This spring, scientists at the Environmental Protection Agency completed a report on the toxicity of a “forever chemical” called PFNA, which is in the drinking water systems serving some 26 million people. The assessment found that PFNA interferes with human development by causing lower birth weights and, based on animal evidence, likely causes damage to the liver and to male reproductive systems, including reductions in testosterone levels, sperm production and the size of reproductive organs.

The report also calculated the amount of PFNA that people could be exposed to without being harmed — a critical measurement that can be used to set limits for cleaning up PFNA contamination in Superfund sites and for removing the chemical from drinking water.

For months, however, the report has sat in limbo, raising concerns among some scientists and environmentalists that the Trump administration might change it or not release it at all.