The Environmental Protection Agency has strongly rejected much of the findings of a controversial research paper published in the US claiming the deaths of horses in Askeaton, Co Limerick, were due to high levels of aluminium in their tissue caused by acid rain pollution.
Suggesting the deaths were "connected with acidification and related to aluminium pollution in the area" does not hold up on the basis of measurements made in the course of ongoing investigations of animal health problems there, the EPA said. The study by the Irish Equine Centre (IEC) of horse deaths on the farm of Andy and Doris Sheehy is published in the latest issue of the journal Veterinary and Human Toxicology.
The EPA's director-general, Mr Bill McCumiskey, said he wished to allay fears which the local community may have following its publication and coverage in a Sunday newspaper. It was "most reprehensible that neither the IEC, nor the Sunday Business Post" consulted the agency before publication. This gave rise to "unwarranted suggestions likely to give rise to public concern", he said, notably the possibility, suggested in the newspaper, that it had implications for human health.
The Mid Western Health Board, one of a number of multidisciplinary teams involved in a series of investigations, had found no evidence to date of high disease levels in the area which could be linked to aluminium. "In addition, whereas the main sources of aluminium for humans are food and water, the level of aluminium found in vegetables grown in the area were found to be similar to those grown in other areas," Mr McCumiskey said.
EPA investigations which include daily monitoring had indicated the area is not subject to acid rain, while there was no evidence of aerial contamination by aluminium. "The suggestion that the presence of high levels of acidity makes it possible for aluminium to be taken up by plants is not compatible with the EPA's investigations."
EPA findings did not support the suggestion that the Aughinish Alumina plant in the area is releasing significant quantities of aluminium oxide into the local atmosphere. Equally, rainfall samples had not shown the presence of the bauxite raw material used at the plant or the alumina product.
Department of Agriculture investigations at farms adjoining the Sheehys' had found no evidence that livestock deaths or illness could be ascribed to aluminium toxicity. Aluminium concentrations in cattle bone and milk were similar to those in other parts of Ireland, Mr McCumiskey said.
The EPA, however, said the report of granulomatous enteritis in the horses, and its link with tissue aluminium, was a significant finding warranting further investigation. "As environmental pollution can effectively be ruled out as a source of aluminium at this stage, other potential sources should be considered," he said.
The EPA said it was disappointed the Department of Agriculture had been denied access to animals and specimens from the Sheehy farm since 1996 and the IEC had refused last year to supply the agency with details of its work. It was nonetheless still prepared to mount a full investigation of factors that caused so many horse fatalities.
The Green MEP, Ms Nuala Ahern, said the IEC study was helping to identify the real causes of the deaths and calling into question "the integrity of the official investigations". She said she would suggest to the EU Environment Commissioner that directives on acid-causing emissions be reviewed.
