Ohio has fallen to 36th in an annual health ranking of the states. The United Health Foundation says Ohio slipped three places from its No. 33 spot in 2010 as smoking and the percentage of children in poverty increased. The study says the state's challenges include high levels of air pollution and relatively low spending on public health programs. Ohio's strengths are said to include widespread immunizations, a low rate of deaths on the job and a moderate level of students completing high school. Vermont topped the list as the healthiest state for the third straight year. For the 10th year in a row, Mississippi ranked as the least healthy state.