A phytoremediation study has been conducted to see if some known aquatic plants can remove the pesticides, endosulfan-α, β and fenitrothion which are frequently used in the crop protection and golf course management, and are likely to exist as residual pollutants in the aquatic ecosystems. Among the five aquatic plants tested in the microcosms, water lily Nymphaea tetragona Georgi showed the highest degradation efficacies (85~95%) for the three pesticides as opposed to the control(13~26%). The efficacies for the other plants were in the range of 46~80% in the order of Pistia stratiotes, Cyperus helferi, Eichhornia crassipes, and Iris pseudoacorus. Fenitrothion, an organo-phosphorus pesticide, was much more vulnerable to the phytoremediation than the organo-chlorine pesticides, endosulfan-α and endosulfan-β. The kinetic rate constants (min-1) for removal of the three pesticides were more than 10 times higher than the control (non-planting) in case of Nymphaea tetragona Georgi. This aquatic plant showed kinetic rate constants about 2 times as much as the lower kinetic rate constants shown by Iris pseudoacorus. The reason for the highest degradation efficacy of water lily would be that the plant can live in the sediment and possess roots and broad leaves which could absorb or accumulate and degrade more pollutants in association with microbes. These results indicate that some of the selected aquatic plants planted near the agricultural lands and wetlands could contribute to remediation of pesticides present in these places, and could be applicable to protection of the aquatic ecosystems.

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 h

Endosulfan은 높은 잔류성과 소수성을 가진 유기염소계 잔류성 농약이다. 이 연구는 십자화과 식물에 다량 함유되어 있고 심혈관계질환의 예방에 효과가 있는 것으로 알려진 인돌을 이용하여 소장에서 endosufan의 흡수에 미치는 영향을 조사하였다. 흰쥐를 이용해서 37 kBq의 14C-endosulfan이 함유된 지질유화액을 시간당 3 mL씩 8시간 동안 지속적으로 공급받은 동물군을 대조군으로 하였고, 인돌이 함유된 지질유화액을 같은 조건에서 공급받은 동물군을 실험군으로 하여 8시간 동안 흡수율을 측정하였다. 림프순환계로 흡수된 대조군의 14C-endosulfan 양에 비해 인돌을 공급받은 실험군의 14C-endosulfan의 양이 유의적으로 감소되었다. 이와 유사하게 콜레스테롤의 흡수도 인돌에 의해서 유의적으로 감소되는 경향을 보였다. 또한, 8시간 동안 흡수되지 않고 장벽에 잔류하는 14C-endosulfan 양이 인돌을 공급받은 실험군에서 유의적으로 증가되는 것으로 나타났다. 이러한 림프순환계로의 endosulfan 흡수 감소현상은 인돌공급에 의해 소장의 점막에 잔류하는 endosulfan의 양이 증가되었기 때문인 것으로 판단된다. 이상의 실험결과들을 종합해 볼 때, 십자화과 식물에 존재하는 인돌 성분의 섭취가 대표적인 잔류성 농약인 endosulfan의 소장에서의 흡수를 감소시켜 체내 잔류 저감화에 효과적으로 영향을 미치는 것을 이 실험을 통해서 확인할 수 있었다.

Endosulfan is an organochlorine pesticide that is widely used throughout the world for higher agricultural production. Its extreme toxicity, however, has caused health and environment concerns that have led to an interest in detoxification. In this study, the radiolytic degradation of endosulfan was investigated. Endosulfan in methanol solution (100 ppm) was irradiated at 0, 10, 30, and 50 kGy, and subsequent changes in immune toxicity and degradation of endosulfan were observed. The concentration of endosulfan that was used in this experiment did not affect the cell proliferation. The irradiation of endosulfan decreased the production of NO, indicating a decrease in the immune toxicity of endosulfan by irradiation. The concentration of endosulfan was significantly reduced by irradiation in a dose-dependent manner. The results suggest that gamma irradiation can degrade endosulfan and can reduce its immune toxicity.

Photodegradation of endosulfan alpha, beta, and sulfate known as the most toxic substance among organochlorine pesticides by UV irradiation was studied at experimental conditions such as different pH aqueous solution and reaction time. The initial concentration of endosulfan alpha, beta, and sulfate in aqueous solution was 500 ppb, respectively. The experiment of photodegradation was conducted in a quartz reactor equipped with a low pressure mercury lamp (100 W, 240 nm). The samples were withdrawn from the photo reactor at intervals of 0, 10 min, 30 min, 1 hr, 2 hr, and 4 hr. Endosulfan sulfate was never hydrolyzed and photodegraded in wide range of pH. At pH 5 and reaction time (240 min), endosulfan alpha was photodegraded up to 67%. Both endosulfan alpha and beta were started to photodegrade at pH 6.5 with the lapse of time, resulting in approximately 99.9% and 87.2% of photodegradation efficiency, respectively. Furthermore, at pH 9, endosulfan alpha and beta was partially hydrolyzed and photodegraded to 99.5% at 120 min of reaction time. During the photolysis, any photo-products of endosulfan alpha, beta, and sulfate were not observed.