Study shows aerial mosquito spraying results in no public health risks
The study, which was published in Public Health Reports, analyzed emergency department records from Sacramento area hospitals during and after the sprayings during the summer of 2005. Scientists and physicians from the university and the California Department of Public Health found no increase in diagnoses associated with pesticides, such as skin, respiratory, eye and neurological conditions.
"Unfortunately, West Nile virus is endemic in California and the United States, and the controversy of mosquito management will likely arise every summer," Estella Geraghty, the lead author of the study, said. "Findings from studies such as this one help public health and mosquito control agencies better understand the risks and benefits of their practices."
The West Nile virus first appeared in California approximately 10 years ago. Around the time of the study in 2004 and 2005, the virus infected hundreds of Californians and caused 48 deaths.
The study found that exposure to aerial spraying was not associated with increased rates of emergency department visits for symptoms related to the pesticides.
Geraghty said it would be worthwhile to reproduce the study for other spraying techniques and pesticides.
When local methods for mosquito control are inadequate, aerial spraying is deployed to quickly reduce large, adult mosquito populations. The adult mosquito population this year has yet to grow to levels requiring aerial spraying over heavily urbanized areas.
Mosquito control officials said last week that recent rainstorms and warming temperatures in the region likely increased favorable conditions for mosquitoes. The virus was detected in at least 10 counties in recent weeks.