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Public health risks

A public health risk  is something that is likely to be harmful to human health or contribute to disease in humans, such as germs carried by rats, mice and mosquitoes. Harmful germs came can also be transmitted from  waste, water, dead or living animals and harmful substances in the environment.


Most public health risks are controlled by local governments, although both state and local governments can work together to reduce, control or prevent these risks to public health. If a person is causing or contributing to a public health risk, they may be ordered to fix the problem.

Public health risks may also be controlled by making standards or rules for things (e.g. permits for animals, pest proofing standards for buildings). Inspections can be performed to make sure the standards are being followed.

Programs may be carried out to prevent or control a plague of rats, mice and mosquitoes and other designated pests, or an outbreak of disease in humans caused by such pests. These programs will be advertised to the public and may include things such as mosquito eradication programs.


If an event occurs whose effects would have serious long term harmful effects for human health, the government can set up a register for the event. This register would gather information from people who have suffered health effects from the event. The information would be used to help monitor effects on human health and prevent or minimise any negative health effects from that or a similar event.

More information

Environmental Health Risk Assessment (PDF, 6MB) Guidelines for assessing human health risks from environmental hazards

Last updated: 16 February 2023