‍ ‍Most data centers rely on numerous backup diesel generators to provide electricity in the event of transmission grid power outages. The carbon monoxide, particulates, sulfur dioxide, nitrous oxides, and other pollutants emitted from data center diesel generators can pose a significant regional and local public health risk. The research presented below indicates a single, data center may adversely affect the health of those living at least 0.6-miles away and possibly miles further under some circumstances. The impact zone of multiple data centers when clustered together, such as at a data center campus, may affect those living even more distant. The research also indicates it is difficult to predict where and when a data center impact zone will expand to affect an even larger number of area residents. This is why all proposed data center designs should be based on something like the Washington state health impact assessment protocol with realistic worse-case assumptions. The data center should only be approved when it is proven that limits on hours of operation, generator emissions controls, alternate power supplies, and other measures will safeguard those living near and far from a proposed data center.

Local Health Impacts Some states, such as Washington, require a Health Impact Assessment (HIA) for the immediate vicinity of a proposed data center while many other states only assess health effects at the regional level. Figure 6 below is from an example of a local HIA, which was for the CyrusOne data center proposed for Quincy, Washington.

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Note that in Figure 6, above the furthest home impacted by just the proposed CyrusOne data center was 0.6-miles away. Figure 6 also shows three other data centers nearby. The maximally affected home due to the cumulative effects of all four data centers was 0.75-miles from the Cyrus One site.

Other Washington state HIAs have shown that a potential exists for relatively high short-term nitrogen dioxide (NO2) impacts miles downwind (due to terrain and conversion rate of NO in plume to NO2). That said, these high impacts likely only occur during outage scenarios when multiple engines (diesel generators) operate at the same time as happen in Loudoun County, VA inJuly 2025. Furthermore, the meteorology that produces these high concentrations (somewhat infrequent) combined with the likelihood of an outage (very infrequent for reliable power systems) leads to a low probability occurrence. Therefore, areas near the facilities (within a few hundred meters) are more likely to experience higher short-term NO2 levels compared to those areas farther downwind.

Regional Air Quality Impacts

In a 2025 paper, The Unpaid Toll: Quantifying and Addressing the Public Health Impact of Data Centers, researchers estimated that:

"Assuming that the actual emissions are 10% of the permitted level as a reference case that reflects both the historical reports and future demand response projections, the [data center] backup generators could already cause 14,000 asthma symptom cases and 13-19 deaths each year among other health implications, resulting in a total annual public health burden of $220-300 million throughout the U.S."

“Moreover, even short-term (hours to days) PM2.5 [2.5-micron particulate matter] exposure is harmful and deadly, accounting for approximately 1 million premature deaths per year from 2000 to 2019 and representing 2% of total global deaths.”

Further insights into the regional implications of data center diesel generator air pollution was provided in the 2026 paper Localized Air Pollution Impacts from Data Centers in Northern Virginia.

Northern Virginia has more data centers than any other place in the world. In this 2026 study, researchers reviewed emissions data for 138 data centers with Virginia Department of Environmental Quality (DEQ) air discharge permits. As of 2022-2023, data center emissions accounted for a small percentage of carbon monoxide (CO), nitrous oxide (NOx), and 2.5-micron particulate matter (PM2.5) released to the atmosphere from all Northern Virginia sources. However, on average data centers were emitting just 3% to 5% of the pollution allowed by DEQ air discharge permits. Some data centers though were emitting far more than the average:

“…we find that 14 out of 104 facilities emitted 20% or more of their allotted totals in 2023, for at least one of the three pollutants. In some cases, the data centers emitted more than 40% of their total permitted emissions for a given pollutant.”

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Among the key findings were:Among the key findings were:

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