Washing fruit and vegetables before eating them is a common practice in most British households.
But new research suggests this may not be enough to remove potentially harmful pesticides from their produce.
Experts at Anhui Agricultural University in China used a highly sensitive film to detect traces of chemicals that other tests fail to detect.
Tests on apples and cucumbers, as well as other foods such as shrimp and rice, found that washing the food did not remove traces of pesticides that have been linked to liver cancer.
The scientists say their findings offer evidence that washing fruits and vegetables is insufficient and suggest peeling foods such as apples and cucumbers.
Have you ever thought about peeling a cucumber? You might want to consider it according to Chinese scientists, who discovered that washing it is not enough to remove pesticides that can be harmful to human health.
Writing in the diary Nano lettersThey concluded: ‘The risk of pesticide ingestion through fruits cannot be avoided by simply washing them instead of peeling them.
We believe that peeling operation can effectively avoid the dangers of pesticides on the epidermis (skin) and near-epidermal pulp of the fruit, thereby reducing the probability of ingesting pesticides.
But is peeling fruits and vegetables really crucial to protecting our long-term health?
For the new study, researchers sprayed the fruit they tested with the pesticides thiram and carbendazim.
Experts at Anhui Agricultural University in Hefei City originally conducted experiments on apples and dried fruit before replicating them on cucumbers, shrimp, chili powder and rice.
They then washed them to mimic the everyday practices of millions of families who buy these items every day.
However, using their special film, they showed that washing was not enough to eliminate the presence of these pesticides and that they could still be detected in “low concentrations”.
They then replicated the study on other foods, including cucumbers, shrimp, chili powder and rice, and produced similar results showing that these were also contaminated with pesticides.
Carbendazim has been shown in some animal studies to increase the risk of developing liver cancer. Thiram has also been linked to developmental problems in fetuses and is a skin irritant, according to the U.S. Environmental Protection Agency.
High exposure to carbendazim is associated with headache, dizziness, nausea and vomiting, as well as movement problems.
However, neither thiram nor carbendazim are approved for use in the UK.
While food imported into the UK may be grown using them and sold on supermarket shelves, traces of these chemicals are too low to cause any of the harmful effects found in the studies.
Separate studies, on pesticides in general, have linked pesticide exposure to an increased risk of cancer in people.
One recent study even claimed that pesticides had a greater impact on cancers such as Hopkins lymphoma, leukemia, and bladder cancer than smoking.
However, experts say the health benefits of eating fruits and vegetables far outweigh the risks of consuming foods with insignificant amounts of pesticides.