Biological effects of inhaled crude oil vapor VI. Altered biogenic amine neurotransmitters and neural protein expression

In the oil and gas industry, workers are potentially exposed to crude oil or crude oil vapor (COV) during upstream (drilling and extraction), midstream (transportation and storage), as well as downstream (refining) activities. Worker exposure to various fractions of crude oil have been linked to mortality, as well as musculoskeletal, respiratory, gastrointestinal, circulatory problems, and cancer. During the Gulf of Mexico Deepwater Horizon (DWH) oil spill, response workers were exposed to a variety of chemical hazards including volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), heavy metals, as well as components of the oil dispersants employed to disperse the oil. The Gulf Long-term Follow-up (GuLF) STUDY had reported that workers involved in the cleanup operations experienced adverse hematologic, pulmonary, hepatic, and cardiac problems. However, long-term neurological effects remain unknown. Health Hazard Evaluation (HHE) surveys conducted by NIOSH among the cleanup workers identified a variety of health effects, including neurological symptoms. Unfortunately, as a significant number of response workers who experienced health symptoms were exposed to both crude oil and the oil dispersant that was aerially sprayed to the contain the spill, the health effects of crude oil exposures alone were difficult to discern from these surveys. It is here that laboratory-based studies are advantageous as they can provide ample health risk information to establish the toxicological potential of the various chemical hazards at the workplace. To that end, the present work evaluated the neurotoxic risks of COV generated from the Macondo well crude oil that was used as a surrogate for the DWH crude oil.