Public warned on raw seafood

PUBLISHED : Friday, 21 March, 2008, 12:00am
UPDATED : Friday, 21 March, 2008, 12:00am

The public should be aware of health threats in raw seafood after swordfish sashimi was found tainted with mercury and raw oysters with norovirus - a common cause of upset stomachs - the Centre for Food Safety said.

Swordfish samples from two supermarkets - Jusco in Kornhill and City'super in Causeway Bay - were found with toxic mercury content of 1.8 and 0.94 parts per million, respectively, exceeding the legal limit of 0.5ppm.

According to the Centre for Food Safety, occasional consumption of such fish would not cause adverse health effects, but consuming it for a prolonged period could affect the nervous system.

Pregnant women, infants and young children are especially sensitive to toxic effects, the centre said.

Some of the fish in question had already been sold, it said, and the remainder discarded.

A Jusco spokeswoman said the tainted swordfish was from Taiwan, and sold at the supermarket's Nakajima Suisan sushi counter. The remaining stock was destroyed last month. The store's food is regularly subjected to lab tests for heavy metals and for microbiological analysis, the spokeswoman said.

The raw-oyster sample was taken from a seafood shop at To Kwa Wan. It was tainted with norovirus nucleic acid, which may cause vomiting, diarrhoea, abdominal pains and fever.

The centre took another sample to follow up and reported that the result was 'satisfactory'.

The centre also examined a sample of rice with curried chicken bought at a restaurant in Tsim Sha Tsui, and found it contained 100,000 organisms per gram of the food-poisoning bacterium Clostridium perfringens. The standard is 10,000 per gram. It can cause abdominal pain and diarrhoea.

The centre said a follow-up sample was again satisfactory.

The centre's assistant director of food surveillance and control, Miranda Lee Siu-yuen, advised the public to buy food from reliable premises. High-risk groups such as children, pregnant women and women planning for pregnancy should avoid eating large predatory fish such as swordfish and tuna.

The centre reported an overall satisfactory rate of 99.5 per cent in about 8,400 tested food samples of various food groups. The inspections were done in January and February.

Dr Lee said the breaches of standards were not serious, and posed no immediate health risks.