Persistant pesticides last longer than non persistant pesticides. This means that they can build up in animals and humans and cause more damage.

causalgia

The athlete had a persistent pain in his knee.

The persistent residential homeowners were finally allowed to talk with the mayor.

Some pesticides remain persistent in the soil for months.

persistent pain

I was vexed by a most annoyingly persistent young man.
"You are very persistent in getting an answer to this question."
The small business owner was very persistent with their product.