Puerto Vallarta will soon implement a vehicular inspection program similar to that in place in Mexico City, making periodic car inspections mandatory. Such a program will create local awareness about Puerto Vallarta's more than 300,000 inhabitants and the 60,000 cars that regularly travel through the city. According to Secretaria del Medio Ambiente para el Desarrollo Sustentable (SEMADES) the program will commence by setting up two verification centers in the city, something that is expected to be defined by October. There are no conclusive studies at this time to support the notion that substantial pollution is caused locally by vehicular emissions. However, SEMADES has considered that, given Vallarta's expansion rate, it is best to be pro-active. Vehicular emissions contribute to the destruction of the ozone layer, generate acid rain, toxic emissions and global warming, all serious threats to the environment.