 as a scientist , administrator , and diplomat , david p. rall pioneered the effort to identify and understand the elements that make up the human environment and their consequences for human health . 
 as an intellectual and aggressive activist , he educated scientists , governments , and the world community to the critical need to address the existence of environmental agents and their consequences for human health . as a leader he marshalled some of the best minds and hearts of his time to the cause of world health through a safe and clean environment . and as a visionary he provided the goals of environmental health science and the direction to guide both current and future generations . 
 his death on september 28 brought to a close a chapter in the evolution of our understanding of the interconnectedness of human health and the environment , a chapter he was largely responsible for writing.imagespa538-a 
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