Walter Tsou, MD, MPH is the interim Executive Director of Philadelphia PSR. He has served in the past as Health Commissioner of Philadelphia and Past President of the American Public Health Association. Dr. Tsou recently authored a resolution passed by the Pennsylvania Medical Society calling for a moratorium on new gas drilling in Pennsylvania based on the precautionary principle. The resolution also calls for the Commonwealth of Pennsylvania to fund research on the health effects of fracking in order to advance our scientific knowledge. The resolution has resulted in a widely read article in the Pittsburgh Post-Gazette and an editorial in the Reading Eagle endorsing a moratorium on gas drilling.