Toxicology of Oil in Vertebrates

In the eight years since the Deepwater Horizon (DWH) oil spill, scientists have conducted an unprecedented number and variety of laboratory and field studies that documented the toxic effects of oil on Gulf of Mexico resources. Scientists on behalf of natural resource trustees, federal agencies, academics, industry, and others have all contributed to describing the type and magnitude of effects from the oil and dispersant releases across the Gulf and beyond.

The natural resource damage assessment (NRDA) studies alone included testing across multiple taxa including plankton, invertebrates, fish, turtles, birds and mammals, covering a wide range of exposure and stressor scenarios. Looking comprehensively across taxa, NRDA scientists found that many of the toxic effects observed in a given taxa were conserved across resources. For example, respiratory impairment, cardiac disease, reproductive failure, low body weight, and behavioral effects, were observed in multiple vertebrate taxa (e.g., fish, birds, and cetaceans; see attached figure). This ‘constellation of toxic effects’, as described as part of the NRDA’s findings, illustrates our comprehensive understanding of oil impacts to multiple resources indigenous to the Gulf and beyond.

In parallel with the NRDA injury assessment, the National Institutes of the Environmental Health Sciences (NIEHS); various entities studying the Uniformed Services (e.g., the Coast Guard); the Army Corps of Engineers (USACOE); the Centers for Disease Control (CDC); and numerous academic institutions were studying the effects of DWH oil on humans, including response/cleanup workers and impacted communities. These human health assessments likely represent the largest set of studies linking oil spills and human health to date.

Toxicology field and laboratory research on vertebrate species comes with ethical, financial, and logistical limitations. The DWH oil spill offers a unique opportunity to advance the field of oil toxicology at the level of specific physiological systems, so that we can better support the planning for, response to, assessment of, and recovery from future oil contamination events.