The chemicals used by a West Virginia factory to make nonstick products are dangerous at levels the U.S. Environmental Protection Agency had thought were safe, according to a federal study that had been previously blocked from publication.

The federal Agency for Toxic Substances and Disease Registry released the study on PFAS chemicals Wednesday, news outlets reported. It said the chemicals are dangerous at levels around 10-times lower than the EPA’s advised exposure of 70 parts per trillion.

The DuPont Co., which used the chemicals to create nonstick products such as Teflon, now faces thousands of lawsuits from people living near its Parkersburg-area Washington Works plant who say their water was contaminated. The chemicals have been linked to cancer, immune effects and adverse developmental effects on fetuses during pregnancy.

Lawmakers had urged the EPA in May to publish the study after Politico reported it had been blocked. Politico said the Trump administration blocked the study, concerned that it could result in a “public relations nightmare.”

Before it was released, the state’s U.S. senators—Democrat Joe Manchin and Republican Shelley Moore Capito—had urged the EPA to come forward with the study.

Manchin said Wednesday that the study paved the way for “additional steps to address these issues in West Virginia and continue to pursue a definitive rule that sets maximum limits on these chemicals.”

Capito said the report was “critical to ensuring the health of West Virginians.”