NIOSH Research Rounds

Laboratory Studies Focus on Exposures Associated with Oil and Gas Operations

During the 2010 Deep Water Horizon oil spill, clean-up workers reported symptoms such as breathing difficulty, headache, and nausea and the health effects associated with mixed exposure to crude oil, dispersant, and combustion products were unknown. From existing data, we don’t know whether or to what extent the symptoms were associated with emissions from the crude oil itself, how long they might persist, and whether these acute symptoms signal risks for other effects that may take years to become apparent These are important questions for protecting responders in any future, large-scale emergencies like Deep Water Horizon, for monitoring long-term risk from past exposures, and for understanding the implications for workers who may be exposed to airborne emissions from crude oil in extraction and production.

To fill this critical knowledge gap, researchers at the National Institute for Occupational Safety and Health (NIOSH) launched the first study of its kind to investigate the health effects of breathing in unrefined (crude) oil. Crude oil releases potentially toxic gases and vapors into the air, posing the risk of inhalation. To study the health effects of these gases in controlled laboratory experiments, researchers developed an innovative system that can generate the same type of gases generated during some oil and gas operations. They hope that their findings, expected later this year, will encourage more research in this under-studied area that, ultimately, will lead to improved understanding of potential hazards and protection for oil workers.

Health Effects of Sand (Silica) Dust and Diesel Exhaust in Hydraulic Fracturing Examined

In a separate but related project, NIOSH researchers also are using controlled laboratory experiments to study the potential health hazards of combined occupational exposure to two air contaminants in hydraulic fracturing (“fracking”) operations: silica dust and diesel exhaust. Silica dust may be generated from moving, transporting and refilling thousands of pounds of sand onto and through sand movers in hydraulic fracturing operations, and diesel exhaust is emitted by the generators used to power the equipment used in these processes. Diesel particulate matter has been classified as a possible carcinogen by both NIOSH and the Environmental Protection Agency. (EPA). Silica dust poses an occupational risk for the serious, irreversible lung disease silicosis, and epidemiologic studies indicate that occupational exposures are also associated with an increased risk of developing lung cancer. As the first study of its kind to examine the combined effects of these substances, this research fills a critical gap in our knowledge. The researchers expect to share the results of these investigations sometime next year.