*Anopheles ; *DDT ; *Dieldrin ; *Malaysia

The authors carried out two series of field test to determine the basic lines of DDT and Dieldrin susceptibility of Anopheles sinensis at Andong(1961) and Yoju(1962), where malaria endemicity is relatively high in Korea. Tests were performed in accordance with the standard method established by the World Health Oraganization(1960). The results were summarized as follows: The LC-50 of DDT for A. sinensis caught at Andong as 1.5 %, while for the same species in Yoju was 1.3 %. The LC-50 of Dieldrin for A. sinensis caught at Andong was 0.075 %, while the LC-50 for the same species at Yoju was 0.07 %. These results therefore indicate Anopheles sinensis, as the malaria vector species in Korea, is susceptible to DDT and Dieldrin.
parasitology-protozoa-Plasmodium vivax ; chemotherapy-malaria ; Anopheles sinensis ; DDT ; Dieldrin

OBJECTIVES: The study was conducted to estimate the carcinogenic risks from the ingestion of some carcinogenic pesticides (CPs) in vegetables sampled at a local agricultural product market in Seoul. METHODS: After applying a hazard identification step, we selected four pesticides, such as DDT, dieldrin, folpet, and heptachlor epoxide, for this risk assessment. Concentrations of each pesticide were measured from randomly sampled vegetables. In order to estimate the human exposure levels, we combined the concentration of pesticides in the vegetables with consumption rate of those vegetables. Three scenarios were hypothesized for human exposure assessment. Scenario I was the most conservative which supposed the undetected CPs would be the detection limit values. Scenario II was assumed that the undetected CPs would be a half of the detection limit values, and finally scenario III merely considered only values greater than the detection limit values. We finally presented the estimated carcinogenic risks on the basis of the traditional risk assessment procedure suggested by U.S. EPA. RESULTS: Pesticides including DDT, dieldrin, folpet and heptachlor epoxide were detected in 9 samples (6%) in the range of 0.0006~0.09ppm. The daily intake levels of carcinogenic pesticides were estimated in the range of 0.0009~0.0079 microgram/day. As we expected, excess cancer risks based on scenario I was also the highest (1.1x10-8~ 5.5x10-5). CONCLUSIONS: We found that the estimated risks from the pesticides we investigated were not serious. We, however, propose that a continuos monitoring is needed to make sure for the protection of public health.
DDT ; Dieldrin ; Eating ; Heptachlor Epoxide ; Humans ; Korea* ; Limit of Detection ; Pesticides* ; Public Health ; Risk Assessment* ; Seoul ; Vegetables*

During the summer season(July-August) in 1967, the insecticide tests for resistance on adult A. sinensis and C. tritaeniorhynchus were carried out in Gobu-Myun Jeongup-Gun, Chollapuk-Do, where many Japanese encephalitis cases occur every year. The mortality by 4.0% DDT in A. sinensis was 88.9% and by 4.0% dieldrin was 84.4%. Therefore the LC-50 of DDT for A. sinensis was 1.75%, while LC-50 of dieldrin was 1.1%. The mortality by 4.0% DDT in C. tritaeniorhynchus was 36.7%, and by 4.0% dieldrin was 6.0% The result indicates that A. sinensis in Korea is susceptible to DDT and resistant to dieldrin. C. tritaeniorhynchus is highly resistant to both DDT and dieldrin.
parasitology-arthropoda ; vector ; mosquito ; Culex tritaeniorhynchus ; Anopheles sinensis ; chemotherapy ; DDT ; dieldrin

In the summer of 1969 from July through October, authors carried out a study of susceptibility in adult female bed bug(Cimex lectularius) in order to ascertain any development of resistance to insecticides in Korea. The test to DDT and Dieldrin was performed in laboratory by the continuous exposure of residues method, with standard impregnated paper used for adult mosqitoes. Some results so far obtained can be summarised as follows: LC(50) were 2.839% in DDT and 0.167% in Dieldrin. The resistance has been arisen 2.4-2.9 times in DDT and 1.6-2.4 times in Dieldrin as compared with London laboratory strain, but they were susceptible 1.4 times in DDT and 180 times in Dieldrin as compared to Israel resistance strain.
parasitology-arthropodology-bed bug-Cimex lectularius ; prevention ; chemotherapy ; resistance ; DDT ; dieldrin

For the previous century, the humans have created an unintended and unwanted problem of endocrine disruptors as a potential threat to our public health. By the name of industrialization, endocrine disruptors are smuggling in the everyday life of people today. Although there are much debate on the reality of their emerging health threat, it is no doubt that there are certain classes of compounds that have the potential to affect hormonal status adversely, leading to abnormal development, reproductive dysfunction, and some cancers. The classes of endocrine disruptors are extensively diverse and even more increasing, such as, polychlorinated biphenyls (PCBs), dioxins, dieldrin, bisphenol A and toxaphene. Although these endocrine disruptors have been prohibited or tightly regulated, many of them are still unrecognized and still used without knowing their potential threat to the biological world. Once they are released into the environment, they usually persist without degradation and even undergo bioaccumulation and bioconcentration in food chain. Comparing with the great concern over the public health, we do not have enough information for these issues. It is now clear that we need further extensive studies for the risk assessment and the protection of human and ecological health from the potential hazards of endocrine disruptors. This article introduces a breif overview of the current status of our knowledge and research on endocrine disruptors.
Dieldrin ; Dioxins ; Endocrine Disruptors* ; Food Chain ; Humans ; Polychlorinated Biphenyls ; Public Health ; Risk Assessment ; Toxaphene

During the period from May to October 1969, the authors carried out a series of tests with the aim to ascertain the present status of susceptibility of adult cockraoches to various insecticides. The tests on the susceptibility of cockroaches to dieldrin, D.D.V.P., Diazinon; Dibrom, Malathion and lindane were performed with the topical application and the residual film methods under the conditions of 26 degrees C and 80% of relative humidity. The insects tested were collected from Seoul City and were reared at the laboratory. Some of the important results so far obtained can be summarized as follows: The median lethal doses (LD(50)) of the five insecticides against female adult cockroaches were: 0.4 ug/roach or 4.02 ug/body weight (gm) by Dieldrin, 0.29/roach or 2.88 ug/body weight (gm) by D.D.V.P., 0.29 ug/roach or 2.96 ug/body weight (gm) by Diazinon, 0.54 ug/roach or 5.37 ug/body weight (gm) by Dibrom, and 2.96 ug/roach or 29.60 ug/body weight (gm) by Malathion. And those against male adult cockroaches were: 0.18 ug/roach or 3.29 ug/body weight (gm) by Dieldrin, 0.27 ug/roach or 4.89 ug/body weight (gm) by D.D.V.P., 0.16 ug/roach or 2.91 ug/body weight (gm) by Diazinon, 0.49 ug/roach or 8.97 ug/body weight (gm) by Dibrom, and 1.32 ug/roach or 24.19 ug/body weight (gm) by Malathion. The level of susceptibility of adult cockroaches to the insecticides tested was 1.0-1.6 times higher as compared with the results obtained on the Japanese Takashi strain. The median knockdown times (LT(50)) of the female adult cockroaches by insectcides at 1% concentration of 3 mg per square centimetre were 1.82 hours by Malathion, 1.36 hours by Diazinon, 0.56 hours by Lindane, 0.50 hours by Dibrom, and 2.56 hours by D.D.V.P. A marked difference was seen to exist between the males and the females. The female cockroaches were more resistant than the male to Dieldrin, Diazinon and Malathion.
parasitology-arthropoda-cockcroach-Blattella germanica ; chemotherapy ; Dieldrin ; D.D.V.P. ; Diazinon ; Dibrom ; Malathion ; lindane ; resistance

The results of the tests carried out in 1971 strongly suggested that a considerable portion of the flea population in MR 2 had developed resistance not only against DDT but also malathion and dieldrin. There is also the possibility of the fleas developing a resistance to diazinon and lindane. Thus careful consideration should be given to the continuous use of diazinon. In areas where fleas had developed a resistance to malathion, further tests should be conducted continuously to confirm the possible development of resistance. Other insecticides which have not been used in Vietnam for any purpose should be ready to be substituted, if the development of resistance is confirmed.
parasitology-arthropoda-flea-Xenopsylla cheopis ; resistance ; Vietnam ; DDT ; dieldrin ; diazinon ; lindane ; malathion

In Tansan and Wondang m 1960, and m Guidandong and Yongju-eup in 1961, routine entomological work was carried out according to the plan of operation for the ma1aria pre-eradication survey. During the present work, six anopheline mosquito species were recorded as follows: 1. Anopheles (Anopheles) sinensis Wiedmann, 1828. 2. Anopheles (Anopheles) sineroides Yamada, 1925. 3. Anopheles (Anopheles) lesteri Baisas and Hu, 1936. 4. Anopheles (Anopheles) koreicus koreicus Yamada and Watanabe, 1918. 5. Anopheles (Anopheles) koreicus edwardsi Yamada, 1925, and, 6. Anopheles (Anopheles) lindesayijaponicus, Yamada, 1918. A. sinensis is the most predominant species, although A. koreicus koreicus was also found to be predominant after A. sinensis in Guidandong (a mountainous area) A. sineroides is the next most predominant species after A. sinensis. Anopheline mosquitos begin to appear from late April or May and disappear in October each year. The resting places for the anopheline mosquitos are mainly cow sheds and outdoors. The population density of A. sinensis in cow sheds shows a peak either in June or in July in most places with a second small peak in late August or in September. Night biting habits appear to be active throughout the whole night but are more active from sunset to midnight. Most of the anophelines caught appeared to be zoophilic; however, the results of precipitin tests for A. sinensis showed a likelihood that these are facul-tative anthropophilic. Dissection of salivary glands in the present study of 2736 female A. sinensis mosquitos failed to show or to prove the presence of sporozoites, although sinensis is suspected as a potential of malaria. The body weight, moisture and fat content in A. sinensis appeared to decrease in July from a high peak in June and then to increase again m September. Insecticide susceptibility tests proved that the species was susceptible to DDT and Dieldrin in Guidandong and Yoju. The bionomics of A. sineroides, A. koreicus koreicus, A. koreicus edwardsi, A. lesteri and A. Iindesayi ja-ponicus was discussed; the latter two species are probably the first to be recorded in Korea. The mosquitos caught in hibernating places were found to be nulliparous and to have sperms in the spermathecae during the winter months. Anopheline hibernated probably in the adult stage.
Adult ; Anopheles* ; Body Weight ; Culicidae* ; DDT ; Dieldrin ; Ecology ; Female ; Humans ; Korea* ; Malaria ; Population Density ; Precipitin Tests ; Salivary Glands ; Spermatozoa ; Sporozoites

OBJECTIVETo investigate the effects of early postnatal exposure to dieldrin on striatum synaptic development in lactation, adolescence and adulthood of mice.

METHODSThe pups were divided into 5 groups randomly. Three groups were exposed to dieldrin (0.01% DMSO solution) at doses of 0.2, 2.0 and 20.0 microg/kg and two control groups were exposed to DMSO or saline by intraperitoneal injection of every other day from postnatal days (PND) 3 to PND13. The striatum were isolated from brain in lactation (PND14), adolescence (PND36) and adulthood (PND98). Western blot assay was used to detect the expression levels of striatal synaptic proteins.

RESULTSThe postnatal exposure to dieldrin could reduce the level of growth associated protein (GAP43) of striatum in lactation in a dose-dependent manner. In adolescence, the level of glial fibrillary acidic protein (GFAP) in striatum increased and the levels of tyrosine hydroxylase (TH), GAP43 and post-synaptic density protein 95 (PSD95) decreased with exposure doses. The level of Synapsin I decreased in adolescence male mice. The changes of expression levels of GFAP, TH and PSD95 proteins lasted to adulthood.

CONCLUSIONEarly postnatal exposure to dieldrin could affect the expression level of GAP43 protein in striatum. The expression levels of TH and PSD95 proteins in striatum decreased in adolescence and adulthood. These results indicated that the early postnatal exposure to dieldrin may persistently interfere in the striatal synaptic development.

Animals ; Animals, Newborn ; Corpus Striatum ; drug effects ; growth & development ; Dieldrin ; toxicity ; Female ; Glial Fibrillary Acidic Protein ; metabolism ; Male ; Mice ; Mice, Inbred ICR ; Nerve Tissue Proteins ; metabolism ; Post-Synaptic Density ; drug effects