PCBs are a set of persistent organic chemicals that are known carcinogens and which have significant toxic results on the disease fighting capability, reproductive system, nervous system and endocrine system. Creation of PCBs was halted in the U.S. In 1977, but they persist in the environment. HSPH researchers led by Robert Herrick, Senior Lecturer on Industrial Hygiene in the Section of Environmental Health, completed an investigation of 24 structures in the higher Boston Area. The investigation uncovered that one-third of the structures contained caulking components with PCB content exceeding U.S. Environmental Safety Agency standards of 50 parts per million, in some cases containing nearly 1,000 times the standard.18 as Antibiotic Awareness Day New national awareness day promotes prudent antibiotic use to greatly help combat antibiotic resistance – website launched at Antibiotic level of resistance is an issue wellness practitioners around the world encounter daily. Numerous health-related businesses have partnered to mark tomorrow as the first Canadian Antibiotic Awareness Day in an effort to promote prudent usage of antibiotics and battle the threat of antibiotic-resistant bacteria. The National Collaborating Center for Infectious Diseases , the general public Health Agency of Canada , the Association of Medical Microbiology and Infectious Disease Canada, the city and Hospital Contamination Control Association Canada, the Canadian Foundation for Infectious Diseases , and the Canadian Paediatric Culture have joined to recognize Nov.