Behavior change, health, and health disparities 2020: Some current challenges in tobacco control and regulatory science.

This Special Issue of Preventive Medicine (PM) is the 7th in a series on behavior change, health, and health disparities. This series focuses on personal behavior patterns, including substance use disorders, physical inactivity/obesity, and non-adherence with medical regimens, which are among the most important modifiable causes of chronic disease and premature death. This 7th issue includes 17 commentaries, reviews, and original empirical studies, 16 of which are devoted to current tobacco control and regulatory science research and policy, topics critically important to protecting the public health from the longstanding and devastating harms of tobacco use. The challenge of balancing efforts to protect youth from e-cigarettes while allowing for evidence-based evaluation of their potential to reduce the harms of cigarette smoking among adults features prominently in many of these contributions, complemented by original studies on rural-urban disparities, tobacco harm perceptions, use patterns and toxin exposure, modeling of tobacco-related mortality, novel tobacco research methods, and reducing cigarette smoking through regulatory policies, including nicotine reduction in cigarettes, and novel clinical interventions. Continuing to give space in this series to the U.S. opioid epidemic, we also include an original empirical report on longitudinal trends of non-medical use of opioids from 2008 to 2020 in rural Appalachia, an epicenter in this epidemic. Across each of these topics we have recruited contributions from well-regarded investigators, clinicians, and policymakers to acquaint readers with recent advances and accomplishments while also noting knowledge gaps and unresolved challenges.