A federal panel of scientists is meeting in Raleigh this week to review the latest research findings about nitrogen oxide pollution and its effects on human health.
The U.S. Environmental Protection Agency’s Clean Air Scientific Advisory Committee is meeting Wednesday and Thursday at the Raleigh Marriott Crabtree Valley. Its review could eventually help determine whether the federal air-quality standard for nitrogen dioxide should remain the same, be strengthened, or be weakened.
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The meeting comes as electricity demand from AI and data centers drives proposals for new power plants, gas turbines, and large fleets of diesel generators. Those combustion sources can emit nitrogen oxides, commonly called NOx.
“The current science is basically an affirmation and a further clarification of the kinds of effects that nitrogen dioxide has on humans, and its impact particularly on susceptible people,” said Dan Costa, a Raleigh-based scientist who spent 35 years at the EPA and previously led the agency’s air quality and health research.
Costa said people with asthma or existing heart and lung conditions are among those most vulnerable. Children with asthma face particular risks. Exercise and higher temperatures can also increase a person’s exposure or sensitivity, he said.
Nitrogen oxides form when fuel burns at high temperatures. Major sources include cars, trucks, power plants, gas turbines and diesel generators. The pollution can irritate the respiratory system and react with other compounds in the atmosphere to form ground-level ozone, commonly called smog.
What the panel is reviewing
The Clean Air Act requires the EPA to periodically review the science and national standards for six widespread air pollutants, including nitrogen dioxide.
The committee is reviewing the EPA’s draft Integrated Science Assessment for oxides of nitrogen. The document brings together evidence from epidemiological research, controlled human-exposure studies and animal studies.
Costa said the latest research generally reaffirms the known health effects and indicates some can occur at lower concentrations than previously understood.
The committee will not set a new pollution limit during this week’s meeting. Its members can recommend changes to the scientific assessment and later advise the EPA administrator on whether the existing standard should remain the same or be revised. The administrator makes the final decision.
Costa said the process has historically provided a rigorous, independent review of the evidence.
“When these standards are established, they’re really solid,” Costa said. “That’s as long as the footing isn’t a political footing, in which case it gets a little soggy.”
Costa raised concerns about the makeup of the newly reconstituted committee. He said the panels were traditionally composed largely of independent, academic scientists representing fields such as epidemiology, medicine, toxicology and exposure science, with occasional representatives from industry or state agencies.
He said the selection process has become increasingly political under recent administrations, potentially leaving gaps in the expertise needed to evaluate complex health research.
“Over the last 15, 20 years, it’s gotten politically soiled, where people come in with agendas,” Costa said.
The data center connection
Computer servers do not directly produce significant nitrogen oxide pollution. The concern comes from the energy infrastructure that is used to power data centers.
Large campuses can rely on hundreds of diesel generators for backup power, while some projects use or propose on-site natural gas turbines. Data centers also draw enormous amounts of round-the-clock electricity from the grid.
If utilities meet that demand by running coal- or gas-fired plants more often, delaying plant retirements or building new fossil-fuel generation, NOx emissions could increase near those facilities and downwind.
“If you’re generating it all in high concentrations locally, there’s going to be a potential health consequence,” Costa said.
Costa said short bursts of high emissions could be especially important because the health effects of nitrogen dioxide can be driven by peak concentrations. That raises questions about what could happen when multiple backup generators run or undergo testing at the same time.
The Environmental Protection Network, a group of former EPA employees, highlighted those concerns in a report released this month. It found pollution linked to data centers can affect communities near the campuses, near the power plants supplying their electricity and farther downwind.
Costa said regulators should conduct air-quality modeling and testing before the facilities begin operating.
“We don’t know what’s going to happen with these centers, how they’re going to be run, and what the impacts are going to be,” Costa said.
How to attend or comment
The public meeting runs from 9 a.m. to 5 p.m. Wednesday, Sept. 16, and from 8:30 a.m. to 2 p.m. Thursday, Sept. 17, at the Raleigh Marriott Crabtree Valley, 4500 Marriott Drive.
The meeting is also being streamed online. Registration information and meeting materials are available through the EPA’s Clean Air Scientific Advisory Committee website.
The deadline to register to deliver an oral statement has passed. The EPA says it will continue accepting written statements throughout the advisory process, although the agency requested submissions by Sept. 2 for timely consideration at this week’s meeting.
Written comments may be emailed to the committee’s designated federal officer, Aaron Yeow, at yeow.aaron@epa.gov. The EPA advises commenters that personal contact information included in a submission may be posted publicly.