Last year, the pesticide Naled was one of several tools officials used to control mosquitoes that carry the Zika virus. Dr. Michael Hall was one of many Miami Beach residents who protested, saying Naled exposure leads to symptoms like headaches and nausea. He and other protesters also expressed fears the pesticide could have longer-term health effects.
South Florida officials no longer use Naled against the Aedes aegypti mosquitoes that carry Zika. They say aerial spraying can be ineffective against that species because the mosquitoes tend to lurk under leaves and foliage.
But mosquito control officials in Miami-Dade, Broward, Palm Beach and Monroe counties are all continuing to use Naled to control another species of mosquito: the salt marsh mosquito. It's not considered a major disease carrier, but it does bite humans and can transmit heartworm in dogs.
Now Hall and Miami Beach lawyer Cindy Mattson have filed a lawsuit in federal court to try to get Miami-Dade to stop spraying Naled. They say they're worried about the effects the pesticide may have on the environment — it can kill bees as well as mosquitoes and can harm fish.
And they're especially concerned about a recent study that found 9-month-olds who had been exposed to Naled scored slightly lower than average on some motor skills tests.
"That’s a risk I’m not willing to take and that’s why I’m speaking out," Hall said.
The study from the University of Michigan looked at about 200 infants in China. Experts say that in such a small sample, it's hard to tell if the developmental differences result from Naled exposure or just from normal differences in development. Study author Monica Silver also said the infants were likely exposed through food, not mosquito spraying, and that her team was unable to determine in what doses they were exposed.
But both Silver and other experts not associated with the study say it’s a red flag if future studies show the infants lag behind their peers.
Hall said he thinks it's just not worth the risk.
"We’re asking, we’re begging, we’re imploring, we’re pleading, we’re really desperate for our community not to be sprayed," Hall said. He added he’d like to see officials depend more on other mosquito control methods like organic larvicides, and to do a better job of communicating with residents when spraying does take place.
A status conference on the lawsuit is scheduled for 4 p.m. on July 12.