Could a seemingly harmless hobby of pottering in the garden be fatal? In some cases it has. With one million adults in the U.S. every year hospitalized with pneumonia and increasing antibiotic resistance of the illness, most people would hope to avoid contracting it. However, one of the less obvious ways pneumonia can be contracted is through the legionella bacteria, and this is where the gardener can fall victim to the deadly illness. Although cases are rare, the high mortality rate associated with pneumonia, particularly for those with weakened immune systems such the young, the frail and the old, means that this risk should not be overlooked.
What are the Risks?
There are two main sources of legionella in the garden; standing water sources and compost. For those keen on water features therefore, legionella can pose a real risk. Legionella is present in many water sources, but at such low levels that no risk is presented. However, when standing water accumulates in pipes and water features, and temperatures reach above 20 degrees celsius, legionella can multiply to deadly proportions. Garden-related scenarios resulting in the growth of legionella could therefore include water left in a hosepipe warmed in the sun, or an ornamental water feature with submerged lighting heating the water.
The bacteria is of course transmitted when coming into contact with the water, so for those water features which create any form of spray, the bacteria can also be inhaled. Another risk can be found in compost. As well as containing essential nutrients to enrich soil, compost also contains a strain of legionella, which can be just as deadly the strain found in standing water. The greatest risk seems to come when a bag of compost is first opened and the unwary gardener inhales the bacteria once it is released from the bag, but the bacteria can also be transferred through the handling of compost if the hands then come close to the face.
After being exposed to legionella bacteria, a gardener may exhibit tiredness for several days. After this they may exhibit several of the symptoms they may associate with influenza, such a cough, aches and a fever and as the condition worsens, they may also develop diarrhea and nausea.
The longer the legionnaires pneumonia is left to develop without antibiotic intervention the more serious the outcome is likely to be, so anyone who suspects they have come into contact with legionella bacteria would be advised to contact a medical professional as soon as possible.
Making Your Garden Safe
Ornamental water features can be beautiful, yet may be hiding dangers in their internal workings. A water fountain cleaning and maintenance schedule should be strictly adhered to, including not only the feature itself but any fittings and pipes through which water can pass.
Waterproof protective clothing would provide an extra layer of protection whilst carrying out cleaning and maintenance. When working with compost, gardeners should take care not to inhale when opening a bag of compost, and wearing a dust mask could give an additional layer of protection. Gloves should be worn when handling compost and hands cleaned thoroughly with cleanser and water after working with compost.
For a small financial outlay for protective apparel such as gloves and a dust mask, and a commitment to cleaning and maintenance routine, the risk of contracting pneumonia as a result of contact with legionella bacteria in the garden should be miniscule. The gardener should not be put off their hobby, but be aware of the potential risks of becoming complacent whilst working with water features and compost.
Author: Lucy Wyndham
Image: Benjamin Combs