Why 'irresponsible' dumping of mercury caused evacuations in outback town

Responders have used atmospheric testers to detect mercury vapour. (Supplied: Queensland Fire Department)

Authorities have spent days combing through suspected contamination sites in a remote Queensland town after students found mercury at the tip.

A researcher says it was irresponsible to dump the vials there due to the metal's health effects.

Instead, the disposer should have contacted authorities or the local council for advice on what to do with it.

It was an unusual sight for the outback Queensland town of Cunnamulla as evacuation areas popped up manned by scientific officers wearing full-body protective suits with breathing tanks.

It was in response to students from the town, about 790 kilometres west of Brisbane, finding vials of mercury at the local tip last Sunday.

The following day, the children decided to bring the toxic element to school, where staff immediately raised the alarm.

Queensland Fire Department scientific officers travelled from Brisbane, Toowoomba and Rockhampton. (Supplied: Queensland Fire Department)

Specialist crews followed, working long hours to conduct testing at potential exposure sites, which included nine homes, a service station and a hospital waiting room.

Mercury is unusual because it stays as a liquid metal at room temperature.

Sustainable Minerals Institute researcher Barry Noller said when found, it often captured the attention.

"Because it's a silver-coloured liquid, if children get hold of it, it's something that fascinates them," Dr Noller said.

"They're likely to want to hold it, pour it between their fingers."

Besides its behaviour, mercury is also an electrical conductor found in old lamps, thermometers and LCD screens.

Different forms of mercury can be absorbed through the skin, inhaled or ingested, but the severity of mercury poisoning can vary.

Authorities evacuated nine Cunnamulla residences for careful testing. (Supplied: Queensland Fire Department)

Darling Downs public health registrar John Ngo said if exposed to a large amount of mercury, a person may feel symptoms almost immediately.

They include shortness of breath, a rash or gastrointestinal reactions.

A south-west Queensland town's school, service station, hospital waiting room and several homes are closed for testing after children found liquid mercury vials at the tip and took them to school.

But if exposed to small amounts over a longer period of time, Dr Ngo said mercury could deliver a more "insidious" form of poisoning.

"Some things you might see are changes in behaviour, numbness or tingling, or muscle weakness or headach