23 October 2008
Gardeners Reminded to Take Precautions When Using Potting Mix
The Ministry of Health is reminding gardening enthusiasts about the dangers of using potting mix without taking the
necessary precautions following the recent increase in case numbers for legionellosis (also known as Legionnaire?s
disease) over the past two to three weeks.
The Ministry's Acting Chief Advisor, Population Health, Dr Richard Hoskins is urging all gardeners, amateur or
professional to heed the warnings as set out on sacks of potting mix and when working around commercial compost
stockpiles in order to minimise the risk of contracting this serious disease. The same care should be taken when
handling ?home made? compost, because legionella can thrive in compost bins.
Since September this year, there have been three cases in New Zealand of legionella longbeachae, the type most commonly
associated with potting mix or compost.
?We are making a plea for people getting out into the garden to be extremely careful? said Dr Hoskins.
Legionella longbeachae bacteria can be inhaled into the body when potting mix or other compost product is used, leading
to a person developing Legionnaire's disease.
"The disease caused by the legionella bacteria is usually pneumonia but there maybe complications, particularly for
those with existing respiratory illnesses, people with weakened immune systems, smokers, drinkers and the elderly," said
Dr Hoskins.
While found naturally in the environment, legionella bacteria is most commonly contracted by inhaling contaminated dust
or droplets. The disease is not spread from person to person.
Legionellosis causes lung infection or pneumonia. People should be aware of the symptoms of the disease, which include:
· Sudden high temperature and/or fever; · Dry cough; · Loss of appetite; · Shortness of breath; · Chills, muscle aches
and headaches; and sometimes · Stomach pain and diarrhoea.
"Anyone suffering from these symptoms should see their doctor," said Dr Hoskins.
People using potting mix can take a number of simple preventative measures:
· Always wear gloves and a mask; · Take care when opening bags of potting mix and avoid inhaling dust; · Moisten potting
mix before use; and · Washing hands thoroughly after using potting mix.
"Directions on how to reduce exposure to Legionella longbeachae bacteria are written on potting mix packaging. People
should follow these instructions to reduce exposure," said Dr Hoskins.
The New Zealand Standard for Composts, Soil Conditioners and Mulches (NZS 4454:2005) launched on 16 December 2005
provides clear guidance to commercial producers of compost on how to process organic materials into compost in a safe
and effective way. The Standard also includes bag labelling requirements, as well as promoting safe and healthy
gardening practices.
Leaflets outlining health and safety while gardening are available from the Ministry of Health?s website
http://www.healthed.govt.nz and Department of Labour?s website http://www.osh.govt.nz/order/catalogue/62.shtml or
alternatively you can contact your nearest public health service.
ENDS