Potting mix dangers need greater public warning, researcher says

‘‘SOMETHING desperately needs to change’’ to improve potting mix warning labels, because many people fail to grasp the health dangers, a University of Otago researcher says

For her MSc research thesis in psychology, Catherine Thomas studied warning labels on potting mix and bleach and asked 100 people about their understanding of the labels and underlying health risks.

She hoped her research would raise awareness of the ‘‘major problem’’ arising from the threat of contracting Legionnaires’ disease from potting mix.

The disease is an acute atypical pneumonia is caused by becoming infected by Legionella bacteria.

‘‘We have one of the highest rates [of the disease] in the world.’’

She had surveyed 100 people, mostly in Dunedin, comprising younger (aged 1835) and older groups (6084), and about 75 of those people had little knowledge of the disease.

Her research suggested that ‘‘something desperately needs to change’’ to cut the number of disease cases.

A 77yearold Christchurch man died last month from complications arising from Legionnaires’ disease after handling potting mix, she said.

Gardeners using the mix are advised to take several precautions, including wearing a face mask and gloves, not opening the mix in confined areas, and washing hands.

She believed that commercial gardeners understood the risks.

But for other users there was no ‘‘statutory requirement’’ to put warnings on mix packets, and the most common ‘‘industrytype labels’’ did not cater specifically for the home gardener.

One such label was ‘‘just a big mass of text that nobody is going to bother reading’’.

She had designed a simplified label warning about specific risks, including of compost, and protective measures.

‘‘Inadequate’’ labels should be improved, and consideration given to mandatory labelling, she said.

Legionnaires’ disease cases have risen sharply in this country, from about 60 laboratory-reported notifications in 1997 to 247 cases in 2016, of which 205 (85%) resulted in hospital admissions.