‘Annual Recurrence’ Controversy Over Safety of Pine Wilt Disease Tree Injections

“Are Pesticide Components in Pine Pollen Safe?” Citizens and Environmental Groups Question
Chungnam Provincial Council Adopts Resolution Urging Suspension of Pesticide Use
Korea Forest Service Refutes, Saying “Verified Pesticides, Minimal Human Impact from Pine Pollen”

The controversy over the harmfulness of pine wood nematode disease prevention tree injections recurs every year. When citizens and environmental groups raise concerns about the human toxicity of the springtime nematode disease control agents, the Korea Forest Service repeatedly issues an official statement asserting that the safety has already been verified and confirmed.

A pine tree infected with pine wilt disease. Provided by the Korea Forest Service

◆Questioning the Safety of Nematode Disease Control Agents= The Daegu Safe Living Practice Citizens' Coalition (hereinafter Ansillyeon) recently questioned in a statement, "Can the Korea Forest Service claim that the residual pesticide components in pine pollen are safe?" They also expressed concern and regret that despite raising similar issues around the same time last year, no clear citizen safety measures have been presented.

Previously, Ansillyeon claimed, "Last year, pesticide components were detected in pine pollen at concentrations 36 times higher than the permissible limit," and urged the government to urgently develop a comprehensive countermeasure. However, they criticized the lack of any measures even after a year as irresponsible behavior threatening public health.

Ansillyeon's claim of harmfulness is based on a report investigated by the Korea Forest Service through the National Institute of Forest Science, which confirmed that residual pesticides were detected in pine pollen at levels exceeding human tolerance standards: emamectin benzoate at 90 ppb (9 times), thiamethoxam at 1145 ppb (114.5 times), and sulfoxaflor at 1609 ppb (160 times), compared to the human tolerance standard of 10 ppb.

Regarding this, Ansillyeon pointed out, "Highly toxic insecticide pesticides are injected into pine trees to prevent nematode disease, and these potent pesticide components remain in the pine trees for more than two years, resulting in high concentrations of pesticides in pine pollen. Since the same pesticides are used in residential areas such as apartment complexes, parks, and sports facilities, there are concerns about citizen safety and health."

They urged, "The Korea Forest Service should recognize the seriousness of residual pesticides in pine pollen and completely stop the chemical control using highly toxic pesticides."

The Chungnam Provincial Council also recently urged the cessation of nematode disease control agents. On the 15th, during the '351st Extraordinary Session 1st Plenary Meeting,' the council adopted a resolution titled 'Request to Stop Using Highly Toxic Insecticides for Nematode Disease Control and Promote Eco-friendly Control.' Considering that the resolution calls for stopping the use of current nematode disease control agents and switching to eco-friendly control methods, it aligns with Ansillyeon's stance.

Officials from the Korea Forest Service are conducting clear-cutting in areas affected by pine wilt disease. Photo by Korea Forest Service

◆Recurring Controversy Every Year... "Safety Has Already Been Verified"= The Korea Forest Service also issued an official stance on the safety controversy of nematode disease control agents. The core message is that "the safety of nematode disease control agents has already been verified." They rebutted Ansillyeon's claim of detecting high concentrations of pesticides in pine pollen as an "error due to confusion."

First, the Korea Forest Service emphasized that the nematode disease control agents at the center of the recent controversy are pesticides whose safety has been verified by the Rural Development Administration under the Pesticide Control Act. They explained that these agents are pesticides recognized for safety after testing efficacy and toxicity and are commonly used for controlling diseases and pests in many crops such as apples and cucumbers.

Regarding the claim that pine pollen from pine trees injected with preventive agents is harmful to humans, they directly refuted it by citing research results from the National Institute of Forest Science. The size of pine pollen is 42?81 μm, which is larger than the minimum particle size (10 μm) that can be absorbed by the human body, making it unlikely to reach the human lungs.

In particular, concerning Ansillyeon's claim about the seriousness of residual pesticides in pine pollen, they dismissed it as a misunderstanding arising from confusing the concentration and amount of residual pesticides. They emphasized that even if pine pollen is absorbed by the human body, the amount absorbed is too small to be harmful.

A Korea Forest Service official said, "The two residual pesticides detected in pine pollen during pesticide residue investigations (sulfoxaflor and thiamethoxam) are pesticides with the lowest health hazard and inhalation toxicity ratings. Moreover, setting aside the fact that pine pollen is structurally difficult to be absorbed by the human body, even assuming that pine pollen (residual agents) is absorbed, the actual amount would be negligible."

In fact, the National Institute of Forest Science calculated the daily inhalation amount of residual agents in pine pollen based on a 70 kg adult male. The maximum daily inhalation amount of thiamethoxam was 2.47 ng, which is extremely small compared to the acceptable daily intake (ADI) of 5.6 mg. Sulfoxaflor was 3.4 ng, only one-millionth of the ADI limit of 3.5 mg. The ADI values for thiamethoxam and sulfoxaflor are regulated by the Ministry of Food and Drug Safety.

Regarding this, a National Institute of Forest Science official said, "The ppb presented by Ansillyeon is a concentration concept, while inhalation is calculated by amount, so simply comparing amount and concentration is erroneous. Above all, ADI is the allowable pesticide amount per 1 kg of human body weight. Without reflecting the adult standard weight (70 kg), it is difficult to be persuasive to simply calculate harmfulness."

Meanwhile, nematode disease is classified as a fatal pest disease that kills 100% of infected pine trees. Since there is no developed treatment yet, prevention is the best option, and the only method to prevent nematode disease is tree injection, according to the Korea Forest Service.

However, recently, the Korea Forest Service emphasized that they are researching eco-friendly control methods such as switching from blanket aerial spraying to precision drone spraying, using natural enemies of nematode disease vectors for control, and breeding nematode disease-resistant varieties.

This content was produced with the assistance of AI translation services.