If it was Roundup (AKA Glyphosate) you will be at a slightly higher risk for non-Hodgkin's lymphoma. Except for organic foods, fruits and vegetables that are farmed using pesticides and weed killers must, under law, not be harvested for a specified length of time. This is to allow the chemicals to break down or sublimate. This is usually a matter of weeks. Still though, some of it remains.
This is why I will not allow any chemical weed killers insecticides or anything along that line on my property. There is always the haunting suspicion of "what will that stuff do to me, my wife, my kids, my pets?" Well, I don't have to worry about that and if I were you, I wouldn't allow anyone to spray chemicals on the lawn seeing as you have a vegetable garden right next to it.