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Table 6 Variability and uncertainty in probabilistic inputs

From: An approach to estimating the environmental burden of cancer from known and probable carcinogens: application to Ontario, Canada

Input RAa PAFb Variable across the population? Uncertain?
Potency values (OSF and IUR) √   Potency may vary across the population, but there was no information to characterize it for this analysis. Yes, different agencies may set different potency values; this is captured in this analysis (see Table 1). However, potency values are themselves uncertain and that was not captured in this analysis.
Exposure factors (e.g., ingestion rate, bodyweight) √   Yes, exposure factors vary within and across age bins. This is captured in this analysis (see Additional file 3). Yes, but there was no information to characterize it in this analysis.
Population √   No, one point estimate for the province (from 2011 Census). Yes, but uncharacterized. Expect the Census number to be robust.
Concentration √ √ Yes, the exposure concentration varies across the population and this is captured in this analysis. However, there may be additional variability that is not captured by the input data sources. Yes, but there was no information to characterize it for this analysis.c
Relative risk   √ Yes, the RR could differ by sub-populations (e.g., by sex or age group). This captured in the analysis whenever possible for UV and SHS. Yes, the analysis captured the statistical uncertainty in the RRs (e.g., 95% confidence intervals) whenever possible. However, there is additional uncertainty associated with the RRs and that was not captured in this analysis for UV, SHS, DPM, and PM2.5.
Population attributable fraction   √ The PAF varies across the population, and this is captured for radon. Yes, though we were unable to characterize it outside of the statistical uncertainty associated with radon and bounding the PAF obtained by different approaches in the UV analysis.
Cancer Incidence   √ No, one estimate for the province (from 2011 Ontario Cancer Registry). Yes, but uncharacterized. Expect the Ontario Cancer Registry estimate to be robust.
  1. DPM diesel particulate matter, IUR inhalation unit risk (IUR), OSF oral slope factor, PAF population attributable fraction, PM2.5 fine particulate matter, RA risk assessment, SHS second-hand smoke, UV ultraviolet
  2. aRefer to Table 1 for the list of environmental carcinogens corresponding to the RA model (n = 19) and Additional file 3 for model details
  3. bRefer to Table 2 for the list of environmental carcinogens corresponding to the PAF model (n = 5) and Additional file 4 for model details
  4. cIn interpreting the results of the simulation, one can imagine that there is maximal uncertainty at every concentration (e.g., 100% of population exposed at 25th percentile concentration for 25th percentile simulation result)
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BMC Public Health

ISSN: 1471-2458

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