is your compost heap killing you?

As scientists warn of the rise of resistant ‘superfungi’, how to save yourself from what’s lurking at the bottom of the garden . . .

THE fresh, sharp smell of decomposing organic matter has long been a source of deep joy for real gardeners.

Oh, the wonderful sight on a cold day of steam rising from their pride and joy — that huge pile of rotting compost at the bottom of a garden.

The possessive pleasure it generates; the sense of nurturing as they ‘turn’ their heap during the long winter months to let the oxygen circulate and help the micro-fauna and bacteria do their bucolic best to transform shrivelled garden cuttings into something bursting with goodness.

And who hasn’t felt the satisfaction (and teeniest touch of smugness) that comes from spreading ripe, two-year- old compost — dark, crumbly, moist, like a rich chocolate cheesecake — over borders and vegetable patches? A home-made superfood for the year to come.

So horror of horrors to then discover your compost heap may be harbouring a drugresistant ‘ superfungi’ that could cause a nasty infection — or even kill you.

Thanks to the widespread use by farmers of anti-fungal sprays to protect crops from moulds and yeast, several variants of these resistant ‘superfungi’ have evolved over recent years.

Now they appear to have spread beyond agricultural land and rural areas and are being reported in suburban gardens and parks.

If the superfungi infect humans, frontline anti-fungal drugs are proving ineffective — just as overuse of antibiotics led to the growth of resistant superbugs.

The most dangerous is aspergillus — a mould that flourishes on dead plant or animal material and is common in compost heaps — which exists in several drug-resistant strains.

People with lung complaints or those with weakened immune systems, such as the elderly, very young or those on immuno- suppressant drugs, are most vulnerable. There are also fears that superfungi could become established in hospitals — just as MRSA bacteria did — causing post-operative blood infections.

ASPERgIlluS,

also responsible for the condition known as Farmer’s lung caused by its proliferation in mouldy hay, is linked to 400,000 cases of asthma and 3,600 lung infections in the uK each year.

In its most lethal form — ‘ invasive aspergillus’ — the spores of the aspergillus enter the body via the bloodstream and invade the lungs, where they grow.

The first inkling that Karen Hook, a 50year- old horticulturist and mother- of-two from Bishop’s Stortford, Hertfordshire, had of her condition was constant fatigue, a persistent cough and bad breath.

Then she started coughing up lumps of green fungus. In an operation to remove it all, part of her lung was destroyed.

In another case, Sandra Hicks, a 51-yearold pharmacist from Dorset was diagnosed with aspergillosis in 2008, and was told her infection was resistant to the drugs prescribed and would eventually kill her.

‘It’s destroying my lungs ... It’s very scary to be told the treatment isn’t working,’ she said.

More than 4,000 people have now been affected by invasive aspergillosis — most of whom fall into high risk groups.

But according to Professor David Denning, head of the National Aspergillosis Centre in Manchester, the number of drug-resistant strains is on the rise, spreading through suburbia — and the risk is increasing.

‘Four or five years ago, only 1 per cent to 1.5 per cent of strains tested were drug resistant. Now it has reached 13 per cent in london and 6 per cent in Wales,’ he said last week. ‘It seems very likely that resistance is increasing and we think farms spraying crops with fungicide is the cause.’

All of which is, of course, extremely alarming.

But before you panic, cordon off your compost heap and have your entire garden tarmacked, read on.

Because if you take some simple precautions, tend your compost heap with care and use common sense, experts says the chances of being affected are negligible. Of course, it goes without saying that if you suffer from a weakened immune system, or any other preexisting respiratory conditions, or are a heavy smoker, then either wear a face mask, get someone else to tend your compost heap or, even better, ditch it altogether and put your garden waste in a green waste bin for removal by the council.

For everyone else, the key to a safe compost heap is moisture.

guy Barter, chief horticulturist for the Royal Horticultural Society, says: ‘If the contents of your compost bin become dry and mouldy, pour a bucket of water on it, leave it for a while and then cover with some potting compost to keep the dust and airborne spores down.’ He suggests the same for piles of garden rubbish: ‘give them a good douse with a hose pipe every so often.’ And, he adds, never, ever, open sealed bags of compost or bark chippings indoors.

Compost bags contain thousands of invisible spores that, in an enclosed space, could be projected into the air when the bag is opened, so open them gently — do not disturb the compost — in the fresh air and, ideally, wear a mask.

Certainly the danger is real. In 2008, an otherwise healthy 47-yearold man died from complications related to aspergillosis just four days after opening several bags of compost he’d prepared from his garden — and being surrounded by a cloud of dust. He was admitted to hospital with breathing problems the next day, and tests showed that he had growths on his lungs.

He developed pneumonia, was transferred to intensive care and by the time the fungal infection was diagnosed, his blood pressure had plummeted, his kidneys failed and he developed sepsis.

Experts also agree that, to minimise the spread of potentially damaging airborne spores, sacks of compost should never be stored in greenhouses or warm sheds where they will dry out, increasing the chance of spreading spores when opened. Instead, stack them outside in the shade.

According to Stefan Buczacki, a former chairman of Radio 4’ s gardeners’ Question Time and a past president of the British Mycological Society (mycology is the study of fungi), another sensible — if not controversial — precaution is to avoid ‘turning’ your compost.

gardeners will probably disagree until the end of time about whether a compost heap should, or should not, be ‘turned’ — the rather malodorous task of mixing the brown and green matter with a fork.

Turning is all about getting a bit of oxygen into your compost, and enthusiasts insist it can make the difference between compost being ready to spread in weeks or months.

However, as fungi digests the organic matter, invisible spores form and any movement of the compost could release them into the air — and, if you’re leaning over the compost heap giving it a good prod — straight into your lungs.

Mr Buczacki never meddles with his compost. ‘ It breaks down satisfactorily without turning and is usually ready within six to nine months,’ he says.

HE

stores his garden waste in a row of eight wooden slatted compost heaps under the shade of a tree.

‘A compost bin should be well aerated — so I wouldn’t touch a plastic compost bin with a barge pole,’ he says. ‘ The breakdown depends on bacteria which won’t thrive in an anaerobic [no oxygen] environment.’

He also cautions against too many grass clippings, which can become too dry — or too soggy.

‘You need a mixture of organic material — grass, finely chopped up woody debris and vegetable detritus,’ he says.

But strictly no leaves, which should go on a separate heap for slower mulching over 12 to 18 months.

Of course, many seasoned horticulturalists are fully aware of the potential danger at the bottom of their garden, but in pursuit of that dark, sticky, smelly mix that adds nutrients to the soil, helps keep it moist and even suppresses weed growth, some have been prepared to take a few risks. Not any more, perhaps. With the tenfold increase in the number of drug-resistant strains of superfungi, it’s high time for gardeners to treat their beloved compost heaps with respect — and a good dollop of common sense.