AUSTIN (CBSDFW.COM/AP) – A new report by a federal environmental watchdog raises questions about public health assurances made after Hurricane Harvey slammed into the Texas coast in 2017.

The Environmental Protection Agency’s inspector general says in a report released Monday that limited data was used to make air quality assessments after the Category 4 storm unleashed an environmental assault to America’s largest corridor of petrochemical plants.

The report supports findings by The Associated Press and Houston Chronicle last year that revealed a far more widespread toxic impact than authorities had publicly reported.

Some 500 chemical plants, 10 refineries and more than 6,670 miles of intertwined oil, gas and chemical pipelines line the nation’s largest energy corridor.

Nearly half a billion gallons of industrial wastewater mixed with storm water surged out of just one chemical plant in Baytown, east of Houston on the upper shores of Galveston Bay.

Benzene, vinyl chloride, butadiene and other known human carcinogens were among the dozens of tons of industrial toxins released into surrounding neighborhoods and waterways following Harvey’s torrential rains.

In all, reporters catalogued more than 100 Harvey-related toxic releases in 2018 — on land, in water and in the air. Most were never publicized, and in the case of two of the biggest ones, the extent or potential toxicity of the releases was initially understated.

Only a handful of the industrial spills were investigated by Texas and federal regulators, reporters found.