Health Risk Assessment for Radium Discharged Offshore in Produced Water

Abstract

This paper reports on a probabilistic risk assessment of estimated incremental individual lifetime fatal cancer risks to recreational fishermen from radium in produced water discharged by offshore oil production platforms. A direct approach used limited measurements of radium concentrations in fishes caught near three shallow offshore platforms. A predictive modeling approach estimated the range of radium concentrahons in fishes caught near deeper platforms. Estimated risks were described as probability distributions. Median predicted risks associated with shallow offshore platforms, representing worst-case conditions, were always less than 1 x 10-5. Median risks for platforms in deeper water were always less than 3 x 10-7.

Produced Water in the North Sea: a Threat for the Environment or a Threat for the Industry?

“…On the whole, the data presented in the 1994 report have been confirmed by more recent monitoring and investigation 3,7,15,18,19,39,47,48,57,58,66,68 . The distribution of the principal components of produced water streams were well documented and have been substantiated and confirmed by the more recent data.…”

Risk assessment for produced water discharges to Louisiana open bays. Final report

“…For comparison, risks from ingestion of fish caught away from platforms in the Gulf of Mexico were estimated. Radium concentrations in fish not associated with platforms were assumed to be uniformly distributed, with a range of 0 to 0.01 pCi/g (Meinhold et a/., 1995).…”

Uncertainties in risk assessment at USDOE facilities

“…Uncertainty was specifically identified as a major area of concerr. in a previous report "Lessons learned: needs for improving human health risk assessment at USDOE sites" (Hamilton et a/., 1993~). That report was based 01 a pilot study consisting of two health risk assessments at each of three USDOE sites, as described in the following sections.…”

“…Similarly, ingestion was a major route of human exposure to radionuclides that entered the food chain as a result of fallout from the Chernobyl accident (Cooper et al, 1992;Shiraishi et al, 1992). Finfish were major routes of exposure in an assessment of radium in produced waters from oil and gas wells in the Gulf of Mexico (Meinhold et al, 1993). In the pilot study, meat, dairy products and homegrown vegetables were exposure pathways from groundwater contamination by uranium at the FEMP (Hamilton et al, 1993b), and from soil contamination by plutonium at the NTS .…”

“…assumed distributions of rural residence (averaging 7.8 years) and urban residence (averaging 4.19 years), based on analysis (Israeli and Nelson, 1992) of data collected by the US Department of Commerce (1 988, 1989). Meinhold et al (1993) used a distribution of 1 to 30 years as an occupational span for workers exposed to radium in produced waters on offshore oilfield platforms in the Gulf of Mexico, as opposed to USEPA's default value of 50 years employment for all workers. did similar analyses of residential and occupational durations.…”