joining us is dr. jon lapook and cbs news contributor dr. tara narula. the fight for zika. for the first time aerial praying on miami beach area used naled insecticide and deemed safe but people have concerns. why the new concerns, jon? >> they are spraying something that kills mosquitoes and the natural question is what can it do to me, especially if i'm pregnant. i've spoken to the epa and the cdc and they explained to me are using, which by the way, is two tablespoons for the equivalent of a football field, it is neurotoxic to mosquitoes. it kills mosquitoes. if that dosage, they are saying it's safe for humans. it's been used for more than 50 years. you can understand people's concern and this is a classic thing of risk benefit and the public health officials are saying, look, the risk of the zika virus outweighs the possible risk of the spray. >> if you have concerns, other precti >> according to the epa no special precautions people need to take and don't need to leave the area while the spraying is occurring. but it's a good idea to avoid unnecessary exposure to pest