The activities of the Gulf study participants responding to the Deepwater Horizon oil release in the Gulf of Mexico in 2010 were studied. The process of developing job exposure matrices (JEM) of exposure group/location/time period combinations to link inhalation and dermal exposures to the participants was investigated. JEM of inhalation and dermal exposure estimates were developed for total hydrocarbons for unique exposure group/vessel/time period combinations. The subjects performed various activities at multiple locations that resulted in different levels of inhalation and dermal estimates. These estimates will be used in the evaluation of exposure-response relationships in the epidemiologic study.