This is something that I listed on my con list about donating a kidney. I wasn't so afraid of death during the surgery which leads doctors to call it minimally invasive and safe. It is the long term studies about how living donors age with one kidney that I am interested in. In addition, not just chemotherapy agents are nephrotoxic but dyes that are used during diagnostic studies like some CT scans, MRI's, angiograms (like for cardiac patients) can also put the lone kidney at risk. As we age, using NSAIDs for pain relief from common ailments like arthritis is also a risk. It would be interesting to see research studies about kidney donors and the effects of their one kidney on aging.