A study has found concerning levels of chemical residues in the vegetable bok choy with some samples containing residues of a chemical banned last year.
The results released today by the New Zealand Food Safety Authority (NZFSA) looked at locally-produced and imported crops, which were prone to exceeding chemical limits, and found no health or safety concerns.
But the study by the Food Residue Surveillance Programme found a number of bok choy samples exceeded the maximum residue limits (MRL) for agricultural chemicals, with 10 out of 23 examples containing the fungicide chlorothalonil or the insecticide thiamethoxam over the allowable limit.
Some samples also contained traces of endosulfan which was banned last year because of the risk it poses to human health.
Traces of endosulfan were also found in cucumbers and although the levels detected in both vegetables were compliant with MRLs and deemed not a food safety concern.
Investigators were following up on the detections, NZFSA adviser Paul Dansted said today.
While the levels of chemicals found in bok choy were not a safety risk they were still a concern, he said.
"Although our safety assessments show that an average-sized adult weighing 70kg could eat 1.7 kilos a day of the bok choy with the highest residue for the whole of their life with no effect, this level of non-compliance is concerning," he said.
Chemical standards had been breached because growers had been confused over how to classify bok choy and many had mistakenly considered bok choy as brassicas instead of leafy vegetables, which have a much lower MRL.
"This understandable confusion has led to fairly widespread non-compliance," Dr Dansted said.
NZFSA was working with Horticulture New Zealand to inform growers of the correct use of agricultural chemicals on bok choy, he said.
Samples for other crops contained non-compliant levels of the insecticides methamidophos and thiacloprid in four samples of New Zealand grown cucumbers, while two samples of imported oranges contained the fungicide imazalil at non-compliant levels.
