1. Exposure Science Lab, Family Medicine, College of Human Medicine, Michigan State University, East Lansing, MI 48824, USA
2. Community Health Nursing, Ann Arbor, MI 48109, USA
3. Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA
4. School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
5. Department of Internal Medicine, Wayne State University, Detroit, MI 48201, USA