Talk to Pediatric Oncologist and Hematologist on Chemotherapy Caregiver Risks

Please tag an oncologist. My nephew is on cancer treatment. he is a child therefore, we have to give him chemo pills by crushing and adding to something. we touch the pills (mercaprine) with bare hands and come into contact with them also we come into contact with his urine, stool, blood etc. I recently read it can cause cancer to us too. Are we really at risk now? please help and tell us what we should do?