• Korean Journal of Environmental Agriculture
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• v.40 no.2
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• pp.92-98
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• 2021

BACKGROUND: Unintentional residual pesticide in soil derived from preceding crops and the transfer to succeeding crops was considered a critical barrier for positive list system (PLS). Thus, an uncertain risk is predicted for ethoprophos applied at cultivation of preceding crop (Korean cabbage) to succeeding crop (spinach). METHODS AND RESULTS: Ethoprophos was treated on soil following the recommended dose and 5 times dose according to the safe use guidelines for Korean cabbage after seeding. On the 4 days after harvesting of preceding crop, spinach was sowed. The initial residual amounts of ethoprophos on soil (7.081-19.493 mg/kg) were decreased to 3.832-7.218 mg/kg until the harvest of Korean cabbage, and then finally decreased to 0.011-0.079 mg/kg after spinach cultivation. The uptake rates of ethoprophos from soil by Korean cabbage were 0.01-0.03% and distributed to root (0.150-0.903 mg/kg) and shoot (0.021-0.151 mg/kg), respectively. The residual amounts of uptake and translocation from preceding crop cultivated soil to spinach edible part were found to be below LOQ. CONCLUSION: The plant back internal (PBI) for ethoprophos is not recommended during sequential cultivation of leafy vegetables, since the residual amounts of ethoprophos in spinach were less than MRL (0.02 mg/kg).

• Korean Journal of Environmental Agriculture
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• v.41 no.3
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• pp.153-157
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• 2022

BACKGROUND: The residue dissipation pattern of pesticides for agricultural products during the pre-harvest period after the final application is important to prevent the maximum residue limit (MRL) violations in domestic and export markets. The MRL violations of carbendazim are observed more often in chamnamul by pesticide residue management surveys by the Ministry of Food and Drug Safety. The residue level at the pre-harvest interval (PHI) and the residue dissipation constant from the critical good agricultural practice (cGAP) trials could be estimated to meet the MRL and pose a health risk to consumers. METHODS AND RESULTS: Chamnamuls were harvested at 0, 1, 3, 5, 7, 10, and 14 days after application of carbendazim in accordance with critical GAP. The residue analysis in chamnanul was performed by HPLC-DAD with the C₁₈ column. The limit of quantitation of carbendazim was 0.04 mg/kg, and the recoveries were 74.4 - 95.8% at the two spiked levels (LOQ and 10LOQ) of carbendazim. The dissipation rates in chamnamul were calculated from the residues at the sampling days by statistical method at a 95% confidence level. The biological half-lives of residual carbendazim in the field trials 1 and 2 were 4.9 and 4.4 days, respectively. CONCLUSION(S): In this dissipation study, the residue concentrations at the recommended PHI were higher than the established MRL in Korea. Therefore, the MRL is proposed based on the residue data sets from the trials conducted at the same cGAP and the dietary exposure assessment.

• The Korean Journal of Pesticide Science
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• v.13 no.1
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• pp.39-44
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• 2009

This study was conducted to evaluate the actual risk of fipronil on worker honey bees (Apis mellifera L.) through acute contact toxicity test, acute oral toxicity test, toxicity of residues on foliage test, and small scale field test. The $48h-LD_{50s}$ of fipronil SC on honeybee were $0.005{\mu}g$ a.i./bee in acute contact toxicity test and $0.004{\mu}g$ a.i./bee in acute oral toxicity test, respectively. In toxicity of residues on foliage test, fipronil showed over 90% of mortality during 28days after treatment at recommended application rate. The $DT_{50}$ of dislodgeable foliar residue was 9 days. Finally, In small scale field test, fipronil showed similar toxicity in the residues on foliage test. It was concluded that fipronil has very high acute toxicity and long residual toxicity to honeybee. Therefore, fipronil is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees are visiting the treatment area. To protect honeybee and wild pollinators from outdoor use of fipronil, ultimately it should need to limit for only indoor use to prevent pollinators from unintentionally exposure of fipronil.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.303-303
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• 2017

Japanese agriculture has faced to several threats: aging and decrease of farmer population, global competition, and the risk of climate change as well as harsh and variable weather. On the other hands, the number of large scale farms is increasing, because farm lands have been being aggregated to fewer numbers of farms. Cost cutting, development of efficient ways to manage complicatedly scattered farm lands, maintaining yield and quality under variable weather conditions, are required to adapt to changing environments. Information and communications technology (ICT) would contribute to solve such problems and to create innovative technologies. Thus we have been developing an early warning and decision support system to reduce weather and climate risks for rice, wheat and soybean production in Japan. The concept and prototype of the system will be shown. The system consists of a weather data system (Agro-Meteorological Grid Square Data System, AMGSDS), decision support contents where information is automatically created by crop models and delivers information to users via internet. AMGSDS combines JMA's Automated Meteorological Data Acquisition System (AMeDAS) data, numerical weather forecast data and normal values, for all of Japan with about 1km Grid Square throughout years. Our climate-smart system provides information on the prediction of crop phenology, created with weather forecast data and crop phenology models, as an important function. The system also makes recommendations for crop management, such as nitrogen-topdressing, suitable harvest time, water control, pesticide spray. We are also developing methods to perform risk analysis on weather-related damage to crop production. For example, we have developed an algorism to determine the best transplanting date in rice under a given environment, using the results of multi-year simulation, in order to answer the question "when is the best transplanting date to minimize yield loss, to avoid low temperature damage and to avoid high temperature damage?".

• Journal of agricultural medicine and community health
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• v.29 no.2
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• pp.249-263
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• 2004

Objectives: The objectives of the present study were to establish the exposure monitoring method of chlorpyrifos and chlorothalonil application to pear and field red pepper by vehicle-mounted sprayer, hand-held sprayer and to assess the risk. Methods and Results: Chlorpyrifos met all of requirements of sampling and analysis method(U.S. EPA), but chlorothalonil met only dermal patch method. Potential dermal and inhalation exposure was evaluated in 42 farmers. Compared with the hand-held sprayer application, vehicle mounted sprayer demonstrated producing relatively lower dermal exposure levels with statistical significance. In dermal exposure during hand-held application, there is no significant difference between pear and red pepper. Conclusions: This results show that application method is the main factor of dermal exposure. There was no statistically significant difference between each group of respiratory exposure level. The margin of safety (MOS) was calculated to assess the risk of pesticide exposure. All Chlorpyrifos MOS values are lower than 0.2, which mean working conditions are unsafe. In order to protect farmers, big efforts to control exposure are needed.

• Journal of Food Hygiene and Safety
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• v.33 no.6
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• pp.438-446
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• 2018

The purpose of this study was to investigate food safety awareness, knowledge, and behavior in college students, to provide basic data for the increase in food safety awareness. Data were collected from 252 college students in Gyeonggi region, using a self-administered questionnaire. In results of concern about food safety, subjects responded 3.48 of 5.00 and have knowledge about food safety education revealing significantly higher awareness and concern than subjects without knowledge about food safety education. Food safety awareness of distributed food was 2.55, considered unsafe. Among reasons in perceiving food as unsafe, 62.3% of subjects expressed distrust about safety relative food production. As for risk factors relative to food safety, subjects responded that the highest risk factor was food additives (2.35), followed by heavy metal (2.38) and endocrine disrupters (2.38). Correlation analysis resulting in risk factors for food had positive correlation with each other, heavy metal revealed highest correlation with pesticide residue (r = 0.674), than with endocrine disrupters (r = 0.672). Also, genetically modified food revealed high correlation with radiation irradiated food. Regression analysis demonstrated that concern about food safety significantly influenced pro-actively engaging in food safety education. Meanwhile, 63.5% of subjects correctly responded to food safety knowledge items. The item 'the heavy metals are contaminated the most, in the roots of vegetables' revealed the lowest correct answer rate (38.1%). In food safety behavior, the item 'always wash hands before handling food and meal's revealed 3.85, and subjects with awareness and concern about food safety education, responded in significantly higher numbers than subject without awareness and concern about food safety. The most neglected concern was relative to frozen food thawed at room temperature. Together, students recognize that distributed foods are unsafe, and students with awareness and concern about food safety education showed higher knowledge compared to without awareness and concern experience about food safety eduction. So, systematic education using accurate and objective data is required to reduce anxiety and raise the level of awareness and concern about food safety.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.255-263
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• 2015

Promoting the organic farming, much of the plant extracts used for controlling pests and fungi have been imported from China, India and Myanmar. But, it is so worrisome that aquatic animals such as muddy loach inhabiting in paddy field and common carps in river exposed to the pests and fungi likely be harmed. This study was conducted in order to evaluate the risks of aquatic animals influenced by the three plant extracts, i.e. Sophora flavescens, Azadirachta indica and Derris elliptica. The toxicities of common carp (Cyprinus Carpio), muddy loach (Misgurnus anguillicaudatus) and PEC (Predicted environmental concentration) exposed to the three plant extracts were estimated by the typical spray volume method. Risks were determined by the toxicity value as 48-hr $LC_{50}$ (Lethal concentration, median) or NOEC (No observed effect concentration) into PEC. 48-hr $LC_{50}$ of Common carp and NOEC by Sophora flavescens extracts was 7.9 and 6.2 mg/L, 26.8 and 21.8 mg/L by Azadirachta indica extracts and 47.0 and < 24.0 mg/L by Derris elliptica extracts, respectively. 48-hr $LC_{50}$ of Muddy loach and NOEC by Sophora flavescens extracts was 16.9 and 10.0 mg/L, 35.6 and 30.0 mg/L by Azadirachta indica extracts, and 73.9 and < 40 mg/L by Derris elliptica extracts, respectively. Therefore, acute toxicities of the three plant extracts for aquatic animals were proved to be very low level. PEC of Sophora flavescens extracts in paddy, drainage and river water was 68.0~3.0, 11.33~0.50 and 3.0~0.0018 mg/L, respectively. TER of Sophora flavescens extracts in the three water was 0.2~5.6, 1.5~33.8 and 2.6~4388.9, respectively. PEC of Azadirachta indica extracts in paddy, drainage and river water was 90.9~1.2, 15.2~0.2 and 4.8~0.00075 mg/L, respectively. TER of Azadirachta indica extracts in the three water was 0.4~29.7, 2.3~178.0 and 4.5~35733.3, respectively. PEC of Derris elliptica extracts in river water was 0.0063 mg/L. TER of Derris elliptica extracts in river water was 5222~15667.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.343-349
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• 2013

Environment-friendly agro-materials tend to be preferred to chemical insecticides recently. For this reason, many studies are conducted to develop environment-friendly insecticides containing natural materials. The purpose of this study was to assess ecotoxicity for pepper extract and cassia oil (11.5+46%, A), pepper extract and cassia oil (23+34%, B), and pepper extract and lavender oil (40+10%, C). They are expected to prevent from pests especially diamondback moth, and can be used for agro-materials. Their formulation was emusifiable concentration (EC). Target species used to assess acute toxicity were aquatic invertebrate (Daphina magna), fish (Cyprinus carpio), honeybee (Apis mellifera L.) and earthworm (Eisenia fetida). The $EC_{50}$ value of A, B, and C to aquatic invertebrate were 0.46, 1.9, 0.25 mg $L^{-1}$ respectively and these values were moderately toxic according to standard of USEPA. In case of acute toxicity test to fish, the $LC_{50}$ of A, B, and C were 1.9, 2.9, 3.8 mg $L^{-1}$ respectively. A was category II in acute toxicity of fish and not acceptable to evaluation criteria of environment-friendly agro-materials. B and C were category III and acceptable. Acute contact and oral toxicity test to honeybee were conducted and the $LD_{50}$ of A, B, and C were > 100 ${\mu}g$ a.i. $bee^{-1}$ in both of tests. It indicated they were low toxic to honeybee. In case of acute toxicity test to earthworm, $LC_{50}$ of A, B, and C were 695, 988, and 564 mg $kg^{-1}$. In conclusion, pepper extract+cassia oil 57% EC and pepper extract+lavender oil 50% EC were expected to be used for environment-friendly insecticide materials with low risk against ecosystem and contribute to developing environment-friendly agro-materials.

• Journal of Food Hygiene and Safety
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• v.26 no.3
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• pp.273-282
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• 2011

This study established hazards which may cause risk to human at farm during cultivation stage of paprika. Samples of plants (paprika, leaf, stem), cultivation environments (water, soil), personal hygiene (hand, glove, clothes), work utensils (carpet, basket, box) and airborne bacteria were collected from three paprika farms (A, B, C) located in Western Gyeongnam, Korea. The collected samples were assessed for biological (sanitary indications and major foodborne pathogens), chemical (heavy metals, pesticide residues) and physical hazards. In biological hazards, total bacteria and coliform were detected at the levels of 1.9~6.6 and 0.0~4.610g CFU/g, leaf, mL, hand or 100 $cm^2$, while Escherichia coli was not detected in all samples. In major pathogens, only Bacillus cereus were detected at levels of ${\leq}$ 1.5 log CFU/g, mL, hand or 100 $cm^2$, while Staphylococuus aureus, Listeria monocytogenes, E. coli O157 and Salmonella spp. were not detected in all samples. Heavy metal and pesticide residue as chemical hazards were detected at levels below the regulation limit, physical hazard factors, such as insects, pieces of metal and glasses, were also found in paprika farms. Proper management is needed to prevent biological hazards due to cross-contamination while physical and chemical hazards were appropriate GAP criteria.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.376-382
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• 2012

Environment-friendly agro-materials are are likely to be preferred to chemical insecticides recently. For this reason, many studies are conducted to develop environment-friendly insecticides containing natural materials. This study was also conducted so as to assess ecotoxicity for Emulsifiable concentrate (EC) containing 30% of garlic extract or two plant essential oils (Zanthoxylum, Lemongrass) expected to prevent from pests and be used for agro-materials. Target species used to assess acute toxicity were invertebrate (Daphina magna), fish (Oryzias latipes), honeybee (Apis mellifera L.) and earthworm (Eisenia fetida). The $EC_{50}$ values for of garlic extract 30% EC, Zanthoxylum oil 30% EC and lemongrass oil 30% EC to Daphina magna were 3.3, 10, and $10mg\;L^{-1}$, respectively. The category of garlic extract 30% EC was moderately toxic, while those of Zanthoxylum oil 30% EC and lemongrass oil 30% EC were slightly toxic according to standard of USEPA. $EC_{50}$ for both of Zanthoxylum oil 30% EC and lemongrass oil 30% EC were more than $10mg\;L^{-1}$ then they were considered as slightly toxicity. In case of acute toxicity test to fish, $LC_{50}$ of garlic extract 30% EC was $3.3mg\;L^{-1}$. Zanthoxylum oil 30% EC and lemongrass oil 30% EC indicated $LC_{50}$ > $10mg\;L^{-1}$. Classification of acute toxicity to all test substances was in Korea criteria. Acute contact and oral toxicity test to Honeybee were conducted. As a result, $LD_{50}$ of all test substances were more than 100 a.i. ${\mu}g\;bee^{-1}$ in the acute contact test while $LD_{50}$ of garlic extract 30% EC was 4.4 a.i. ${\mu}g\;bee^{-1}$ and $LD_{50}$ of Zanthoxylum oil 30% EC and lemongrass oil 30% EC were more than 100 a.i. ${\mu}g\;bee^{-1}$. In case of acute toxicity test to earthworm, $LC_{50}$ of garlic extract 30% EC, Zanthoxylum oil 30% EC and lemongrass oil 30% EC were 267, 592, and $430mg\;kg^{-1}$, respectively. In conclusion, if the safety for earthworm is confirmed, these substances are expected to be use for environment-friendly insecticide materials with low risk against ecosystem and contribute to developing environment-friendly agro-materials.