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DR. BILL'S SITE. - SUMITHRIN

Pyrethrins - natural pyrethrins are botanical pesticides extracted from daisy species - Chrysanthemum cinerariaefolium and/or C. coccineum. Pyrethroids - are synthetic or semi-synthetic pesticides. According to EXTOXNET - PYRETHRUM - is a general name used to cover both pyrethrins and pyrethroids.                                    Dr. Bill would like to use, as an example of one of the pyrethroids, sumithrin ( ANVIL 10 + 10) - Clarke Mosquito Control Products Inc Active ingredients for their sumithrin formulation: 10.00% --3-Phenoxyphenyl - (1RS, 3RS, 1RS, 3SR) -2,2-dimethyl-3-(2-methylprop-1-enyl) cyclopropanecarboxylate (SUMITHRIN - CAS # 026002-80-2) 10.00% -- Piperonyl Butoxide, (Alpha-(2-(1-Butoxyathoxyl)-4,5-Methylenedioxy-2-propyltoluene) - CAS # 000051-03-6 0.40 Glycol Ethers                       CAS # none 40-78 White Mineral Oil (Supplier CAS # 064742-55-8 Recommended TWA/PEL            CAS # 064742-56-9 1-15 Aromatic Hydrocarbon         CAS # 064742-94-5  According to information provided on the Clarke Environmental Mosquito Management Inc web site: "Sumithrin. The secret ingredient. It's perfect for use around inlets, creeks, swamps and marshes, and in residential and recreational areas where adult mosquitoes are present in annoying numbers. Sumithrin synergizes with piperonyl butoxide (PBO) providing a fast knockdown of adult mosquitoes. Droplet tests are the same as other pyrethroids with a spread factor of 0.69.  Anvil is particularly effective against organophosphate-resistent species."

Estrogenic Potential of Pyrethroids including SUMITHRIN

The title of this section involves research published by Vera Go, et al., and involves studies of SUMITHRIN, FENVALERATE, D-TRANS ALLETHRIN, and PERMETHRIN (all pyrethroid insecticides).  The results of their study suggests that SUMITHRIN and others exerted an ESTROGENIC activity using MCF-7 human breast carcinoma cell line studies.  The estrogenic action of SUMITHRIN was abolished with co-treatment with an antiestrogen (ICI 164, 384).  The estrogenic activity of sumithrin, in increasing cell proliferation of MCF-7 cells in a dose-response fashion.  The article can be found in Environ Health Perspect 107:173-177 (1999).

This report is in contrast to results published in 1979 - Bioassay of Piperonyl Butoxide for possible carcinogenicity CAS No. 51-03-6. Rats and mice were used in this study in 1979 and is the main report quoted by the authorities who espouse the safety of piperonyl butoxide.

A listing of the known effects of pyrethrins and pyrethroids can be found on EXTOXNET.

Dr. Bill will now focus on PIPERONYL BUTOXIDE the other active ingredient in sumithrin (ANVIL). Piperonly butoxide is used to enhance the insecticidal properties of the pyrethrins by blocking the pyrethrin detoxification enzymes in the insect. In a technical report found at: www.nccnsw.org.au/member/tec/projects/tcye/tox/Piperonylbutoxide.html this compound is suspected of causing anorexia, carcinogenesis, coma, convulsions, dermal irritation, hepatic and renal damage, hyperexcitability, prenatal damage, unsteadiness, vomiting and weight loss.Acute oral LD 50;>7500 mg/kg (rats); Acute dermal LD 50; 1880 mg/kg (rabbits). Not toxic to fish or bees. According to a bioassay of piperonyl butoxide for possible carcinogenicity: at:   http://ntp-server.niehs.nih.gov/htdocs/LT-studies/TR120.html  - while doses showed increased lymphomas in female rats that were dose related (P=0.007); in a direct comparison, the incidence of the tumor in the high-dose group was higher (P=0.020) than that in the control group (controls 1/20, low-dose 7/50, high-dose 15/50). However, the incidence of lymphomas, and other cancers in historical-control female Fischer 344 rats at the same laboratory was 19/191 (10%). These historical-control groups include one with an incidence of animals with lymphoma or leukemia of 7/20 (35%) and another with an incidence of 6/20 (30%). Thus, the incidence of lymphomas in the control female rats of the present bioassay may have been abnormally low, the the occurrence of the higher incidence in the dosed groups cannot be clearly related to administration of piperonyl butoxide. Dr. Bill would like to point out to the reader that sometimes science results that show one thing may not be the case. So even though cancer increases were seen in this study (with controls), the overall experience in the laboratory over years suggests that cancer was not seen.

It should be obvious to the reader that more research is necessary to resolve the conflict of possible carcinogenicity of piperonyl butoxide - the OTHER MAJOR ingredient in ANVIL and SCOURGE. The spraying of nearly 10 million people with an insecticide that we have very little data about on its long term effects is frightening.

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