Public health is the science and practice of protecting and improving health through research, monitoring, prevention, education, disease control, sanitation, and advocacy. It also refers to the collective personal health of a population. As examples, the field of Public Health considers air and water quality, vaccinations, transmission of communicable diseases, access to health care, environmental conditions, and health behaviors such, as diet, physical activity, drug and tobacco use. Public health researchers examine how these kinds of factors may impact acute and chronic disease and disability, while Public health practitioners attempt to actively promote and facilitate improved health outcomes. At the forefront of the field, UC San Diego Public Health faculty are also engaged in activities such as leveraging wireless and mobile technologies to improve health, and researching the public health effects of climate change.