Chlorpyrifos may harm fetal nerves; banned in the US, Taiwan pre-announces ban on use in rice, vegetables and fruits
A US court recently ruled to ban chlorpyrifos, and related studies have repeatedly pointed out that chlorpyrifos may cause fetal nerve damage. On the 21st, the Bureau of Animal and Plant Health Inspection and Quarantine of the Council of Agriculture held a pesticide technical advisory meeting and resolved to restrict the scope of chlorpyrifos use, banning its use on rice, vegetables, and crops with relatively high intake such as citrus, lychee, longan, peach, plum, Japanese apricot, pear, apple, loquat, persimmon, and jujube. A pre-announcement is expected in early September, and after a 60-day public comment period to gather opinions from all parties, a final decision will be made.
Insecticide chlorpyrifos is used in large amounts; the Bureau of Animal and Plant Health Inspection and Quarantine resolves to restrict its use
Chlorpyrifos is an insecticide with a fairly high usage volume in the country; in 2016, usage was 535.1 metric tons, accounting for 19% of all insecticides (calculated by active ingredient), and sales ranked sixth among all pesticides. Considering the public's risk of exposure to chlorpyrifos, at the end of August last year the Bureau of Animal and Plant Health Inspection and Quarantine lowered the acceptable daily intake (ADI) for chlorpyrifos from 0.01 milligrams per kilogram of body weight per day (0.01 mg/kg bw/day) to 0.003 milligrams.
Zou Huijuan, deputy director-general of the Bureau of Animal and Plant Health Inspection and Quarantine, pointed out that after lowering the ADI to 0.003 milligrams, the public's chlorpyrifos intake was reassessed, and the data showed it had exceeded the regulatory upper limit, so discussions were held on removing approval for use on crops consumed in relatively large amounts. "Yesterday, experts in pests and diseases, pesticides, and toxicology met together to discuss and reached a consensus to restrict the use of chlorpyrifos and reduce the public's dietary intake risk."
Banned on rice, vegetables and many fruits
The approved scope of use removes crop categories consumed in relatively large amounts, including rice, vegetables, and fruits such as citrus, lychee, longan, peach, plum, Japanese apricot, pear, apple, loquat, persimmon, and jujube. Once approved in the future, chlorpyrifos may not be used on these crops.
However, other crops such as coffee and tea trees are also often consumed by the public, so why not ban them directly? Zou Huijuan explained that the first wave is to first cancel crops consumed in relatively large amounts by the public, and risk assessments will continue to be conducted for other crops afterward, with coffee, tea trees and others all included in the assessment scope. After last year's decision to lower the ADI, the pesticide institute collected relevant information and listed crop categories consumed in relatively large amounts, pesticide monitoring data, and so on, before deciding to restrict use on these crops. "Alternative pesticides must be considered; a complete ban is still not possible now."
"Lowering the ADI tolerance and removing approval for use on crops consumed in relatively large amounts is only the first step." Zou emphasized that next, individual risks will be estimated for different age groups, such as assessing exposure risk for children aged zero to three and three to six. If the risk is too high, would a complete ban be considered? "We cannot make assumptions now; it depends on subsequent assessment results and scientific reports, and the Bureau of Animal and Plant Health Inspection and Quarantine will also continue to adjust the regulations."
Chlorpyrifos is also an environmental pesticide, and the public still faces exposure risk
However, chlorpyrifos belongs to the organophosphate class, has contact, respiratory and gastric toxicity, is a broad-spectrum insecticide and acaricide, and is also neurotoxic to mammals. In addition to agricultural use on hundreds of crops, it is also commonly used to eliminate household pests such as cockroaches, termites and mosquitoes. Even if the Bureau of Animal and Plant Health Inspection and Quarantine resolves to restrict the use of chlorpyrifos, if environmental pesticides are not controlled, the public will still be exposed to the risk of chlorpyrifos.
Zou Huijuan pointed out that although the agricultural side tries to reduce the use of chlorpyrifos and strengthen pesticide management, environmental pesticides must also improve accordingly. On this part, there have been ongoing communications and discussions with the Toxic and Chemical Substances Bureau of the Environmental Protection Administration. "We have let the Environmental Protection Administration know the agricultural side's control methods and provided them as a reference for our management operations."
The Bureau of Animal and Plant Health Inspection and Quarantine first designated the crops on which chlorpyrifos use is restricted, and after a 60-day pre-announcement, will seek opinions from stakeholders. Zou said that after approval is confirmed, the Ministry of Health and Welfare will appropriately adjust food residue tolerances.
Will there be a wave of stockpiling? Bureau of Animal and Plant Health Inspection and Quarantine: even if stockpiled, it cannot be used when the time comes
Once this wave of use-restriction news came out, will it cause farmers to stockpile? What supporting measures does the Bureau of Animal and Plant Health Inspection and Quarantine have? Zou Huijuan responded that farmers currently using it will be urged through stronger outreach not to stockpile, just like paraquat, which will be banned next year: "Even if you stockpile it, you cannot use it when the time comes. If illegal use is discovered, it will be handled according to law. If you bought extra paraquat, it must also be sent back to the pesticide dealer for handling."
Zeng Deci, honorary distinguished professor in the Department of Plant Pathology at National Chung Hsing University, pointed out that chlorpyrifos has been on the market for more than 50 years, and in edible crop cultivation, there are plenty of low-toxicity, environmentally friendly and safe agents that can replace it. Moreover, chlorpyrifos is a heterocyclic derivative class, with a benzene ring in its molecular structure, and its metabolic decomposition products are more diverse, some of which are even unclear, making tracking and detection relatively difficult. He suggested, "On edible crops, try not to use it; sensitive groups such as pregnant women should absolutely not come into contact with it." Its agricultural application must be especially prudent.
Zeng Deci believes that pesticide risk should be comprehensive, including the safety of applicators and consumers as well as ensuring growers' quality and yield. To assess it, accurate flow and volume data must be grasped; otherwise, estimating the public's ADI is merely guesswork. "Without this data, how can there be an ADI close to reality? Most importantly, we must grasp where it is used and how much is used, and only then can risk be further assessed." He urged that the professional prescription system for plant doctors should be implemented as soon as possible, so that professional doctors bear this responsibility.