On quiet, residential streets in Sterling, Virginia, residents often wake to the roar of diesel backup generators and smog that leaves their throats raw by morning — the price of AI data centers built without proper zoning oversight.

This is the leading edge of a much bigger problem. Virginia alone hosts roughly a quarter of the nation’s data centers, backed by some 10,500 diesel generators, many the size of semitrucks. Virginia Commonwealth University researchers who examined emissions permits for more than 130 Northern Virginia data centers found that running those generators less than an hour a week creates a public health burden equivalent to five large natural gas plants operating continuously — at least three premature deaths a year and 14,000 annual asthma episodes. And the AI buildout has barely begun.