Hi Diane,
Just a lurker here, but have been for so long I almost feel like family. About the contrails, we have been getting them every other clear day almost, since last year. At first everyone would get very bad sinus infections or strep. Only strong antibotics could help. Until I put 2 & 2 together and at the first sign of a sore throat or sniffle I give whomever has a problem some CS about an ounce two times a day for one to two days depending on the sympoms. If they spray a lot by your dads' place you might give it a try.