U.S. Environmental Protection Agency offers research and educational services. It works to protect human health and environment in the United States. The agency conducts a variety of monitoring, standard-setting and enforcement activities. It conducts research on issues such as, drinking water, land, global changes, and pesticides and toxic substances. U.S. Environmental Protection Agency offers the Chesapeake Bay and Long Island Sound programs. The agency operates the Office of Air and Radiation, Office of Environmental Information, Office of Enforcement and Compliance Assurance, and Office of Research and Development. It maintains over 5 regional offices and nearly 12 labs. U.S. Environmental Protection Agency employs more than 15,000 people.