Beware the potential perils of potting mix

Green thumbs gearing up for a spot of autumn gardening are being reminded to take extra care while handling potting mix.

Legionella longbeachae bacteria is often found in potting mix and can cause the lung infection Legionnaires’ disease if someone inhales dust from contaminated soil.

NSW Health Executive Director Health Protection, Dr Jeremy McAnulty, said gardeners can protect themselves by donning a special P2 mask and gardening gloves, while handling potting mix.

“Wetting the potting mix first also helps prevent any contaminated potting mix dust blowing up into the air and being inhaled,” he said.

“Even if you’ve been wearing gloves, make sure to wash your hands thoroughly with soap before eating, drinking or smoking as the bacteria could still be there.

“Taking these precautions means you can enjoy gardening knowing you’re safe.”

Symptoms of Legionnaires’ disease include fever, cough, shortness of breath, muscle aches, headache, tiredness, loss of appetite and diarrhoea.

There were 81 cases of Legionnaires’ disease from the type of bacteria that can be found in potting mix and soils in NSW last year.

A more common source of Legionnaires’ disease is due to a different strain of bacteria, usually found in contaminated air conditioning cooling systems on large buildings.

Dr McAnulty said as some cooling systems are switched on and off in autumn, building operators need to be especially vigilant keep maintain them well and clean them to stop Legionella pneumophila bacteria building up.

“The pools of water in cooling systems are often at just the right temperature for these bacteria to thrive,” he said.

“Then when a contaminated cooling system is turned back on and off again, the bugs get a jolt and could be released into in the air via water droplets.”

NSW Health last year strengthened the Public Health Regulation to reduce the community’s risk of Legionnaires’, requiring building owners to conduct monthly inspections and tests on cooling towers, notify high levels of Legionella and other bacteria to councils, and develop risk management plans. For more information: