Diesel-powered backup generators at data centers release toxic pollutants that significantly threaten public health, particularly in communities located near these facilities. According to the authors of the newly released report, these emissions are linked to higher risks of cancer, heart problems, and severe respiratory issues like asthma.
“Diesel generators emit diesel particulate matter, a toxic air contaminant associated with increased cancer risk as well as adverse cardiovascular and respiratory health outcomes, including asthma.” The report also notes that “pollutant emissions from data centers nationwide could contribute to more than one-third of asthma-related deaths by 2028.”
This means that even if these backup engines only run for a few hours a year during emergencies or testing, they pump out a massive amount of concentrated pollution. For example, just one set of generators at a single large data center running for 20 hours can create as much exhaust as hundreds of cars driving for a full year. Because data centers are often grouped together in cities like San Jose and Los Angeles, the combined effect of these tiny soot particles can worsen heart and lung conditions for people living nearby.
The Little Hoover Commission published its report ‘Data Centers and California Electricity Policy’ in Sacramento in March 2026. Led by Chair Pedro Nava, the oversight agency outlines a strategic framework to integrate energy-intensive data centers into the state’s grid without compromising ratepayer affordability or climate targets.
