Shortly after President Trump’s election but before his formal inauguration, a Centers for Disease Control and Prevention agency focused on conducting research to improve workers’ health watered down a website on climate change’s contributions to occupational hazards, a new report has revealed.

The National Institute for Occupational Safety and Health’s “Occupational Safety and Health and Climate” page had its name changed, so as to remove the phrase “climate change,” sometime on or after Nov. 14, 2016, according to a report by the Environmental Data and Governance Initiative. The old name was “Climate Change and Occupational Safety and Health.” Multiple other removals of the phrase “climate change” occurred at or around the same time.

It’s unclear why the changes were made. In a statement, the CDC described the changes as “planned updates.”

The Trump administration has de-emphasized climate change and has scrapped some Obama administration programs, but the changes were made before President Trump took office, meaning his team would not have been in a position yet to change an agency website.

Some suspect, however, that the changes were made by agency employees looking to keep the Obama-era, climate-focused program below the radar and avoid drawing a new president’s ire.

“What they’ve done is, they’ve tried to curtail the language and keep their heads down so they can continue doing the work they want to do,” said Jason Glaser, co-founder of La Isla Network, a group that tries to protect outdoor agricultural workers from kidney conditions tied to working in high heat. “To me, that’s a war of attrition, and eventually you lose.”

Asked about whether the changes were made in anticipation of the Trump administration’s skepticism of climate-change-related programs, NIOSH spokeswoman Christina Spring also said that given the agency’s focus, the term “climate change” could be confusing since that’s not what NIOSH focuses on.

“The use of the term ‘climate change,’ which is typically used to discuss research into factors that may be affecting the environment, can be confusing to audiences when discussing NIOSH efforts because it is not the focus of our Institute’s research,” Spring said in a statement. “The change in terminology to climate conditions clarifies that NIOSH is looking at how climate conditions in general can affect worker safety and health.”

Other examples of such re-branding following Trump’s election have been seen at a variety of agencies, including the Department of Energy and the Department of Transportation.

“The use of vaguer terms to obfuscate online emphasis on climate change is among the first instances to occur during the past presidential transition,” said Justin Derry, member of the Environmental Data and Governance Initiative’s website monitoring team, in a statement.

“Because the website was altered before inauguration, it’s possible the decision was made by career staff anticipating the incoming administration’s new priorities, although communication by Obama administration staff or by incoming Trump administration transition teams cannot be ruled out,” he continued.

Heat’s dangerous impact on workers

The National Institute for Occupational Safety and Health, or NIOSH, is a $338 million agency that conducts research to improve the safety of workers. During the Obama years, it developed a working group to study climate change “and develop an action plan to ensure NIOSH is proactively addressing this topic.” It’s an area, the agency said then, where there is a large need for research.

Workers are on the front lines of climate change because they are often toiling outdoors and so are exposed to the elements, including heat extremes. Certain types of work, such as wildland firefighting, might also be growing more physically dangerous as the climate changes.

It isn’t clear exactly when the NIOSH climate change website first launched, but in a September 2014 blog post that contains similar content (and can still be found on the NIOSH site), four agency experts announced the working group and called climate change “one of the most visible environmental concerns of the 21st century.” They also linked to the site — which they called by its older name, the “Climate Change and Occupational Safety and Health” page. The first instance of the page recorded by the Internet Archive dates a little bit later, to February 2015.

This means the changes in question, which took place in late 2016, may represent the site’s first major edit.

The site’s landing page, as of Nov. 14, 2016, began as follows: “Climate change is any significant variation in temperature, precipitation, wind, or other type of weather that lasts for decades or longer. These changes have the potential to affect human health in several direct and indirect ways.”

But by Dec. 25, 2016, if not earlier, that had changed to “Variation in temperature, precipitation, wind, or other type of weather have the potential to affect human health in several direct and indirect ways.” Two other uses of the phrase “climate change” also vanished from the entry page at that time (not including the change to the page’s title).

Meanwhile, sometime between Oct. 16 and Dec. 16, 2016, an extensive sub-page detailing the impacts of climate change on workers was edited to remove no less than 15 mentions of the phrase “climate change,” often substituting instead the word “climate” or other formulations, such as “climate conditions” or “climate variations.”

In other cases, language shifted to de-emphasize the concern that an overall global-warming trend is causing extreme weather events or other present-moment changes of concern to workers.

For instance, the page had previously stated that “extreme weather events or natural disasters such as floods, landslides, storms, lightning, droughts, and wildfires are becoming more frequent and intense. Weather disasters may be associated with deaths, injuries, diseases, and mental stress. Workers involved in rescue and cleanup have more exposure to risky conditions as the frequency and severity of extreme weather events increase.” (emphasis added)

By contrast, the current page states that “extreme weather events or natural disasters such as floods, landslides, storms, lightning, droughts, and wildfires are associated with occupational deaths, injuries, diseases, and mental stress. Workers involved in rescue, cleanup, and restoration are exposed to hazardous conditions during and after extreme weather events.”

The agency countered that the site changes were routine.

“These were planned updates as the original working group that created the content on those pages had completed their work in 2015 and the information needed to be updated to reflect current information,” said Christina Spring, a NIOSH spokeswoman, by email. “We routinely go through our website and update content on a variety of topic pages.”

Max Kiefer, a former senior scientist at NIOSH who is now retired but worked closely on its climate initiative, said he was not involved in the actual edits but doesn’t think they came as a Trump directive.

“I’m not aware of any edict that came down from the new administration to make any changes,” Kiefer said. “It was up for a regular update.”

Because of the timing of when the sites were sampled by the Internet Archive, the Environmental Data and Governance Initiative could only confirm that the NIOSH landing page was changed after Trump’s election. For the more detailed page, it could have been changed at any time between Oct. 16 and Dec. 16, 2016, leaving a possibility the editing occurred before the 2016 election (which was on Nov. 8).

The page itself says it was last updated on Dec. 6, 2016.

Removing ‘change’ from ‘climate change’

Several experts differed on what to make of the changes — saying they amount to a subtle reframing without introducing any obvious inaccuracies or change in mission.

“My impression would be that they’ve done a careful job of removing the administration’s buzzwords, but not really changed the content substantially,” said David Wegman, an emeritus professor of work environment at the University of Massachusetts at Lowell.

Kiefer agreed in an email. “I guess I don’t see that the changes make much, if any, substantive difference from the previous version other than the word ‘change’ was removed and think any reader would recognize that the purpose of the page is to highlight issues regarding climate, including climate change, on workers,” he wrote.

But another expert focused on climate change and workers disagreed.

“It’s clear the world is getting hotter, it’s clear the recovery temperature at night is getting warmer . . . and it’s having very clear outcomes like kidney failure and outright heat stroke,” said Glaser, of La Isla Network, which is dedicated to battling a condition called chronic kidney disease of unknown etiology, which is believed to be tied to labor conditions and in particular to afflict outdoor agricultural workers exposed to high levels of heat and dehydration.

“And if you can’t have a conversation about these things based on the data, using the terminology that we’re familiar with, then eventually you can’t even ask for the funding to continue it. And that’s going to have a real cost.”

The changes parallel other moves at the CDC to proceed cautiously on the subject of climate change in the Trump era.

Shortly before Trump’s inauguration, the CDC also canceled a conference on climate change and public health that had been planned for early 2017. And as recently as last month, the agency showed a hesitancy to talk plainly about climate change.

In early May, the CDC released a report showing that Americans are suffering from a major increase in vector-borne diseases carried by organisms such as ticks, fleas, and mosquitoes. During the news briefing, journalists asked about the role of human-caused global warming in helping these diseases to be able to spread to new areas.

“I can’t comment on why there is increasing temperatures,” said Lyle Petersen, a scientist who heads the agency’s Division of Vector-Borne Diseases, in response. “That’s the job of meteorologists.”