CFS announces Total Diet Study findings on pesticide residues

The dietary exposure of the local population to 85 commonly encountered pesticide residues under four pesticide groups was found to be low, thus unlikely threatening our community's health, according to the fourth report of the First Hong Kong Total Diet Study released by the Centre for Food Safety (CFS) today (June 28).

A spokesman for the CFS emphasised the unique importance of pesticides in modern agriculture in producing safe and quality crops in abundance.

"Generally speaking, so long as farmers follow good agricultural practice (GAP) in the use of pesticides, only acceptable amounts of pesticide residues should remain in crops or foods of animal origin, and that should not put public health at risk."

He said that the study focused on assessing the dietary exposure of the local population to the residues of 85 commonly encountered pesticides or their metabolites under four groups, namely organophosphorus pesticides (OPPs), carbamates, pyrethrins and pyrethroids, and dithiocarbamate metabolites. They are generally used as insecticides, herbicides or fungicides on agricultural crops.

"A total of 600 composite samples involving 150 food items were analysed. Among them, pesticide residues were detected at only low levels in about 30 per cent of the composite samples which were largely of plant origin, such as vegetables and fruits," the spokesman said.

As regards individual pesticides, ethylene thiourea (a dithiocarbamate metabolite) was the most widely detected (in 13 per cent of composite samples), followed by cypermethrin (11 per cent), propamocarb (5 per cent) and chlorpyrifos (5 per cent).

"With the current study's findings, it can be concluded that the estimated dietary exposures of the local population to all 85 individual pesticide residues analysed were unlikely to pose unacceptable health risks, given that all were well below their respective safety reference values (i.e. Acceptable Daily Intakes, ADIs)," the spokesman remarked.

"Even for high consumers, the percentage contributions of the estimated dietary exposures to individual pesticide residues, respectively, were less than 1 per cent of the ADIs for the carbamates, and pyrethrins and pyrethroids; less than 4 per cent for the dithiocarbamate metabolites; and below 24 per cent for the OPPs," he continued.

On the adverse health effects of pesticides, the spokesman said that OPPs and carbamates could lead to signs of neurotoxicity, but they generally did not accumulate in the human body. The acute toxic effects of pyrethrins and pyrethroids were also related to their adverse effects on the nervous system. As for two dithiocarbamate metabolites, due to their known thyroid toxicity, they were of greater concerns than their respective parent compounds.

"It cannot be over-emphasised that food items detected with pesticide residues are unsafe for consumption," the spokesman said.

"In assessing the health risks of pesticide residues, apart from their toxic nature, the amount and the duration of exposure must also be considered.

"The findings re-affirmed the safety of the Centre's basic dietary advice on healthy eating, i.e. have a balanced and varied diet which includes a wide variety of foods, including fruits and vegetables. To minimise potential exposure to water soluble pesticide residues, the public can wash vegetables and fruits thoroughly in clean running water, and soak the vegetables in water for one hour and then rinse, or alternatively blanch the vegetables in boiling water for one minute and discard the water," the spokesman advised.

"To further reduce their pesticide exposure, the public can also remove the outer leaves of the vegetables or peel the vegetables and fruits as appropriate," he added.

The spokesman also reminded farmers to observe GAP, such as using only pesticides registered with the competent authority and applying the minimum quantities necessary to achieve adequate pest control. The use of pesticides should also be in strict accordance with the label requirements. For example, the crops should not be harvested within the specified withholding period after the last pesticide application.

To further safeguard public health, the Government has introduced the Pesticide Residues in Food Regulation (the Regulation) under the Public Health and Municipal Services Ordinance to enhance the regulatory control on pesticide residues in food. The Regulation will come into operation on August 1, 2014, after a grace period of some two years.

The full report on pesticide residue study is available on the CFS' webpage at www.cfs.gov.hk.

Ends/Thursday, June 28, 2012
Issued at HKT 15:01