Studies of synthetic pyrethroid insecticides,

*Anvil (Sumithrin) is a synthetic pyrethroid.

Health Effects

Human Exposure to Mosquito-Control Pesticides—Mississippi, North Carolina, and Virginia, 2002 and 2003   JAMA. 2005;294:419-421.

Pyrethroids found in urine of school children A Longitudinal Approach to Assessing Urban and Suburban Children's Exposure to Pyrethroid Pesticides

**They could tell how old a child was by their pyrethroid level. They could tell if their parents used pyrethroid pesticides. - J**

Thyroid Danger "In animal studies,...exposure to pyrethroids can suppress both the thyroid's T4 and T3 levels, and raise Thyroid Stimulating Hormone (TSH) levels"

Breast Cancer Risk: Estrogenic potential of certain pyrethroid compounds in the MCF-7 human breast carcinoma cell line.

Endocrine and other systems at risk: "immense care is warranted in the use of insecticides, because they not only affect the liver, kidney and other organs but also may alter the activity of the endocrine glands."

Neurotoxic Effects: "... the distribution and function of these across the central nervous system are poorly characterized. The review also provides an overview of recent studies that suggest additional effects of pyrethroids: developmental neurotoxicity, the production of neuronal death, and action mediated via pyrethroid metabolites. The evidence for these is at present equivocal, but all 3 carry important implications for human health."

Effects on the Environment

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environ Sci Technol. 2006 Mar 1;40(5):1700-6. "This study was intended to determine if pyrethroids are detectable and widespread in diverse urban systems and if concentrations are high enough to cause associated aquatic toxicity. Urban creeks in California and Tennessee were tested on up to four occasions for pesticide residues in sediments, and aquatic toxicity was determined by acute toxicity tests using the amphipod, Hyalella azteca. In California, 12 of the 15 creeks tested were toxic on at least one sampling"

Aquatic toxicity due to residential use of pyrethroid insecticides. Environ Sci Technol. 2005 Dec 15;39(24):9778-84. "despite their dominance in the marketplace, there has been no attempt to analyze for most of these compounds in watercourses draining residential areas. Roseville, California was selected ...Nearly all creek sediments collected caused toxicity in laboratory exposures to an aquatic species, the amphipod Hyalella azteca, and about half the samples caused nearly complete mortality.... The dominant sources of these pyrethroids are structural pest control by professional applicators and/ or homeowner use of insecticides, particularly lawn care products."

Use and toxicity of pyrethroid pesticides in the Central Valley, California, USA. Environ Toxicol Chem. 2005 Apr;24(4):966-72. "The use of pyrethroid insecticides is increasing ... Little is known about the toxicity of sediment-associated pyrethroid residues to aquatic organisms, ...Minimal data exist on the sensitivity of standard sediment toxicity testing species to pyrethroids...Sediment concentrations causing acute toxicity and growth impairment to the amphipod Hyalella azteca were determined for six pyrethroids in three sediments...A reanalysis of previously reported field data using these toxicity data confirms that the compounds are exceeding concentrations acutely toxic to sensitive species in many agriculture-dominated water bodies."