Dioxin Levels in Ireland well below EU Limits, EPA reports

Date released: Dec 02 2009

The latest Environmental Protection Agency (EPA) report on dioxin levels in the Irish environment shows that all of the samples had dioxin levels well below the relevant EU limits.  The report also shows that dioxin levels measured in this survey compare favourably with those taken from similar surveys in EU and other countries. The report is based on dioxin levels measured in cows’ milk in a 2008 survey.

Commenting on the results, EPA Programme Manager Dr. Ciaran O’Donnell said, 

"The concentrations of dioxins were low by international standards and comparisons.  The survey confirms the continuing low levels of dioxins and dioxin-like substances in the Irish environment.”

Survey Methodology
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.  Since any dioxins on grass ingested by cows tend to concentrate in the milk fat, sampling for dioxin levels in the milk of grazing cows is the approach adopted in this as well as in previous assessments of dioxin levels in the Irish environment.
 
The survey was carried out in June and early July 2008, 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.

Results


The WHO Toxic Equivalent is the current internationally recognised system for comparing dioxin toxicities of different samples.  Results are expressed in picograms of WHO Toxic Equivalent per gram of fat: 1 pg is 10-12 of a gram. 

The reported ranges for dioxins in milk fat (37 samples) were 0.190 to 0.673 pg WHO-TEQ/g with a mean of 0.269 pg WHO-TEQ/g.  When PCBs (Polychlorinated biphenyls) were included, the ranges were 0.304 to 0.835 pg WHO-TEQ with a mean of 0.440 pg WHO-TEQ/g.  These levels are well below the EU limit in milk and milk products of 3.0 pg WHO-TEQ/g for dioxins only, and 6.0 pg WHO-TEQ/g for dioxins and PCBs combined. 

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.  However, only Polybrominated Diphenyl Ethers (PBDEs) were detected.  The range for Polybrominated Diphenyl Ethers (PBDEs) (5 samples) was 57 to 144 ng/kg fat with a mean of 93 ng/kg fat, in line with the levels found in the two previous surveys in 2006 and 2007.  These levels are relatively low by international comparisons.

Download the report Dioxin Levels in the Irish Environment -Sixth Assessment