Depressing news for Beijingers in today’s Wall Street Journal: the air quality in China is officially getting worse again. After steadily improving for the last few years, the WSJ article says China’s Ministry of Environmental Protection acknowledged last month that China’s air pollution levels rose in the first quarter of 2010 for the first time since 2007. Yesterday came worse news: “The first half of 2010 had the worst air quality since 2005.”

According to the WSJ, one of the key factors was an increase in particulate matter, which shot up from “0.091 milligrams per cubic meter in 113 major cities from just 0.002 milligrams a year earlier.”

Extreme heat this summer has only made things worse – for most of this week the US Embassy’s Air Particle Index for Beijing has been well over 200 and in the “very unhealthy” range. Fortunately we haven’t seen the extreme levels of last November, when the index shot up over 500 for several prolonged periods (according to Dr Richard Saint Cyr of Beijing’s International Medical Center, “Anything over 300 is considered a public health emergency”).

The worsening figures for 2010 are the result of a range of factors, including a particularly nasty sandstorm in April. Primarily, however, the rise in pollution is the result of increasing economic activity after a marked slow down following the financial crisis that swept the globe in late 2008.

Heavy industry is still a key component of China’s economy, and the nation’s power supply still mostly comes from coal burning plants. A surging economy means surging pollution levels that continue to outstrip any gains made through greener energy sources and stricter environmental standards.

The fact that Beijing’s car fleet is now well over 4 million vehicles (in case you missed it we passed that milestone last December) also doesn’t help.