A review of exposure assessment methods for epidemiological studies of health effects related to industrially contaminated sites
BACKGROUND: this paper is based upon work from COST Action ICSHNet. Health risks related to living close to industrially contaminated sites (ICSs) are a public concern. Toxicology-based risk assessment of single contaminants is the main approach to assess health risks, but epidemiological studies which investigate the relationships between exposure and health directly in the affected population have contributed important evidence. Limitations in exposure assessment have substantially
... antially contributed to uncertainty about associations found in epidemiological studies. OBJECTIVES: to examine exposure assessment methods that have been used in epidemiological studies on ICSs and to provide recommendations for improved exposure assessment in epidemiological studies by comparing exposure assessment methods in epidemiological studies and risk assessments. METHODS: after defining the multi-media framework of exposure ENVIRONMENTAL HEALTH CHALLENGES FROM INDUSTRIAL CONTAMINATION www.epiprev.it ARTICLES applied in 39 studies, air pollution dispersion modelling in 6 studies, and human biomonitoring in 9 studies. Exposure assessment in epidemiological studies on incinerators included indicators (presence of source in municipality and distance to the incinerator) and air dispersion modelling. Environmental multi-media modelling methods were not applied in any of the three groups of studies. CONCLUSIONS: recommendations for refined exposure assessment in epidemiological studies included the use of more sophisticated exposure metrics instead of simple proximity indicators where feasible, as distance from a source results in misclassification of exposure as it ignores key determinants of environmental fate and transport, source characteristics, land use, and human consumption behaviour. More validation studies using personal exposure or human biomonitoring are needed to assess misclassification of exposure. Exposure assessment should take more advantage of the detailed multi-media exposure assessment procedures developed for risk assessment. The use of indicators can be substantially improved by linking definition of zones of exposure to existing knowledge of extent of dispersion. Studies should incorporate more often land use and individual behaviour. KEYPOINTS What is already known n Health risks related to living close to industrially contaminated sites (ICSs) are a public concern. n Risk assessment of single contaminants is the main approach to assess health risks, but epidemiological studies have contributed important evidence. n Limitations in exposure assessment have substantially contributed to uncertainty about associations found in epidemiological studies. What this paper adds n We conducted a review to examine exposure assessment methods used in epidemiological studies of ICSs in comparison with risk assessment. n The majority of studies used proximity indicators of exposure; air pollution dispersion modelling, soil monitoring, and human biomonitoring have been used in a small number of epidemiological studies. n Detailed multi-media environmental modelling methods, such as those used for regulatory risk assessment, were not applied. n Recommendations for refined exposure assessment in epidemiological studies were developed, including taking more advantage of the procedures developed for risk assessment, improvement of proximity indicators and the need for validation studies using personal exposure or human biomonitoring to assess misclassification of exposure.