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The Acrylamide, the molecular formula is CH2=CH-CONH2, is a kind of white crystal substance, its molecular weight is 70.08. It has been widely used as the precursor material for the production of the chemical product polyacrylamide since 1950. The polyacrylamide is widely used for the purification treatment of the water, for the production of the paper pulp and for the inner coating processing of the pipelines etc. In the European Union, the annual production output of the acrylamide is about 8 million to 10 million.
In April of 2002, the researchers from the Swedish National Food Administration (NFA) and the Stockholm University firstly reported that the acrylamide is detected to be existed in some fried and grilled starchy foods, such as the fried French fries and the fried potato chips, and the existing content exceeds the maximum allowed limit of 500 times to the drinking water standard. After that report, the other countries like the Norway, the UK, the Switzerland and the United States also reported the similar researching results.
Because the acrylamide has the potential neurotoxicity, the genotoxicity and the carcinogenicity, the pollution caused by the acrylamide in the food attract great concerns of the international community and the governments. Therefore, in June 25, 2002, the World Health Organization (WHO) and the United Nations Food and Agriculture Organization (FAO) emergently held an expert consulting meeting together on the acrylamide pollution in the food, the safety of the acrylamide in the food is discussed. In February of 2..5, The United Nations Food and Agriculture Organization (FAQ) and the World Health Organization (WHO) Joint Expert Committee on Food Additive (JECFA) did a system risk assessment on the acrylamide in the foods on the No. 64 meeting, based on the new data in the recent two years.
The Contact Way of the Human Body to the Acrylamide
The human body can get in contact with the acrylamide through the multi ways, such as the digestive tract, the respiratory tract, the skin and the mucous membrane etc, among which the drinking water is an important way for the human body to intake the acrylamide substance. So, the WHO’s acrylamide content limit in water is 1μg /L. In April, 2002, the research of the Stockholm University reported, that the acrylamide content in the fried French fries is more than 500 times of the maximum allowed limit in the drinking water which is recommended by the WHO. Therefore, the food is considered as the main source of the acrylamide intake to the human body. Besides, the human body can also get in contact with the acrylamide by smoking etc.
The Absorption and the Metabolism of the Acrylamide
The acrylamide can be absorbed by the human body through a variety of ways, while the gastrointestinal absorption is the fastest way, the acrylamide is widely distributed in different tissues of the human body, including the breast. Rats by mouth the acrylamide amount at 0.1 mg/kg bw, its absolute bioavailability is 23% ~ 48%. About 90% of the acrylamide entered into the human body is metabolic, only a small amount of the acrylamide excretes via the urine as the prototype shape. When the acrylamide enters into the human body, in the role of the cytochrome P4502E1, the acrylamide is generated the reactive glycidamide (glycidamide). This glycidamide is more easily combined with the DNA’s guanine than the acrylamide, the generated adduct formation cause the genetic damage and the gene mutation, therefore, the glycidamide is considered to be the main active metabolite of the acrylamide carcinogenicity. The research reports, after mouth giving the rats and the mice the acrylamide, the glycidamide guanie adduct is detected in the mouse liver, lung, kidney and testis and the white blood cells, and in the rate liver, thyroidgland, testis, breast, bone narrow, white blood cells and the brain tissue. There is not report showing the formation of such DNA adducts of the acrylamide in human body after the exposure of the acrylamide.
Additionally, the acrylamide and the glycidamide can also combine with the hemoglobin and generate the adduct formation. The acrylamide and the hemoglobin adducts are detected in the animals which are given the acrylamide and in the human bodies who intake the foods containing the acrylamide. Therefore, it is suggested that the acrylamide and the hemoglobin adducts can be used as the biomarker of the exposure level of the people to the acrylamide.
For the risk analysis of the non genotoxic substances and the non carcinogens, the ordinary method is to couple with the factor of safety based on the NOAEL, to get the acceptable daily intake (ADI) or the tolerable weekly intake (PTWI), use the people actual intake level to compare with the ADI or the PTWI, we can evaluate the risk of the materials to the general population. And for the hazard to the carcinogens of the genetic toxicity, the previous analysis believed it should avoid the contact with these substances as much as possible, without the consideration of the relationship between the intake volume of these kind of substances and theirs carcinogenic effect strength, and without the acceptable tolerance of these substances. Therefore, the management can not determine the focus of the supervision of the pollutants and the corresponding prevention measures. But the management also needs very much the different health risk information caused by different intake from the analysis providers, so in the international risk assessment of such kind of substances, it is suggested using the dosage reaction model BMDL and the exposure limit (MOE) assessment. BMDL is the low confidence limit rate of the tumor inducement at 5% or 10%, the BMDL is divided by the population estimated intakes for the exposure limit (MOE). The smaller of the MOE, the bigger of the carcinogenic risk of this substance, whereas the same.
The control and the prevention
Because the fried food is the main food in China, in order to reduce the acrylamide harm to the health, our country should strengthen the monitoring and the control of the dietary acrylamide exposure, develop the exposure assessment of the acrylamide to the population, and study the possible method in reducing the formation of the acrylamide in the food processing. For the public consumers, it is recommended that:
1.Try to avoid the excessive cooking to the food, such as the high temperature or the long heating time, but to guarantee the food to be well cooked and to ensure the termination of the microorganisms in the food in order to avoid the foodborne disease.
2.The balanced diet should be promoted, reduce the intake rate of the fried food and the high faty food, eat more fruits and the vegetables.
3.It is suggested for the food production and food pressing factory, it should improve the food processing technics and the conditions, study the workable method to reduce the acrylamide content in the food, discuss the optimization of the processing and cooking conditions to the industrial production of the food ingredients, research the method to reduce and even eliminate the acrylamide in the food.