Sir, - As a professor of toxicology, a medical doctor and a consultant to the World Health Organisation, I wish to take serious issue with the letter from Dr Conchur O Bradaigh in your edition of January 29th. The public health facts that he stated are misleading and inaccurate in a number of respects.
His statement that the dioxin levels in Danish cows' milk are 12 times higher than in Ireland is quite wrong. Data from Danish cows' milk can be found in COWI's Dioxin Inventory of Denmark, and shows slightly higher average values than in Ireland. According to these data, levels are not 2.6 pg ITEQ/g fat as suggested by Dr O Bradaigh, but 0.49 pg I-TEQ/g fat. Despite the fact that the Danes have incinerated municipal waste for many years now, the level of dioxins in Danish cows' milk is not dissimilar to that of Irish cows' milk, which ranges from 0.13 to 0.51 pg TEQ/g fat, according to the Irish Environmental Protection Agency.
The Danish values for mothers' milk cited by Dr O Bradaigh are not "extremely high", but are within the lower range of European values for the past 20 years. The misinterpretation is that Dr O Bradaigh is comparing data for human mothers' milk with cows' milk. TEQ values in mothers milk are always higher than those in cows for dioxins and most other environmental pollutants. Furthermore, mothers' milk is not subject to food regulations as the WHO makes a distinction between human mothers' milk and cows' milk. I suggest Dr O Bradaigh does the same.
Finally, the levels of dioxins in mothers' milk have been falling steadily in Europe at a time when incineration practice is increasing - 40 per cent more waste is now incinerated in Europe than in 1990. - Yours, etc.,
Dr Dieter Schrenk, Professor of Food Chemistry and Environmental Toxicology, University of Kaiserslautern, Germany.