A warning is being issued to gardeners and those working in horticulture about a hidden health danger that can be found in soil and compost.
Spartan Environmental Director Paul Drakeley says people may unknowingly expose themselves to a Legionella strain called longbeachae while tending to plants.
It can lead to Legionnaires’ disease – a severe form of Pneumonia – or the respiratory illness Pontiac fever.
Longbeachae can be found in soil, compost and bagged potting material and is especially dangerous to people with weakened immune systems, smokers or those aged over 50.
Legionella Consultant Paul, a member of the Water Management Society with 37 years’ experience, is issuing the warning now as people prepare to return to their gardens as winter draws to an end.
And he’s also urging people to stay alert to the more well-known water borne variant of Legionella (pneumophila) as it can thrive in stagnant water – such as in garden tubs and hosepipes left connected.
Paul, whose business is based in Stoke-on-Trent, said: “Gardening is a beloved activity, however, there exists a hidden danger that can be particularly hazardous to the elderly and immunocompromised gardeners—the Legionella bacteria.
“While Legionella pneumophila is the most commonly known strain, the Legionella longbeachae variant poses a unique threat when present in soil and compost.
“These bacteria can cause Legionnaires’ disease, a severe form of pneumonia, or Pontiac fever, a milder respiratory illness.
“Gardeners, especially those with weakened immune systems, smokers, or aged 50-plus, may unknowingly expose themselves to Legionella longbeachae while tending to plants. This variant has been found in soil and compost, raising concerns about the potential for inhalation or ingestion during gardening activities.”
Studies have shown that Legionella longbeachae can survive and multiply in soil, creating a risk of them going airborne when it is disturbed.
For susceptible individuals, the inhalation of contaminated dust or water droplets may lead to respiratory infections.
Paul added: “Legionella longbeachae can be transferred from soil to hands during gardening. If individuals touch their face or consume food without proper handwashing, there is also a risk of ingesting the bacteria.
“Disturbing soil during activities like digging or watering plants or opening bags of potting compost can aerosolize contaminated particles. If all the risks align then inhaling these tiny water droplets or dust can lead to the inhalation of Legionella longbeachae, resulting in respiratory infections.”
He added: “This can affect anyone from amateur gardeners to those working with soil and compost on a day-to-day basis.
“Whilst working outside minimises the risks, they are still there. For instance, opening a sealed bag of compost and shaking it over a flower bed could release those spores into the air and if all conditions fall into place, then you are at risk.”
Paul says specific statistics on Legionella longbeachae cases are limited, but Legionnaires’ disease, caused by various Legionella strains, have been documented in gardening-related scenarios.
A number of people caught Legionnaires’ Disease, including one fatally, linked to the longbeachae strain in Scotland in 2012 and 2013 – all were reported to be keen gardeners using compost.
There were also outbreaks of cases in Australia and New Zealand, where longbeachae was identified as the causative agent – again linked to gardening.
Meanwhile in Cromer, Norfolk, a 63-year-old grandad and keen gardener died just a week after inhaling poisonous Legionella pneumophila spores that had grown in stagnant water located in a hose.
Public Health England’s 2019 figures report 503 recorded cases of Legionnaires’ disease but believe actual numbers could range from 4,000 to 6,000.
The Royal Horticultural Society also warns about the risk of both kind of Legionella variants in their health and wellbeing guide to gardening.
Paul advises that risk can be minimised by following some simple techniques – washing hands thoroughly after gardening and wearing gloves, regularly cleaning and disinfecting water tubs and disconnecting hosepipes and ensuring proper ventilation in indoor garden areas.
