ratio = 0.22, 95% confidence interval: 0.05 to 0.93), while those who became obese increased their diabetes risk (odds ratio = 8.85, 95% confidence interval: 2.53 to 31.0). Weight reduction observed over a long period can result in clinically important reductions in diabetes incidence. Workplace health promotion programs may prevent diabetes among workers by encouraging weight loss and adoption of healthy lifestyle habits.

The Workforce Wellness Index

To devise a methodology to create a single health risk-cost score that can be applied to health risk assessment survey data and account for the medical costs associated with modifiable risks. We linked person-level health risk assessment data with medical benefit eligibility and claims data for 341,650 workers for the period 2005 to 2010 and performed multivariate analyses to estimate costs associated with high risks. We used the estimated costs and risk prevalence rates to create a composite Workforce Wellness Index (WWI) score. Increasing obesity rates among employees was found to be the most important contributor to increased health care spending and the main reason the WWI score worsened over time. Employers that address employees' health risk factors may be able to reduce their medical spending and achieve an improvement in their WWI scores.

Finding Employees with Undiagnosed Diabetes

Purpose: Implement a confidential and low cost method to identify employees with undiagnosed diabetes. Methods:Blood samples from fasting plasma glucose measurements obtained by a third party vendor from the annual employee health risk assessment data were re-run at a cut-point of 117 mg/dL or greater to obtain a hemoglobin A1c (A1c) value. Individual letters were sent from the third party vendor to employees with a HbA1c value of 5.7% or greater informing them of an employee diabetes management program. Results: 1611 of 3044 (53%) employees participated in the annual health risk assessment; 87 employees demonstrated a fasting plasma glucose >117 mg/dL; 27 employees had a A1c of 5.7-6.3%; and 16 employees had an A1c > 6.5%; 9 employees volunteered to participant in the diabetes management program. The employer spent a total of $783 to find 16 employees with undiagnosed diabetes and 27 employees with undiagnosed pre-diabetes. Conclusion: The process used by this employer maintained confidentiality and was considered a low cost means of finding employees with undiagnosed diabetes.

Online Tailored Weight Management in the Worksite: Does It Make a Difference in Biennial Health Risk Assessment Data?

Overweight and obesity are directly associated with heart disease, cancer, and diabetes and pose a serious cost-related challenge to employers. As most of the rise in health care spending is traced to the rise in population risk factors, maintaining or reducing the prevalence of disease represents a strategy with large potential payoffs. Tailored communication is a promising communication strategy for influencing health behavior change, including behaviors for weight management. Much of the tailored communication research is based on communication developed for research purposes, yet access to commercially available tailored health programs for worksites is growing. As health risk assessments are increasingly used for setting health programming and insurance priorities in U.S. workplaces and worksites have opportunities to purchase tailored programs, it is important to understand the effect of tailored communication on health risk assessment data. The purpose of this study was to evaluate the long-term effects of a commercially available web-based tailored weight management program on employee weight, body mass index, blood pressure, cholesterol, and blood glucose. The authors compared health risk assessment data at baseline and 2 years later from 101 overweight and obese employees who participated in the tailored weight management program and 137 overweight and obese employees who did not participate in the program. Results show that there were significant mean differences in systolic blood pressure, HDL cholesterol, and blood sugar levels, but each in a clinically undesirable direction. More research is needed to understand the effect of tailored programs used in worksite health promotion.

Uranium in vegetable foodstuffs: should residents near the Cunha Baixa uranium mine site (Central Northern Portugal) be concerned?

Large uranium accumulations in vegetable foodstuffs may present risks of human health if they are consumed. The objective of this study was to evaluate the uranium concentrations in different vegetable foodstuffs and grown in agricultural soils, which are then consumed by the residents of the village of Cunha Baixa (Portugal),--located in an former uranium mining area. This study was conducted to address concerns expressed by the local farmers as well as to provide data for uranium-related health risk assessments for the area. Soils, irrigation water and edible tissues of lettuce, potato, green bean, carrot, cabbage, apple and maize (Latuca sativa L., Solanum tuberosum L., Phaseolus vulgaris L., Daucus carota L., Brassica oleracea L., Malus domestica Borkh, Zea mays L., respectively) were sampled and uranium determined. High uranium concentrations were found in some soils (U(total) > 50 mg/kg), in irrigation waters (218 to 1,035 μg/l) and in some vegetable foodstuffs (up to 234, 110, 30, 26, 22, 16 and 1.6 μg/kg fresh weight for lettuce, potato with peel, green bean pods, cabbage, corn, carrot and apple, respectively). However, the results of the toxicity hazard analysis were reassuring the estimated level of uranium exposure through the ingestion of these vegetable foodstuffs was low, suggesting no chemical health risk (hazard quotient <1) to this uranium exposure pathway for a local residents during their lifetime, even for the most sensitive part of the population (child).

An inter-laboratory trial of the unified BARGE bioaccessibility method for arsenic, cadmium and lead in soil

The Bioaccessibility Research Group of Europe (BARGE) has carried out an inter-laboratory trial of a proposed harmonised in vitro physiologically based ingestion bioaccessibility procedure for soils, called the Unified BARGE Method (UBM). The UBM includes an initial saliva phase and simulated stomach and intestine compartments. The trial involved the participation of seven laboratories (five European and two North American) providing bioaccessibility data for As (11 samples), Cd (9 samples) and Pb (13 samples) using soils with in vivo relative bioavailability data measured using a swine model. The results of the study were compared with benchmark criteria for assessing the suitability of the UBM to provide data for human health risk assessments. Mine waste and slag soils containing high concentrations of As caused problems of poor repeatability and reproducibility which were alleviated when the samples were run at lower soil to solution ratios. The study showed that the UBM met the benchmark criteria for both the stomach and stomach & intestine phase for As. For Cd, three out of four criteria were met for the stomach phase but only one for the stomach & intestine phase. For Pb two, out of four criteria were met for the stomach phase and none for the stomach & intestine phase. However, the study recommends tighter control of pH in the stomach phase extraction to improve between-laboratory variability, more reproducible in vivo validation data and that a follow up inter-laboratory trial should be carried out.

On the Use of Satellite Data for Spatial Health Risk Assessment of Urban Air Pollutants

PP-31-181 Background/Aims: The state of the art in air quality assessment comprises information and data processing tools using only data from ground-based measurement and atmospheric modelling. Ground measurements are not taken from dense enough monitoring networks around the world to permit a satisfactory analysis of the influence of air pollution on the health of vulnerable population groups. Attempts to improve our estimation of atmospheric pollutant concentrations at the urban and regional scale from combining ground data with numerical modeling are hampered by the need for high quality and up-to-date emissions inventories, as well as accurate estimates of initial and boundary conditions of the models. Information derived from earth observation satellites can bridge the gap between models, simulating the transport and chemical transformation of atmospheric pollutants and analytical observations. Methods: A data fusion methodology was developed to integrate satellite data with ground-based information and atmospheric modeling to derive particulate matter and ozone loading at the ground level. Physical properties of tropospheric aerosol and ozone are linked with the atmospheric physical–chemical processes that determine the total mass concentration and size distribution of particulate matter and the concentration of ozone. Coupling these with spatially explicitly exposure–response functions and population data, it results in refined maps of health risk attributable to air pollution. Results: The methodology was implemented in Athens, Greece and Rome, Italy, 2 capitals characterized by intense photochemical pollution and long-range transport of dust. Maps of health risk were produced. The spatially scalar nature of the approach allowed us to evaluate the impact of risk modifiers such as the existence of urban vegetation and population susceptibility. Conclusion: Satellite data can be used efficiently to improve the spatial link between environmental pollution and human health. The data fusion method proposed in the present study opens the way toward the enhanced use of this valuable information in spatial epidemiology and environmental health science.

Financial implications of coverage for laparoscopic adjustable gastric banding

Background Employers and insurers have become increasingly concerned about the cost implications of providing coverage for bariatric procedures. We sought to quantify the costs and potential cost savings resulting from coverage for laparoscopic adjustable gastric banding (LAGB) using a claims analysis. Methods U.S. healthcare claims data of >7000 LAGB patients and a propensity score-matched control group were used to quantify the costs and potential cost savings resulting from LAGB for the overall surgery-eligible population and for the subset of the surgery-eligible population with diabetes mellitus. The matched control group consisted of those with a morbid obesity diagnosis code and/or a body mass index >35 kg/m 2 as reported in the Health Risk Assessment data. Results Including the related medical payments in the 90 days before and after the procedure, the mean cost of LAGB was approximately $20,000. After placement, a modest reduction occurred in the health expenditures relative to the preoperative payments. In the postoperative period, these decreases were maintained for the LAGB sample. In contrast, the payments for the comparison sample continued to increase. As a result, the net cost of coverage for LAGB was reduced to 0 by approximately 4 years after band placement. For those with diabetes, the net costs resulting from LAGB were reduced to 0 in just >2 years. Conclusion These results suggest that the LAGB procedure pays for itself within a relatively short period, especially for those with diabetes.

Urban air pollution and mitigation options in Sri Lanka

This paper reports on a study carried out to examine human exposure to street-level air pollutants in Sri Lanka and explores the effectiveness of mitigation options. Baseline air pollution and health risk assessment data were collated and a free-ware computer model (Envi-met) was then applied to a selected urban area to test the effectiveness of air pollution mitigation options. Model variables included changes to street vegetation, soil conditions and building geometry. Background aerosol (particulate matter, sulfur dioxide and nitrogen dioxide) exposure was found to be significantly different for urban and rural populations. More greenery and reduced vehicular traffic on roads entering main traffic arteries resulted in a decreased particulate matter concentration, whereas the presence of high-rise buildings resulted in an increase. On the basis of the research findings, the paper suggests a ‘best case’ with a marked decrease in particulate matter concentration compared with the current situation. The possibility of using this methodology in the schematic planning stages of new developments and the regeneration of existing neighbourhoods is highlighted.

Obesity-related costs and the economic impact of laparoscopic adjustable gastric banding procedures: benefits in the Texas Employees Retirement System

Objective: To assess the return on investment (ROI) and economic impact of providing insurance coverage for the laparoscopic adjustable gastric banding (LAGB) procedure in classes II and III obese members of the Texas Employees Retirement System (ERS) and their dependents from payer, employer, and societal perspectives.Methods: Classes II and III obese employee members and their adult dependents were identified in a Texas ERS database using self-reported health risk assessment (HRA) data. Direct health costs and related absenteeism and mortality losses were estimated using data from previous research. A dynamic input–output model was then used to calculate overall economic effects by incorporating direct, indirect, and induced impacts. Direct health costs were inflation-adjusted to 2008 US dollars using the Consumer Price Index for Medical Care and other spending categories were similarly adjusted using relevant consumer and industrial indices. The future cost savings and other monetary benefits were discounted to present value using a real rate of 4.00%.Results: From the payer perspective (ERS), the payback period for direct health costs associated with the LAGB procedure was 23–24 months and the annual return (over 5 years) was 28.8%. From the employer perspective (State of Texas), the costs associated with the LAGB procedure were recouped within 17–19 months (in terms of direct, indirect, and induced gains as they translated into State revenue) and the annual return (over 5 years) was 45.5%. From a societal perspective, the impact on total business activity for Texas (over 5 years) included gains of $195.3 million in total expenditures, $93.8 million in gross product, and 1354 person-years of employment.Limitations: The analysis was limited by the following: reliance on other studies for methodology and use of a control sample; restriction of cost savings to 2.5 years which required out-of-sample forecasting; conservative assumptions related to the cost of the procedure; exclusion of presenteeism; and no sensitivity analyses performed.Conclusion: This analysis indicates that providing benefits for the LAGB procedure to eligible members of the Texas ERS and their dependents is worthy of support from payer, employer, and societal perspectives.

Degradation of Chlorpyrifos and Fipronil in Rice from Farm to Fork and Risk Assessment

Degradation of pesticide residues (chlorpyrifos and fipronil) in rice from farm to fork and risk assessment for human health were studied to reveal the magnitude of risks faced by different populations of interest, so that appropriate measures can be taken to control the risks, and to refine and update the human health risk assessment data while helping to determine the maximum residue level (MRL) value and harvest interval. Different dosages and treatments were used in field trials for the harvest residue test. Residue levels of postharvest-applied chlorpyrifos and fipronil during storage, exposure to sunlight, washing and boiling processes (boiled rice) were investigated for brown rice. The dietary exposure evaluation model (DEEM) was employed to estimate acute and chronic risks faced by different populations of interest. Percent of reference dose (POR) and margin of exposure (MOE) were calculated. A positive correlation between pesticide residues and the dosage and application frequency of pesticide was found in the field trials. Risk quotients indicate that multiple applications and double dosages of chlorpyrifos increase the risks to the entire population and prolong exposures to toxic concentrations. The concentration of pesticide residues decreased as a function of time, after sunlight exposure, storage, washing, and boiling processes. 91.6 and 96.16% degradations were achieved at the end of the experimental period for fipronil and chlorpyrifos, respectively. The boiling process played an important role in the degradation of these pesticides. The result of risk assessment to human health showed that harvest residues of chlorpyrifos in rice and acute dietary risks of chlopyrifos were of concern. The acute dietary (food only) risk estimated for chlorpyrifos as percent of acute population adjusted dose (aPAD) was frequently over 100%. The risk faced by boys under the age of 14 was higher than that for girls of the same age. For the subpopulation above age 14, the risk reversed. The chronic dietary risk from food alone showed that dietary exposures with fipronil were below the level of concern for the entire population, including children. The risk faced by rural residents was more serious than that for urbanite residents with the most sensitive populations being children and male residents who faced higher acute dietary risk than the other subpopulation groups. The harvest interval was found to be the critical measure to mitigate risk for all populations for safe rice eating. All risk levels decreased to acceptable levels when the harvest interval was extended to 14 d. To address these risks, a number of measures including reduced application rates (should not be doubled at single application), increased retreatment intervals (longer than 7 d) and extended interval of harvest (at least 14 d) will be needed. The MRL for fipronil in rice is recommended to be 0.01 mg kg −1 in accordance with Codex (ref).

The Effectiveness and Cost-Effectiveness of a Rural Employer-Based Wellness Program

The cost-effectiveness of employer-based wellness programs has been previously investigated with favorable financial and nonfinancial outcomes being detected. However, these investigations have mainly focused on large employers in urban settings. Very few studies examined wellness programs offered in rural settings. This paper aims to explore the effectiveness and cost-effectiveness of a rural employer-based wellness program. Six rural employers were categorized into 3 groups: a control group and 2 intervention groups with varying degrees of wellness activities. Participants were asked to complete an annual health risk assessment (HRA) that addressed 16 wellness areas. At the conclusion of 4 years, HRA and effectiveness data were utilized to examine program effectiveness and combined with program costs to estimate cost-effectiveness. The "Coaching and Referral" group-the highest in intensity of participant engagement-exhibited superior improvement in several wellness areas and in percentage of employees with good health indicators compared to the control and the Trail Marker, lower-intensity intervention groups. However, the Trail Markers had more favorable cost-effectiveness ratios. Rural worksite wellness programs have shown great potential in their effectiveness and cost-effectiveness. Such programs need not be too aggressive, tedious, and costly to generate a favorable return for employers and funders. However, employers should be encouraged to experiment with different levels of wellness program intensities until a more favorable outcome can be realized.

Nanotechnologies, engineered nanomaterials and occupational health and safety – A review

The significance of engineered nanomaterials (ENM) and nanotechnologies grows rapidly. Nanotechnology applications may have a positive marked impact on many aspects of on human every day life, for example by providing means for the production of clean energy and pure drinking water. Hundreds of consumer nano-based products are already on the market. However, very little is known of the risks of ENM to occupational safety and health (OSH), even though workers are likely to be at extra risk, as compared with other potentially exposed groups of people, because the levels of exposure are usually higher at workplaces than in other environments. However, knowledge of the exposure to, or effects of, ENM on human health and safety in occupational environments is limited and does not allow reliable assessment of risks of ENM on workers’ health. Several issues related to ENM in the workplaces require marked attention. The most topical issues include: (1) improved understanding of ENM metrics associated with ENM toxicity; (2) development of monitoring devices for ENM exposure assessment; (3) understanding the changes of ENM structure and state of agglomeration at different concentrations in aerosols; (4) understanding translocation of ENM in the human body; (5) identifying the key health effects of ENM including pulmonary toxicity, genotoxicity, carcinogenic effects, and effects on circulation; (6) development of tiered approaches for testing of safety of ENM; and (7) utilizing these data for health risk assessment, with a special emphasis on occupational environment. Available data on several ENM – ability to enter the body and reach almost any organ, to cause pulmonary inflammation and fibrosis, and even to cause increased risk of mesotheliomas in animal models, call for immediate action. It is crucial to identify those ENM that may cause occupational health and safety risks from those ENM which are innocent, hence allowing prioritization of regulatory and preventive actions at workplaces at national, regional and global levels.

PS2-05: The Readiness of U.S. Health Plans to Manage Cardiometabolic Risk

Background: A large proportion of health status is determined by personal behavior. One manifestation of unhealthy personal behavior is the development of elevated cardiometabolic risk. Because health plans already manage care for a large proportion of the United States population, they are in a position to make a significant contribution to the control of cardiometabolic risk if they are prepared to offer health assessment, feedback, and behavior change support. Our goal in conducting this research was to assess health plan awareness of cardiometabolic risk and their current activities aimed at preventing and managing cardiometabolic risk. Methods: In January 2008, Americas Health Insurance Plans, in collaboration with the HealthPartners Research Foundation, surveyed 74 member health insurance plans that offer commercial Health Maintenance Organization, Point of Service and Preferred Provider Organization insurance. The response rate was 47%, representing 47 million lives. Results: The 35 responding health plans reported that they identify members with cardiometabolic risk through referral from case or care management (89%), health risk assessment data (86%), claims data (82%), and pharmaceutical utilization data (79%). Nearly all (97%) plans currently offer interventions for tobacco use, obesity/overweight, and nutrition. Ninety-four percent of the plans reported that they offer interventions to increase physical activity. All plans reported that they offer health risk appraisal or assessment with feedback and education, 91% reported that they use web-based tools, and 85% reported that they use health coaching to help plan members lower their risk. Perceived barriers to broader implementation of cardiometabolic risk control programs included lack of resources (79%), limited availability of enrollee level data (74%), and lack the reporting systems that would be necessary to manage individual plan members (79%). While one quarter of the responding health plans viewed lack of purchaser interest in cardiometabolic risk management programs as an important barrier to program implementation, only 6% named lack of purchaser interest as one of the three most important barriers to implementation. Conclusion: While the responses probably represent the best case scenario because of potential response bias, U.S. health plans appear to be well positioned to provide cardiometabolic risk control services.

Risk to all or none?

Bisphenol A (BPA) is an endocrine disruptor for which health risk assessment has proven controversial. Conclusions regarding health risks of BPA vary between assessments from "there is no risk to any part of the population" to "there is risk to the entire population". We have carried out a literature study investigating what might be the scientific and/or policy-related reasons for these differences. Ten risk assessments for BPA were scrutinized and several factors were compared between assessments, including estimations of exposure levels, identification of critical study and NOAEL, assessment factors and significance attributed to reports of low-dose effects. Differences in conclusions were mainly influenced by the evaluation of low-dose effects and the uncertainties surrounding the significance of these data for health risk assessment. The results illustrate the impact of differences in risk assessment policy and expert judgment on the risk assessment process and highlight the importance of transparency in this process.

Resources for global risk assessment: The International Toxicity Estimates for Risk (ITER) and Risk Information Exchange (RiskIE) databases

The rate of chemical synthesis and use has outpaced the development of risk values and the resolution of risk assessment methodology questions. In addition, available risk values derived by different organizations may vary due to scientific judgments, mission of the organization, or use of more recently published data. Further, each organization derives values for a unique chemical list so it can be challenging to locate data on a given chemical. Two Internet resources are available to address these issues. First, the International Toxicity Estimates for Risk (ITER) database ( www.tera.org/iter) provides chronic human health risk assessment data from a variety of organizations worldwide in a side-by-side format, explains differences in risk values derived by different organizations, and links directly to each organization's website for more detailed information. It is also the only database that includes risk information from independent parties whose risk values have undergone independent peer review. Second, the Risk Information Exchange (RiskIE) is a database of in progress chemical risk assessment work, and includes non-chemical information related to human health risk assessment, such as training modules, white papers and risk documents. RiskIE is available at http://www.allianceforrisk.org/RiskIE.htm, and will join ITER on National Library of Medicine's TOXNET ( http://toxnet.nlm.nih.gov/). Together, ITER and RiskIE provide risk assessors essential tools for easily identifying and comparing available risk data, for sharing in progress assessments, and for enhancing interaction among risk assessment groups to decrease duplication of effort and to harmonize risk assessment procedures across organizations.

Effect of temperature on growth, germination, germ-tube extension and survival of Paecilomyces lilacinus strain 251

Paecilomyces lilacinus and in particular the commercial strain 251 has been intensively tested for biological control of plant parasitic nematodes. Since this species has been mentioned in a number of reports concerning infection of humans, the human health risk for Paecilomyces lilacinus strain 251 was investigated. The effects of time, temperature and growth medium on radial colony growth and germination were determined. Additionally, exposure to 36°C and its effect on germ-tube extension and on survival of conidia was evaluated. Radial growth was significantly affected by temperature, growth medium and their interaction. Optimum temperatures were between 24 and 30°C, but no growth was found at 36°C. Germination rate was significantly influenced by time, medium, temperature and their interactions. The optimum temperature range for germination was between 28 and 30°C. Formulated conidia were capable of germinating at 36°C. However, studies on germ-tube extension conducted at 36°C showed a delay in development for 28–49 h and no further germ-tube extension was found after exposure for 80–95 h. Slopes of survival curves were significantly influenced by the type of conidia tested. In general, conidia did not survive exposure to 36°C for 168 h. These experiments indicate the temperature conditions where the strain is likely to be active and provide supporting data for full environmental and health risk assessments of biocontrol fungi.

Agricultural Chemical Safety Assessment: A Multisector Approach to the Modernization of Human Safety Requirements

Better understanding of toxicological mechanisms, enhanced testing capabilities, and demands for more sophisticated data for safety and health risk assessment have generated international interest in improving the current testing paradigm for agricultural chemicals. To address this need, the ILSI Health and Environmental Sciences Institute convened a large and diverse group of international experts to develop a credible and viable testing approach that includes scientifically appropriate studies that are necessary without being redundant, and that emphasize toxicological endpoints and exposure durations that are relevant for risk assessment. Benefits of the proposed approach include improved data for risk assessment, greater efficiency, use of fewer animals, and better use of resources. From the outset of this endeavor, it was unanimously agreed that a tiered approach should be designed to incorporate existing knowledge on the chemistry, toxicology, and actual human exposure scenarios of the compound, with integration of studies on metabolism/kinetics, life stages, and systemic toxicities. Three international task forces were charged with designing study types and endpoints on metabolism/ kinetics, life stages, and systemic toxicities to be used in the tiered approach. This tiered testing proposal departs from the current standardized list of hazard studies used by many national authorities, and represents the first comprehensive effort of its kind to scientifically redesign the testing framework for agricultural chemicals.

ANALYSIS OF AIRBORNE PARTICULATE MATTER COLLECTED AFTER AN ERUPTION EPISODE OF THE POPOCATÉPETL VOLCANO

Samples of airborne particulate matter were collected in four sites along an east-west line from the Popocatépetl volcano after the eruption episode of June 30, 1997. The Popocatépetl volcano, with variable activity since it was known, is currently under low but continuous activity prolonged for almost one decade, with occasional moderate eruption episodes producing mainly fumes, ashes and volcanic dusts. The main objective of this study is to determine whether or not some elements have increased their presence in the atmosphere as a result of the volcanic activity, and also if some others, not usually found in urban aerosols, have appeared because of the same reason. In addition, the information obtained will be a source of scientific data for health risk assessment of the population exposed to volcanic emanations. The sample collection was performed on alternate days from July 10 to August 13 1997 in Puebla and Atlixco in Puebla State. Tlalpan within Mexico City, and Salazar in the State of Mexico. Two samples a day were taken in two periods: 7-19 h and 19-7 h. The samplers separated particles into two particle size fractions. PM25 and PM15. Elemental concentrations were determined by PIXE and the results obtained showed increased concentrations of mainly Ti and Fe in all sampling sites, thus indicating a long range transportation of volcanic dusts in both particle size fractions. Concentrations of Ti were found clearly above the average values of urban areas such as Mexico City, and although this element can be considered of low toxicity, the biological, metabolic and toxic effects on human beings are still under investigation.

Risk assessment of chemicals -- the role of epidemiological methods.

The paper discusses methodological approaches in the evaluation of epidemiological data for health risk assessment. The discussion is based on the overviews of epidemiological evidence for health hazard characterisation from primary and multiple studies and for health impact assessment. Evaluation of the epidemiological evidence requires a systematic review of relevant studies with the aim of achieving transparency with regard to applied methods and procedures, avoidance of bias and validity of conclusions. Epidemiological studies are useful for health hazard characterisation if they provide estimates for exposure-response relationships. Epidemiological evidence plays a key role in health impact assessment of complex causes such as industrial emissions or urban traffic. The WHO Expert Group identified ten major steps in the quantification of the health impact assessment. There is a continuous need that future epidemiological studies should seek, where possible, to provide results that enhance the health impact assessment at the interface of epidemiology, other fields of research, and decision making.