I was recently diagnosed with diaphragm paralysis on my right side. i work in lawn care. could exposure to pesticides cause this?

Possible, unlikely: The cause of weakness or paralysis of the diaphragm is injury or dysfunction of the phrenic nerve or from muscle disease of the diaphragm muscles. An electromyogram can help sort this out. Usually other nerves or muscles are affected that can be more easily tested. Pesticide exposure is a remote, unlikely cause but could be considered in the work-up. Good wishes:)