This NYT piece is interesting in that oh-I-never-thought-of-that sort of way. Grass playing fields are — in New York City, at least — an endangered species:

To avoid the ignominy of being trampled underfoot, the grass fields need to be idle all winter, and once a week the rest of the year. As a result, there is increasing pressure from league coaches to install synthetic turf to allow the fields to be used year-round to meet local demand.

But not only can synthetic turf suck up enough sun to heat to potentially dangerous levels, the recycled tire rubber that gives it its springiness has “worrisome” levels of a carcinogenic chemical, according to researcher William Crain. In addition, Crain objects: “In a city where there is very little nature left, kids are already living in a synthetic indoor setting. When they go outside, they should feel grass and soil. Instead, we’re putting artificial surfaces outside, too.”

Beijing 2008 update: General Electric will show off its energy-efficient “Ecomagination” products at the Games; pre-Games test events ran much more smoothly than expected; and today, Beijing began testing a four-day vehicle ban to keep 1.3 million cars off of the city streets.