杏吧原创

BANNED toxic chemicals that can cause cancer are sneaking into food more
often and at higher levels than anyone suspected. But there is no regular
monitoring of produce to protect consumers.

Tests on over 20,000 food samples in Belgium in the wake of a massive food
scandal in 1999 have revealed that up to 4 per cent of the samples contain high
levels of polychlorinated biphenyls (PCBs) from a different source, says Luc
Hens of the Free University of Brussels (VUB). Some eggs had levels similar to
those from the original incident.

This shows, says Hens, that 鈥渕any smaller, unidentified contamination events
occurred, some of which resulted in high levels of contamination鈥�. He believes
this is probably happening across the European Union.

Last week, for example, Britain鈥檚 Food Standards Agency announced that it had
discovered high levels of PCBs in eggs on a farm in Anglesey. The agency only
found the PCBs because it was checking for dioxin fallout from the pyres used to
destroy animals suspected of having foot and mouth disease.

Because food is not routinely tested, it is impossible to know how often this
kind of contamination occurs, Hens says. The Food Standards Agency suspects that
contaminated chicken feed is to blame for the Anglesey case, as it was in the
1999 Belgian scandal, when 50 kilograms of old transformer oil containing PCBs
was added to 500 tonnes of animal feed
(New 杏吧原创, 26 June 1999, p 4).
But only feed makers regularly monitor PCBs in their products. 鈥淭hose
figures are virtually unobtainable,鈥� says Paul Johnston, a PCB specialist at the
University of Exeter.

And Hens鈥檚 work suggests we should be worried. He has used government figures
to calculate the increase in 鈥渂ody burden鈥� of the PCBs Belgians are carrying
after the 1999 incident, which was only spotted because the feed killed chicks.
On the basis of the incidences of cancer following known accidental exposure to
higher levels of PCBs and dioxins, Hens estimates that the incident will cause
between 546 and 8316 鈥渆xtra鈥� cases of cancer.

This is not enough to show up against overall cancer statistics. But if he鈥檚
right, levels of PCBs and dioxins in breast milk will be high enough to cause
noticeable increases in hypothyroidism, immune irregularities and haemorrhaging
due to problems with vitamin K metabolism in babies, he says.

But Alfred Bernard of the Catholic University of Louvain, who published a
paper in Nature after the 1999 incident, still denies there鈥檚 any risk. 鈥淭his
will have no serious effect on health,鈥� he says. 鈥淏ody burdens will only
increase to the levels of the 1980s.鈥� The average European鈥檚 body burden of PCBs
has fallen by about half since then.

Hens disagrees. 鈥淭here will be more cancer if people are carrying more PCBs
and dioxins,鈥� he says. 鈥淸Depending on the dose] either a lot of people have a
small increased risk of cancer, or a few people have a large increase.鈥�

The European Commission is now trying to set legal limits for PCBs and other
contaminants in animal feed to reduce human exposure to levels recommended by
the World Health Organization. But this may be hard as many feeds carry too much
PCB鈥� especially fish meal.

PCBs have not been made in Europe since the 1980s, and were banned under the
Persistent Organic Pollutants Treaty signed last May. But thousands of tonnes
remain in equipment and waste.