Twelve papers in this series were derived from two conference sessions focusing on causality in field studies. Eight of these papers involve case studies examining biological effects of chemical contaminants in field situations. Using a weight-of-evidence approach, these case studies were evaluated against seven proposed criteria for establishing causality. The seven criteria were: strength of association; consistency of association; specificity of association; time order; biological gradient; experimental evidence; and biological plausibility. One of these seven criteria, ‘specificity of association’ was found to be of little utility for establishing causality in these field studies. The case studies are presented in approximate order of increasing levels of biological organization (i.e., going from endpoints at the suborganismal level to endpoints at the population or community level). In case studies examining higher levels of biological organization, it appears that the ‘biological gradient’ criterion was also not useful in establishing causality. These results, together with suggestions from other papers in the series, are used to recommend a set of modified criteria for establishing causality in field studies of the biological effects of chemical contaminants.
Source:
Tracy K. Collier. Human and Ecological Risk Assessment: Vol. 9, No. 1, pp. 259-266 (2003), attached
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Two of the 7 causality criteria used by Hill are not very useful
In a recent paper entitled "Dietary traces of neonicotinoid pesticides as a cause of population declines in honey bees: an evaluation by Hill's epidemiological criteria" (Pest Management Science, Volume 68, Issue 6, pages 819–827, June 2012), James E Cresswell, Nicolas Desneux, and Dennis van Engelsdorp conclude that "dietary neonicotinoids cannot be implicated in honey bee declines". Tracy Collier's 2003 paper shows that two of the 7 causality criteria used by Hill are not very useful. Perhaps Cresswell et al. should have taken notice of it before writing their disparaging paper last year.