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Organochlorine Pesticides - Science topic

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The examples of organochlorinated pesticides are DDT, heptachlor etc. which have longer residual effects and sevin, furadan etc. are under organocarbamate group that have shorter residual effect. But why?
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Organochlorine pesticides are strong lipophilic that proved to be stored in the fat tissue for several years and even found in mammals milk passing generation. their half-life is high and their persistence is due to the string chlorine-carbon bond which is not the case in Carbamate compounds where esters are the main functional area in their composition
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Singh, A., Nag, S. K., & Singh, S. (2014) tests goat blood for organochlorine pesticides. In their methods it is stated that 10 mL samples were stored in heparinised residue-free 20 ml glass vials at -20ºC until analyzed, but it does not specify how long the samples were stored for.
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Thank you Anju Baroth
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I am currently doing a study on the analysis of organochlorine pesticides in herbal products. Recently, I had decided to run an aldrin standard into my GC-MS in order to determine the effects of the different concentrations of sulfuric acid on the standard. There were two aldrin standards, one with 10% water and one with merely concentrated sulfuric acid. Even though I had expected only aldrin to appear in the chromatogram, there were other chemical compounds present such as valeric acids and aromatic compounds. May I ask if there is any possible explanation for this result? Could it possibly be due to contamination of the standard solution or maybe an reaction of the standard with the solvent used?
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I am currently using a Aldrin standard which contains only one component, aldrin itself.
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I would like to know the opinion of experts in the matter, about this issue of special concern for me.
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Dear all,
Thank you very much for your answers.
Shivani and Abdalla, I was rather thinking in multiresidue analysis of several type of pesticides in vegetable matrices.
Armando, I agree with you in that pKa is the key. This situation can be managed with more or less success when the type of pesticides of samples are known. However, the problem increases with field samples of unknown record. In these cases, could not be the pH control counterproductive? What is your opinion?
Does anybody have more suggestions/opinions? Thanks in advance!
JJ
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Hi everyone,
I've been read in many literatures that during cytotoxicity assay, when we want to evaluate the effect of a defined compound on the gene regulation in a cell line, or even in some other tests like MTT, serum concentration in complete medium has to be reduced. Could anyone suggest a clear explanation for the reason of this reduction ?
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Hi Ramin,
Usually, the cells are serum deprived in the culture media during a migration test. In that way you can observed the migration of the cells instead of proliferation. You can also starve your cells if you want to know if the effect that you mesure is mediated by a paracrine or endocrine system.
However, I never heard that you have to starve your cells before a gene expression analysis. I don't think that modifying your culture system will improved your result, specially if the serum is necessary for the cell line viability. In my opinion, the most important is that your control cells are cultured in the same way that your treated cells.
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I have read about extraction methods of organochlorine pesticides in sediments and fish tissue using microwave for specific organic compounds, but I don't have this equipment at my institution. Could you direct me to another method with good recovery?
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soxhlet extraction  but I prefer US extraction will not take less time 
as mentioned by Dr. Polesello  Solvent are ( Hexane and DCM)
kind regards
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Today I had the opportunity to test some home-made compost made from chicken and rabbit manure, sawdust, feathers and rabbit carcasses, together with plant matter deriving from papyrus plant and other pruned vegetation. Tap water was only applied once at the beginning.
I was quite surprised with the high level of Na and Cl ions present in the tested sample. This led me to ask myself if compost can cause any damage to soil and how can a farmer/gardener get rid of such ions when present in soil. Are there any plants which are capable to extract such ions from soil? and if so, what will happen if vegetative matter deriving from such plants is used to produce compost?
It is to be said that in my country, we experience rainfall only from November until February/March. Tap water is made out of a 50:50 mixture between de-salinized water and ground water. The latter's quality is unknown as the majority is said to be a bit saline as a result to over-extraction throughout the years. Moreover, tap water is treated with chlorine. 
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Sodium is replaced by more favorable calcium ions. You may use calcium based amendment or calcium carbonate present in the soil whose solubility may be enhanced by application of organic amendments or acid formers. The amount and type of chemical amendments required to reclaim depend upon pH, EC and ESP of the soil/material.Crop tolerance to sodicity and economic condition of the farmers determine the desired level of replacement of exchangeable sodium. You may use Gypsum or phospho-gypsum. I also agree with Dr. Lucas that Cl may not be harmful at your concentration. You may also go for flushing as suggested by Dr. Srivastava.
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Northern Egyptian Lakes and Lagoons ( Mariut, Edku, Brulus, Manzala and Bardaweel). The only one that may have attention is Bardaweel due to its location which is far from pollution and industrial discharge but the rest are suffering a lot from all kind of pollutants and also from cuttage or filling with wastes ad decrease it area so could we as environmentalists and oceanographer provide a good solutions for it?
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Thanks for all your inputs.
I believe that we have a wide historical database of the lakes, however there are some gaps still need to be covered. All we need as a scientific community is to put a strategic plan in clear objectives stating clear numbers after 5 years or 10 years in case of ongoing active hazards, the loss will be ...such number. On the other side, estimation in economic values gained from saving and protecting these resources in the same time frame will be ....
All the government, the parliament and public through the media, schools, and in youth centers are part of this plan. 
I know that most of researchers do most of that review only to get fund for their projects to continue monitoring and observing of the damage, and repeat the same work without any step to circulate these information between the parties that i just mentioned, or to make the data available for public and by the way this is one of the reject reasons of funding the Egyptian projects proposed by the Egyptian researchers.
I see a good example here in my research group in US, they have annual meeting with the Congress, regular meetings with the media, and good collaboration with schools. Hope to see this one day in Egypt!!
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Water, Analytical, Environmental Scientists
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Dear all,
The literature showed there is a Phytotoxicity of the propanil to Broad leave crop. So, to conquer this problem kindly share your valuable suggestions.
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  1. Rice has the enzyme aryl acylamidase wich hydrolyzes propanil,  but when you use EC formulation, rice has a low phytotoxicity, and  it depends of stress conditions. When the stress level is higher you Will have higher level of phytotoxicity. 
Rice Co has a WG formulation that does not presents those problems 
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I am using C18 cartridge for extraction and solvent acetonitrile and Dichloromethane(DCM) for elution of organochlorine pesticides. But I am not getting good recovery (only 30%). what other important parameter I need to optimize especially with the pesticides?
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SPE recovery is very dependent upon technique.  Once you get the technique down you will be fine.  Couple of hints.... never re-use a cartridge, condition cartridge with ~ 10mLMeOH, then ~10mLwater, and while there is still a thin layer of water on top of your sorbent, start adding your sample. DO NOT LET THE CARTRIDGE DRY OUT - There should always be a layer of water above the packing.  The Oasis HLB cartridge 6cc/500 mg will work well, and is more forgiving as far as allowing the packing to go dry.  Follow Jan's direction in preparing your spike solution (we use acetone) but the solution must be soluble in water.  Also analytically check your spike solution, you may be getting 30% recovery because your spike solution was prepared the wrong way!  Also allow the spike solution to come to room temp, then vortex or sonicate it for 1 min prior to spiking samples.  Check all other iterations of the procedure to be sure you are not losing recovery somewhere else.  For instance during the concentration step - just spike a blank solvent - concentrate and run without spe step to make sure it is the spe step where you are losing the analytes.
With persistence you will eventually have an Ahh-Hahh moment and discover where you are going wrong.  We love those moments!
good luck!  
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I am trying to extract Endrin, Lindane (organochlorine pesticides)from water using organic solvents. Which is the best solvent with higher recovery rates?
which is the best solvent for making calibration standards?
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Dichloro methene is the  Best solvent for the  pesticide residue extraction as per USEPA Standards 
after extraction concentrate the solvent fractioin to 1or 5 ml  2with n-Hexane 
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I am going to analysis organochlorine pesticide residues in fish by using GC-ECD with Quechers method. According to quechers method, sample is extracted by acetonitrile solution. We haven’t programmable temperature control unit in injector side. We use 1 uL as inject volume, split less mode. But some literature said quick expansion of acetonitrile (1 ul) is not good for GC column. Can you help me the overcome this?
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I would recommend two choices to try out.
1) do the solvent exchange from acetonitrile to acetone or toluene.
2) if you want to do acetonitrile, you can try to use spit injection with split ratio of 1:1 or 1:3. Jack Cochran from Restek has a paper that you would not loose sensitivity much. However, acetonitrile may give the response to the ECD so if you need to use ECD, I would do the solvent exchange.
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I want to know whether there is a quantitative method within GC-MS that could synchronously analyze polycyclic aromatic hydrocarbons (16 priority PAHs) and organochlorine pesticides (OCPs) in environmental matrix such as water or sediment? If not, what's the difficult point? Since they could be extracted and purified by using one method at the same time.
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I found that no residues in winter and not understand why? please help me even by paper? samples was collected from tap and underground water from egypt?
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There are many reasons when come to pesticides variation in groundwater, it could be due to seasonal agriculture activities. Depending on the water treatment technology and sources of water intake, tap water could have variation from time to time. Monitoring and trending over a period of time might give you a better picture.
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Out of liquid liquid extraction and Solid phase extraction which one is the best sample preparation method for the detection of organochlorine pesticides (OCPs) in water by HPLC & GCMS?
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Indeed,   the OCPs are apolar and each sample extract resuspended in a organic solvent such acetonitrile or hexane. You can extract the residues of OCPs in water as follow:
-Each sample was subjected to centrifugation (5000 g for 10 min) and evaporation of supernatant in Speed Vac (Varian), the various extracts from water stored at −10°C until analysis.
-Each extract was dissolved in acetonitrile- water (50 - 50) and small aliquots (10 - 20 μL) injected into HPLC.
Please find two publications concerning extraction (from different compartiments : water, tissuses..) and analysis of residues of a benzoylurea derivatives by HPLC.
Best regards Pr. N. Soltani
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I am going to analysis of fish samples for organo-chlorine pesticides residues. I have only GC-ECD detector. As well I wish to use the QuEChERS method. Here we havent facility to access AOAC etc. So, any one can help me to find the detail (step by step) method (AOAC or EU or any standard methods) for above analysis?
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try my method on PCB in fish. Food Chemistry 192(2016)900-906 or look at my profile.
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In EPA cleaning method 50% H2SO4 used, while few other literatures it is 96% or concentrated, which is suitable?
Is there any column chromatographic cleaning required after sulfuric acid/permanganate cleanup for the same compounds?
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We do thousands of these samples every year.......To clean PCB extracts - We dilute concentrated sulfuric acid 50/50 with water. (add acid to water slowly while stirring in an ice bath).  We follow this with florisil clean-up, which is critical.  It is all dependent upon matrix and size of sample (soil/oil/air/fish).  For fish tissue we first do GPC clean-up to remove lipids, followed by acid then do a large florisil column and fractionate the pests from the pcb's.  Please follow-up with what your matrix is, size of sample (in grams) and I can recommend appropriate clean-up solution. 
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I want to analyse PAH and organochlorine compounds from Sediment, water and Aerosols. Please suggest the latest available US-EPA methods for the same.
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Look for this link EPA Method 8272: PAHs by Gas Chromatography/Mass :   :   https://www.o2si.com/docs/epa-method-8272.pdf
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IS ANY PROVEN TOXIC IMPACT OF ORGANO CHLORO PESTICIDES IN HUMAN being?
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Hi Susan
The kepone (chlordecone) has caused acute toxicity in workers of the Hopewell plant, leading to the ban of this organochlorine in the USA, in the 1970's
until now environmental pollution is though to cause hormone-like disorders and pathologies in the Caribbean
some paper deal with this topic
Adir, J., Y. H. Caplan, B. C. Thompson (1978). "Kepone serum half-life in humans." Life Sciences 22(8): 699-702
Boylan, J. J., J. L. Egle, P. S. Guzelian (1978). "Cholestyramine: use as a new therapeutic approach for chlordecone (kepone) poisoning." Science 199(4331): 893-5
Cannon, S. B., J. M. Veazey, Jr., R. S. Jackson, V. W. Burse, C. Hayes, W. E. Straub, P. J. Landrigan, J. A. Liddle (1978). "Epidemic kepone poisoning in chemical workers." American Journal of Epidemiology 107(6): 529-37
Cohn, W. J., J. J. Boylan, R. V. Blanke, M. W. Fariss, J. R. Howell, P. S. Guzelian (1978). "Treatment of chlordecone (Kepone) toxicity with cholestyramine. Results of a controlled clinical trial." New England Journal of Medicine 298(5): 243-8
Martinez, A. J., J. R. Taylor, P. J. Dyck, S. A. Houff, E. Isaacs (1978). "Chlordecone intoxication in man. II. Ultrastructure of peripheral nerves and skeletal muscle." Neurology 28(7): 631-5
Taylor, J. R., J. B. Selhorst, S. A. Houff, A. J. Martinez (1978). "Chlordecone intoxication in man. I. Clinical observations." Neurology 28(7): 626-30
Larson, P. S., J. L. Egle, Jr., G. R. Hennigar, R. W. Lane, J. F. Borzelleca (1979). "Acute, subchronic, and chronic toxicity of chlordecone." Toxicology and Applied Pharmacology 48(1 Pt 1): 29-41. http://dx.doi.org/10.1016/S0041-008X(79)80005-8
Fariss, M. W., R. V. Blanke, J. J. Saady, P. S. Guzelian (1980). "Demonstration of major metabolic pathways for chlordecone (kepone) in humans." Drug Metabolism and Disposition 8(6): 434-8
Saunders, L., P. Kadhel, N. Costet, F. Rouget, C. Monfort, J.-P. Thome, L. Guldner, S. Cordier, L. Multigner (2014). "Hypertensive disorders of pregnancy and gestational diabetes mellitus among French Caribbean women chronically exposed to chlordecone." Environment International 68: 171-176. http://dx.doi.org/10.1016/j.envint.2014.03.024
Kadhel, P., C. Monfort, N. Costet, F. Rouget, J.-P. Thome, L. Multigner, S. Cordier (2014). "Chlordecone Exposure, Length of Gestation, and Risk of Preterm Birth." American Journal of Epidemiology 179(5): 536-544. http://dx.doi.org/10.1093/aje/kwt313
Boucher, O., M.-N. Simard, G. Muckle, F. Rouget, P. Kadhel, H. Bataille, V. Chajes, R. Dallaire, C. Monfort, J.-P. Thome, L. Multigner, S. Cordier (2013). "Exposure to an organochlorine pesticide (chlordecone) and development of 18-month-old infants." Neurotoxicology 35: 162-168. http://dx.doi.org/10.1016/j.neuro.2013.01.007
Dallaire, R., G. Muckle, F. Rouget, P. Kadhel, H. Bataille, L. Guldner, S. Seurin, V. Chajès, C. Monfort, O. Boucher, J. P. Thomé, S. W. Jacobson, L. Multigner, S. Cordier (2012). "Cognitive, visual, and motor development of 7-month-old Guadeloupean infants exposed to chlordecone." Environmental Research 118: 79-85. http://dx.doi.org/10.1016/j.envres.2012.07.006
Clere, N., E. Lauret, Y. Malthiery, R. Andriantsitohaina, S. Faure (2012). "Estrogen receptor alpha as a key target of organochlorines to promote angiogenesis." Angiogenesis 15(4): 745-760. http://dx.doi.org/10.1007/s10456-012-9288-7
Multigner, L., J. R. Ndong, A. Giusti, M. Romana, H. Delacroix-Maillard, S. Cordier, B. Jegou, J. P. Thome, P. Blanchet (2010). "Chlordecone exposure and risk of prostate cancer." J Clin Oncol 28(21): 3457-62. http://dx.doi.org/10.1200/JCO.2009.27.2153
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I am extracting PAH, PCBs and other organochlorine compounds using 100%DCM. Then added 100% Hexane in it and concentrated to 1 ml. Then separated the extract in to two for both PAH and organochlorine compounds.
I want to know is the cleaning procedure for organochlorine compounds including PCBs can be done by  96% sulfuric acid or dichromate??
Is there any column chromatography step needed for PCBs and organochlorine compounds from the above procedure?
Thanks,
Rasiq
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Rasiq, you can use column chromatography. There are standard procedure available for the same. You can find on US EPA website. 
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I want to apply this for final remval of water from my  samples of OCPs
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Interesting Saima. sodium sulphate is chemically  very stable , being unreactive towards any oxidizing or reducing agents at normal temperatures . at high temperatures, it can be converted into sodium sulphide . sodium sulphate has ten molecules of water of hydration . A simple controlled heating will lead to formation of anhydrous sodium sulphate after loosing water of hydration .  
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Hello,
I'm looking for the TEF or TEQ values of organochlorines including:
- The dioxin-like PCBs (28,52,101,153,138 and 180);
- The organochlorine pesticides (DDT, DDE, DDD, lindane, aldrin, heptachlor and HCB).
Can you help me plz ? !!
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TEQ is essentially a summed parameter, the reporting limit is a matter of convention rather than a statistically based value.For example, from the Organochlorine pesticides, the sum of DDT+DDE+DDT and the sum of Aldrin and Dieldrin are required.
Benzo(a)Pyrene TEQ: EP075 and EP132 (ultra-trace).
DDT+DDE+DDD and sum of Aldrin + Dieldrin: EP068, EP131 (ultra-trace) and EP075 (SVOC).
LIMITS OF REPORTING (LOR)
Benzo (a) Pyrene TEQ is equal to the LOR for Benzo(a) Pyrene for each method.
Aggregate Organochlorines: This equates to the individual LOR of DDE or DDD for each method and the LOR of Aldrin or Dieldrin for each method.
REFERENCE
NEPM Schedule B1, Investigation Levels for Soil and Groundwater, 2013.
Here is some information on TEF/TEQ of OCs. You can go back on this and calculate the values on the basis of assigned values of different groups/constituents.
TEF values for Dioxins:
(Birnbaum L.S., Denison M., Vito M. De, Farland W., Feeley M., Fiedler H., Hakansson H., -1#den Berg The, Hanberg A. et al. (2006). "World Health Organization reevaluation of human and mammalian toxic equivalency factors for dioxins and dioxin-like compounds". Toxicol Sci 93 (2): 223–241. doi:10.1093/toxsci/kfl055. PMC 2290740. PMID 16829543), (http://en.wikipedia.org/wiki/Dioxins_and_dioxin-like_compounds
All dioxin-like compounds share a common mechanism of action via the aryl hydrocarbon receptor (AHR), but their potencies are very different. This means that similar effects are caused by all of them, but much larger doses of some of them are needed than of TCDD. Binding to the AHR as well as persistence in the environment and in the organism depends on the presence of so-called "lateral chlorines", in case of dioxins and furans, chlorine substitutes in positions 2,3,7, and 8.[2] Each additional non-lateral chlorine decreases the potency, but qualitatively the effects remain similar. Therefore a simple sum of different dioxin congeners is not a meaningful measure of toxicity. To compare the toxicities of various congeners and to render it possible to make a toxicologically meaningful sum of a mixture, a toxicity equivalency (TEQ) concept was created.[4]
Each congener has been given a toxicity equivalence factor (TEF). This indicates its relative toxicity as compared with TCDD. Most TEFs have been extracted from in vivo toxicity data on animals, but if these are missing (e.g. in case of some PCBs), less reliable in vitro data have been used.[4] After multiplying the actual amount or concentration of a congener by its TEF, the product is the virtual amount or concentration of TCDD having effects of the same magnitude as the compound in question. This multiplication is done for all compounds in a mixture, and these "equivalents of TCDD" can then simply be added, resulting in TEQ, the amount or concentration of TCDD toxicologically equivalent to the mixture.
The TEQ conversion makes it possible to use all studies on the best studied TCDD to assess the toxicity of a mixture. This resembles the common measure of all alcoholic drinks: beer, wine and whiskey can be added together as absolute alcohol, and this sum gives the toxicologically meaningful measure of the total impact.
The TEQ only applies to dioxin-like effects mediated by the AHR. Some toxic effects (especially of PCBs) may be independent of the AHR, and those are not taken into account by using TEQs.
TEFs are also approximations with certain amount of scientific judgement rather than scientific facts. Therefore they may be re-evaluated from time to time. There have been several TEF versions since the 1980s. The most recent re-assessment was by an expert group of the World Health organization in 2005.
 
The skeletal formula and substituentnumbering scheme of the parent compound dibenzo-p-dioxin
WHO Toxic Equivalence Factors (WHO-TEF) for the dioxin-like congeners of concern: 
Polychlorinated dioxins
 
2,3,7,8-TCDD
1
1,2,3,7,8-PeCDD
1
1,2,3,4,7,8-HxCDD
0.1
1,2,3,6,7,8-HxCDD
0.1
1,2,3,7,8,9-HxCDD
0.1
1,2,3,4,6,7,8-HpCDD
0.01
OCDD
0.0003
Polychlorinated dibenzofurans
 
2,3,7,8-TCDF
0.1
1,2,3,7,8-PeCDF
0.03
2,3,4,7,8-PeCDF
0.3
1,2,3,4,7,8-HxCDF
0.1
1,2,3,6,7,8-HxCDF
0.1
1,2,3,7,8,9-HxCDF
0.1
2,3,4,6,7,8-HxCDF
0.1
1,2,3,4,6,7,8-HpCDF
0.01
1,2,3,4,7,8,9-HpCDF
0.01
OCDF
0.0003
Non-ortho-substituted PCBs
 
3,3',4,4'-TCB (PCB77)
0.0001
3,4,4',5-TCB (PCB81)
0.0003
3,3',4,4',5-PeCB (PCB126)
0.1
3,3',4,4',5,5'-HxCB (PCB169)
0.03
Mono-ortho-substituted PCBs
 
2,3,3',4,4'-PeCB (PCB105)
0.00003
2,3,4,4',5-PeCB (PCB114)
0.00003
2,3',4,4',5-PeCB (PCB118)
0.00003
2',3,4,4',5-PeCB (PCB123)
0.00003
2,3,3',4,4',5-HxCB (PCB156)
0.00003
2,3,3',4,4',5'-HxCB (PCB157)
0.00003
2,3',4,4',5,5'-HxCB (PCB167)
0.00003
2,3,3',4,4',5,5'-HpCB (PCB189)
0.00003
(T = tetra, Pe = penta, Hx = hexa, Hp = hepta, O = octa)
 Dr. Mirza Arshad Ali Beg
 Former Director General PCSIR
Author of Book: Pesticides Toxicity Specificity & Politics
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I am looking for published data on the neurotoxic levels of organochlorines such as PCBs, HCH and DDTs, in the brain of human/animals.
Could anyone help?
Many thanks
jfr
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Many thanks for your suggestions!
Jean-François 
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Thank you.
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World Health Organization (WHO) is still supporting the use of DDT in indoor residual spraying for countries where malaria is endemic. DDT has low cost, long persistence in the environment, and effectiveness against malaria vectors. Currently, the global use of DDT for vector control around the world ranges 4–5000 metric tons per year, and several countries are reintroducing its production and use. In the areas where DDT is used, personal and collective protective equipment and preventive procedures can be applied to reduce exposure for the workers and the population, with special precaution for children and adolescents. There are many issues about DDT, I’m enclosing two recent papers about DDT effects on humans. Best regards, stefania
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DDT and its metabolites are well known and while there is data available on the effects on frogs and other amphibians, I am struggling to find a paper describing the metabolic pathways followed when amphibians are exposed to DDT or other persistent pesticides.
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Hi, Nico!
I work in the field of ecotoxicology and I am also interested in the effects of pesticides, including DDT. However, I work with fish. Check the following papers, they might help -
Best of luck!
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I am trying to interpret the bio concentration of pesticides but to calculate the Kow I need the octanol concentration of pesticides. Must I carry out the experiment to determine this concentration or can I use derived values from previous studies?
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Octanol/water partitioning coefficient is the same, denoting the lipophilicty or hydrophobicity of a chemical. It is the ratio of a chemical’s concentration in the octanol-phase to its concentration in the aqueous-phase of a two-phase system at equilibrium. Some pesticides such as endosulfan, DDT have a high low kow compare to herbicides such as glyphosate. It means that glyphosate is less hydrophobic and endoulfan and DDT are more or very hydrophobic. Some references can be helpful is listed below:
1.Sujit. Banerjee , Samuel H. Yalkowsky , C. Valvani 1980. Water solubility and octanol/water partition coefficients of organics. Limitations of the solubility-partition coefficient correlation. Environ. Sci. Technol., 14 (10): 1227–1229
2.Michele M. Miller , Stanley P. Wasik , Guo Lan. Huang , Wan Ying. Shiu , Donald. Mackay.1985. Relationships between octanol-water partition coefficient and aqueous solubility. Environ. Sci. Technol.,19 (6): 522–529
3.Noble, Alan. 1993. Partition coefficients ( n-octanol—water) for pesticides
Journal of Chromatography A, 642(1): 3-14
4.Finizio, A. ; Vighi, M. ; Sandroni, D. 1997. Determination of n-octanol/water partition coefficient (Kow) of pesticide critical review and comparison of methods .34 (1):131-161.