This thesis statement is clear and straightforward, but it is not particularly effective. It is a widely accepted fact that cigarettes are bad for a person's health, so the statement does not offer any new insight or perspective. To be more effective, a thesis statement should take a stance or make an argument that is debatable and supported by evidence. For example, a more effective thesis statement could be: Despite the known health risks, the tobacco industry continues to market cigarettes to young people through targeted advertising, contributing to the ongoing public health crisis caused by smoking.