Drug residue in food is caused by improper use of drugs and additives such as antibiotics, sulfa drugs and growth hormone. If injected directly or entering the body from the environment or the food chain, drug residue can be toxic, increase bacterial resistance, or even render medication completely ineffective.
A batch of hairy crabs imported from China were found to contain nitrofuran, a banned antibacterial substance. Thanks to nitrofuran's low price and effectiveness, it was widely used in the past as an additive in food or bathing water for livestock, poultry and aquatic animals to prevent bacterial enteritis, furuncles and aeromonas hydrophila infections -- a species of bacterium present in all freshwater environments and in brackish water, some strains of which can cause illness in fish, amphibians and humans by infection through open wound or ingestion of a sufficient number of the organisms in food or water, ulcers and other diseases.
The side effects on humans of nitrofuran residue include rashes, heart palpitation, or even heart arrhythmia or coma. Due to concerns over the carcinogenic and gene-mutating toxic effects that could possibly be caused by nitrofuran or its metabolites, the use of the drug in food-producing animals has been banned in the EU since 1997.
Exports of Taiwan's tilapia, milkfish and snapper to the EU were on several occasions found to contain nitrofuran and Taiwan suffered economic losses. As a result, the government has banned the use of nitrofuran.
The detection of nitrofuran in products means either that nitrofuran has been used or that the products have been contamin-ated. Thus, if the level detected is not in violation of the law, it points to poor quality management, and consumer interest demands that the product should not be sold.
Questionable food products should not be tolerated and food products with a bad record should of course never be imported. The impact on disease prevention of travelers importing hairy crabs and other food products from China cannot be predicted, but serious disease outbreaks cannot be ruled out. It also leaves open a possibility of biological warfare by bringing in foot-and-mouth disease, avian influenza, rabies, SARS, anthrax and other sources of disease. The relevant government bodies must immediately prohibit any possible harm to public health or the nation's defense capabilities.
The EU, Japan and the US have on several occasions banned imports of Chinese agricultural produce due to the detection of chloramphenicol residues. The Consumers' Foundation randomly inspects Chinese food imports for Spring Festival every year, and about 30 percent do not meet national standards.
For example, Chinese fish fins have been found to contain excess levels of hydrogen peroxide, which can cause vomiting, diarrhea and headaches, while cuttle fish have been found to have high concentrations of formaldehyde, which can lead to abnormal liver and kidney functions.
Chinese meat products may also contain excessive amounts of nitrite, which can induce stomach cancer and other diseases.
Faced with the possibility that questionable Chinese agricultural products may cause health risks, I ask that the relevant authorities implement clear source of origin labeling and internationally recognized health inspection certification for all agricultural imports. This is the most basic health regulation requirement.