ROSELAND (La. Illuminator) — Seafood tissue samples taken from the Tangipahoa River last month contained harmful levels of arsenic in five of the 13 samples tested, the Louisiana Department of Environmental Quality reported.

It’s the latest update from state officials on the river’s health after the Aug. 22 fire and explosion at the Smitty’s Supply Inc. petroleum products facility in Roseland. The industrial disaster coated nearby homes and businesses with oily soot, while huge tanks filled with automotive oils and fluids spilled into the river and adjacent ponds. Cleanup efforts have collected 11 million gallons of liquid waste, according to state estimates. 

The state made its seafood test findings public late Friday in a news release, explaining Wildlife and Fisheries officials collected samples from fish, shrimp and crabs from the river as well as similar catch from Bayou Lacombe 40 miles away for comparison. 

The samples were taken Sept. 16-23 and submitted to the Louisiana Department of Health for testing. 

“With the exception of arsenic, no contaminants detected in seafood samples from the Tangipahoa River were present at levels expected to pose harm to public health,” the LDEQ statement said.

The agency explained further its analysis did not differentiate between organic and inorganic arsenic, the former being far less toxic. A 2016 study from the National Institutes of Health found human exposure to organic arsenic is most common through eating seafood though it is generally nontoxic.

Inorganic arsenic, when the heavy metal element combines with carbon or other materials, has been linked to different types of cancer and nerve damage. Exposure to this form is most common from drinking water contaminated with industrial products, according to the American Cancer Association. Fertilizers are also a recognized source of inorganic arsenic. 

State officials also pointed out there is already a state health advisory against eating fish from the Tangipahoa River for mercury levels that dates back to 2003. It covers black drum, bowfin, crappie, flathead catfish, freshwater drum, largemouth bass, red ear sunfish, rock bass, smallmouth buffalo and spotted bass.      

Earlier Friday, the Department of Environmental Quality and parish officials reopened a small lower stretch of Tangipahoa River to maritime traffic, though upper portions remain closed as cleanup crews continue to deploy spill containment booms.