Authorities say the the insecticide Pyrenone 25-5 used in exterminating mosquitoes carrying the West Nile Virus in Cosa County, NC, is "far less toxic to pets than commonly used household cleaners."
The statement was issued after pet owners complained they have not received sufficient notice of spraying in their areas.
Steve Schultz, an entomologist with the Contra Costa County Mosquito and Vector Control District, said Pyrenone 25-5 has been widely used throughout the United States for the past 20 to 30 years without any reported incidents of harmful effects to humans or pets.
Pyrenone 25-5 is extracted from chrysanthemum flowers and is also the same chemical used in flea collars. Although the Environmental Protection Agency (EPA) approved the use of Pyrenone 25-5 protecting public health, the agency also reported pyrethrins is the second leading cause of insecticide poisonings.
PBO, one of the ingredients in Pyrenone 25-5 is classified as a possible human carcinogen because it caused tumors in laboratory tests. Pyrethrins also disrupt the normal functioning of sex hormones while PBO affect the functioning of hormone related organs.
Products containing Pyrethrins carry the following warning label: "Harmful if inhaled. Avoid breathing vapor or spray mist." It is also advertised that the chemical leaves a clear residue on surfaces that kills pests for up to 3 months.
But Schultz said that the amount of Pyrenone being sprayed into the air to kill mosquitoes are in very low conditions.
The district intensified its mosquito control program after an 85-year-old woman died in early August from West Nile virus. The virus is mainly transmitted by mosquitoes. So far this year, the county confirmed five human cases of West Nile virus.
The disease was also reported in 6 squirrels, 24 chickens and 17 mosquito samples. There were 61 dead birds positive with West Nile virus recorded in the county.
Across the across the US there were 159 confirmed human cases of West Nile virus with two fatalities. There were also 38 horses, 932 dead birds, 683 mosquito samples, 393 chickens and 12 squirrels found with the virus this year.
