An independent report released Wednesday morning looking at the air quality concerns following the train derailment in East Palestine shows that concentrations of some gases rose of above normal baselines, according to the American Chemical Society (ACS) report.

The ACS’ Environmental Science & Technology report found that some gases, including acrolein, reached levels that could be hazardous.

To determine the findings in the report, Dr. Albert Presto of Carnegie Mellon University and his colleagues from ACS downloaded air-quality monitoring data from two U.S. Environmental Protection Agency (EPA) stations at fixed locations. They drove a monitoring van, capable of identifying a wide array of gases, around the region for two days in late February and then calculated the health risks if the gases that were above average or background levels.

According to the report, it determined that the levels of nine of the 50 gases initially rose above their normal baselines, especially acrolein, a respiratory irritant.

The report stated that if these nine compounds remained at those elevated levels, the ambient air could have posed health risks.

However, throughout February, the report showed that the amounts of many pollutants decreased significantly.

Vinyl chloride declined to concentrations below long-term limits of health concern.

The report showed that mobile monitoring detected changes over time and space that the stations could not. The report indicated that during the day, acrolein and butyl acrylate were up to six times higher near ground zero than background levels, but during the evening, dropped to the background amount.

The reporter said that the results indicate the importance of complementary stationary and mobile air-quality assessment techniques, the researchers say, and both should continue as cleanup activities proceed.