I believe that people have the right to do things that are a detriment to their own health; my own diet is evidence of that opinion. However, I also believe that one loses that right when those things are a detriment to the health of others. This law, the Iowa Smokefree Air Act which went into effect today, was passed on the understanding that second-hand smoke is a detriment to the health of others. The first section addresses this:
The general assembly finds that environmental tobacco smoke causes and exacerbates disease in nonsmoking adults and children. These findings are sufficient to warrant measures that regulate smoking in public places, places of employment, and outdoor areas in order to protect the public health and the health of employees.
The purpose of this chapter is to reduce the level of exposure by the general public and employees to environmental tobacco smoke in order to improve the public health of Iowans.
While the methods that they've implemented aren't perfect (the exemption of casinos is quite a glaring one, in my opinion), they're definitely a step in the right direction. Of course, I'm asthmatic, so I'll readily admit that my opinion is bias.
More than anything, it's great to know that my kids will never have to worry about second-hand smoke, at least not from public exposure.