• Proceedings of the PSK Conference
• /
• 2000.04a
• /
• pp.125.1-125.1
• /
• 2000

• Korean Journal of Environmental Agriculture
• /
• v.11 no.2
• /
• pp.116-124
• /
• 1992

This study was conducted to elucidate degradation pattern of two synthetic pyrethroid insecticides, bifenthrin having 2-methylbiphenyl group and cyhalothrin having ${\alpha}$-cyano benzyl ester group in theirs alcohol moiety, in two soils and aqueous media under laboratory conditions. The half-life of bifenthrin was 85.1 days and 12,4 days in Chilgok and Bokhyen soil of aerobic upland condition, respectively, and that of cyhalothrin was 54.6 days and 32.2 days. Bifenthrin and cyhalothrin were degraded very slowly under anaerobic flooded condition and sterilized. Their degradation seemed to be mainly mediated by aerobic microorganisms in soil. Bifenthrin and cyhalothrin were degraded more rapidly in Bokhyen soil with rich organic matter than Chilgok soil. Cyhalothrin was degraded 30 days faster than bifenthrin under aerobic upland condition of two soils. Cyhalothrin was degraded more than bifenthrin in alkaline solution of pH 10, but cyhalothrin and bifenthrin were degraded very slowly in acidic solution of pH 2 and 6.

• The Korean Journal of Pesticide Science
• /
• v.19 no.1
• /
• pp.41-46
• /
• 2015

This study was conducted to evaluate the use of biological monitoring to determine the factors that influence the effects of exposure to pyrethroid pesticides among highland cabbage farmers. Urine was collected from farmers who was cultivating Chinese cabbage in the relatively highground in Gangwon-do the morning following pesticide application and was analyzed for cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcy-clopropane carboxylic acid (DCCA) and 3-(2,2-dibromovinyl)-2,2-dimethyl cyclopropane carboxylic acid (DBCA). Factors affecting exposure to pesticides, such as wind speed, spraying location, and the use of protective gear, were also investigated. Statistical analysis was performed by the Kruskal-Wallis test. Our analysis indicated that highland cabbage farmers were exposed to a higher level of pesticides than the general public or other types of farmers. When the wind speed was low, workers who sprayed pesticides were exposed to a higher level of pesticides compared to the exposure level in an assistant. However, there was no difference in exposure between the two when wind speed was high.

• Journal of Environmental Health Sciences
• /
• v.48 no.2
• /
• pp.96-105
• /
• 2022

Background: Pyrethroid insecticides account for more than 30% of the global insecticide market and are frequently used in agricultural settings and residential and public pest control among the general population. While several animal studies have suggested that exposure to pyrethroids can alter glucose homeostasis, there is only limited evidence of the association between environmental pyrethroid exposure and diabetes in humans. Objectives: This study aimed to report environmental 3-phenoxybenzoic acid (3-PBA) concentrations in urine and evaluate its association with the risk of diabetes in Korean adults. Methods: We analyzed data from the Korean National Environmental Health Survey (KoNEHS) Cycle 2 (2012~2014) and Cycle 3 (2015~2017). A total of 10,123 participants aged ≥19 years were included. Multiple logistic regressions were used to calculate the odds ratios (ORs) for diabetes according to log-transformed urinary 3-PBA levels. We also evaluated age, sex, education, monthly income, marital status, alcohol drinking, physical activity, urinary cotinine, body mass index, and sampling season as potential effect modifiers of these associations. Results: After adjusting for all the covariates, we found significant dose-response relationships between urinary 3-PBA as quartile and the prevalence of diabetes in pooled data of KoNEHS Cycles 2 and 3. In subgroup analyses, the adverse effects of pyrethroid exposure on diabetes were significantly stronger among those aged 19~39 years (p-interaction<0.001) and those who consumed high levels of cotinine (p-interaction=0.020). Conclusions: Our findings highlight the potential diabetes risk of environmental exposure to pyrethroids and should be confirmed in large prospective studies in different populations in the future.

• Korean journal of applied entomology
• /
• v.61 no.1
• /
• pp.117-128
• /
• 2022

In this study, we have examined pyrethroid actions on sodium channels in the pest insect Heliothis virescens. The synthetic pyrethroid permethrin increased steady-state sodium current in H. virescens central neurons and prolonged tail currents (I_Na-tail) due to extreme slowing of sodium channel deactivation. Prolongation of I_Na-tail was evident at permethrin concentrations as low as 60 nM, which modified ~1.7% of sodium channels and 10 μM permethrin modified about 30% of channels. The average time constant (τ₁) of tail current decay was ~335 ms for permethrin-modified channels. These modified channels activated at more negative potentials and showed slower activation kinetics, and failed to inactivate. Permethrin modification of sodium channels was dramatically potentiated by the α scorpion toxin LqhαIT, showing positive cooperativity between two binding sites. The amplitude of the tail current induced by 0.3 μM permethrin was enhanced ~8-fold by LqhαIT (200 pM). Positive cooperativity was also observed between permethrin and the insect-specific scorpion toxin AaIT as 10 nM permethrin potentiated the shift of voltage dependence caused by AaIT (~2-fold).

• The Korean Journal of Pesticide Science
• /
• v.20 no.4
• /
• pp.286-292
• /
• 2016

Malaria is mainly transmitted by Anopheles sinensis which is dominant species in malaria high-risk area, northern part of Gyeonggi province in Korea. Pyrethroid insecticide is used for malaria vector, An. sinensis in Korea and the previous investigation consistently reported insecticide resistance from the vector. This study investigated insecticide susceptible and resistant alleles from An. sinensis and the status of malaria vector control in malaria high-risk area. For the study, An. sinensis collected from Paju, Gimpo and Ganghwa were sequenced for kdr detection. In Paju, there was no homozygous susceptibility and all of tested samples had homozygous or heterozygous resistance. There were 6.7% for susceptible homozygosity and 93.3% for resistant homozygosity or heterozygosity in Gimpo. Furthermore, the percentages of homozygous susceptibility and homozygous or heterozygous resistance in Ganghwa were 5.7% and 94.3% respectively. The results showed that the frequency of the insecticide resistance from An. sinensis in malaria high-risk area were increased much more than the previous investigation. Hence, this study suggests that malaria vector control programs should have to be prepared for the management of pyrethroid insecticide resistance.

• The Korean Journal of Pesticide Science
• /
• v.11 no.2
• /
• pp.87-94
• /
• 2007

Pyrethroid insecticide have widely been used for agricultural sector and residential environments. To assess the exposure of insecticide which is absorbed through skin the analysis of urinary metabolite is essential. At present, the urinary 3-PBA was analyzed using liquid-phase extraction. But LPE have many limitations, such as long pre-treatment time and low recovery. So, this study was conducted to determine the optimum conditions for analysing 3-PBA in urine using solid phase extraction. Furthermore, this study intend to investigate the relation of concentrations of pyrethroid, deltamethrin in air and 3-PBA in urine. The optimum condition for hydrolysis was found to be done with hydrochloric acid for one hour. The recovery rates of 3-PBA were $84.6%{\pm}1.2%$, $54.8{\pm}0.9%$, $99.8{\pm}1.2%$ with XAD-2, XAD-7, XAD-16 using as the aborbents and acetone as eluents respectively. But acetonitrle and methanol gave low recovery rate and methyl cellosolve could not elute the compound. The amount of acetone for elution were 6mL, 9mL, 3mL for XAD-2, XAD-7, XAD-16 as absorbents respectively. The non-absorbed rates was $0.8{\pm}0.5%$, and $0.7{\pm}0.3%$ under XAD-16, mesh size 140-200, amount of resin 1.4g and the flow rate of eluent was 0.1mL/min. In the concentration process, we obtained 11 times higher concentration of material. The amounts of urinary 3-PBA were. The LODs of 3-PBA and deltamethrin were 0.004 mg/L, 0.038 mg/L, respectively. The further research of minute monitoring which include spray pattern, environmental condition is needed And more research about the relation between total pyrethroid exposure and urinary various metabolite are also necessary.

• Korean journal of applied entomology
• /
• v.31 no.4
• /
• pp.338-344
• /
• 1992

This test has been carried out to clear the effectiveness of pyrethroid insecticides to the Diamond back moth, that was complained by a farmer. The results obtained are summarized as follows. Effectiveness of Pyrethroids to suceptable strain and the results of chemical anaysis on the ingredients of pyrethroikds were normal at recommended concentrations. The effect ualue of pyrethroid by which the blocks were only one time treated was 57-59%, whereas the blocks sprayed 4 consecutive times of pyrethroid didn't show any effectiveness as shown in larval increasing rate of 489-552%. Among the results of field test conducted from 1990 to 1991 at 7 area, Dae Gu area showed the highest Effectiveness as 95-98%. However, Pyong Taek area, showed the least effectiveness as 0% in effect value. The resistant population which was collected at Tae kwan Ryung area was resurrected susceptability as much as JMC, in case of Placing it in non-treatment environment, whereas the pupulation which was revealed to pyrethroids for 6 genetations showed as much as 341-544 times of resistance compared with JMC. The non-effectiveness of pyrethroids to Diamondback moth which was complainted by a certain farmer named Mr Ju, was clearly resulted by the development of insect resistance. In Korea, the resistance of Diamondback moth to pyrethroids has developed in some area, as well as the resistance of pyrethroids has developed according to the continuous use of Insecticides, and the susceptability resurrected by stopping the use of pyrethroids. The result from this test would suggest that the pyrethroid insecticides should be applied in turb with other insecticides.

• Proceedings of the Korean Society of Applied Entomolohy Conference
• /
• 2004.05a
• /
• pp.167-167
• /
• 2004

• Bulletin of the Korean Chemical Society
• /
• v.8 no.2
• /
• pp.128-130
• /
• 1987