May the control banding risk management method be useful for exposure assessment in epidemiology of workers exposed to engineered nanomaterial (ENM)?

摘要

Control banding (CB) is a method to guide risk management whenever there is uncertainty concerning the input data needed for risk assessment (uncertainty about the hazards of nanomaterials and about exposure levels). It takes into account existing information, the available technical and scientific data, and is based on a number of assumptions. In the CB the risk is function of severity of hazard and the anticipated probability of exposure. Although it seems tempting to use some of CB methods for epidemiology, direct application of risk levels inconsistently reflects the workers' occupational exposure and may result in biased results of the dose-response analysis based on such an exposure proxy. Nevertheless, after appropriate transformation, some of CB methods may be useful for exposure assessment of nano-workers in epidemiological studies. Basically, it may consist of: a withdrawal from the CB matrix of the hazard determinants related to ENM's toxicological properties (which are subject to the greatest uncertainty and overlap with epidemiological purpose); an extracting of the ENM's physicochemical properties (shape, size, solubility) as determinants for a further ENM's uptake and resulting internal dose assessment; and a conservation of the exposure probability calculated based on the process and organisational information (amount of ENMs handled, its dustiness/mistiness, frequency and duration of operations and use of personal and collective protection equipment). A nanotechnology-company information field-based form and worker's individual questionnaire were developed within EpiNano project. The collected data will be used for assessing workers' individual potential exposure to ENM in a forthcoming epidemiologic study and, meanwhile, might be useful to provide basic information for the inner-company risk assessment using CB approach.