While im not worried about the parasites (its a very low risk to find a parasite that can jump to chams, those horrible horse hair worms that look like they came from nightmare fuel, can be eaten all day long by lizards), You get one bad pesticide, herbicide, or even fertilizer, and you are done. Once symtoms start to show there is nothing you or a vet appointment can do, either the cham is going to get through it on its own, or its going to kick the bucket.
There are plenty of people who live in nice areas, and have been very successful with live insect traps. I do not trust my county commissioner nor my neighbors...