• Journal of Food Hygiene and Safety
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• v.16 no.1
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• pp.21-26
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• 2001

Risk assessment traditionally are conducted on individual chemicals; however, humans are exposed to multiple chemicals in daily life. The organophosphorus (OP) pesticides are considered in a single risk assessment because they act by a common mechanism of toxicity, and there is likely to be expose to multiple OP pesticides simultaneously or sequentially. The OP pesticides act by inhibiting the enzyme acetylcholinesterasc (AChE) and have available extensive database. AChE is widely distributed throughout the body, most importantly in the nervous system. Inhibition of AChE results in accumulation of acetylcholine in the nervous system that results in clinical signs of cholinergic toxicity, including increased salivation and lacrimation, nausea and vomiting, muscle fasciculation, lethargy and fatigue, among others. To conduct an exposure assessment for pesticides in the diet, we need to know the food consumption patterns of the populations, and the pesticide residue levels in the foods that are consumed. This study was conducted to identify cumulative dietary risk due to multiple OP pesticides that can be exposed through various foods. Total 22 food samples including cereals, vegetables and fruits were collected randomly two times from food markets in several sites (4 cities). The subjected foods were selected by regarding of highly consumed foods to general Korean people. The 12 OP pesticides including Acephate, Azinphos-methyl, Chlorpyrifos, and Diazinon were monitored. For the exposure assessment, general adult group of 60 kg body weight was regarded as target population and food consumption data suggested by Lee et al. (2000) were used as consumed value of individual food. Analyses of samples for OP pesticides have been carried out according to the multiclass multiresidue analysis method and acephate and methamidophos analysis method of Korea Food Code. In general the levels of OP pesticides found in the food samples were very low or not detected.

• The Korean Journal of Pesticide Science
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• v.9 no.1
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• pp.70-80
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• 2005

To evaluate the exposure of molinate in agricultural environment and its effect against the non-target crop in air, this experiment was conducted to elucidate volatilization characteristics of molinate in aquatic condition and to determine critical concentration of molinate in the air causing phytotoxicity to Chili pepper. Cumulative volatilized rate of molinate from water was 22.7% at $35^{\circ}C$ for water temperature and 20 L/min for air velocity while 3.2% at $25^{\circ}C$ and 10 L/min within 47 hour after applied under closed system, respectively. The molinate concentrations in air above 60 cm height from soil surface of valley and open paddy rice field were reached the highest value of 18.17 and $11.59{\mu}g/m^3$, respectively within 24 hours after applying granular formulation at dose rate of molinate 150 g/1,000 $m^2$. However, their concentrations were drastically diminished to around 0.18 and $0.51{\mu}g/m^3$ level in 20 days after application, which volatilization pattern were similar to both regions. Also, the concentration of molinate in air above 60 cm height from soil surface was distributed higher 2 times than that above 180 cm height. Meanwhile, a phytotoxic symptom against the nearby chili pepper was revealed within three days after applied and molinate was detected $0.004{\sim}0.006$ mg/kg level from severe damaged leaves. The dose and exposure relations of molinate in the air against the non-target crop was also investigated in lab trial. The phytotoxic symptom, shriveled leaves, of the chili pepper was encountered by exposing two days with concentration of $13.6{\mu}g/m^3$, three days with $6.8{\mu}g/m^3$ or four days with $3.4{\mu}g/m^3$. The symptom was still recovered within four weeks after the plants had received fresh air. On the other hand, the phytotoxic response through root uptake of the herbicide in water culture was relatively insensitive, in which the symptom is observed ten days with the concentration of 300 ${\mu}g/L$.

• 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.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.256-261
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• 2009

Molinate (S-ethyl hexahydro-1H-azepine-1-carbothioate), a selective, preemergence thiocarbamate herbicide used for grass weed control in rice fields, is being most widely used in Korea. This study was conducted to assess the comparative toxicity of molinate on two aquatic insects, Chironomus riparius and Cloeon dipterum in four larval stages. First-instar larvae of C. riparius appeared to be the most sensitive to acute exposure of molinate with a 48-h $EC_{50}$ of 7.8 mg/L, followed by third instar (48-h $EC_{50}\;=\;22.9\;mg/L$), second instar (48-h $EC_{50}\;=\;25.0\;mg/L$) and fourth instar (48-h $EC_{50}$ > 50 mg/L) larvae. Also, the sensitivity of the larvae of C. dipterum was presented as the same manner of the larvae of C. riparius. The youngest group of larvae of C. riparius appeared to be the most sensitive to molinate, with 96-h $EC_{50}$ values ranged from 14.3 to 24.1 mg/L. The authors assume that the young instar lavae of aquatic insects, Chironomus riparius and Cloeon dipterum are more sensitive to molinate. Also, the authors propose that Mayfly, Cloeon dipterum is well suited as a bioassay organism because it is one of the most vulnerable aquatic insects inhabiting agricultural ecosystem in Korea.

• Korean journal of applied entomology
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• v.44 no.2
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• pp.97-108
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• 2005

Samples of water, soil, and sediment were taken from 10 streams near Andong, Korea in May 2004. To assess the degree of environmental pollution of each stream, chemical pollutants such as total notrogen (T-N), total phosphorus (T-P), chemical oxygen demand (COD), heavy metals, organophosphorus pesticides, organochlorine pesticides, and dioxin-like PCB congeners were analyzed by standard process tests or U.S. EPA methods. In addition, biomarkers originated from insect immune systems of beet armyworm, Spodoptera exigua, were used to analysis of the environmental samples. Except Waya-chun stream showing T-N content of 9.12 mg/L, most streams were contaminated with relatively low levels of overall pollutants in terms of T-N, T-P, and COD, compared to their acceptable environmental levels designated by the Ministry of Environment. Contents of Pb and Cd in samples of each stream were much lower than environmentally permissible levels. However, several times higherconcentrations of Pb and Cd were found in locations at Mi-chun, Kilan-chun, and Hyunha-chun streams, in comparison with other streams. Diazinon, parathion, and phenthoate compounds among organophosphorus pesticides were detected as concentrations of 0.19, 0.40, and $1.13\;{\mu}g/g$, respectively, from soil sample collected in the vicinity of Mi-chun stream. On the other hand, 16 organochlorine pesticides and 12 dioxin-like PCB congeners, known as endocrine disrupting chemicals, selected in this study were not found above the limit of detection. Biomarker analyses using insect immune responses indicated that Waya-chun stream was suspected as exposure to environmental pollutants. Limitation and compensation of both environmental analysis techniques are discussed.

• Korean Journal of Food Science and Technology
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• v.50 no.1
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• pp.28-36
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• 2018

Studies on suspected endocrine disrupting pesticide (EDP) residues in agricultural products were carried out in 2016 in Busan, Korea. Twelve different EDPs, ranging in concentration between 0.003-2.049 mg/kg, were detected in 19.5% of 462 samples. About 0.2% of agricultural product samples exceeded the maximum residue limits (MRLs). Risk indices of all of the EDPs were less than 10% of the acceptable daily intake (ADI). The outcomes indicated that the risk groups at highest risk of exposure to diazinon (found in Korean cabbages) and carbendazim (found in apples) were females aged 40 to 49 and young males less than 10 years old, respectively. Based on the stochastic assessment at $95^{th}$ percentile (P95), risk index in these risk groups accounted for 8.38 and 2.98% of ADIs. The results showed that the occurrence of EDP residues in agricultural products could not be considered a public health problem.

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.211-216
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• 2017

BACKGROUND:This study was conducted to investigate residual organochlorine pesticides (ROCPs) in agricultural soils and crops. Agricultural soil samples and crop samples were collected from 93 cities and counties. METHODS AND RESULTS: Extraction and clean-up for the quantitative analysis of ROCPs were conducted by the modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. Recovery and limit of detection (LOD) of ROCPs in agriculturalsoils and crops were 76.5-103.0 and 75.2-93.2%, 0.01-0.08 and $0.10-0.15{\mu}g/kg$, respectively. Detected ROCPs in agricultural soils were ${\alpha}$-endosulfan, ${\beta}$-endosulfan, and endosulfan sulfate, the residue were 2.0-12.0, 1.2-53.1, and $2.2-329.8{\mu}g/kg$, respectively. But these pesticides in all green perilla leaf and green pepper samples were not detected. CONCLUSION: These results showed that ROCPs residues in agricultural soils were not as high as crop safety threatening.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.114-119
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• 2013

The superiority and safety of eco-friendly agricultural products are well-known. The purpose of this study is to provide fundamental data for creating a safe food culture, to improve the quality of school food services, and to increase student satisfaction with school food services. We compared the perception of eco-friendly agricultural products and food service satisfaction between students with and without exposure to a dedicated event for learning about eco-friendly products (an Eco-friendly Food Service Day) in elementary and middle school. When students were asked to define eco-friendly products, "organic products" was a highly frequent response in schools with an Eco-friendly Food Service Day, while "pesticide-free products" was a highly frequent response in school without this event. For most students, a factor in choosing eco-friendly products was a quality certification mark. Students from elementary schools with an Eco-friendly Food Service Day had a higher frequency of using eco-friendly agricultural products at home compared to students from schools without the event (p<0.01). In addition, the satisfaction with school food service was higher in schools with an Eco-friendly Food Service Day (p<0.05). These results suggest it is important to promote the use of superior and safe eco-friendly agricultural products while developing a variety of menus considering students' preferences.

• Journal of The Korean Society of Clinical Toxicology
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• v.8 no.1
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• pp.7-15
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• 2010

Purpose: There are an insignificant number of studies done on the demographics of intoxication patients and on the characteristics of toxic exposure on a long term basis in Korea. The objective of our survey is to investigate the epidemiologic characteristics of intoxication in a metropolitan emergency department in order to more efficiently manage intoxication patients. Methods: We retrospectively reviewed the medical records of intoxication patients who visited the emergency department of a high end medical facility between January, 1998 and June, 2009. We investigated the trend of the substances people became intoxicated with during the study period and we analyzed the age, gender, year and distribution of patients and the outcome of the patients. Results: There were 1544 cases of intoxication during the study period, and the cases made up 0.37% of the total visitors to our emergency department, which is a high end medical facility located in the city. Most of the patients were female (70%) in their twenties and thirties. The most commonly ingested intoxication substances were sedatives, analgesics and pesticides. Unlike in the province, antidepressant abuse is on the rise while pesticide abuse is falling. The overall admission rate was 24.8% and the mortality rate was 1.6%. Pesticides intoxication was the most common cause of death (76%). Pesticides intoxication, a male gender and old age were the most significant fatality-related factors. Conclusion: We think that there is a need to investigate the actual conditions of drug intoxication in the city and prepare measures to prevent drug intoxication.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.316-322
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• 2011

BACKGROUND: Pesticides concentration was monitored in 50 agricultural lakes, and ecological risk for aquatic organism was assessed using risk quotient (RQ) and probabilistic methods. METHODS AND RESULTS: Pesticides concentrations detected in 50 agricultural lakes during peak season (June and September) were in the range of $0.17{\sim}0.99{\mu}g/L$. The RQ for algae and the other species was estimated to be 0.25 and below 0.01, indicating medium risk and no risk. Oxadiazon predominantly contributed to RQ value of 99% for algae, fishes, and amphibians. In terms of hazardous concentration at 5% of species ($HC_5$), ecological risk quotients (ERQ) for oxadiazon ranged from 0.18~0.33, showing a medium risk level. Overall, the concentrations of pesticides were much lower than $HC_5$), value. Probability of combined ecological risk for pesticides ranged from 1.82% to 2.41%. CONCLUSION(s): Combined ecological risk probability did not exceed the acceptable level of 5%, indicating no ecological risk for selected aquatic species. This study suggests that regular ecological risk assessment (ERA) will be required to protect and manage an agricultural lake. Not only ERA at screening level by comparing exposure with toxic effects for aquatic species also advanced ERA technique considering species in indigenous to Korea, chronic toxicity, pulse dose, fate, and environmental factors should be required.