Toxicology is the study of effects of toxic substances on living systems. These toxic substances can either be organic or inorganic, synthetic or natural materials. As a field of research, it crosses traditional disciplinary boundaries such as chemistry, biology, and the environmental sciences. Environmental toxicology further extends to aspects of chemical transport, fate, persistence and biological accumulation of toxic substances and their effects at the population and community levels. The University of Ottawa and Carleton University offer a collaborative program leading to a Master of Science or PhD degree with Specialization in Chemical and Environmental Toxicology through the management of a committee of representatives from the Ottawa-Carleton Institute for Biology, the Ottawa-Carleton Chemistry Institute and the Ottawa-Carleton Geoscience Centre.