The author of an independent report into an investigation carried out into animal deaths in Askeaton Co Limerick in the early 1990s found industrial pollution cannot be ruled out.
The report, commissioned by the Irish Farmers Association (IFA) and authored by Professor Brian Alloway of the Imperial College in London is critical of the original Environmental Protection Agency (EPA) investigation of the deaths.
The EPA report said industrial pollution was not the cause of death and instead indicated farming practices in the area may have played a part.
The IFA study found that while industrial pollution was not the major cause of health problems in cattle, there are aspects which are either unclear or in need of further investigation.
While Professor Alloway could not ascertain the actual cause of the deaths the IFA has called for a more scientific approach to the monitoring of potential pollutant hazards and the monitoring of animal performance in the area.