Preparation of Concise International Chemical Assessment Documents (CICADs). This work is done for the International Program on Chemical Safety of the World Health Organization. Concise International Chemical Assessment Documents (CICADs) provide internationally accepted reviews on the health and environmental effects of chemicals or combinations of chemicals. The purpose of the documents is to characterize chemical hazard and dose response and to provide examples of exposure estimation and risk characterizations at the national or local level. The documents summarize the information considered critical for risk characterization in sufficient detail to allow independent assessment but are concise in not repeating all the information available on a particular chemical.

Review of Toxicity Reference Values and Exposure Characterization for Chemicals to Support the Development of Health-based Toxicity Reference Values. This work was performed under a contract with the Ministry of the Environment of Ontario. The goal of the project was to provide background information and research on a group of environmentally-relevant chemicals for the purpose of developing health-based toxicity reference values. Toxicity reference values are doses of a chemical at which humans can be exposed for a specified period of time without adverse health effects. The Ministry of the Environment developed an AMD Framework (Adopt-Modify-Develop) for selecting toxicity reference values for deriving health-based standards and for use in site-specific risk assessments. This framework provided the Ministry with an international database of toxicity reference value information to determine if existing toxicity reference values could be adopted or modified, or had to be developed de novo.

Risk Assessment: Chromium. Dr. Gibb, the president of Tetra Tech Sciences, is the author of the most detailed study of lung cancer and clinical irritation among occupationally-exposed chromium workers ever conducted. The study was used by OSHA in 2006 to establish a new Permissible Exposure Limit (PEL) for hexavalent chromium; Dr. Gibb was invited as the first witness at the OSHA hearings on the proposed PEL in 2005. Dr. Gibb also provided peer review of the December 2004 New Jersey Chromium Workgroup Report which evaluated risks from chromium in soil.

Asbestos. Asbestos was once commonly used throughout the world for its fire-proofing abilities. Over 40 years ago, however, asbestos was found to be associated with a number of lung diseases, including asbestosis, lung cancer, and mesothelioma. Sciences International has evaluated asbestos risk associated with air releases from industrial facilities and soil contamination at sites where asbestos has been used and assessed risk from consumer products which historically included small amounts of asbestos.

Evaluation of Occupational Mercury Exposure in Ukraine. Sciences 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.