Garden centres are updating safety advice to customers after a cluster of legionella cases linked to the use of compost in Scotland.
This month, five people – four in Lothian, one in Tayside – have fallen ill with legionella longbeachae, a form of Legionnaire’s disease linked to compost.
NHS Lothian is investigating.
Dobbies is among those which have updated advice but has pointed out that no source of the problem has yet been found.
A Dobbies representative said: "Dobbies is committed to offering our customers the best possible advice and we would recommend the public follow advice from the health board while doing any form of gardening. There are customer notices in all our garden centres displaying NHS advice on the recommended safe use of compost."
Homebase is also monitoring the situation: "Our growing-media suppliers are members of the GMA [the Growing-Media Association] and are in direct contact with the investigations team in Scotland.
"The GMA has offered advice and support to the investigation into the recent incidents. We fully support the advice being given by the Horticultural Trades Association and bags of our own-brand growing-media carry on-pack advice to wear gloves when handling the product and wash hands after gardening activity."
Symptoms include headaches, diarrhoea or a dry cough followed by pneumonia. Treatment is with antibiotics.
To reduce the risk, gardeners should wear gloves and a dust mask, wash hands after use and open bags in a well-ventilated area.
Dr Martin Donaghy, medical director at Health Protection Scotland, said: "While the risk of becoming unwell from gardening activities – such as working with compost – remains very low, we would recommend good hygiene in relation to gardening and, particularly, dealing with compost, potting mixes, mulches and soils."