Environmental Issues Breakfast | April 10, 2019
ENVIRONMENTAL ISSUES BREAKFAST
WEDNESDAY, APRIL 10, 2019
7 AM Registration | 7:30-9 AM Program
A Serving of Arsenic and New Lace: Scientific Developments Related to Arsenic Risk Assessment
Joyce Tsuji, Ph.D., DABT, Fellow ATS, Principal Scientist, Exponent
Human exposures to arsenic are common from various industrial and natural sources. Regulations focus on the more toxic inorganic form (without carbon) of arsenic that is found in air, water, and soil. Inorganic arsenic has also been targeted for regulation in foods. Typical exposures to inorganic arsenic from food are lower than from water at the current drinking water standard for arsenic (10 parts per billion); whereas, exposures to arsenic in soil are even less than from food. Inorganic arsenic is a known human carcinogen at high doses, and the U.S. Environmental Protection Agency has been re-assessing the carcinogenicity of arsenic for the past several decades. While previous updates and draft assessments have assumed that any exposure confers some risk of cancer; it has long been theorized that arsenic has a threshold dose for oral exposure, below which there would be no increased risk of cancer. Considerable scientific evidence, as will be discussed, now supports conclusions on the process of how arsenic causes cancer, depending on the dose, and suggests a threshold level for arsenic in drinking water.
Dr. Joyce Tsuji is a board-certified toxicologist and a Fellow of the Academy of Toxicological Sciences. She specializes in assessing exposure and risks associated with chemicals, and in communication of scientific issues. She has worked on projects in the United States and internationally for industry, trade associations, U.S. EPA, state agencies, the U.S. DOJ, the Australian EPA, municipalities, and private citizens. She has designed and directed dietary and environmental exposure studies and community programs involving health education and biomonitoring for populations potentially exposed to chemicals in the environment, including soil, water, and food-chain exposures. She has also assessed exposure and health risks associated with chemical exposures from air, foods, medical devices, and a variety of consumer products, including those containing nanotechnology or nanomaterials. Dr. Tsuji regularly serves on expert panels on toxicology and health risks issues for the National Academy of Sciences/National Research Council (including their Board on Environmental Studies and Toxicology), Institute of Medicine, and federal and state agencies.