The goals of environmental protection are akin to those of the National Park Service, but are more broad-based. The principle of precaution holds that every effort should be made to avoid causing harm. Another key principle is the polluter pays principle, which states that the party that causes pollution should pay to clean up afterward. The public right to know principle is concerned with protecting public health. The ultimate goal of environmental protection is to preserve human health. The EPA's mission extends beyond safeguarding the natural environment. In 2004, the EPA formed the National Homeland Security Research Center to conduct research relating to homeland security. Among other things, the EPA's Homeland Security Research Program aims to provide science and technology necessary for responding to natural disasters. This research program will help the United States to protect its environment and prevent future catastrophes. There are a wide range of benefits to these programs. In addition to its domestic mission, the EPA also has a role in addressing homeland security concerns. Through legislation, the EPA is charged with enforcing several laws and regulations on air, water, and toxic substances. In the US, the EPA is a federal agency that administers legislation on environmental protection. Its responsibilities are detailed in the Environmental Protection Act, the Clean Water Act, and the Clean Air Act. The EPA's laws have led to significant advances in the field of environmental protection.