The Danish ministry for the environment recently conducted a workshop on combination effects of chemicals (28-30 January 2009). Although I was invited I unfortunately couldn’t make it. During the time I was hosting some nice, lively influenza viruses. All the fun you can have…
Andreas Kortenkamp from the School of Pharmacy in London was organising the workshop, hence it might not be that surprising, that the main focus was on mixtures of endocrine disrupters. However, most of the conclusions also hold true for mixtures of chemicals from other areas.
To just quote the summary:
An expert workshop on effects of combined exposure to chemicals, with special emphasis on chemicals with endocrine activity was held under the auspices of the Danish Ministry of the Environment. The aim of the workshop was to examine existing scientific knowledge on combination effects of endocrine disrupters, with a focus on regulatory aspects. The workshop participants considered the state of the science of mixtures risk assessment for endocrine disrupters, and discussed the feasibility of approaches to cumulative risk assessment.
A consensus about a number of important issues could be formulated, and this included a series of recommendations:
Cumulative risk assessment (CRA) for endocrine disrupters was seen as both necessary and feasible. The predominant chemical-by-chemical approach in risk assessment was regarded as insufficiently protective against the possibility of mixture effects/ effects of combined exposure.
The application of dose (or concentration) addition as an assessment method was recommended as a default, until evidence as to the suitability of alternative assessment concepts emerges.
A pre-occupation with mechanisms or modes of action as the starting point for the grouping of endocrine disrupters into classes to be subjected to mixtures risk assessment was seen as not practical and scientifically hard to justify. Instead, grouping criteria should focus on common health related effects and the likelihood of co-exposures.
The full potential of CRA for endocrine disrupters cannot be reached without filling a number of data gaps, most importantly in the area of mixtures exposure assessment.
An enhancement of the legal framework in Europe with a view to mandating CRA should be given serious consideration.
The final workshop report hast just been published and can be downloaded here (PDF, in English).