2,2-Bis(4-chlorophenyl)-1,1-dichloroethylene

Spatial distribution of organochlorine contaminants in soil, sediment, and fish in Bikini and Enewetak Atolls of the Marshall Islands, Pacific Ocean.[Pubmed:21616519]

Chemosphere. 2011 Aug;84(7):1002-8.

Several nuclear tests were performed at Enewetak and Bikini Atolls in the Marshall Islands between 1946 and 1958. The events at Bikini Atoll involved several ships that were tested for durability during nuclear explosions, and 24 vessels now rest on the bottom of the Bikini lagoon. Nine soil samples were collected from different areas on the two islands of the atoll, and eighteen sediment, nine fish, and one lobster were collected in the vicinity of the sunken ships. Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polychlorinated terphenyls (PCTs) in these samples were analyzed using gas chromatography/ion trap mass spectrometry (GC/ITMS). The average recoveries ranged from 78% to 104% for the different PCB congeners. The limits of detection (LOD) for PCBs, PCTs, DDE, DDT, and dieldrin ranged 10-50 pg g(-1). Some fish from Enewetak contained PCBs at a concentration range of 37-137 ng g(-1), dry weight (dw), and most of the soils from Enewetak showed evidence of PCBs (22-392 ng g(-1)dw). Most of the Bikini lagoon sediment samples contained PCBs, and the highest was the one collected from around the Saratoga, an aircraft carrier (1555 ng g(-1)dw). Some of the fish samples, most of the soil samples, and only one of the sediment samples contained 2,2-Bis(4-chlorophenyl)-1,1-dichloroethylene (DDE) and PCBs. In addition to PCBs, the soils from Enewetak Atoll contained PCTs. PCTs were not detected in the sediment samples from Bikini Atoll. The results suggest local pollution sources of PCBs, PCTs, and OCPs.

2,2-bis(4-chlorophenyl)-1,1-dichloroethylene stimulates androgen independence in prostate cancer cells through combinatorial activation of mutant androgen receptor and mitogen-activated protein kinase pathways.[Pubmed:18819937]

Mol Cancer Res. 2008 Sep;6(9):1507-20.

Therapy resistance represents a major clinical challenge in disseminated prostate cancer for which only palliative treatment is available. One phenotype of therapy-resistant tumors is the expression of somatic, gain-of-function mutations of the androgen receptor (AR). Such mutant receptors can use noncanonical endogenous ligands (e.g., estrogen) as agonists, thereby promoting recurrent tumor formation. Additionally, selected AR mutants are sensitized to the estrogenic endocrine-disrupting compound (EDC) bisphenol A, present in the environment. Herein, screening of additional EDCs revealed that multiple tumor-derived AR mutants (including T877A, H874Y, L701H, and V715M) are sensitized to activation by the pesticide 2,2-Bis(4-chlorophenyl)-1,1-dichloroethylene (DDE), thus indicating that this agent may impinge on AR signaling in cancer cells. Further investigation showed that DDE induced mutant AR recruitment to the prostate-specific antigen regulatory region, concomitant with an enhancement of target gene expression, and androgen-independent proliferation. By contrast, neither AR activation nor altered cellular proliferation was observed in cells expressing wild-type AR. Activation of signal transduction pathways was also observed based on rapid phosphorylation of mitogen-activated protein kinase (MAPK) and vasodilator-stimulated phosphoprotein, although only MAPK activation was associated with DDE-induced cellular proliferation. Functional analyses showed that both mutant AR and MAPK pathways contribute to the proliferative action of DDE, as evidenced through selective abrogation of each pathway. Together, these data show that exposure to environmentally relevant doses of EDCs can promote androgen-independent cellular proliferation in tumor cells expressing mutant AR and that DDE uses both mutant AR and MAPK pathways to exert its mitogenic activity.

Mixed liquids for single-drop microextraction of organochlorine pesticides in vegetables.[Pubmed:18371681]

Talanta. 2008 Jan 15;74(4):599-604.

A new approach for the extraction of nine kinds of organochlorine pesticides (OCPs) from vegetable samples coupling single-drop microextraction with gas chromatography-mass spectrometry was presented. Experimental parameters, such as organic solvent, exposure time, agitation and organic drop volume were controlled and optimized. An effective extraction was achieved by suspending a 1.00microL mixed drop of p-xylene and acetone (8:2, v/v) to the tip of a microsyringe immersed in a 2mL donor aqueous solution and stirred at 400rpm. The approach was applied to the determination of OCPs in vegetable samples with a linearity range of 0.05-20ng mL(-1) for alpha-, beta-, gamma-, delta-hexachlorobenzene (BHC) and dicofol, 0.5-20ng mL(-1) for dieldrin and 2,2-bis(4-chlorophenyl)-1,1-dichloroethane (DDD) or 0.5-50ng mL(-1) for 2,2-Bis(4-chlorophenyl)-1,1-dichloroethylene (DDE) and 2-(2-chlorophenyl)-2 (4-chlorophenyl)-1,1,1-trichloroethane (p,p'-DDT). Correspondingly, the determination limit at an S/N of 3 ranged from 0.05ng mL(-1) for alpha-, beta-, gamma-, delta-BHC to 0.2ng mL(-1) for dicofol, dieldrin or p,p'-DDT. The relative recoveries were from 63.3 to 100%, with repeatability ranging from 8.74 to 18.9% (relative standard deviation, R.S.D.). The single-drop microextraction was proved to be a fast and simple approach for the pre-concentration of organochlorine pesticides in vegetable samples.

Environmental implications of soil remediation using the Fenton process.[Pubmed:18068206]

Chemosphere. 2008 Mar;71(1):43-50.

This work evaluates some collateral effects caused by the application of the Fenton process to 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) and diesel degradation in soil. While about 80% of the diesel and 75% of the DDT present in the soil were degraded in a slurry system, the dissolved organic carbon (DOC) in the slurry filtrate increased from 80 to 880mgl(-1) after 64h of reaction and the DDT concentration increased from 12 to 50microgl(-1). Experiments of diesel degradation conducted on silica evidenced that soluble compounds were also formed during diesel oxidation. Furthermore, significant increase in metal concentrations was also observed in the slurry filtrate after the Fenton treatment when compared to the control experiment leading to excessive concentrations of Cr, Ni, Cu and Mn according to the limits imposed for water. Moreover, 80% of the organic matter naturally present in the soil was degraded and a drastic volatilization of DDT and 2,2-Bis(4-chlorophenyl)-1,1-dichloroethylene was observed. Despite the high percentages of diesel and DDT degradation in soil, the potential overall benefits of its application must be evaluated beforehand taking into account the metal and target compounds dissolution and the volatilization of contaminants when the process is applied.

Multiple organochlorine pollution and the thyroid.[Pubmed:17100546]

Endocr Regul. 2006 Jun;40(2):46-52.

OBJECTIVE: Although the biological effects of major persistent organochlorinated pollutants (POPs) appear to be essentially similar, some effects which would be specific for certain substance cannot be excluded. We attempted to study the thyroid volume and thyrotropin level in the population living in the area with multiple pollution by polychlorinated biphenyls (PCBs) and pesticides (DDE and hexachlorobenzene - HCB). METHODS: A total of 454 adults was examined within the pilot field survey in 1998. Among them were 237 males (age range 19-78 years, median 47) and 227 females (age range 19-78 years, median 48). Fifteen environmentally prevalent congeners of polychlorinated biphenyls and also p,p-DDE (2,2-Bis(4-chlorophenyl)-1,1-dichloroethylene), p,p-DDT (2,2-bis(4-chlorophenyl)- 1,1,1-trichloro-ethane), hexachlorobenzene (HCB) as well as alpha-, beta- and gamma-hexachlorocyclohexane (HCH) were determined in serum by high resolution gas chromatography using microelectron capture detector and microcapillary column. Thyroid volume (ThV) was measured by real time sonography using the ellipsoid method with the aid of sonographic instrument Sonoline SI-400 (Siemens, Germany). The level of TSH was estimated by supersensitive immunoradiometric method using commercial kits by Immunotech (Marseille, France). Pearsons correlation coefficients after logarithmic transformation of values and Spearmans correlation coefficients were used for statistical evaluation. RESULTS: Significant positive association (p<0.01) was found between DDE and PCB, DDE and HCB, while that between PCB and HCB was not significant. Similar positive association (p<0.01) was also found between each individual organochlorine and their sum. Significant negative association (p<0.01) was found between ThV and TSH. When using categorical PCB values either >2000 (N=208) or >3000 (N=127) ng/g lipid, significant positive association (p<0.05 and p<0.01, respectively) was found between the sum of all organochlorines (PCB+DDE+HCB) and ThV, while that between PCB and ThV (p<0.01) was found only at the PCB levels >3000 ng/g lipid. When using Spearmans correlation coefficients, significant negative association appeared between PCB and TSH (p<0.05), sum of organochlorines and TSH (p<0.05) and ThV and TSH (p<0.01). CONCLUSIONS: Although several significant positive and negative associations were found, this study, like several others, could not exactly define the participation level of individual POPs in their common toxic effects, but possibly contributed to the recognition and elucidation of some problems related to this task.

Oxidation of p,p'-DDT and p,p'-DDE in highly and long-term contaminated soil using Fenton reaction in a slurry system.[Pubmed:16782172]

Sci Total Environ. 2006 Dec 1;371(1-3):11-8.

The degradation of DDT [1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane] and DDE [2,2-Bis(4-chlorophenyl)-1,1-dichloroethylene] in highly and long-term contaminated soil using Fenton reaction in a slurry system is studied in this work. The influence of the amount of soluble iron added to the slurry versus the mineral iron originally present in the soil, and the influence of H(2)O(2) concentration on the degradation process are evaluated. The main iron mineral species encountered in the soil, hematite (Fe(2)O(3)), did not show catalytic activity in the decomposition of H(2)O(2), resulting in low degradation of DDT (24%) and DDE (4%) after 6 h. The addition of soluble iron (3.0 mmol L(-1)) improves the reaction reaching 53% degradation of DDT and 46% of DDE. The increase in iron concentration from 3.0 to 24 mmol L(-1) improves slightly the degradation rate of the contaminants. However, similar degradation percentages were obtained after 24 h of reaction. It was observed that low concentrations of H(2)O(2) were sufficient to degrade around 50% of the DDT and DDE present in the soil, while higher degradation percentages were achieved only with high amounts of this reagent (1.1 mol L(-1)).