 Dr Klaus Chen said in 2007 that this was still the dominant pool.Concerns that some poorer countries were answering donor shortages by selling organs to richer countries led the World Medical Association (WMA) to condemn the purchase and sale of human organs for transplantation at Brussels in 1985, in 1987 and at Stockholm in 1994.In Madrid in 1987, the World Health Organization (WHO) condemned the practice of extracting organs from executed prisoners due to the difficulty of knowing if they had given consent.