Legionnaires’ disease is a type of pneumonia caused by breathing in the bacteria, with public health recording an increase in notifications linked to soil products each spring.
Medical officer of health Dr Matthew Reid said the illness could be severe, but gardeners could take simple steps to reduce the risk.
“To reduce the risk of breathing in Legionella bacteria, only handle potting and compost mix bags outdoors or in well-ventilated areas, and open them carefully and away from your face.”
Reid recommended wearing gloves and a well-fitting face mask, preferably an N95, dampening soil products to reduce dust and thoroughly washing and drying hands afterwards.
Not everyone who breathes in Legionella bacteria becomes unwell and some people only develop a milder illness called Pontiac fever.
However, people over 50, smokers and those with chronic illnesses or weakened immune systems are more susceptible to the disease.
Symptoms can include a cough, fever, chills, shortness of breath, muscle aches, headaches, nausea, vomiting and diarrhoea.
The illness typically worsens over several days and requires antibiotics, with most cases requiring hospitalisation.
Reid said anyone experiencing symptoms, particularly after using potting mix or compost, should contact their healthcare provider or Healthline.