Researchers at the University of Minnesota are launching a study that will follow over 3500 Minnesota teenagers to measure how their tobacco use patterns and attitudes change over time. The researchers will survey the teens every six months for three years. They have a 3.9 million dollar grant from the National Cancer Insitutute to conduct the study. Dr. Jean Forster is a professor in the University's School of Public Health and the lead researcher in the study. She says this study is unique in two ways. Forster says she hopes the survey will track the impact of the state's aggresive anti-smoking programs.