Scophthalmus maximus (Duobao fish) is the main species of marine cultured fish in China. It is necessary to scientifically interpret the nitrofuran problem of Scophthalmus maximus. On the one hand, it will further enhance the self-discipline awareness of the aquaculture industry, so as not to use illegal drugs. More importantly, it will make consumers clearly understand that the use of illegal drugs in aquaculture is only a very rare phenomenon in Scophthalmus maximus, and even if nitrofuran drugs are used in the aquaculture process, there will be no ".

1.? Introduction of basic situation of nitrofuran

Nitrofurans are an important class of anti-infective drugs, and they are synthetic broad-spectrum antibacterial drugs with the basic structure of nitrofuran. Furazolidone, furacilin, furantoin and furaltadone are commonly used. Nitrofurans have been widely used in livestock, poultry and aquaculture to treat diseases caused by Gram bacteria, fungi and some protozoa. Studies have shown that furazolidone and its metabolites have certain toxic and side effects and may induce cancer. Therefore, the United States 1993 banned the use of furazolidone as a veterinary drug in food animals.

2.? Comparison of toxicity of nitrofuran/metabolites (rats and mice as experimental objects)

The Joint Expert Committee on Food Additives (JECFA) and the European Food Safety Authority (EFSA) have systematically studied the toxicity of nitrofuran and its metabolites in rats and mice. Although nitrofuran and its metabolites have certain toxic effects on mammals, whether it is acute toxicity or chronic toxicity, its effective toxic dose is up to mg of nitrofuran/metabolites per unit weight per day, which is thousands or even tens of thousands of times of the existing limit standard, and it is necessary to be exposed to nitrofuran/metabolites for many days before the relevant toxicity may occur.

3.? Scientific Assessment of Nitrofuran Residue Risk in Scophthalmus maximus (1) Basic Situation of Nitrofuran Residue in Food (including Scophthalmus maximus)

As a banned drug, the Chinese government has very strict supervision and control over nitrofuran residues in turbot, which is included in the special law enforcement scope of "three fish and two drugs", and the judgment standard is 1 μ g/kg, which is internationally accepted. Judging from the results in recent years, the unqualified samples of turbot are rarely detected.

(2) The proportion of turbot in the consumption structure of Chinese residents.

According to FAO data, in 20 16, the annual consumption of global per capita seafood exceeded 20 kg for the first time. The 20 16 edition of Dietary Guidelines for China Residents suggests that the average daily intake of aquatic products is 50g, so the annual intake of aquatic products is about 16kg, and the seafood may only account for 50% or 8kg. If turbot accounts for 20% of the seafood consumed by residents, the per capita annual consumption of turbot is only 1.6 kg, and the daily consumption is about 5 grams.

(3) Risk analysis of nitrofuran residues in turbot.

The criterion for determining nitrofuran residues in turbot in China is 1 μ g/kg, which is adopted by Europe and America at the same time and is also the benchmark for exposure assessment in developed countries. According to the highest value of nitrofuran metabolites per kilogram of turbot detected by relevant departments, consumers need to eat at least 300-400 kilograms of turbot fish every day, which is equivalent to taking 3-4 tablets of furazolidone every day. Not to mention whether someone will eat so many fish a day, even if there is, it is just equivalent to taking drugs for "diarrhea" for a day, and it will not cause any harm to people's health.