This story was originally published by the Guardian a nd is reproduced here as part of the  Climate Desk  collaboration. Nearly half of children in the United States are breathing dangerous levels of air pollution, according to a new report, as experts warned Donald Trump’s expansive rollback of protections will make the situation worse. The 27th annual air quality report from the American Lung Association, or ALA, released on Wednesday evaluates pollution across the country by grading levels of ground-level ozone — also known as smog —as well as year-round and short-term spikes in particle pollution, commonly referred to as soot. The report analyzed quality-assured data collected between 2022 and 2024. It found that 33.5 million children in the U.S. — 46 percent of those under 18 — live in areas that received a failing grade for at least one measure of air pollution.…