KUALA LUMPUR: Consuming mandarin oranges with pesticide residues exceeding safe levels can have both short and long-term health effects, depending on the type of chemicals used and the extent of exposure.
Universiti Putra Malaysia's Land Management Department head, Associate Professor Dr Christopher Teh Boon Sung, said that in the short term, symptoms may include stomach pain, nausea, vomiting, diarrhoea, dizziness, and inflammation of the throat or skin.
"Some pesticides, such as organophosphates - particularly chlorpyrifos - can affect the nervous system and cause muscle spasms or breathing difficulties.
In the long term, prolonged exposure to pesticide residues can lead to more serious health issues, including damage to internal organs such as the liver and kidneys," he said.
However, he reassured that mandarin oranges are generally safe to consume. To reduce the risk of exposure to pesticide residues and harmful chemicals in fruit, he also suggested several effective safety measures for consumers.
"One of the best approaches is to choose fruit from trusted sources, particularly products with labels or certifications such as Good Agricultural Practice (GAP) or organic certification from reputable bodies.
Before consumption, fruit should be washed under clean running water and scrubbed with a soft brush to remove dirt and pesticide residues from the skin," he said.
Teh added that soaking fruit in water, or a salt or vinegar solution, could also help reduce pesticide residues to some extent.
"For fruit with thick skins, such as oranges, peeling the skin before eating can further minimise the risk of exposure to surface pesticides. Some studies suggest that soaking fruit in water for 10 to 15 minutes or washing it under running water can reduce pesticide residues by 40 to 90 per cent, depending on the type of chemical used," he said.
However, he said that these methods are ineffective against systemic pesticides such as imidacloprid and dimethoate, which are absorbed into the fruit's tissues.
"Although washing and soaking can help lower exposure to pesticide residues, they do not guarantee that the fruit will be entirely free of these chemicals," he added.
Meanwhile, to ensure the safety of imported food, including mandarin oranges, he suggested that authorities implement stricter controls through more systematic measures.
"One step that can be taken is increasing the frequency of laboratory tests on imported fruit samples using advanced technology, such as mass spectrometry, to detect pesticide residues more accurately and efficiently.
Collaboration with exporting countries is also crucial to ensure that only fruit meeting safety standards is permitted into the local market," he said.
Additionally, Teh said there is a need for stricter enforcement against importers who fail to comply with food safety regulations.
"Harsher penalties, including hefty fines or import restrictions for violators, could serve as effective deterrents.
A clearer and more detailed labelling system outlining farming methods and pesticide usage should also be introduced, enabling consumers to make more informed choices when purchasing imported fruit."
Earlier, the Health Ministry, in analysing 243 mandarin orange samples during the festive season, revealed that nine samples, or 3.7 per cent, exceeded the maximum pesticide residue limits under the Food Regulations of the Food Act 1983. The ministry said all non-compliant samples had been disposed of.