The strengths of this study are fourfold. First, this study
used a population-based design. Cases were actively identified
through multiple sources within defined geographic
areas and benefited from a very high georeferencing rate.
Second, this study used sophisticated modelling of emissions
as a proxy for dioxin exposure. The modelled
ground-level concentrations represented the best available
surrogates for past dioxin exposure measurements
given that no earlier measurements (in soils or blood of
nearby residents) had been taken. Third, owing to the fine
geographical level used, this study was able to allocate a
different exposure to NHL cases living in the same town,
but not in the same block group, thus making an exposure
misclassification less likely (but we had to assume that
residents within a given contour were homogeneously
exposed). Fourth, the total number of cases (3974)