Scholars urge assessment of the carcinogenic risk of glyphosate herbicides and stricter inspection of imported genetically modified crops
The International Agency for Research on Cancer (IARC), an agency under the World Health Organization, recently raised the carcinogenic risk classification of the herbicide "glyphosate." In response, the Bureau of Animal and Plant Health Inspection and Quarantine of the Council of Agriculture stated that it will further assess the exposure risk of agricultural workers, while scholars called on the Food and Drug Administration to increase the frequency and level of inspection of imported agricultural products containing glyphosate, in order to safeguard consumers.
The IARC classifies carcinogenic risk factors for humans into four levels, from high to low: "carcinogenic," "probably carcinogenic," "possibly carcinogenic," and "not classifiable as to its carcinogenicity." Glyphosate was originally in the "possibly carcinogenic" category, which means that there is currently international research showing that glyphosate can cause cancer in animals. The IARC's upgrade this time to the "probably carcinogenic" category indicates that some studies have pointed to glyphosate's carcinogenic effects on the human body, but the research data is still insufficient to conclude that it definitely causes cancer.
Inspection Bureau: Reassessing the Exposure Risk of Workers
Glyphosate, also known as Roundup, is a type of non-selective herbicide. Feng Hai-tung, deputy director-general of the Bureau of Animal and Plant Health Inspection and Quarantine, explained that because it is non-selective, spraying it on crops will cause phytotoxicity, so domestically it is mostly used on fallow fields or field weeds. In addition, because it is cheap, at about 100 yuan per liter, it has been the best-selling herbicide across Taiwan for the past 5 years, at about 1,500 tons per year.
Feng Hai-tung said that because Taiwan does not grow genetically modified crops, there is no concern about glyphosate residues. However, regarding pesticide use by agricultural workers, the Bureau of Animal and Plant Health Inspection and Quarantine will further assess exposure risks and then formulate special guidelines or warnings to guide agricultural personnel who use it in large quantities to modify their methods of use. Since the IARC has not yet determined that glyphosate is a carcinogenic-grade pesticide, the Council of Agriculture currently has no plans to ban it.
In international research, glyphosate has been confirmed to cause kidney, pancreatic and skin cancer in rats. Although evidence for carcinogenicity in humans is limited, case studies in the United States, Canada and Sweden have found that people who have long-term occupational exposure to glyphosate have an increased risk of non-Hodgkin lymphoma, and some studies even suggest the possibility of gene mutation and gene damage.
In response, Wu Kun-yu, a professor at National Taiwan University's Department of Public Health and Institute of Occupational Medicine and Industrial Hygiene, believes that glyphosate can still spread through the wind during spraying and affect nearby residences. Such potential health risk assessments have rarely received attention in the past, and government agencies have a responsibility to use this opportunity to research and investigate.
FDA to Discuss Further; Scholars Call for Higher Sampling Frequency
As for whether the glyphosate residue limits for imported foods should be revised, Pan Chih-kuan, head of the Food Division of the Food and Drug Administration, said that regulations from Europe, the United States and Japan must still be referenced, and further discussion with the Council of Agriculture is needed. However, he admitted that if the Council of Agriculture does not make a determination to ban it, then basically there will not be major changes in the FDA's risk assessment of pesticide residues.
However, Kuo Hua-jen, a professor in National Taiwan University's Department of Agronomy, and Chen Chun-cheng, an adjunct lecturer in Chinese Culture University's Department of Health and Nutrition, both pointed out that the FDA should increase the frequency and level of inspection of imported agricultural products containing glyphosate. Chen Chun-cheng said that current general pesticide residue testing covers only more than 200 types, and there are still 30 or 40 types of pesticides that slip through the net, with glyphosate being one of them. Since the WHO has made a determination to raise its carcinogenic level, government agencies have a responsibility to spend more time conducting precise testing; otherwise, consumers simply cannot guard against it.
Kuo Hua-jen emphasized that consumers can avoid eating genetically modified soybeans, because genetically modified soybeans are not afraid of herbicides, and farmers spray large amounts for convenient harvesting, so glyphosate ends up inside the seeds.
Yen Jui-hung, a professor in National Taiwan University's Department of Agricultural Chemistry, also said that some genetically modified crops abroad are sprayed with glyphosate, so the residue risk is naturally higher than that of domestic agricultural products. Consumers can reduce the risk of ingestion by choosing the place of origin of agricultural products and thoroughly washing them before eating. However, he pointed out that glyphosate is highly water-soluble, so even if a person ingests it, theoretically it will quickly be excreted from the body through excretion. For actual toxic harm to occur, it would likely require long-term ingestion of large amounts of fruits and vegetables with severe residues.