Are Pesticide Residue Standards Safe? Read This One Article to Understand
Interviewees:
Gu Baogen, Deputy Director of the Center for Agri-Food Quality and Safety, Ministry of Agriculture
Liu Xingang, Researcher at the Institute of Plant Protection, Chinese Academy of Agricultural Sciences
Wang Yongjiang, Director of the Information Station, Yongqing County Agriculture Bureau, Hebei
Zhang Jianyan, vegetable farmer of Beichakou Village, Yongqing Town, Yongqing County, Hebei
Moderator:
Feng Hua and Zhao Yongping, reporters of this newspaper
1. Can we do without pesticides?
Failure to control pests and diseases causes losses of nearly 40%. Rational pesticide use does not affect quality and safety; the pass rate of spot checks on vegetables and fruits is above 96%
Yongqing County in Hebei has a vegetable planting area of 360,000 mu and is one of the vegetable basket bases supplying Beijing and Tianjin. Do farmers here spray pesticides, and how do they use them?
Zhang Jianyan: My family has 5 greenhouses, 2 for cucumbers and 3 for melons. Compared with open-field planting, greenhouse melons and vegetables have fewer insect pests, and mainly fungicides are sprayed to prevent diseases. Take spring cucumbers: they are planted in December before the New Year, and because bacterial fertilizer was applied, spraying only starts when they enter the fruiting stage in February. The fungicides I use are Yibao, chlorothalonil, carbendazim and so on, sprayed about once every 10 days; plus acaricides, 4 to 5 sprayings from planting to harvest are enough, and spraying must stop about 10 days before picking. These days, after the cucumbers are pulled up, winter melons are planted; winter melons are disease-resistant and basically need no spraying. But every year in the high-incidence period of pests and diseases in August and September, the greenhouse must be sealed, planting nothing, to sterilize it with high temperature and prepare for the next year.
Wang Yongjiang: Farmers like Zhang Jianyan are ordinary farming households in Yongqing. Through two to three decades of exploration and extension, vegetable farmers have basically mastered safe vegetable production techniques. First, physical control, such as sealing and fumigating greenhouses for sterilization before planting, applying bacterial fertilizer, off-season planting, and crop rotation to prevent disease. Second, safe pesticide use; for example, several pesticides used in Zhang Jianyan's greenhouse are all slightly toxic and can decompose before the products go to market.
Are the melons and vegetables we eat covered in "medicine"?
Gu Baogen: That statement is inaccurate. During crop growth, affected by climate and many other factors, pests and diseases inevitably occur and need pesticide control to preserve yields. Theoretically, after pesticide use there will be residues, but residues do not mean unsafe. As long as they are within the national standard range, they are safe and reassuring.
Can we do without pesticides?
Zhang Jianyan: If vegetables are not sprayed, once disease breaks out it simply cannot be controlled. A few years ago, villagers' cucumbers caught "paomagan," a kind of gray mold; in less than 3 days, all the leaves in a greenhouse dropped off, and the whole harvest was lost.
Liu Xingang: At present, pesticides are still an indispensable means of production for agricultural production in countries around the world, including developed countries. According to estimates by the UN Food and Agriculture Organization, without pest and disease control, crop losses can reach 37%.
Are melons and vegetables on the market safe to trust?
Gu Baogen: Agri-food quality and safety is a matter of the utmost importance. Monitoring data show that in recent years the pass rate of spot checks on vegetables and fruits nationwide has remained stable above 96% and has shown an upward trend year by year. Overall, the quality of our agricultural products is reliable, and consumer safety is guaranteed.
2. Are pesticide residue standards safe?
Most are now bionic pesticides, with lower toxicity and controllable risk. Some pesticides carry risks comparable to table salt; national standards leave enough safety margin
Some people turn pale at the mention of pesticides. Are pesticides "poison"?
Gu Baogen: It is a common belief that pesticides are toxic. But today's pesticides are very different from those of the past. First, the chemical composition and structure of pesticides have changed greatly; in the past most were chlorine-containing, arsenic and organophosphorus pesticides, while now most are bionic pesticides with greatly reduced toxicity. Second, the mechanism of action is also different; in the past most were nerve agents that affected the nervous system and easily caused human poisoning, while now there are new pesticides that affect insect energy metabolism and substance synthesis and have little effect on humans. Third, they are effective and used in small amounts. At present, products containing highly toxic pesticide ingredients account for less than 2% in China, while low-toxicity and slightly toxic pesticide products reach more than 75%. The overall trend is that pesticide toxicity is decreasing, usage is decreasing, and safety risk is decreasing.
Liu Xingang: According to China's "Regulations on Pesticide Administration," pesticide toxicity has 5 levels: slightly toxic, low toxicity, moderate toxicity, high toxicity, and extremely high toxicity. Let us make a comparison: for the table salt everyone eats every day, the median lethal dose (LD50) in animal experiments is 3750 mg/kg, while the LD50 of many pesticides is greater than 5000 mg/kg. The larger the LD50 data, the lower the toxicity, so the safety risk of these pesticides is comparable to table salt, and pesticides cannot be called synonymous with poison.
How are pesticide residue standards set?
Gu Baogen: Pesticide residue standards are safety values calculated using risk assessment techniques based on pesticide toxicity, pesticide residues in agricultural products, our food consumption structure, and so on. When setting standards, the basis is the greatest possible risk, that is, calculated on the basis that a person eats a certain agricultural product every day for a lifetime and in the maximum amount he might eat. On this basis, considering species differences and the safety of pregnant women and children, a 100-fold safety factor is added, so the standards are very strict and have a large margin of safety. Therefore, as long as pesticide residues in agricultural products are within the national standard range, they are safe. China has now established 3650 pesticide residue standards, involving 387 pesticides and 284 types (categories) of foods, covering almost all major agricultural products such as vegetables, fruits, and grains.
Can household-by-household production uphold safety standards?
Wang Yongjiang: Nowadays vegetable growing is done in specialized villages or even an entire township; only with scale is there a market. In specialized vegetable production villages, farmers' cooperative organizations are generally set up, with households jointly guaranteeing one another and farmers supervising one another. In addition, the county has formulated harmless production technical operating procedures for 13 types of vegetables, one booklet per household. There are 128 county and township vegetable technicians and more than 1100 farmer technicians, active in the fields year-round, promoting scientific and standardized vegetable quality and safety.
Zhang Jianyan: For vegetable farmers, using high-toxicity and extremely high-toxicity pesticides is like cutting off the road to prosperity. Once something goes wrong, you cannot hold your head up in front of the whole village. In addition, the three agricultural input dealerships in the village have banned high-toxicity pesticides; even if you want to buy them, you cannot.
Gu Baogen: At present, China still allows 12 high-toxicity and extremely high-toxicity pesticides to be produced, sold, and used. Why not ban them completely? Because control of some soil insects, storage pests, and other pests and diseases still cannot do without high-toxicity and extremely high-toxicity pesticides. According to regulations, high-toxicity and extremely high-toxicity pesticides must not be used on vegetables, melons and fruits, tea, or Chinese herbal medicines. Since 2010, the Ministry of Agriculture has implemented designated operation and traceable management of high-toxicity pesticides nationwide, strictly guarding the source.
3. Is market supervision adequate?
A full-chain supervision system from field to table has been formed; 3332 quality inspection institutions achieve surface coverage
From field to table, will market testing let anything "slip through the net"?
Zhang Jianyan: My family's vegetables mainly have 3 sales channels: one is Xinyuan Sunshine Company, for the high-end consumer market; one is Huimin Vegetable Company, supplying Beijing supermarkets; and one is fixed dealers. The first two channels test more strictly, with spot checks on every batch of vegetables; dealers generally do not test when purchasing vegetables. To ensure quality, the village cooperative is also equipped with simple testing equipment and conducts irregular self-inspections of villagers' greenhouses.
Wang Yongjiang: As a pollution-free vegetable base, the county has built a vegetable testing center and 6 township-level testing stations. In the past three years, 25,000 samples have been tested, and self-inspection coverage has reached more than 90%.
Gu Baogen: Agri-food quality and safety is both produced and supervised. China has formed a full-chain supervision system, with supervision from fields, pig pens, and fish ponds to the purchase, storage, and transportation of agricultural products. A complete set of agri-food quality and safety monitoring systems has been established and improved, including routine monitoring, special monitoring, and supervisory spot checks of key agricultural products and agricultural inputs. The state has invested in building 2553 quality testing institutions at the ministry, provincial, prefecture (city), and county levels; adding agri-food quality inspection institutions built by various localities themselves, the total reaches 3332, with 35,000 testing personnel. It should be said that China has made great efforts in supervising agri-food quality and safety, but because agricultural production covers a wide range and the industrial chain is long, some weak links are unavoidable.
Next, the Ministry of Agriculture will grasp both standardized agricultural production and full-process control on one hand, and law enforcement supervision and special rectification on the other. In pesticide supervision, this year it will continue to carry out the special rectification action on "pesticides and pesticide use," strictly investigate and punish illegal acts such as adding high-toxicity pesticides in production and operation, fake and inferior pesticides, and fraudulent use or misappropriation of registration certificates; implement the system of designated operation and real-name purchase of high-toxicity pesticides; and carry out pilot projects for electronic traceability code labeling of pesticide products.
4. How can zero growth in pesticides be achieved?
Support specialized service organizations, carry out large-scale unified prevention and control, improve pesticide utilization efficiency, and reduce pesticide use
What is the overall situation of pesticide use nationwide?
Liu Xingang: Due to climate change and changes in cultivation methods, crop pests and diseases show a trend of frequent, recurrent, and severe outbreaks. Coupled with outdated pesticide application equipment and insufficient popularization of use techniques, excessive pesticide use still exists at present, and the problem of "leakage and spillage" is serious. Data show that China's average pesticide utilization rate is only about 35%, 10 to 20 percentage points lower than that of developed countries.
Gu Baogen: Scientific pesticide use and reduced pesticide dosage are urgent. This year the Ministry of Agriculture formulated an action plan for zero growth in pesticide use. By 2020, the pesticide utilization rate for major crops should reach more than 40%. The focus is on "control, substitution, precision, and unification," striving to achieve "three reductions and one increase": first, reduce the number of sprayings by applying green control techniques such as agricultural control, biological control, and physical control; second, reduce spray dosage by applying pesticides at key periods, according to the target, and in appropriate amounts; third, reduce pesticide loss by developing and applying modern plant protection machinery to replace outdated machinery with leakage and spillage; fourth, improve control effects by carrying out large-scale specialized unified prevention and control.
From practice, this technical route is feasible. In last year's national demonstration areas for the integrated advancement of specialized unified prevention and control and green control, general field crops reduced pesticide use by 1-2 times per season, horticultural crops reduced pesticide use by 3-4 times per season, and chemical pesticide dosage decreased by 20%-30%. Not only was control effectiveness not affected, but more than 8% yield increase per mu and cost savings and efficiency gains of more than 150 yuan could also be achieved.
Are green control and biological pesticides easy to promote and popularize?
Wang Yongjiang: At present, Yongqing's vegetable production is mostly intensive cultivation by individual households, and there is still a gap from organic agriculture and modern agriculture. Biological pesticides and green control require high input and have high technical thresholds. Larger-scale growers use them more, while most ordinary farmers cannot accept them in a short time.
Liu Xingang: China has registered more than 3700 biological pesticide products, accounting for about 12% of all pesticide products. Compared with traditional chemical pesticides, biological pesticides are relatively safe for human and animal health and the environment. In terms of market price, there is no significant difference between biological pesticides and chemical pesticides. However, because biological pesticides have shortcomings such as relatively low control efficacy and slow effects, farmers are not highly motivated to use them. With the development of agricultural production scale and unified prevention and control services, and the continuous deepening of agricultural technical training, this problem will gradually be solved.