What particular attention should be paid if members of public harvests clams or shellfish from sandy shore?
Members of public should not consume shellfish harvested from possibly contaminated water region. Shellfish with incomplete shell or abnormal smell should be discarded.
What is the risk for consuming shellfish?
Shellfish (such as oysters, clams and scallops) are filter feeders which ingest food and absorb nutrients through filtering sea water. The shellfish may be contaminated with viruses if nourished with contaminated water. One may be infected by norovirus or other pathogenic microorganism if consuming undercooked shellfish which is contaminated. So, shellfish should be thoroughly cooked before consumption. Young children, elderly people, pregnant women and others with weakened immune systems should pay special attention when consuming shellfish.
How can the members of public reduce the risk when consuming shellfish?
Members of public should follow the Five Keys to Food Safety. They should buy shellfish from reliable shops and sources. Raw shellfish should be well-packed and stored in fridges at or below 4 ℃ . They should be stored below ready-to-eat food or cooked food in the fridges to prevent their juices from dripping onto those food. The shells of shellfish should be scrubbed and rinsed, and their intestine should be removed during preparation. The shellfish should be thoroughly cooked before consumption. They should be heated to internal temperature of 90 ℃ for 90 seconds or boiled at 100 ℃ until their shells open and boiled for additional three to five minutes afterwards. The cooking liquid should be discarded before consumption.
Will there be any health effect if consuming shellfish contaminated with heavy metals?
Consuming food contaminated with heavy metals in trace amount generally will not affect our health. Health condition may be affected if consuming food (including shellfish) with exceeding levels of heavy metals in prolong period of time. Maintaining balance diet is important to avoid excessive intake of contaminants from small ranges of food.
Can washing remove the heavy metals in shellfish?
Washing can only remove the surface contaminants in the food. It cannot effectively remove heavy metals absorbed inside the bodies of shellfish.
Is there any regulation controlling the heavy metal contents present in shellfish sold in Hong Kong?
Food Adulteration (Metallic Contamination) Regulations (Cap 132V) lists out the standards of heavy metals present in specified food. The maximum permitted concentration of lead, mercury, arsenic and cadmium present in general seafood are 6 parts per million (ppm), 0.5ppm, 10 ppm and 2ppm respectively. According to the regulation, it is an offence if selling specified food exceeding the above standards.