• Safety and Health at Work
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• v.12 no.1
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• pp.127-132
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• 2021

Background: Herbicides such as glyphosate, paraquat, and 2,4-dichlorophenoxyacetic acid have been reported to cause adverse side effects through production of reactive oxygen species. However, there were no data representing the adverse effects of a mixture herbicide usage in farmers, especially the changes in oxidative marker and antioxidant defense. This study aimed to determine the urinary malondialdehyde (MDA) and glutathione (GSH) level in farmers using mixed herbicides. Methods: Ninety-three farmers were recruited, and two spot urine samples (before and after work) were collected. The urinary MDA level was evaluated by thiobarbituric acid reactive substance assay, and the urinary GSH level was determined using the enzymatic recycling method. Results: Sixty-two percent of the participants were men, and 59% of the participants worked in a farm for 20-40 years. The common combinations of herbicide usage were glyphosate with 2,4-dichlorophenoxyacetic acid (36.5%). There was no significant difference between pre- and post-work urinary MDA and GSH levels among the 3 groups of herbicides. However, the urinary MDA levels in farmers using the combination of glyphosate and paraquat were significantly higher than those found in farmers using glyphosate alone. The associated factors with changes in MDA levels found that the exposure intensity index (B = 0.154), the cumulative exposure intensity index (B = 0.023), and wearing gloves while working (B = -2.347) were found to be significantly associated with MDA level. Conclusion: The results suggest that the combined use of glyphosate and paraquat caused a significant increase in urinary MDA levels. Moreover, intensity of exposure to herbicide and wearing gloves were associated with the level of MDA.

• Biomolecules & Therapeutics
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• v.10 no.4
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• pp.224-229
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• 2002

Triazine herbicide has been reported to directly suppress the immune response. In the present study, we examined various functions of murine peritoneal macrophages that were isolated and stimulated with LPS after simazine (300 and 600 mg/kg body weight), a triazine herbicide, was administered every day for 4 weeks. Simazine decreased the capacity of phagocytosis, compared to those of carboxymethylcellulose (CMC)-treated control group. In addition, the production of NO and TNF-$\alpha$ was decrcased in macrophages of simazinetreated mice. However, the production of hydrogen peroxide ($H_{2}O_{2}$) was not altered. In vitro tumoricidal activity of in vivo simazine-treated macrophages was reduced against target cell. B 16 melanoma. Taken together, these results suggested that simazine might have the immunosuppressive effect on macrophages after in vivo exposure, which was related to the reduction of tumoricidal activity.

• The Korean Journal of Ecology
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• v.24 no.3
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• pp.157-168
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• 2001

Herbicides have been used to control weeds for decades. If detoxification upon exposure to herbicides requires considerable amounts of energy, it could affect the pattern of resource allocation to growth and reproduction of crops. We examined the effects of three levels of a herbicide (Control, Low, and High) on germination, growth and reproductive characters of Glycine max treated twice, i.e., before and after seed germination. Since flowering time of G. max was separated into two groups, flowering time was also considered as a variable in this study. The rate of seed germination tended to be higher at the low level of herbicide compared to other levels. Chlorosis and shape variation of leaves were apparent after the second herbicide treatment, but completely disappeared after six weeks of treatment. The herbicide effects on growth characters were somewhat different between early and late flowering plants, but plants treated with both low and high levels of herbicide reduced their growth compared to those in the control group regardless of flowering time. Plants at the high level of herbicide exhibited the highest growth rate later in the season, suggesting that plants compensated to some extent for reduced growth. However, growth reduction among plants at the high level of herbicide was persistent until the end of growing season. Among plants flowered late in the season, plants in the control level bore a higher number of nodules per plant than those in other levels; such a pattern did not exist among plants flowered early in the season. Plants treated with low and high levels of herbicide produced a lower number of flowers than those in the control. Thus, the herbicide examined affected not only the growth and reproductive characters of non-target crops but also the development and growth of root nodules.

• Journal of The Korean Society of Clinical Toxicology
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• v.18 no.1
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• pp.26-33
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• 2020

Purpose: Agent Orange (AO) is a herbicide and defoliant used by the United States and its military allies during the Vietnam War. Pneumonia is a common cause of death among Vietnam veterans in our hospital. There have been no previous studies researching any association between AO exposure and the prognosis for pneumonia. The primary objective of this study was to investigate associations between AO exposure and 30-day mortality due to pneumonia. The secondary objective was to examine the clinical factors associated with therapeutic outcomes in veterans with pneumonia, and to assess the prevalence of combined diseases in AO-exposed veterans. Methods: This study retrospectively included veteran patients diagnosed with pneumonia in the emergency department and hospitalized between February 2014 and March 2018. The enrolled patients were grouped according to their defoliant exposure history, and the clinical information of defoliant-exposed and non-defoliant-exposed groups were compared. Patients were divided according to 30-day mortality, and significant factors influencing mortality were evaluated by using univariate analysis and multivariate analysis. The final multivariate model revealed the effect of AO exposure on therapeutic outcomes of pneumonia. Results: A total of 1006 patients were analyzed. Of these, 276 patients had a history of AO exposure, whereas 730 patients had not been exposed. Factors positively associated with 30-day mortality were malignancy, respiratory rate, blood urea nitrogen, and albumin which was negatively associated with mortality. Conclusion: Exposure to defoliant is not associated with 30-day mortality in patients with pneumonia. However, veterans with defoliant exposure are associated with a high prevalence of diabetes mellitus, hypertension, cerebrovascular accident, malignancy, and chronic kidney disease.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.2
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• pp.102-107
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• 1991

This trial was carried out to investigate the effect of oversowing on the fodder value and the life form of standing crop in the low productive grassland with a western exposure at the Korean Native Cattle Improvement Center in Seosan. Chungnam Province. The results obtained are summarized as follows: 1. The inferior plant community of low productive grassland was improved to the most desirable pasture association by oversowing after herbicide application. At the experimental area most of the native grasses were not suitable for the pasture plant due to less fodder value(0-2). 2. The fodder value of standing crop in the improved grassland with 6.04(grasses: 4.72, legumes: 1.07 and herbs: 0.25) was much more increased by 108% than that of low productive grassland. 3. The life forms of plant community in the low productive grassland were composed of Hemicryptophytes of 36.29'0, Therophytes of 30.47~, Chamaephytes of 17.0% and Geophytes of 16.4%). But by oversowing after herbicide application their life forms of Hemicryptophytes increased greatly by 51.4%, on the other hand Therophytes, Chamaephytes and Geophytes were much more decreased by 25.4, 15.6 and 10.470, respectively.

• Journal of The Korean Society of Clinical Toxicology
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• v.2 no.2
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• pp.101-105
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• 2004

Purpose: Paraquat is the most commonly used herbicide in Korea. Exposure to paraquat through the skin has resulted in local irritation or inflammation of varying degree, sometimes severe. The purpose of this study was to review the patients with paraquat poisoning by skin absorption. Methods: We analysed retrospectively the clinical and laboratory findings of 45 patients with paraquat poisoning after dermal exposure, who were admitted to Soonchunhyang University Cheonan Hospital from January 1999 to December 2003. Results: Among 870 cases of paraquat poisoning, 45 cases were exposed to paraquat through the skin. The peak incidence was the fifth decade($40\%$). The clinical symptoms were pain, pruritus, nausea, and vomiting. The major skin lesions were generalized vesicobullae and necrotic erosion in face, scrotum, trunk, upper and lower extremities and etc. All patients were survived after skin contact or inhalation of paraquat. Conclusion: This study illustrates the extreme toxicity of paraquat and demonstrates that lethal quantities of paraquat may be absorbed if repeated exposure to it. Stricter precautions, including the mandatory use of protective clothing, should be recommended whenever this material is used.

• The Korean Journal of Pesticide Science
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• v.3 no.2
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• pp.54-59
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• 1999

In order to investigate the behavior of the herbicide metolachlor [2-chloro-6'-ethyl-N-(2-methoxy-1-methylethyl)aceto-O-toluidide] in fish, carps (Cyprinus carpio L.) were exposed to the herbicide at $LC_{10}$(1.93 mg/L) for 4 days. Metolachlor dissolved in water was absorbed rapidly into carps to mark the maximum concentration 6 hours after exposure. The amounts of the $^{14}C$-metolachlor and its metabolites absorbed in gall were much higher than those in the other parts, strongly suggesting that biliary excretion involving enterohepatic recirculation could be an important route for the elimination of metolachlor. The $^{14}C$-radioactivity distributed into aqueous phase fraction in test water and in carp extract was increased in time-dependent manner. Extraction rate of $^{14}C$ absorbed in carp tissues was decreased remarkably up to 6 hours after exposure, suggesting that the possible polar metabolites of metolachlor were transformed into the conjugates to form non-extractable bound residues.

• Korean Journal of Environmental Biology
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• v.22 no.2
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• pp.300-307
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• 2004

The chloroacetanilide herbicide alachlor (2-chloro-2', 6'-diethyl-N-(methoxymethyl)-acetanilide) and organochlorine insecticide endosulfan (6, 7, 8, 9, 10, 10-hexachloro-l, 5, 5a, 6, 9, 9a-hexahydro-6, 9-methano-2, 3, 4-benzodioxathiepin-3-oxide)are the highly toxic agricultural chemicals. Bombina orientalis is one of the most common amphibians in the world and comprises a large proportion of their total number. B. orientalis spawns in the farming regions at Spring when the massive application of agricultural chemicals occurs. These chemicals in farmland may threaten the reproduction of this frog. Therefore, we examined the embryotoxic and survival effects of alachlor and endosulfan at various concentrations in B. orientalis embryos. The survival rates of embryos at 312h post fertilization treated with alachlor and endosulfan were decreased with concentration dependent manner. Also, developmental malformations appeared by alachlor and endosulfan in B. orientalis embryos. The malformations showed in order of frequency with bent trunk, tail dysplasia, bent tail, thick-set body and ventral blister in alachlor treated embryos. The exposure of endosulfan produced 7 types of severe external malformations with tail dysplasia, pectoral blister, bent trunk, bent tail, cephalic dysplasia, ventral blister, and thick-set body. Following exposure to alachlor and endosulfan the types of malformations were diverse, suggesting these chemicals target multiple events in embryonic and larval development in this species. These results suggested that alachlor and endosulfan were detrimental for survival and development of B. orientalis embryos.

• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.26-26
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• 2003

During the Viet Nam war, A Luoi located in Thua Thien Hue Province was heavily sprayed herbicides by the Ranch Hand Operation of U.S.A force (549.274 gallons). After 30 years of knocking the operation off, Dioxin has still contaminated on environment and human body in A Luoi valley. The results of the study show that there is an epidemiological relationship between AO/Dioxin exposure and increasing rate of reproductive anomalies and birth defects (the rate of reproductive anomalies including congenital deformities after the war during 10-year and 25-year is higher than that before the war from 1.5 to 4 times). The study found that the highest rate of reproductive anomalies is spontaneous abortion. The average is premature death and congenital deformities, and the lowest rate is dead foetus and hydratidiform mole. The results of the primary assessment suggested that Dioxin transport from environment to human body through the food chain exposed by Dioxin such as fish, chicken, duck. A mitigation plan for residual dioxin contamination from Agent Orange Hervicides is requeste indispensable to inhabitants in Aluoi District.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.3
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• pp.162-168
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• 2022

Mecoprop-p, a chlorophenoxy herbicide, has been widely used since the 1980s. Due to its high water solubility, it could be detected in the aquatic environment, as it has already been detected in the surface water or groundwater in several countries. The toxicity of other chlorophenoxy herbicides has been reported; however, there are few studies on the toxicity of mecoprop-p, one of the chlorophenoxy herbicides, on aquatic organisms. Here, we investigated the toxic effects of mecoprop-p using zebrafish. After mecoprop-p exposure, we observed that the zebrafish larvae eyes did not form normally, heart edema was generated, and the body length was shortened. The number of cells undergoing apoptosis also increased in the anterior part including head, heart, and yolk sac of the mecoprop-p-treated zebrafish compared to the untreated controls. Moreover, cardiovascular structures, including the heart and aortic arches, were also malformed after exposure to mecoprop-p. Therefore, our results suggest that mecoprop-p could cause abnormal development in zebrafish larvae and there is also a high possibility that mecoprop-p would be toxic to other aquatic organisms.