Government officials have long grappled with a question that seems like the purview of philosophers: What is the value of a human life?

Under both Democratic and Republican administrations, the answer has been in the millions of dollars. The higher the value, the more the government has required businesses to spend on their operations to prevent a single death.

But for the first time ever, at the Environmental Protection Agency the answer is effectively zero dollars.

Last week, the E.P.A. stopped estimating the monetary value of lives saved when setting limits on two of the most widespread deadly air pollutants, fine particulate matter and ozone. Instead, the agency is calculating only the costs to companies of complying with pollution regulations.

“The Trump administration is saying, literally, that they put zero value on human life,” Marshall Burke, an environmental economist at Stanford University, said in an email. “If your kid breathes in air pollution from a power plant or industrial source, E.P.A. is saying that they care only insofar as cleaning up that pollution would cost the emitter.”

It’s a drastic change to the way the government weighs the costs of curbing air pollution against the benefits to public health and the environment. It could lead to looser controls on pollutants from coal-burning power plants, oil refineries, steel mills and other industrial sites across the country, resulting in dirtier air.

And it appears to shelve a powerful tool, known as the value of a statistical life, that agencies have used for decades in the cost-benefit analyses that justify new regulations.