Surgeon says shortages of donors mean they must use imperfect organs . 49 percent of last year 's lung donors in the UK were smokers . U.S. doctors say one in five donated organs may have a problem . They are thoroughly checked for suitability before transplant , says surgeon .
Surgeon says shortage of donors mean they must use imperfect organs . 49 percent of last year 's lung donors in the UK were smokers . U.S. data suggest one in 5,000 donated organs may have a tumor . Organs are thoroughly tested for suitability before transplant , says surgeon .