Sarah Janssen is a senior scientist in the health program at NRDC and is based in San Francisco. She is a physician and scientist with expertise in chemicals that mimic hormones and interfere with fertility, reproduction and development of the brain. Many of these chemicals have been found in common consumer products and NRDC is working to reduce exposures by removing the worst offenders. Dr. Janssen is board-certified in Occupational and Environmental Medicine and has a PhD in Reproductive Physiology from the University of Illinois, Urbana-Champaign. She blogs on NRDC's Switchboard.