The most recent Environmental Protection Agency (EPA) report on dioxin levels in the Irish environment shows that the dioxin levels in all of the samples tested were well below the relevant EU limits. The report is based on dioxin levels measured in cows’ milk in a survey carried out in 2011. The report also shows that dioxin levels measured in this survey compare favourably with those taken from similar surveys in the EU and other countries.
Commenting on the results, Dr Colman Concannon, Dublin Regional Chemist, EPA Office of Environmental Assessment said,
“The most recent dioxin report published by the EPA shows continually low levels of dioxins and dioxin-like substances in the Irish environment, in line with earlier EPA studies. The concentrations of dioxins were low by international standards and comparisons. This is the ninth such survey and on this occasion a total of 38 samples were taken with the average dioxin level less than 10 per cent of the EU limit.”
The principal mechanism for the entry of dioxins into the environment in Ireland is by low-level emissions from multiple combustion sources to the atmosphere, with subsequent deposition onto vegetation such as grass. Any dioxins on grass ingested by cows tend to concentrate in the milk fat. Hence, sampling for dioxin levels in the milk of grazing cows is the approach adopted.
The survey was carried out between June and early August 2011, during the peak outdoor grazing season, by taking a series of milk samples mainly from representative regional dairies. Additional samples were also taken from localities that might be seen as areas of potential risk of raised dioxin levels.
The WHO Toxic Equivalent is the current internationally recognised system for comparing dioxin toxicities of different samples. Samples were tested for dioxins only and for dioxins and PCBs combined and the levels found were well below the EU limit in milk and milk products.
In view of the increased international awareness of the presence in the environment of brominated flame retardants (BFRs) and brominated dioxins (PBDD/PBDF), a broad range of these substances was also tested in the survey. Only Polybrominated diphenyl ethers (PBDEs) were detected and were at low levels by European comparison.
The report Dioxin Levels in the Irish Environment – Ninth Assessment is available on the EPA website at http://www.epa.ie/downloads/pubs/other/dioxinresults/