Evaluation of Occupational Mercury Exposure in Ukraine. Sciences International participated in an evaluation of mercury exposure at a mercury recycling plant in Gorlovka, Ukraine. Workers at the facility were interviewed as to occupational and personal history. Blood, urine, nail, and hair samples were collected from the participants and analyzed for mercury at the U.S. Armed Forces Institute of Pathology. Environmental samples (dust, soil, water) were also collected and analyzed by the U.S. Geological Survey. Sciences has analyzed the results of the blood and urine analyses by occupational classification and other variables which could affect urine and blood mercury (e.g., fish consumption, presence of dental amalgams, tattoos). The results have been presented at several scientific meetings including the 2006 meetings of the International Society of Metal Ions in Biology and Medicine in Lisbon, Portugal, the 8th International Conference on Mercury as a Global Pollutant in Madison, Wisconsin, and the International Society of Environmental Epidemiology in Paris, France.

West Louisville Air Toxics Study (WLATS). The Louisville Metro Air Pollution Control District, the U.S. EPA, the Commonwealth of Kentucky, and the West Jefferson County Community Task force are in the process of conducting an air monitoring study of toxic air pollutants in the West Louisville, KY area. The purpose of the study is to determine if residents of the area are being exposed to airborne concentrations of toxic air pollutants via inhalation that may pose unacceptable risks to human health. Sciences International has conducted risk assessments of the air monitoring data from 2000-2005 collected in the WLATS. Exposures via inhalation were evaluated, with risks calculated on a location-specific basis for individuals that may reside within each of the WLATS monitoring areas. Both chronic (long-term) and acute (short-term) exposures were evaluated. The chronic exposures assumed an individual was exposed to the air concentrations continuously for 24 hours per day over a 70-year period. For the acute risk assessment, maximum air concentrations at each monitor location were compared to the toxicity criteria to determine the potential human health impact.

Peer Review of Proposed Framework for Calculating the Plausible Maximum Estimate of Consumer Exposure to Substances on Canada's Domestic Substances List. The Health Canada Framework provides a methodology for ranking consumer exposure for approximately 23,000 substances on the Canadian Domestic Substances List (DSL). The methodology includes an extensive range of algorithms to estimate exposures for consumer products in 17 product categories, 56 product sub-categories, and 220 different exposure scenarios. Sciences International provided Health Canada with a peer review of the framework addressing four major topics: (1) scenario selection, (2) evaluation of exposure algorithms, (3) exposure factor assumptions, and (4) ground-truth of the exposure tool.

Multi-Pathway Risk Assessment. Sciences International conducted a multi-pathway risk assessment in response to public health concerns regarding emissions at a cement facility and as a supplement to the cement corporation’s petition to the State of Pennsylvania for expanding the burning of liquid-hazardous waste fuels in their cement kiln. Sciences had a dual role, both as potential expert witnesses should a plaintiffs' case be filed and as the expert multi-pathway risk assessors for the State permit application. The complex multi-pathway risk assessment which was performed involved indirect exposure pathways including dairy products, poultry, pork, beef, and fish. The results showed very low health risk. The State of Pennsylvania risk assessors were complimentary of the detailed risk assessment performed by Sciences. Subsequently, our experts presented the results of the risk assessment to the citizens of the community. The plaintiff cases were not brought forward, and the facility obtained its permits for increased hazardous waste fuel usage.

Petroleum Products. Sciences has conducted detailed risk assessments of leakage of petroleum products from underground storage tanks including the soil-gas transport to ambient air and to homes and businesses. Benzene has been a major subject of the analyses. Through a dispersion modeling analysis for a case in New York, we found that the levels of benzene were too low to pose a hazard. In a case in South Carolina, the vadose zone transport of petroleum products, particularly benzene, was found to be minimal thus contributing very low risk to residents.