AI’s Hidden Threat to Public Health

Most people have heard about the environmental impact of today’s AI boom, stemming from sprawling data centers packed with power-hungry servers. In the United States alone, the demand for AI is projected to push data-center electricity consumption to 6.7 to 12.0 percent of the nation’s total by 2028. By that same date, water consumption for cooling these data-center facilities is predicted to double, or even quadruple, compared to the 2023 level.

But many people haven’t made the connection between data centers and public health. The power plants and backup generators needed to keep data centers working generate harmful air pollutants, such as fine particulate matter and nitrogen oxides (NOx). These pollutants take an immediate toll on human health, triggering asthma symptoms, heart attacks, and even cognitive decline.

But AI’s contribution to air pollution and the public health burden is often missing from conversations about responsible AI design. Why?

Because ambient air pollution is a “silent killer.” While concerns about the public health impacts of data centers, including potential links to cancer rate increases, are beginning to surface, most AI-model developers, practitioners, and users simply aren’t aware of the serious health risks tied to the energy and infrastructure powering modern AI systems.

The Sanger of Ambient Air Pollution

Ambient air pollution is responsible for approximately 4 million premature deaths worldwide each year. The biggest culprit are tiny particles 2.5 micrometers or less in diameter (referred to as PM 2.5), which can travel deep into the respiratory tract and lungs. Along with high blood pressure, smoking, and high blood sugar, air pollution is a leading health risk factor. The World Bank estimates the global cost of air pollution at US $8.1 trillion, equivalent to 6.1 percent of global gross domestic product.

Contrary to common belief, air pollutants don’t stay near their emission sources: They can travel hundreds of miles. Moreover, PM 2.5 is considered a “nonthreshold” pollutant, meaning that there’s no safe level of exposure.

With the danger of this pollution well established, the question becomes: How much is AI responsible for? In our research, we’ve set out to answer that question.

Quantifying the Public Health Cost of AI

To ensure that AI services are available even during grid outages, data centers rely on large sets of backup generators that usually burn diesel fuel. While the total operation time of backup generators is limited and regulated by local environmental agencies, their emission rates are high. A typical diesel generator can release 200 to 600 times more NOx than a natural gas power plant producing the same amount of electricity.

A recent report by the state of Virginia revealed that backup generators at Virginia’s data centers emitted about 7 percent of what permits allowed in 2023. According to the U.S. Environmental Protection Agency’s COBRA modeling tool, which…