Why Australians need a national environment protection agency to safeguard their health


David Shearman, University of Adelaide

Australia needs an independent national agency charged with safeguarding the environment and delivering effective climate policy, according to a new campaign launched today by a coalition of environmental, legal and medical NGOs.

Most Western democracies have established national regulatory action, such as the US Environmental Protection Agency – yet Australia is a notable exception.

Today in Canberra, the Australian Panel of Experts on Environmental Law (APEEL) will hold a symposium on the reform of environmental laws in Australia. If enacted, these proposals would offer protection to Australia’s declining biodiversity and environment, as well as helping to safeguard Australians’ health.




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The proposal would involve establishing a high-level Commonwealth Environment Commission (CEC) that would be responsible for Commonwealth strategic environmental instruments, in much the same way that the Reserve Bank is in charge of economic levers such as interest rates.

The new CEC would manage a nationally coordinated system of environmental data collection, monitoring, auditing and reporting, the conduct of environmental inquiries of a strategic nature, and the provision of strategic advice to the Commonwealth government on environmental matters, either upon request or at its own initiative. The necessary outcomes would then be delivered by government and ministers via a newly created National Environmental Protection Authority (NEPA).

Tomorrow, this call will be echoed by a major alliance of leading environmental groups, including Doctors for the Environment Australia. Similar to the CEC/NEPA proposal, this group has called for an independent “National Sustainability Commission” that would develop conservation plans, monitor invasive species, and set nationally binding air pollution standards and climate adaptation plans.

The new body would replace the EPBC Act, which has failed to deliver the protections it promised in key areas such as land clearing and species protection, and has no role in limiting climate change which is a major factor in species loss.

The new agencies would be in a position to provide authoritative and understandable consensus reports, similar to those produced by the Intergovernmental Panel on Climate Change but with a stronger legal basis on which the government should act on its advice.

Why change the system?

The rationale for reform is clear. Only last week the International Energy Agency reported that Earth’s greenhouse emissions have increased yet again. Meanwhile, extreme weather events have increased, while wildlife diversity is on the decline.

Having failed so far to arrest these trends, the governments of countries with high standards of living and high greenhouse emissions should be held particularly accountable. Clearing land and burning forest for firewood are understandable survival strategies for the poor, but unacceptable in rich nations.

Australia’s national laws would be strengthened to address the challenge of climate change and ensure we can mitigate, adapt to and be resilient in the face of a warming world.

Action on climate change, essential to protect biodiversity, is also vital to protect human health as a quarter of world disease has its root causes in environmental change, degradation and pollution.

The World Health Organisation regards climate change as the greatest health threat of the 21st century, a view recognised by the statements of the Australian Medical Association and Doctors for the Environment Australia.

Already, it is responsible for thousands of deaths worldwide, and that figure is projected to rise to 250,000 by 2030. In Australia, air quality reform could prevent an estimated 3,000 air pollution deaths per year.

Causes of current inaction

There are fundamentally two causes of inaction. First, in this increasingly
complex world, governments now more than ever need impartial advice based on the best available evidence. Yet all too often, such advice is politicised, ignored, or both.

Second, in leading democracies – particularly in Australia with its relatively short election cycles – the pressure to focus on re-election prospects dictates that governments emphasise jobs, growth, and living standards. It takes strong leadership to promote the interests of future generations as well as current ones.

It seems counterintuitive to suggest that for its survival, a government might need to delegate decisions for human survival to systems beyond its immediate political control. Yet it already does delegate crucial decisions, such as the monthly interest rate calls made by the Reserve Bank.

A newly created CEC and NEPA would be charged with safeguarding the climate, wildlife, fresh water and clean air. It would be in a position to improve air quality to standards recommended by the World Health Organization, protect water quality, and deliver effective climate change mitigation and adaptation policy uniformly in all states.




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The success of such a national system would manifest itself in a growing number of decisions similar to the recent rejection of the expansion of Stage 3 of the Acland coal mine. The judge in that case turned it down on the basis of a range of health and environmental transgressions, yet it is currently more common for states to approve this type of developments rather than reject them.

The ConversationNationally enforceable standards for resource developments are likely to bring effective preventative health benefits, as well as certainty of process. These reforms present an overdue opportunity for Australia to offer leadership and catch up on lost time, to ameliorate the progression of climate change and biodiversity loss, and thus lessen their future impacts.

David Shearman, Emeritus Professor of Medicine, University of Adelaide

This article was originally published on The Conversation. Read the original article.

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Your asthma puffer is probably contributing to climate change, but there’s a better alternative



File 20180305 146655 1azvp4m.jpg?ixlib=rb 1.1
There is an environmentally friendly option.
from http://www.shutterstock.com

Brett Montgomery, University of Western Australia

I breathe all the way out. There’s a quiet puff of gas from my inhaler, and I breathe all the way in. I hold my breath for a few seconds and the medicine is where it needs to be: in my lungs.

Many readers with asthma or other lung disease will recognise this ritual. But I suspect few will connect it with climate change. Until recently, neither did I.

In asthma, there is narrowing of the airways that carry air into and out of our lungs. The lining of the airways becomes swollen, muscles around the airways contract, and mucus is produced. All these changes make it hard to breathe out.

The most commonly used medicines in asthma are delivered by inhalation. Inhaling gets the medicines straight to the airways, speeding and maximising their local effects, and minimising side effects elsewhere compared to, say, swallowing tablets.

Some medicines (“relievers”) work quickly to relax the airway muscles. Others (“preventers”) work more slowly but do more good, preventing asthma’s swelling and inflammation of the airways.




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These medicines are available in various sorts of inhaler devices. The devices fall into two broad types: “metered dose inhalers” and “dry powder inhalers” of various shapes and sizes.

In metered dose inhalers, the medicine and a pressurised propellant liquid are mixed together in a little canister, and then sprayed out of the inhaler in a measured puff of fine mist. This is inhaled, often after passing through a “spacer” which allows more of the medicine to reach the lungs. While the medicine is absorbed by the body, the propellant, now a gas, is exhaled unchanged.

In dry powder inhalers, the medicine is in the form of a fine powder which is swept into the lungs as the user breathes in — there is no spray and no spacer.

Powder inhalers don’t release any gases at all.
Author provided

It’s feasible for many (but not all) people to use either sort of device. Young children do better with metered dose inhalers and spacers, as do people who struggle to inhale. But most asthmatics can inhale well from dry powder inhalers.

The two types of inhaler seem to work just as well as each other; if anything the dry powder ones might be a little better.

Metered dose inhalers are more often prescribed than dry powder devices in many countries, but this has more to do with history and familiarity than effectiveness.

What about those gases?

You might remember hearing, years ago, about “CFCs” — chlorofluorocarbons — and their dire effect on the ozone layer. A successful international treaty, the Montreal Protocol, led to their phase-out from various uses, including medical inhalers. And with that, I thought, the environmental problems of inhaler gases had ended.




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But CFCs were replaced with “HFCs” — hydrofluorocarbons — which are safe for the ozone layer, but which are potent global warming gases. HFCs are better known in their role as refrigerant gases in air conditioners and refrigerators.

A recent amendment to the Montreal Protocol has now planned a phase-out of HFCs, too, but it’s slow, with deadlines decades away. Earlier prudent management of these gases could make a big difference to climate change.

The one most often found in asthma metered dose inhalers, norflurane, is 1,430 times more potent than the best-known warming culprit, carbon dioxide. Another, apaflurane, is 3,220 times more potent than carbon dioxide.

Such warming power explains why even the small amounts in an inhaler are significant. Globally, tens of millions of tons of carbon dioxide equivalent are attributable annually to these inhaler gases.

How much pollution are inhaler gases responsible for in Australia? I wrote to several companies marketing asthma inhalers in Australia, asking them how much of these gases are present in their products. Some gave straight answers, but some hedged on grounds of commercial confidentiality. This makes it hard for me to be exact.

But based on some reasonable assumptions, and multiplying these by the number of inhalers dispensed on our Pharmaceutical Benefits Scheme last year, I tallied nearly 116,000 tonnes of carbon dioxide-equivalent pollution.

That’s equivalent to the emissions of about 25,000 cars annually. And this is surely an underestimate, as it doesn’t account for reliever inhalers sold over the counter. A person using a preventer inhaler monthly, plus the odd reliever inhaler, could easily release the annual equivalent of a quarter of a ton of carbon dioxide — that’s like burning 100 litres of petrol.




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How to change

The good news is, for many people with asthma, there’s an easy solution: shifting from metered dose inhalers to dry powder inhalers. As above, this won’t suit everyone, but will be possible for many.

I am both a doctor and a person with asthma. As an asthmatic, I’ve found changing inhalers to be easy — if anything, my dry powder inhalers are simpler to use. And as a doctor, I’ve been pleasantly surprised by how open my patients have been to this topic. I worried people might find it weird their GP was raising environmental issues at their appointment, but my fears were unfounded.

If you have asthma, a chat with your doctor or pharmacist would be a good way to gauge whether a dry powder inhaler is feasible for you. Don’t be surprised if they haven’t heard of this gas issue — awareness still seems limited.

The ConversationIf metered dose inhalers are a better choice for you, please don’t panic or quit your medicines. These gases probably won’t be the biggest contributor to your personal carbon footprint. Asthma control is really important, and these medicines work really well. But consider changing if it’s an option for you — when it comes to reducing our footprint, every little bit counts.

Brett Montgomery, Senior Lecturer in General Practice, University of Western Australia

This article was originally published on The Conversation. Read the original article.

I’ve always wondered: why many people in Asian countries wear masks, and whether they work


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Face masks are a common sight in Asia. Why?
David Chang/AAP

C Raina MacIntyre, UNSW and Abrar Ahmad Chughtai, UNSW

This is an article from I’ve Always Wondered, a series where readers send in questions they’d like an expert to answer. Send your question to alwayswondered@theconversation.edu.au


In Japan, many people wear face masks – is that to prevent the wearer getting the infection, or is the wearer already infected and protecting those around? Is the mask useful in protecting against viruses or bacteria? – Petrina, Greenwich

Thanks for your question, Petrina. You’re right, in countries like Japan and China, facemask use in the community is widespread – much more so than in Western cultures. People wear them to protect the respiratory tract from pollution and infection, and to prevent the spread of any pathogens they might be carrying.

Whether this works depends on the type of mask.

There are three supposed ways a mask can provide protection: by providing a physical barrier (which prevents splashes and sprays), by filtering the particles (blocking particles of a certain size from entering the respiratory tract), and by fitting around the face to prevent leakage of air around the sides.

Some mask makers have also gone the extra step of using antimicrobials and claim to kill bugs on the surface of the mask, but these haven’t been tested to see if they provide any benefit.

Healthcare workers have been using cloth masks (made of cotton or other materials and with ties to secure them at the back) while caring for patients since the late 19th century to protect from various respiratory infections such as diphtheria, scarlet fever, measles, pandemic influenza, pneumonic plague and tuberculosis.

Cloth masks have been around since the late 19th century.
Author provided



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During the mid 20th century, disposable surgical facemasks (similar in look to the cloth masks but made of paper) were developed. Surgical masks were developed to prevent the surgeon from contaminating the wound during surgery, but studies have not proven they help.

Surgical masks have no evidence of effectiveness.
from http://www.shutterstock.com

These were followed by respirators, which vary in shape and material but are designed to fit around the face and filter particles. Respirators are designed specifically to protect the respiratory tract from inhaled germs. There are many types, which may be reusable or disposable.

People must undergo fit-testing to ensure respirators are correctly fitted, with a good seal around the face. Unlike masks, respirators are subject to certification and regulation, and are proven to protect against respiratory infection.

Respirators are proven to protect against infection.
from http://www.shutterstock.com

Surgical masks are unregulated for filtration and do not fit around the face, and the evidence for their use is less convincing. In a community study, families with a sick child who wore such a mask were less likely to get sick if they also wore a mask, but many family members didn’t wear their masks all the time.

In a university setting, students were protected from sick classmates if they wore the mask within 36 hours of their classmate getting sick.

In many low income countries, the cost of even paper surgical masks is prohibitive, so cloth masks are used, washed and re-used. But these don’t protect against infection, and may even increase the risk of infection.

Prevention of infection vs source control

Masks can be used to protect healthy people (such as nurses and doctors) from exposure to infection, but are also used by sick people (such as a TB patient) to prevent spread of infections to others (called “source control”). There is less research on this use than on the use of masks by well people. The efficacy of source control is unknown.




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Do masks work?

It’s long been thought surgical masks protect from transmission of pathogens, which spread through the air on large, short-range droplets, while respirators protect against much smaller, airborne particles, which may remain suspended in the air for several hours and transmit infection over long distances. So most guidelines recommend a mask for droplet transmitting infections (such as influenza) and a respirator for airborne infections (such as TB and measles).

But we’ve shown respirators protect better than masks even against droplet-spread infections. And the longstanding belief that infections neatly fit into either droplet or airborne transmission is not correct. Respiratory transmission of infections is more complex than this.

To say whether masks work, we have to specify whether we’re talking about a respirator, a surgical mask or a cloth mask.

The respirators are the Rolls Royce option and do protect, and this is a tool for frontline health workers facing epidemics of known and unknown infections. Surgical masks probably also protect but to a lesser extent. But there’s no evidence cloth masks will protect against invading or escaping bugs.


The Conversation* Email your question to alwayswondered@theconversation.edu.au

* Tell us on Twitter by tagging @ConversationEDU with the hashtag #alwayswondered, or

* Tell us on Facebook

C Raina MacIntyre, Professor of Infectious Diseases Epidemiology, Head of the School of Public Health and Community Medicine, UNSW and Abrar Ahmad Chughtai, Epidemiologist, UNSW

This article was originally published on The Conversation. Read the original article.

Health Check: how can extreme heat lead to death?



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Our climate is going to get warmer, and we need to protect ourselves from heat-related illness.
from shutterstock.com

David Shearman, University of Adelaide

Our climate is becoming hotter. This is our reality. Extreme heat is already responsible for hundreds of deaths every year. It’s a big environmental killer, and deaths from heatwaves in Australian cities are expected to double in the next 40 years.

Those most at risk are the elderly, people with chronic illness, those living in socioeconomic disadvantage, outdoor workers, and athletes who play their sport in brutally high temperatures. But extreme heat can affect anyone at any age.

So, what happens in our body during times of extreme heat? And how can it lead to fatal consequences?




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How we lose and gain heat

Our core body temperature sits at around 37℃. If it rises or falls, a range of very efficient physiological mechanisms come into play. In good health, our body can usually cope well with deviations of about 3.5℃, but beyond that the body begins to show signs of distress.

In hot weather, the body maintains core temperature by losing heat in several ways. One is to transfer it to a cooler environment, such as surrounding air or water, through our skin. But if the surrounding temperature is the same or higher than the skin (greater than 35-37℃) the effectiveness of this mechanism is markedly reduced.

Blood vessels supplying blood to the skin dilate. This allows more warm blood to flow near the surface of the skin, where the heat can be lost to the air. That’s why some people’s skin looks redder in hot environments.

One way the body loses heat is by directly transferring it to a cooler environment.
from shutterstock.com

Evaporation (or sweat) is another way to lose heat from the body. If there is enough airflow and humidity is low enough, we can lose large amounts of heat through sweat. But on humid days, the rate of evaporation is reduced, as the air cannot absorb so much if it is already saturated with water vapour.

We can also reduce our heat production by resting. About 80% of the energy produced by working muscles is heat, so any activity will increase the amount of heat the body has to lose. This is why athletes and outdoor manual workers are at particular risk when performing at high levels of physical activity.




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What happens if the body can’t lose heat

Heat stress describes a spectrum of heat-related disorders that occur when the body fails to lose heat to maintain core temperature. Heat stress ranges from heat cramps to heat exhaustion (pale, sweating, dizzy and fainting). If the core temperature rises above 40.5℃, it can lead to heatstroke, which is a medical emergency, can occur suddenly and often kills.

The hypothalamus works as the body’s thermostat.
from shutterstock.com

Heatstroke is caused by a failure of the hypothalamus, the region of the brain that works as our thermostat and co-ordinates our physiological response to excessive heat. It’s what leads to mechanisms like sweating and rapid breathing, dilated veins and increased blood flow to the skin. So, when the hypothalamus fails, so does our ability to sweat and lose heat in other ways.

At temperatures higher than 41.5℃, convulsions are common. Irreversible brain damage can occur at temperatures above 42.5℃. Patients with heatstroke can show neurological signs such as lack of co-ordination, confusion, seizures and loss of consciousness.




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When sweating stops, the skin may become hot and dry, heart rate and breathing increase and blood pressure is low. Cells and nerves in the body become damaged. Liver damage is also common, but may not manifest for several days. The kidneys stop working, normal blood clotting is impaired, the heart muscle can be damaged and skeletal muscles start breaking down.

Essentially, this is what we describe as multi-organ failure. People with heatstroke can die within a few hours, or several days or even weeks later from organ failure.

Protecting yourself

Heatstroke could be “exertional”, as with athletes, or “classic”, which occurs in patients with impaired thermostatic responses, as a result of age, illness or medications.

Heatstroke can be caused by exertion, such as with athletes putting their body through stress in extreme temperatures.
from shutterstock.com

Much of the increase in deaths during hotter temperatures occurs in older patients with a chronic illness. This is because they may have a poorly functioning central nervous system that cannot orchestrate the physiological changes needed to lose heat.

Older hearts may not be able to cope with the changes in circulation needed for more blood flow to go to the skin. Some medications can also interfere with the mechanisms for heat loss.

People experiencing any of the warning signs of heat stress (headache, nausea, light-headedness and fatigue) need to alter their behaviour to reduce it.

The best way to do this is to find a cool spot indoors or in the shade, put on light clothing, avoid physical exertion, put a damp cloth on your skin, immerse yourself in cold water and stay well hydrated.

But for some people, like children who are too young to make changes to their environment (such as those left in cars), this is not possible. Also, for the elderly, perhaps those with chronic mental illness or on certain medications that impair their ability to respond to increasing core temperature, these signs may not be apparent or noticed.




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Strategies for coping with extremely hot weather


This means we need safeguards to ensure the vulnerable stay cool. This is especially a problem for elderly people who live alone.

So, as our climate warms up, we need to do all we can to minimise the consequences of an increasingly hot environment. That means we must adapt our behaviour, our understanding of the issues, our urban environments, our sporting events and our systems that look out for the vulnerable in our community.


The ConversationThis article was co-authored by Dr Mark Monaghan, an emergency physician, and Dr Liz Bashford, an anaesthetist, who are both members of Doctors for the Environment Australia.

David Shearman, Emeritus Professor of Medicine, University of Adelaide

This article was originally published on The Conversation. Read the original article.

Going to ground: how used coffee beans can help your garden and your health



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Coffee’s usefulness doesn’t have to end here.
Yanadhorn/Shutterstock.com

Tien Huynh, RMIT University

Did you know that your morning cup of coffee contributes to six million tonnes of spent coffee grounds going to landfill every year? This does not have to be the fate of your caffeine addiction and there are many opportunities to up-cycle spent coffee grounds into valuable commodities.

From fresh fruit, to roasted bean, to used up grounds, coffee’s chemical composition offers a range of uses beyond making your daily brew.




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Potential applications range from biofuels, to health products, and fertiliser for farms or your garden. So why are we throwing this precious product away?

The answer is that processing and production can be more complex than you might imagine – even when we’re talking about simply using coffee grounds in your garden. What’s more, many recycling initiatives to turn waste coffee into valuable commodities are still in their early stages.

When composted properly, coffee can be an excellent fertiliser.
Author provided

You may have noticed that some cafes now offer free spent coffee grounds for customers to take home and use in the garden. In theory, this is a great initiative but the reality is that fresh coffee grounds are high in caffeine, chlorogenic acid and tannins that are beneficial to humans but toxic to plants.

The spent coffee must be detoxified by composting for a minimum of 98 days for plants to benefit from the potassium and nitrogen contained in the roasted beans. Without adequate composting, the benefits are scant (see below). So if you do take some coffee grounds home from your local cafe, make sure you compost them before sprinkling them on the veggie patch.

Parsley plants after 70 days in soil containing a) 21 days composted spent coffee; b) fresh spent coffee grounds; c) newspaper; d) soil only; and e) fertiliser.
Brendan Janissen, unpublished experimental results., Author provided

The good news is that properly composted coffee grounds offer a cheap alternative to agro-industrial fertilisers, potentially helping urban communities become greener and more sustainable. Savvy businesses have begun processing coffee grounds on a commercial scale, turning them into nutrient-rich fertilisers or soil conditioners in convenient pellets for use in the garden.

The coffee berries before harvest.
Author provided

But why stop there? A potentially even more valuable ingredient is the chlorogenic acid. Although toxic to plants, as mentioned above, chlorogenic acid has potential as a natural health supplement for humans, because of its antioxidant, anticancer and neuroprotective properties.




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The whole coffee production process is abundant in chlorogenic acid, particularly in raw coffee beans. Chlorogenic acid conversion efficiency is even better from green coffee pulp, with a 50% recovery rate, compared with 19% for spent coffee grounds.

As undersized and imperfect beans are discarded at this raw stage, many businesses have seized the opportunity to market green coffee extracts as a weight loss product, although more research is needed to confirm this potential.

Roasted coffee beans ready for grinding.
Author provided

The list doesn’t end there. Coffee waste can be used to create a diverse list of chemicals, including enzymes and hormones for digestion of common biological compounds and to improve plant growth; and feedstocks for high-end crops such as mushrooms. Coffee oil has even been trialled as a fuel for London buses.

The ConversationWith abundant waste supplies due to the popularity of coffee consumption, by recycling the byproducts, perhaps we can enjoy one of our favourite beverages without too much guilt.

Tien Huynh, Senior Lecturer in the School of Sciences, RMIT University

This article was originally published on The Conversation. Read the original article.

(At least) five reasons you should wear gardening gloves



File 20171220 4995 60vm3z.jpg?ixlib=rb 1.1
Not just to avoid creepy crawlies.
from http://www.shutterstock.com

Mark Blaskovich, The University of Queensland

Gardening is a great way to relax, be one with nature and get your hands dirty. But lurking in that pleasant environment are some nasty bacteria and fungi, with the potential to cause you serious harm. So we need to be vigilant with gardening gloves and other protective wear.

Soils contain all sorts of bacteria and fungi, most of which are beneficial and do helpful things like breaking down organic matter. But just as there are pathogenic bacteria that live on your body amid the useful ones, some microorganisms in soil can cause serious damage when given the opportunity to enter the body. This commonly happens through cuts, scrapes or splinters.

Plants, animal manure, and compost are also sources of bacteria and fungi that can cause infections.


Read more – The science is in: gardening is good for you


1. Tetanus

Traditionally, the most common and well-known infection is tetanus, caused by Clostridium tetani, which lives in soil and manure. Infections occur through contamination of cuts and scrapes caused by things in contact with the soil, such as garden tools or rose thorns.

Fortunately, most people have been vaccinated against tetanus, which means even if you are infected, your body is able to fight back against the bacteria to prevent it becoming serious. Symptoms include weakness, stiffness and cramps, with the toxins released leading to muscular paralysis and difficulty chewing and swallowing – hence the common term for tetanus of lockjaw.

2. Sepsis

Bacteria such as Escherichia coli, Salmonella, Campylobacter jejuni, and Listeria monocytogenes are often present in gardens as a result of using cow, horse, chicken or other animal manure. Bacterial infections can lead to sepsis, where the bacteria enter the blood and rapidly grow, causing the body to respond with an inflammatory response that causes septic shock, organ failure, and, if not treated quickly enough, death.

A high-profile case recently occurred in England, where a 43-year-old solicitor and mother of two died five days after scratching her hand while gardening. This hits close to home, as a number of years ago my mother spent ten days in intensive care recovering from severe sepsis, believed to be caused by a splinter from the garden.

3. Legionellosis

Standing pools of water may hold Legionella pneumophila, the bacteria causing Legionnaires’ disease, more commonly known to be associated with outbreaks from contaminated air conditioning systems in buildings.


Read more: Are common garden chemicals a health risk?


Related bacteria, Legionella longbeachae, are found in soil and compost. In 2016 there were 29 confirmed cases of legionellosis in New Zealand, including a Wellington man who picked up the bug from handling potting mix.

Potting mix should be handled with gloves, while wearing a dust mask.
from http://www.shutterstock.com

Another ten cases were reported in Wellington in 2017, again associated with potting soil. In New Zealand and Australia, Legionella longbeachae from potting mix accounts for approximately half of reported cases of Legionnaires’ disease. There were around 400 total cases of Legionellosis in Australia in 2014.

The bacteria is usually inhaled, so wearing a dust mask when handling potting soil and dampening the soil to prevent dust are recommended.

4. Melioidosis

An additional concern for residents of northern Australia is an infection called melioidosis. These bacteria (Burkholderia pseudomallei) live in the soil but end up on the surface and in puddles after rain, entering the body through cuts or grazes, and sometimes through inhalation or drinking groundwater.

Infection causes a range of symptoms, such as cough and difficulty breathing, fever or sporadic fever, confusion, headache, and weight loss, with up to 21 days before these develop.


Read more: Five reasons not to spray the bugs in your garden this summer


In 2012, there were over 50 cases in the Northern Territory leading to three deaths, with another case receiving publicity in 2015. Preventative measures include wearing waterproof boots when walking in mud or puddles, gloves when handling muddy items, and, if you have a weakened immune system, avoiding being outdoors during heavy rain.

5. Rose gardener’s disease

A relatively rare infection is sporotrichosis, “rose gardener’s disease”, caused by a fungus (Sporothrix) that lives in soil and plant matter such as rose bushes and hay. Again, infections through skin cuts are most common, but inhalation can also occur.

Skin infection leads to a small bump up to 12 weeks later, which grows bigger and may develop into an open sore. An outbreak of ten cases was reported in the Northern Territory in 2014.

Aspergillus, usually Aspergillus fumigatus, and Cryptococcus neoformans are other fungi that can cause lung infections when inhaled, usually in people with weakened immune systems. Gardening activities such as turning over moist compost can release spores into the air.

Of course, there are plenty of other dangers in the garden that shouldn’t be ignored, ranging from poisonous spiders, snakes and stinging insects, to hazardous pesticides and fungicides, poisonous plants, and physical injuries from strains, over-exertion, sunburn, allergies, or sharp gardening tools.

The ConversationSo enjoy your time in the garden, but wear gloves and shoes, and a dust mask if handling potting soil or compost. And be aware if you do get a cut or scrape then end up with signs of infection, don’t delay seeing your doctor, and make sure you let them know what you’ve been doing.

Mark Blaskovich, Senior Research Officer, The University of Queensland

This article was originally published on The Conversation. Read the original article.

Why we shouldn’t be too quick to blame migratory animals for global disease


Alice Risely, Deakin University; Bethany J Hoye, University of Wollongong, and Marcel Klaassen, Deakin University

Have you ever got on a flight and the person next to you started sneezing? With 37 million scheduled flights transporting people around the world each year, you might think that the viruses and other germs carried by travellers would be getting a free ride to new pastures, infecting people as they go.

Yet pathogenic microbes are surprisingly bad at expanding their range by hitching rides on planes. Microbes find it difficult to thrive when taken out of their ecological comfort zone; Bali might just be a tad too hot for a Tasmanian parasite to handle.

But humans aren’t the only species to go global with their parasites. Billions of animals have been flying, swimming and running around the globe every year on their seasonal migrations, long before the age of the aeroplane. The question is, are they picking up new pathogens on their journeys? And if they are, are they transporting them across the world?


Read more: A tale of three mosquitoes: how a warming world could spread disease


Migratory animals are the usual suspects for disease spread

With the rate of zoonotic diseases (pathogens that jump from animals to humans) on the rise, migratory animals have been under increasing suspicion of aiding the spread of devastating diseases such as bird flu, Lyme disease, and even Ebola.

These suspicions are bad for migrating animals, because they are often killed in large numbers when considered a disease threat. They are also bad for humans, because blaming animals may obscure other important factors in disease spread, such as animal trade. So what’s going on?

Despite the logical link between animal migration and the spread of their pathogens, there is in fact surprisingly little direct evidence that migrants frequently spread pathogens long distances.

This is because migratory animals are notoriously hard for scientists to track. Their movements make them difficult to test for infections over the vast areas that they occupy.

But other theories exist that explain the lack of direct evidence for migrants spreading pathogens. One is that, unlike humans who just have to jump on a plane, migratory animals must work exceptionally hard to travel. Flying from Australia to Siberia is no easy feat for a tiny migratory bird, nor is swimming between the poles for giant whales. Human athletes are less likely to finish a race if battling infections, and likewise, migrant animals may have to be at the peak of health if they are to survive such gruelling journeys. Sick travellers may succumb to infection before they, or their parasitic hitchhikers, reach their final destination.

Put simply, if a sick animal can’t migrate, then neither can its parasites.

On the other hand, migrants have been doing this for millennia. It is possible they have adapted to such challenges, keeping pace in the evolutionary arms race against pathogens and able to migrate even while infected. In this case, pathogens may be more successful at spreading around the world on the backs of their hosts. But which theory does the evidence support?

Sick animals can still spread disease

To try and get to the bottom of this question, we identified as many studies testing this hypothesis as we could, extracted their data, and combined them to look for any overarching patterns.

We found that infected migrants across species definitely felt the cost of being sick: they tended to be in poorer condition, didn’t travel as far, migrated later, and had lower chances of survival. However, infection affected these traits differently. Movement was hit hardest by infection, but survival was only weakly impacted. Infected migrants may not die as they migrate, but perhaps they restrict long-distance movements to save energy.

So pathogens seem to pose some costs on their migratory hosts, which would reduce the chances of migrants spreading pathogens, but perhaps not enough of a cost to eliminate the risk completely.


Read more: Giant marsupials once migrated across an Australian Ice Age landscape


But an important piece of the puzzle is still missing. In humans, travelling increases our risk of getting ill because we come into contact with new germs that our immune system has never encountered before. Are migrants also more susceptible to unfamiliar microbes as they travel to new locations, or have they adapted to this as well?

Guts of migrants resistant to microbial invasion

To investigate the susceptibility of migrants, we went in a different direction and decided to look at the gut bacteria of migratory shorebirds – grey, unassuming birds that forage on beaches or near water, and that undergo some of the longest and fastest migrations in the animal kingdom.

Most animals have hundreds of bacterial species living in their guts, which help break down nutrients and fight off potential pathogens. Every new microbe you ingest can only colonise your gut if the environmental conditions are to its liking, and competition with current residents isn’t too high. In some cases, it may thrive so much it becomes an infection.

The Red-necked stint is highly exposed to sediment microbes as it forages for the microscopic invertebrates that fuel its vast migrations.
Author provided

We found the migratory shorebirds we studied were exceptionally good at resisting invasion from ingested microbes, even after flying thousands of kilometres and putting their gut under extreme physiological strain. Birds that had just returned from migration (during which they stopped in many places in China, Japan, and South East Asia), didn’t carry any more species of bacteria than those that had stayed around the same location for a year.

The ConversationAlthough these results need to be tested in other migratory species, our research suggests that, like human air traffic, pathogens might not get such an easy ride on their migratory hosts as we might assume. There is no doubt that migrants are involved in pathogen dispersal to some degree, but there is increasing evidence that we shouldn’t jump the gun when it comes to blaming migrants.

Alice Risely, PhD candidate in Ecology, Deakin University; Bethany J Hoye, Lecturer in Animal Ecology, University of Wollongong, and Marcel Klaassen, Alfred Deakin Professor and Chair in Ecology, Deakin University

This article was originally published on The Conversation. Read the original article.