University College Cork will house the State's first dedicated dioxin laboratory which will measure levels of this carcinogen in food. Dioxin is a dangerous carcinogen but we don't know how much of it there is in our food, writes Dick Ahlstrom.
Nor is there national testing to measure dioxin levels in the air.
All of this is about to change, however, following the announcement last week of the State's first specialised testing laboratory for dioxins. The Government has provided University College Cork with a €2 million grant to open and staff the new lab which will begin measuring dioxins in food.
It will be based at the Lee Maltings complex in Cork, close to the National Microelectronics Research Lab.
"Food will be the first testing done using a wide range of food samples," says Prof James Heffron, director of the biochemical toxicology lab in UCC's Department of Biochemistry."It will allow us to meet the EU requirements to measure and record levels and make interpretations of the risk that might be involved."
EU law dictates that each member state must measure dioxin levels in food, air and water. Only Ireland and Greece do not have an active measurement programme, he says. It requires measurement of 17 dangerous "isomers" or forms of the chemical, seven true dioxins and 10 related compounds known as furans.
Dioxins are produced when substances are burned. These include coal, petrol, diesel, tobacco and domestic waste. Dioxins immediately arise as an issue whenever waste incineration is discussed because of fears that atmospheric dioxin levels will rise and it will find its way into our food.
Prof Heffron is, however, less fearful of municipal waste incineration than he is of the burning of refuse in the fireplace or back garden,which is still a common practice amongst many people. "The backyard incineration of domestic refuse is a major source of dioxin and this is ignored. It accounts for a very high proportion of the dioxins that are emitted to the atmosphere." Low temperature domestic burning produces 10,000 times more dioxins per kilogram burned than industrial incineration, according to international studies.
Dioxins are dangerous even at extremely low levels, says Heffron, and the World Health Organisation has set accordingly low limits for human exposure. It says levels should not exceed four million millionths of a gram of dioxin per kilogram of body weight per day, whether absorbed in food or air.
"If we stay within that we will have an increased cancer risk of less than one in a million in a lifetime of exposure. That would be an extremely low risk and far lower than most other [chemical\] exposure risks."
Dioxin levels in air and food here have remained unknown, something that the new dioxin lab will correct. Three limited studies did give some information. There were two studies in 1995 and 2000 looking at cow's milk. The samples were sent to Germany for analysis because there was no lab doing it here.
The 2000 survey included areas where there was no industrial activity and areas where there were factories. The highest levels were measured in the east coast, probably a result of diesel and petrol fuels, Heffron says.
Earlier air sampling in 1990-91 showed dioxin levels well within international limits. "They were very low at that stage," says Heffron, something suggested in the later studies. "Our levels are approximately a tenth of our European neighbours' levels, so they would be very low."
The lab's key piece of equipment is a €600,000 high-resolution mass spectrometer. "It will tell us levels of the molecular fragments of each of the 17 dioxin isomers to be measured," he explains.
Dioxin dissolves in fatty tissues and can remain in the body for up to five years. For this reason fatty foods, including meat, fish, oils and milk, will be tested first. About 40 per cent of the dioxins we ingest come from meat and between 10 and 15 per cent from milk.
The EU regulations were not the only thing that prompted the Government investment, adds Heffron. "The main reason we are concerned is the number of contamination scares that have occurred." He mentions the 1999 scare in Belgium in which dioxin-contaminated mineral oil was added to poultry feed. This in turn pushed up dioxin levels in chicken sent to market. There was a scramble to test imported chicken here but again samples had to be analysed in Germany. "That is not a satisfactory solution. The country should have its own capacity to do the analysis." Now it does.