Saturday, 9 October 2010
Athens News on the Asopos Tragedy/heavy metals in vegetables
Athens News, 8.10.2010, pages 1 and 14.
CARROTS, potatoes and onions grown in the plain of the polluted Asopos River contain high levels of nickel and chromium, new research by a team of Greek scientists indicates.
Carried out by researchers from the chemistry department of Athens University, the study was presented on October 2 at an international conference on Lesvos and will be considered for publication in the journal of analytical chemistry Analytical Letters.
The study’s results are based on samples of the three root vegetables labelled as coming from Thiva, the main town in the river basin. The produce is sold in 10 well-known Athens supermarkets.
However, Yannis Zabetakis, one of the report’s authors, stopped short of saying that consumers should be alarmed by his team’s findings.
“They should be informed,” said Zabetakis, adding that more toxicity studies are required to determine whether the levels of the heavy metals pose a danger to public health.
While the study found that an adult consuming average amounts of root vegetables from the Asopos area would not exceed his or her acceptable daily intake, Zabetakis said that high-risk groups such as pregnant women and the elderly need to be better aware of what goes on in water, soil and food. Young children may also be at risk, he said.
Zabetakis noted that a 10-year-old child could exceed the tolerable upper intake level for nickel (300 micrograms per day) by consuming 200g of carrots from the Asopos region, for example, as a soup or juice.
“When I feed my children, I want to know what they are eating,” said the father of two.
The team’s study found that the levels of nickel in Asopos-sourced tubers were up to five times higher than in the same vegetables grown in areas with little or no industrial activity.
Carrots from the area were found to have on average 4.1 times more nickel, 1.15 times more chromium and 1.75 times more cadmium than samples from other, non-polluted areas.
Nickel levels in onions were 6.4 times higher than produce from other areas.
The highest level recorded in Asopos produce - a nickel level 9.3 times higher than elsewhere - was found in potatoes, which also showed chromium levels that were 3.5 times higher.
According to Zabetakis, the research confirms that the polluted Asopos River, which flows through the prefecture of Viotia and enters the sea in northern Attica, does not only affect residents of the farming region but, through the sale of vegetables, the wider society as well.
Zabetakis said more research is necessary, particularly in order to establish how the heavy metals get into the tubers.
“We know that there is water pollution in the area,” he said, “but we don’t know if the heavy metals pass from the water into the soil and then to the food.”
He added that future research will also have to do what to date has been prevented by local farmers.
“What we should have done was to take samples from each individual farm of its water, soil and produce,” explained the scientist, who in the past has been physically attacked by local farmers who fear the results of his research could damage their livelihood.
Zabetakis said that existing EU legislation (EC 1881/2006) is insufficient to deal with the extent of heavy-metal pollution of food produce, an increasing problem worldwide.
“More and more heavy metals are entering the food chain,” he said. “Legislation should adapt to this trend and set limits.”
As it stands, European legislation only sets maximum limits for four metals in food: tin, lead, cadmium and mercury.
The bizarre consequence of this, Zabetakis added, is that no matter what the level of nickel or chromium is in a carrot, for example, a producer could even use it to “make baby food”.
Apart from legislation, controls also need to be beefed up, said Zabetakis, who doubts the effectiveness of the Hellenic Food Authority in this regard.
Now that the scientists have discovered heavy metals in groundwater and the food in Asopos, future research will have to examine how and whether the heavy metals progress from water to food.
A student under Zabetakis’ supervision is currently engaged in a PhD on the topic, which involves the cultivation of tubers with polluted water in a greenhouse at the university.
Zabetakis also said that it is imperative that research similar to this one be carried out in other areas where the ground water is known to be polluted with heavy metals, such as Evia.
“It’s a hot political potato and no one wants to touch it,” Zabetakis said.
* THE ASOPOS region is a haphazard melange of industrial plants, particularly around the town of Oinofyta (map). In some cases the sites are strung along country roads and surrounded by potato, onion and carrot fields. Marked on the map by coloured dots, the industries of the area, which has no proper waste-water management system, produce everything from parts for fighter jets and biscuits to aluminium windows and soft drinks.