In recent years, China has been experiencing an unprecedented economic and industrial boom. Cities are growing, manufacturing (with the exception of the onset of a worldwide recession in 2008) has been flourishing, and living standards are rising. This has been great news for many Chinese citizens, but it has come with a cost: a huge environmental problem. Although China has many environmental regulations on the books, it has had tremendous problems enforcing them. The result is that the country is probably the most polluted on the planet, with only India as a rival in this infamous area. The air quality in about two thirds of the cities is considered unhealthy for people, acid rain is damaging crops, and life expectancy rates are dropping because of pollution-related health issues. The Chinese government is not unaware of this shameful problem, and the country made news in 2008 when it hosted the Olympic Games. Heavy restrictions were placed on auto traffic and factories so that the air would be clear enough that the athletes would not be sickened by the smog.