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 2010. 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.
Dr Colman Concannon, Dublin Regional Chemist, EPA Office of Environmental Assessment, comments: “The concentrations of dioxins were low by international standards and comparisons. A total of 38 samples were taken and the average level was less than 10% of the EU limit. This is the eighth such survey undertaken by the EPA since 1995 and the results are in line with the earlier studies. The survey confirms the continuing low levels of dioxins and dioxin-like substances in the Irish environment.”
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 2010, 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. One sample showed elevated levels of Polybrominated diphenyl ethers (PBDEs) though this level was not high by European comparison. The elevated levels originated from one farm in Cork. The EPA notified the anomaly to the Department of Agriculture, Food and the Marine and the Food Safety Authority of Ireland for further investigation.