APPENDIX II-AU:  Eash, Pyrethroid Toxicity, EHN, Oct., 2000


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Pyrethroid Toxicity



By: Connie Eash
EHN web-posted October 26, 2000 by permission of Connie Eash


I did a little research on a question someone had about a pyrethroid and the effects on platelet count. Thought I would share what I found.

I know some of you are specifically interested in the toxicity of pyrethroids and there isn't much info out there. So someone might find it useful. -- Connie


A consultant asked whether an insecticide could be responsible for low platelet counts. His client and his client's dog have both shown low platelet counts and other symptoms since moving into a house previously sprayed quarterly with deltamethrin.

According to the EPA publication,"Recognition and Management of Pesticide Poisoning", only the inorganic arsenicals have this effect (thrombocytopenia) documented. But this is not a symptom that would show up in most routine studies of pesticide toxicity.

A medline search turned up 4 published articles that may be of interest. I've only seen the abstracts, so the information is limited, but the full articles may be of help to your client:

"Chronic sequelae and irreversible injuries following acute pyrethroid intoxication" Toxicol Lett 1999 Jun 30;107(1-3):161-76

An undisclosed number of pyrethroid intoxicated patients were observed for 2 years following the exposures. Residual effects after 2 years were 1) cerebro-organic disorders (reduced intellectual performance with 20-30% reduction of endurance during mental work, personality disorder), visual disturbances, dysacousia, tinnitus 2) sensomotor-polyneuropathy most frequently in the lower legs 3) vegetative nervous dosiorders (paroxysmal tachycardia, pollakisuria, increased heat-sensitivity, orthostatic hypotonia and reduced exercise tolerance due to circulatory disorder) 4) Non-neurological symptoms (deficiency of cellular and humoral system established by lab findings) Many patients exhibit pathological autoimmune diagnostical findings and developed autoimmune diseases, INCLUDING AUTOIMMUN-THROMBOCYTOPENIC PURPURA.

"A new method for early detection of neurotoxic diseases (exemplified by pyrethroid poisoning)(see comments)" Gesundheitswesen 1995 Apr;57(4):214-22

This is an earlier pilot study by the above author. The list of symptoms observed from pyrethroid poisoning included disturbances of blood clotting and suspected hematopoetic disorders.

"Statistical description of health complaints after pyrethroid exposure" Gesundheitswesen 1994 Nov;56(11):622-8

This still earlier report specifies that out of 96 patients with pyrethroid exposures, 51 were used in the analysis because the actual pyrethroid concentrations in dust samples from residential dwellings or from work places could be determined. Three groups included: 26 cases exposed to permethrin and tetramethrin (type-I pyrethroids), 13 cases exposed to deltamethrin, cyfluthrin or cypermethrin (type II pyrethroids), and 12 cases with mixed exposure to both type I and type II. The mean concentrations of pyrethroid in the 3 groups are 425.7, 56.1 and 958.9 mg pyrethroid/ kg dust, respectively. The full text of this article might be useful. But the method of measuring the pyrethroid levels in dust seems to be a good way of determining pyrethroid exposure.

"Induction of micronuclei by five pyrethroid insecticides in whole-blood and isolated human lymphocyte cultures" Mutat Res 1995 Jan;341(3): 169-84

Five pyrethroid insecticides, including deltamethrin, were tested on whole blood and lymphocyte cultures from 5 human donors. Three indices of cytotoxicity were used. Deltamethrin produced a positive response in the cultures of 2 out of 5 donors.

I always look at EXTOXNET information for information about stability and cursory information about the health effects. The EXTOXNET Information Sheet for deltamethrin is:

Note that under environmental fate, information is for outdoor use, in which the chemical is broken down in a few weeks, with the help of micro-organisms and other environmental factors. Under physical properties, however, it says this chemical is very stable:

"There is no degradation of deltamethrin in storage for 6 months at 40 degrees C. It is extremely stable to atmospheric oxygen. Under UV irradiation and in sunlight, a cistrans isomerization, splitting of the ester bond, and loss of bromine occur (12). Deltamethrin is noncorrosive to metals (12). By contrast with natural pyrethrins, it is stable to air and sunlight (86, 92). When exposed to air and light, deltamethrin remains unchanged after two years at 40 degrees C. It is considered stable when exposed to air and sunlight, and more stable in acid than alkaline media (87)"

From this information, it appears that the chemical stays around for a while indoors. The health effects mentioned here do not include thrombocytopenia, but are still pretty undesirable.

I'm glad that you have thought to track down the symptoms to pesticide use by a former owner. If I were them, I would leave the property, since health damage can be debilitating and irreversible, according to the published articles from Germany. There are methods to pull the toxins out of the system and improving health of pesticide poisoning victims. I hope they find the proper medical help as well.



Note from Barb Wilkie:

My chiropractor noticed a monthly patterrn to my tinnitus, yet as far as we could tell, there was no reason why my body should have a cyclical pattern of tinnitus.

Julia Kendall (1935 - 1997, victim of malathion poisoning) suggested that I ask my workplace about its pesticide practices. Bingo!

I'm embarrassed to admit, that once they stopped spraying during working hours and around the feet of staff, I really never thought of pesticides. Truly, out of site, out of mind. But, it became obvious that the pesticides were in my body. And the bodies of other staff, who although did not live with MCS, lived with cancers, asthma and other respiratory problems, headaches, pneumonia, . . .

My tinnitus coincided with their monthly spraying schedule. And when my tinnitus was off by a week, so was their pesticide spraying! Later I began developing spontaneous cratering of my skin, mainly on my legs and feet. These open and deep sores would vary in size from a penny to about a quarter, but generaly were about the size of a nickle in diameter, and occasionally about the size of a half dollar. They took many months to slowly heal, from the inside out. The ones on my inside right ankle were particularly painful, and took the longest to heal . . . pushing close to a year.

There were several times when I developed tinnitus and the open sores, off schedule and when I inquired about spraying, it was emphatically denied. However, after several days of my continued questioning, it would be proved that yes, indeed, there had been spraying the previous weekend afterall. My body never lied. My employer, however, had. -- barb


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