Natural Attenuation Potential of Vinyl Chloride and Butyl Acrylate Released in the East Palestine, Ohio Train Derailment Accident

The
East Palestine, Ohio train derailment released toxic
vinyl
chloride (VC) and butyl acrylate (BA), which entered the watershed.
Streambed sediment, surface water, and private well water samples
were collected 128 and 276 days postaccident to assess the natural
attenuation potential of VC and BA by quantifying biodegradation biomarker
genes and conducting microcosm treatability studies. qPCR detected
the aerobic VC degradation biomarkers etnC in ∼40%
and etnE in ∼27% of sediments collected in
both sampling campaigns in abundances reaching 105 gene
copies g–1. The 16S rRNA genes of organohalide-respiring Dehalococcoides and Dehalogenimonas were,
respectively, detected in 50 and 64% of sediment samples collected
128 days postaccident and in 63 and 88% of sediment samples collected
276 days postaccident, in abundances reaching 107 cells
g–1. Elevated detection frequencies of VC degradation
biomarker genes were measured immediately downstream of the accident
site (i.e., Sulphur Run). Aerobic VC degradation occurred in all sediment
microcosms and coincided with increases of etnC/etnE genes and Mycobacterium, a genus comprising
aerobic VC degraders. The conversion of VC to ethene and an increased
abundance of VC reductive dechlorination biomarker genes were observed
in microcosms established with sediments collected from Sulphur Run.
All anoxic microcosms rapidly degraded BA to innocuous products with
intermediate formation of n-butanol and acrylate.
The results indicate that microbiomes in the East Palestine watershed
have natural attenuation capacity for VC and BA. Recommendations are
made to improve first-response actions in future contaminant release
accidents of this magnitude.