The people of the state of Washington recognize that exposure to secondhand smoke is known to cause cancer in humans. Secondhand smoke is a known cause of other diseases including pneumonia, asthma, bronchitis, and heart disease. Citizens are often exposed to secondhand smoke in the workplace, and are likely to develop chronic, potentially fatal diseases as a result of such exposure. In order to protect the health and welfare of all citizens, including workers in their places of employment, it is necessary to prohibit smoking in public places and workplaces.