Environment
Dioxin Levels in Ireland are well below EU Limits
7, Nov 2008 - 18:14

The latest Environmental Protection Agency (EPA) report on dioxin levels in the Irish environment (based on dioxin levels measured in cows’ milk in a 2007 survey) 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.

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.’

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 between late May and early July 2007, 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 reported ranges for dioxins in milk fat (37 samples) were 0.141 to 0.611 pg WHO-TEQ/g with a mean of 0.225 WHO-TEQ/g.  When PCBs (Polychlorinated biphenyls) were included, the ranges are 0.232 to 1.51 pg WHO-TEQ with a mean of 0.425 pg WHO-TEQ/g (picograms of WHO Toxic Equivalent per gram of fat; 1 pg is 10-12 of a gram).  The WHO Toxic Equivalent is the current internationally recognised system for comparing dioxin toxicities of different samples.  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.  Some PCB results for the greater Dublin area were higher than previously but nonetheless remained at less than half of the EU action level.

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 PBDEs (5 samples) was 95 to 279 ng/kg fat with a mean of 152 ng/kg fat, slightly lower than the levels found in 2006 when these substances were included for the first time.  These levels are relatively low by international comparisons.

Download the report Dioxin Levels in the Irish Environment – Fifth Assessment.