Five facts about pesticides.

Editor's note

Not long ago, an article entitled "how to Save China soaked in pesticides" released by an official Wechat account spread widely in WeChat circles, causing a strong reaction in the agricultural and pharmaceutical circles. Industry insiders have said that this article failed to objectively evaluate the use of pesticides in China, which was seriously inaccurate and had a bad impact on the pesticide industry and agricultural production. The China Pesticide Industry Association also issued an official letter to the official Wechat account, protesting and calling for not to smear or demonize pesticides, but to evaluate the merits and demerits of pesticides in a scientific spirit and attitude.

Do we really eat so many pesticides every year? Is it okay not to use pesticides? What is the status of pesticide residues in agricultural products in China at present? Let's listen to industry experts refute false rumors and restore the truth.

Rumor

Do we use more than 3 million tons of pesticides every year?

The actual consumption is more than 300,000 tons, most of which are decomposed in the environment.

The article "how to save China soaked in pesticides" mentioned-- "China's annual pesticide consumption of 3.37 million tons is apportioned to 1.3 billion people, that is, 2.59kg per person." Is the truth really so sensational?

In response, Li Zhonghua, secretary general of the China Pesticide Industry Association, pointed out that 3.37 million tons are output data released by the National Bureau of Statistics, of which about 45 per cent are used for export, as well as forestry, health, public epidemic prevention, rodent control and other drugs. According to the statistics of the National Agricultural Technology Center of the Ministry of Agriculture, China uses more than 300,000 tons (100% active ingredients) of pesticides every year, not more than 3 million tons.

Liu Changling, secretary-general of the Pesticide Committee of the Chemical Society of China, said there were many inaccuracies in the data in this article. For example, 10% of suspensions contain only 10% of raw drugs, and there are auxiliaries, most of which are water. In addition, the average value obtained by dividing the total number directly by the total population is not consistent with the facts.

Gu Baogen, deputy director of the Agricultural products quality and Safety Center of the Ministry of Agriculture, said that the actual use of pesticides in China is only more than 300,000 tons. Due to the mode of application and equipment, the actual utilization rate of pesticides is only 25% to 30%, and a considerable part of them remain on plants or flow into the environment. Pesticides entering the environment will slowly decompose under the action of water, light and microorganisms. At present, the half-life of pesticides (half of the decomposition time) is mostly in a few days, special agents take longer, and now the state will not approve the registration and use of drugs with a long half-life. Therefore, although a large number of pesticides enter the environment after use, and there are pesticide residues in the environment, there will be no accumulation problem.

Rumor

Is it okay not to use pesticides at all?

Crops will be reduced by 35% or 40%, fruits and vegetables will lose 40% or 60%.

"is it all right without pesticides?" Many people have similar questions, so is such an idea realistic?

In the "letter on explaining the situation of China's Pesticide Industry" issued by the China Pesticide Industry Association, it was pointed out that due to improper use or cessation of drug use, crop production could be reduced by 35% to 40% in that year, of which fruits and vegetables suffered losses of up to 40% to 60%, and even lost production in the second year. Pesticides save an average of 50 million tons of grain, 1.5 million tons of cotton, 15 million tons of vegetables and 6 million tons of fruits every year, reducing direct economic losses by more than 100 billion yuan. from the point of view of input and output, direct economic benefits of 10 to 20 yuan can be obtained for every one yuan of pesticides used.

The National Agricultural Technology Center has assessed the damage and loss of rice diseases and insect pests. Seven experiments were carried out in southwest rice region, Jiangnan rice region, South China rice region, middle and lower reaches of Yangtze River rice region and northeast rice region. Judging from the experimental results, without control at all, in the year of recurrence of diseases and insect pests, the losses caused by the experimental sites in South China and Jiangnan were as high as 77.94% and 59.63% respectively, with an average of 64.08% and 50.31% in three years, and 26.47%, 28.36% and 19.67% in southwest, middle and lower reaches of the Yangtze River and northeast rice regions respectively. It can be seen from these data that food security and grain self-sufficiency in our agriculture would not have been possible without the protection provided by chemical pesticides.

Liu Changling also pointed out that in addition to insect pests, crops are often affected by diseases. For example, the Great Famine in Ireland around 1846 was caused by the outbreak of potato late blight. There is also the tragic fact that rice blast has not been harvested due to poor prevention and control. There are also literature studies that say that if pesticides are not used, some crops will relatively increase their own toxins against exotic diseases and pests, such as gibberellin and aflatoxin, which are known to cause cancer. For example, if wheat scab does not use pesticides or poor control, not only the yield is low, eating moldy wheat and its food will be poisoned.

Rumor

Is it realistic to rely solely on natural enemies to control pests? Chemical control is still the most effective and economical means.

"how to save China soaked in pesticides" mentioned-"there are more than 1000 kinds of pesticides in China, but only more than 20 kinds of pests." According to the pest species and occurrence characteristics of main crops in the National Agricultural Technology Center for five years, it is confirmed that there are 3238 pest species in China, including 599 species of diseases, 1929 species of pests, 644 species of weeds and 66 species of harmful rats.

If so many pests, as mentioned in this article, do not need pesticides to rely solely on natural enemies for control, is it reliable? Liu Changling pointed out that this statement is absolutely unrealistic. Natural enemies can solve some pests but not all pests, and it is useless to rely on natural enemies in the event of a major outbreak.

Li Zhonghua believes that at the current level of scientific development of plant protection, chemical control is still the most convenient, stable, rapid, effective, reliable and cheapest means of prevention and control, especially when sudden and invasive biological disasters occur, there is no control method that can replace chemical pesticides.

Gu Baogen said: in order to reduce the use of pesticides, the state is vigorously promoting the technology of integrated prevention and control of crop diseases and insect pests, comprehensively adopting green prevention and control technology, and making comprehensive use of biological, physical, and cultivation measures to control diseases and insect pests. In addition to local organic agricultural production and a small number of forest diseases and insect pests, it is unrealistic to rely solely on natural enemies to control diseases and insect pests, both at home and abroad.

Rumor

Is pesticide very toxic?

Highly toxic pesticides less than 3% Pesticide Safety is getting higher and higher

"the more the medicine is used, the more poisonous it is, and the more insects are treated." "how to save China soaked in pesticides" came to such a conclusion, is this really the case?

"in China, pesticides in the minds of most people actually refer to pesticides, especially highly toxic organophosphorus products. But the public also needs to know that pesticides also include fungicides, herbicides, plant growth regulators and other products. At present, many pesticide products are less toxic than salt. " Liu Changling said.

Li Zhonghua said that by 2015, China had banned 33 highly toxic pesticides. China is in the forefront of the world in banning and eliminating highly toxic pesticides, with the largest number of banned varieties in the world. At present, the proportion of highly toxic pesticides in China has dropped from about 70% in the 1980s to less than 3% at present, so the safety level of pesticide products is getting higher and higher, and there is no saying that pesticides become more and more toxic.

"with the elimination of highly toxic pesticides, the toxicity of pesticides in China has decreased significantly, the proportion of highly toxic pesticides has been less than 3%, the proportion of low toxic and slightly toxic pesticides is more than 75%, and highly toxic pesticides such as BHC, DDT and methamidophos that have caused a large number of poisoning have long been eliminated." Gu Baogen said that it should be said that today's pesticides are no longer what they used to be, and are getting safer, which is why there are fewer and fewer cases of poisoning at present. The general trend is that the toxicity of pesticides is decreasing, the usage is decreasing, and the safety risk is decreasing.

Rumor

Is pesticide residue that scary?

Don't be afraid of pesticide residues that do not exceed the standard.

Pesticide residues are the most concerned issue for consumers, so what is the harm of pesticide residues on the agricultural products we usually eat?

Liu Changling said, for example, that the use of glyphosate is one of the largest pesticide products. But glyphosate uses less than 100 grams per mu. Some pesticides use only 1 gram per mu of land, even if they eat all the grain or fruits and vegetables in this mu of land, how many pesticides can they eat? Most pesticides use 5 to 10 grams per mu, and the maximum is no more than 50 grams according to four calculations. In short, pesticide residues exist objectively, but whether they are toxic or not is related to the dose. Today's pesticides only rely on residues and will not affect human health.

"one of the main reasons for excessive pesticide residues is that users do not follow the instructions for the use of pesticides, that is, they do not consider the safe interval, for example, it is stipulated that they can be harvested 10 days after application, and as a result, the users will harvest and sell them 3 days after the use of the pesticide. At present, most of the pesticide application is 5g / mu, even if there are residues, the residues are usually calculated in terms of ppm or ppb, which is very small. It has been reported that even if there are pesticide residues, its toxicity is much lower than that of rice burning. " Liu Changling said.

Gu Baogen pointed out that in rural areas, because of direct exposure to pesticides, pesticide users are the groups most affected by their health. Normal application will not produce poisoning phenomenon, and most of the poisoning symptoms are that the necessary safety protection measures have not been taken during drug application. With the continuous elimination of highly toxic pesticides, there are fewer and fewer cases of actual pesticide poisoning in our country. Now more than 98% of them are medium and low toxic pesticides. Unless taken by mistake, the possibility of poisoning and illness is very small.