Public health impacts of gasoline vapor releases from gas stations

2015-2016 E²SHI Seed Grant

Research Team

Markus Hilpert
former Senior Scientist, Department of Environmental Health and Engineering, School of Public Health
Ana Rule
Assistant Scientist, Department of Environmental Health and Engineering, School of Public Health
Keeve Nachman
Assistant Professor, Departments of Environmental Health and Engineering, and Health Policy and Management, School of Public Health
Jian Ni
Associate Professor, Carey Business School

Gas stations significantly contribute to air pollution and can harm human health. Unburned fuel at gas stations contains substantial amounts of toxic and carcinogenic chemicals that are continuously released in the air – usually from refueling vehicle tanks, pipe/hose leaks, and during the process of breathing storage fuel tanks.

To address this environmental and public health problem, Stage II Vapor Recovery was enacted by the Environmental Protection Agency (EPA) to reduce vapors released into the air by collecting vapors released from vehicle tanks. Subsequently auto-manufacturers equipped vehicles with On-Board Refueling Vapor Recovery (ORVR) technology in order to reduce vapor emissions at the source. In 2012, the EPA allowed states to decommission Stage II Vapor Recovery because many modern vehicles already have ORVR systems. However, decommissioning could have significant negative consequences because many older cars, non-road engines, motorcycles, boats, and canisters are still not equipped with ORVR – and unburned gasoline can continue to be released into the environment.

To help develop policy recommendations, researchers Hilpert, Rule, Ni, and Nachman have been determining the severity of gasoline vapor release for different combinations of vapor recovery technologies. They are exploring the efficiency of each vapor recovery technology, the cost-benefit analyses of each strategy, and the associated public health risks. If the cost-benefit analyses show that vapor recovery is profitable, the team hopes such analyses will help to inform gas station owners that using more efficient vapor recovery technologies could be profitable, such as reselling condensed vapor that is recovered. The team ultimately hopes to use their data to advise policymakers on air quality control in Maryland and other states that have been considering waiving the Stage II Vapor Recovery requirements. 


M. Hilpert, B. Mora, A. Rule, and K. Nachman. (2015). "Hydrocarbon Release during Fuel Storage and Transfer at Gas Stations: Environmental and Health Effects," Current Environmental Health, 2: 412-422.


Article: "Tiny Fuel Spills at Gas Stations Can Contaminate Soil." GeoSpace (American Geophysical Union), 17 December 2015.

Article: "Fuel drips at gas stations may add up to big problem, study says." Baltimore Sun, 31 October 2014. 

What is On-Board Refueling Vapor Recovery (ORVR)? (video)

See what happens to vapor emissions due to vehicle refueling without any vapor recovery (video)






Markus Hilpert notes that research indicates gasoline can seep through concrete, probably in vapor form.
Photo credit: Algerina Perna, Baltimore Sun.

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