Sir, - Your editorial "Ireland's dirty water" July 9th is grossly unfair to those engaged in the agricultural industry and very misleading for your readership.
There is something almost perverse in using the misbehaviour of one party (industrial pollution in Cork) as an opportunity to attack another party (agriculture) which was not involved in the incident (fish kill) in question. It is not the first time that agriculture has been unjustly singled out in relation to its record on environmental abuse and it is time that the media started to ask why it is happening.
No-one can deny that many pollution incidents have arisen from the negligent management and handling of animal manures and farmyard effluents, but it takes an enormous leap to go from that factual recognition to conclude that farmers in general are using too much phosphate fertiliser. Even if they are, there is no documented scientific evidence that fertiliser phosphate is a significant contributor to phosphate levels in rivers or lakes in this country.
Instead the case against fertiliser phosphate is predicated almost entirely on the inability of the known and admitted sources of phosphate to account for amounts measured. As it stands, for your editorial estimate of the influence of phosphate fertiliser to be sustained, no other known source of phosphate can be underestimated, nor can there be any presently unrecognised source contributing. One wonders how those responsible for other sources of phosphate would feel if their contribution was estimated from the difference between the total amount and that admitted by the agricultural industry.
When used as intended, there is no direct pathway for fertiliser phosphate to move into rivers or lakes. In this it is alone - all other forms of phosphate under the influence of man are, at least in part, directly discharged into water, whether the context is industrial or domestic. Thankfully the enormous concentrations of phosphate in raw sewage are slowly being reduced by the introduction of tertiary treatment in many instances.
It should not be forgotten, however, that even with tertiary treatment, the concentrations of phosphate in the discharge effluent remain well above any that could possibly arise from fertiliser sources. Nor should it be forgotten that there are many licensed (not to mention unlicensed) discharges to water which are much more likely to have adverse effects than fertiliser phosphate.
The current biased assessment of the role of phosphate fertiliser, as articulated in your editorial, requires the setting aside of substantial bodies of scientific evidence on the dynamics of phosphate (indigenous and anthropogenic) in the environment. This cannot be good. The question is why is it happening and being allowed to happen. - Yours, etc., Dr G. W. Smillie,
Soil Science, University College Dublin, Dublin 4.