Frequent extreme bushfires are our new reality. We need to learn how to live with smoke-filled air



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Gabriel da Silva, University of Melbourne

As fires ravaged large sections of the Australian bush last summer, cities and towns all along the coast were blanketed in toxic smoke. Air pollutants were measured at unheard of levels across the country.

Hazardous air descended on cities hundreds of kilometres away from the fires themselves. This air was the most dangerous to breathe on the planet.




Read more:
The bushfire royal commission has made a clarion call for change. Now we need politics to follow


The bushfire royal commission was tabled on October 30, with some sobering findings about fires and air pollution. Unfortunately, it showed that as a nation we were not prepared to deal with this public health emergency.

These disasters are inevitable under climate change, and while we need to urgently act on climate change to protect future generations, we also need to make changes now to mitigate the risks that already face us.

Australia must get better at communicating how to identify and then stay safe in hazardous air. A national set of air quality categories would go a long way to achieving this.

Over 400 deaths attributed to bushfire smoke

The royal commission heard that air pollution from the summer fires likely caused more than 400 deaths. Thousands of additional hospital admissions put added strain on our hospitals. All up the added burden to our health system was estimated at almost A$2 billion.

Even in the absence of extreme natural disasters, air pollution is one of Australia’s biggest public health concerns. Pollution from all sources causes thousands of deaths per year. This includes emissions from coal-fired power stations, diesel cars and wood-fired heaters.

Better preparing ourselves to deal with bushfire smoke will have flow-on benefits in tackling these problems.

Different state, different health advice

The royal commission found “there is an urgent need for national consistency in the categorisation of air quality”. At the moment, every state has their own system to categorise air quality and communicate it to the public.




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How does bushfire smoke affect our health? 6 things you need to know


But there are major discrepancies with how different states identify the worst air quality.

Air quality is the sum impact of the concentration of various unhealthy chemicals in the air. These include ozone, nitrogen and sulfur oxides, and fine particulate matter. To communicate this to the public, most countries convert these chemical concentrations into an Air Quality Index (AQI).

In the US, there is a standardised AQI categorisation for the whole country.

In Australia, the situation is very different. Every state has its own bands, with their own colour codes. These bands trigger at different pollutant levels and carry different health advice. The Royal Commission told us this needs to be standardised, and now.

For example, in NSW the worst air quality category is “Hazardous”, which triggers at an AQI of 200. South Australia, however, only recognises “Very Poor” as the worst class of air quality, with an AQI of 150 and above.

During the summer bushfires, AQI values as high as 5,000 were measured. It’s clear the highest bands of air pollution are no longer appropriate.

We need a national air quality system

We have faced a similar problem before. After Victoria’s Black Saturday fires in 2009, we recognised that our fire danger ratings were inadequate.

The Black Saturday royal commission found we needed a higher category for the most dangerous fire conditions. The “Catastrophic” category (“CODE RED” in Victoria) was added. It carried clear advice about what to do in such dangerous conditions, instructing people to safely leave as early as possible.

Fire danger rating sign in front of a grass fire
The ‘CODE RED’ or ‘Catastrophic’ fire danger rating was added after the Black Saturday fires.
Shutterstock

Something similar now needs to happen with air quality ratings.

When facing future extreme bushfires, we need a way to identify when catastrophic conditions have led to air so unhealthy that everyone should take precautions, such as staying indoors and wearing masks. We then need to get clear health advice out to the public.




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Our buildings aren’t made to keep out bushfire smoke. Here’s what you can do


A national air quality rating system could achieve this, and would also help address other important recommendations of the Royal Commission: That we need improved means of getting reliable information out to the public, along with better community education around what to do when air quality plummets.

There’s work to do

An Australian AQI should be featured on national weather reports and forecasts, providing important health information to the public every day of the year. At the same time it would familiarise Australians with air quality measures and actions that need to be taken to protect ourselves from unhealthy air.

But there is work to do. First, we need to develop a new set of air quality categories that work for the entire country, and reflects both the everyday hazards of industrial pollution and the extreme dangers of bushfires. These categories also need to be matched with sound health advice.




Read more:
The bushfire royal commission has made a clarion call for change. Now we need politics to follow


And if we are going to report these measures more widely then we also need to get better at measuring and predicting air quality across the nation — two other important royal commission recommendations.

Achieving all of this won’t be easy. But if we can get it right then we will be much better placed to deal with smoke risk the next time severe bushfires inevitably happen.The Conversation

Gabriel da Silva, Senior Lecturer in Chemical Engineering, University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Japan plans to dump a million tonnes of radioactive water into the Pacific. But Australia has nuclear waste problems, too


Tilman Ruff, University of Melbourne and Margaret Beavis

The Japanese government recently announced plans to release into the sea more than 1 million tonnes of radioactive water from the severely damaged Fukushima Daiichi nuclear plant.

The move has sparked global outrage, including from UN Special Rapporteur Baskut Tuncak who recently wrote,

I urge the Japanese government to think twice about its legacy: as a true champion of human rights and the environment, or not.

Alongside our Nobel Peace Prize-winning work promoting nuclear disarmament, we have worked for decades to minimise the health harms of nuclear technology, including site visits to Fukushima since 2011. We’ve concluded Japan’s plan is unsafe, and not based on evidence.

Japan isn’t the only country with a nuclear waste problem. The Australian government wants to send nuclear waste to a site in regional South Australia — a risky plan that has been widely criticised.

Contaminated water in leaking tanks

In 2011, a massive earthquake and tsunami resulted in the meltdown of four large nuclear reactors, and extensive damage to the reactor containment structures and the buildings which house them.

Water must be poured on top of the damaged reactors to keep them cool, but in the process, it becomes highly contaminated. Every day, 170 tonnes of highly contaminated water are added to storage on site.

As of last month, this totalled 1.23 million tonnes. Currently, this water is stored in more than 1,000 tanks, many hastily and poorly constructed, with a history of leaks.

How does radiation harm marine life?

If radioactive material leaks into the sea, ocean currents can disperse it widely. The radioactivity from Fukushima has already caused widespread contamination of fish caught off the coast, and was even detected in tuna caught off California.




Read more:
Four things you didn’t know about nuclear waste


Ionising radiation harms all organisms, causing genetic damage, developmental abnormalities, tumours and reduced fertility and fitness. For tens of kilometres along the coast from the damaged nuclear plant, the diversity and number of organisms have been depleted.

Of particular concern are long-lived radioisotopes (unstable chemical elements) and those which concentrate up the food chain, such as cesium-137 and strontium-90. This can lead to fish being thousands of times more radioactive than the water they swim in.

Failing attempts to de-contaminate the water

In recent years, a water purification system — known as advanced liquid processing — has been used to treat the contaminated water accumulating in Fukushima to try to reduce the 62 most important contaminating radioisotopes.

But it hasn’t been very effective. To date, 72% of the treated water exceeds the regulatory standards. Some treated water has been shown to be almost 20,000 times higher than what’s allowed.




Read more:
The cherry trees of Fukushima


One important radioisotope not removed in this process is tritium — a radioactive form of hydrogen with a half-life of 12.3 years. This means it takes 12.3 years for half of the radioisotope to decay.

Tritium is a carcinogenic byproduct of nuclear reactors and reprocessing plants, and is routinely released both into the water and air.

The Japanese government and the reactor operator plan to meet regulatory limits for tritium by diluting contaminated water. But this does not reduce the overall amount of radioactivity released into the environment.

How should the water be stored?

The Japanese Citizens Commission for Nuclear Energy is an independent organisation of engineers and researchers. It says once water is treated to reduce all significant isotopes other than tritium, it should be stored in 10,000-tonne tanks on land.

If the water was stored for 120 years, tritium levels would decay to less than 1,000th of the starting amount, and levels of other radioisotopes would also reduce. This is a relatively short and manageable period of time, in terms of nuclear waste.

Then, the water could be safely released into the ocean.

Nuclear waste storage in Australia

Australians currently face our own nuclear waste problems, stemming from our nuclear reactors and rapidly expanding nuclear medicine export business, which produces radioisotopes for medical diagnosis, some treatments, scientific and industrial purposes.




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Australia should explore nuclear waste before we try domestic nuclear power


This is what happens at our national nuclear facility at Lucas Heights in Sydney. The vast majority of Australia’s nuclear waste is stored on-site in a dedicated facility, managed by those with the best expertise, and monitored 24/7 by the Australian Federal Police.

But the Australian government plans to change this. It wants to transport and temporarily store nuclear waste at a facility at Kimba, in regional South Australia, for an indeterminate period. We believe the Kimba plan involves unnecessary multiple handling, and shifts the nuclear waste problem onto future generations.

The proposed storage facilities in Kimba are less safe than disposal, and this plan is well below world’s best practice.

The infrastructure, staff and expertise to manage and monitor radioactive materials in Lucas Heights were developed over decades, with all the resources and emergency services of Australia’s largest city. These capacities cannot be quickly or easily replicated in the remote rural location of Kimba. What’s more, transporting the waste raises the risk of theft and accident.

And in recent months, the CEO of regulator ARPANSA told a senate inquiry there is capacity to store nuclear waste at Lucas Heights for several more decades. This means there’s ample time to properly plan final disposal of the waste.

The legislation before the Senate will deny interested parties the right to judicial review. The plan also disregards unanimous opposition by Barngarla Traditional Owners.




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Uranium mines harm Indigenous people – so why have we approved a new one?


The Conversation contacted Resources Minister Keith Pitt who insisted the Kimba site will consolidate waste from more than 100 places into a “safe, purpose-built, state-of-the-art facility”. He said a separate, permanent disposal facility will be established for intermediate level waste in a few decades’ time.

Pitt said the government continues to seek involvement of Traditional Owners. He also said the Kimba community voted in favour of the plan. However, the voting process was criticised on a number of grounds, including that it excluded landowners living relatively close to the site, and entirely excluded Barngarla people.

Kicking the can down the road

Both Australia and Japan should look to nations such as Finland, which deals with nuclear waste more responsibly and has studied potential sites for decades. It plans to spend 3.5 billion euros (A$5.8 billion) on a deep geological disposal site.




Read more:
Risks, ethics and consent: Australia shouldn’t become the world’s nuclear wasteland


Intermediate level nuclear waste like that planned to be moved to Kimba contains extremely hazardous materials that must be strictly isolated from people and the environment for at least 10,000 years.

We should take the time needed for an open, inclusive and evidence-based planning process, rather than a quick fix that avoidably contaminates our shared environment and creates more problems than it solves.

It only kicks the can down the road for future generations, and does not constitute responsible radioactive waste management.


The following are additional comments provided by Resources Minister Keith Pitt in response to issues raised in this article (comments added after publication):

(The Kimba plan) will consolidate waste into a single, safe, purpose-built, state-of-the-art facility. It is international best practice and good common sense to do this.

Key indicators which showed the broad community support in Kimba included 62 per cent support in the local community ballot, and 100 per cent support from direct neighbours to the proposed site.

In assessing community support, the government also considered submissions received from across the country and the results of Barngarla Determination Aboriginal Corporation’s own vote.

The vast majority of Australia’s radioactive waste stream is associated with nuclear medicine production that, on average, two in three Australians will benefit from during their lifetime.

The facility will create a new, safe industry for the Kimba community, including 45 jobs in security, operations, administration and environmental monitoring.The Conversation

Tilman Ruff, Associate Professor, Education and Learning Unit, Nossal Institute for Global Health, School of Population and Global Health, University of Melbourne and Margaret Beavis, Tutor Principles of Clinical Practice Melbourne Medical School

This article is republished from The Conversation under a Creative Commons license. Read the original article.

PFAS ‘forever chemicals’ are widespread and threaten human health – here’s a strategy for protecting the public



Firefighting foam left after a fire in Pennsylvania. These foams often contain PFAS chemicals that can contaminate water supplies.
Bastiaan Slabbers/NurPhoto via Getty Images

Carol Kwiatkowski, North Carolina State University

Like many inventions, the discovery of Teflon happened by accident. In 1938, chemists from Dupont (now Chemours) were studying refrigerant gases when, much to their surprise, one concoction solidified. Upon investigation, they found it was not only the slipperiest substance they’d ever seen – it was also noncorrosive and extremely stable and had a high melting point.

In 1954 the revolutionary “nonstick” Teflon pan was introduced. Since then, an entire class of human-made chemicals has evolved: per- and polyfluoroalkyl substances, better known as PFAS. There are upward of 6,000 of these chemicals. Many are used for stain-, grease- and waterproofing. PFAS are found in clothing, plastic, food packaging, electronics, personal care products, firefighting foams, medical devices and numerous other products.

But over time, evidence has slowly built that some commonly used PFAS are toxic and may cause cancer. It took 50 years to understand that the happy accident of Teflon’s discovery was, in fact, a train wreck.

As a public health analyst, I have studied the harm caused by these chemicals. I am one of hundreds of scientists who are calling for a comprehensive, effective plan to manage the entire class of PFAS to protect public health while safer alternatives are developed.

Typically, when the U.S. Environmental Protection Agency assesses chemicals for potential harm, it examines one substance at a time. That approach isn’t working for PFAS, given the sheer number of them and the fact that manufacturers commonly replace toxic substances with “regrettable substitutes” – similar, lesser-known chemicals that also threaten human health and the environment.

Graphic showing how PFAS moves from many sources into soil and water
As PFAS are produced and used, they can migrate into soil and water.
MI DEQ

Toxic chemicals

A class-action lawsuit brought this issue to national attention in 2005. Workers at a Parkersburg, West Virginia, DuPont plant joined with local residents to sue the company for releasing millions of pounds of one of these chemicals, known as PFOA, into the air and the Ohio River. Lawyers discovered that the company had known as far back as 1961 that PFOA could harm the liver.

The suit was ultimately settled in 2017 for US$670 million, after an eight-year study of tens of thousands of people who had been exposed. Based on multiple scientific studies, this review concluded that there was a probable link between exposure to PFOA and six categories of diseases: diagnosed high cholesterol, ulcerative colitis, thyroid disease, testicular cancer, kidney cancer and pregnancy-induced hypertension.

Over the past two decades, hundreds of peer-reviewed scientific papers have shown that many PFAS are not only toxic – they also don’t fully break down in the environment and have accumulated in the bodies of people and animals around the world. Some studies have detected PFAS in 99% of people tested. Others have found PFAS in wildlife, including polar bears, dolphins and seals.

Attorney Robert Billott describes suing Dupont for knowingly releasing millions of pounds of hazardous PFOA in Parkersburg, West Virginia.

Widespread and persistent

PFAS are often called “forever chemicals” because they don’t fully degrade. They move easily through air and water, can quickly travel long distances and accumulate in sediment, soil and plants. They have also been found in dust and food, including eggs, meat, milk, fish, fruits and vegetables.

In the bodies of humans and animals, PFAS concentrate in various organs, tissues and cells. The U.S. National Toxicology Program and Centers for Disease Control and Prevention have confirmed a long list of health risks, including immunotoxicity, testicular and kidney cancer, liver damage, decreased fertility and thyroid disease.

Children are even more vulnerable than adults because they can ingest more PFAS relative to their body weight from food and water and through the air. Children also put their hands in their mouths more often, and their metabolic and immune systems are less developed. Studies show that these chemicals harm children by causing kidney dysfunction, delayed puberty, asthma and altered immune function.

Researchers have also documented that PFAS exposure reduces the effectiveness of vaccines, which is particularly concerning amid the COVID-19 pandemic.

Regulation is lagging

PFAS have become so ubiquitous in the environment that health experts say it is probably impossible to completely prevent exposure. These substances are released throughout their life cycles, from chemical production to product use and disposal. Up to 80% of environmental pollution from common PFAS, such as PFOA, comes from production of fluoropolymers that use toxic PFAS as processing aids to make products like Teflon.

In 2009 the EPA established a health advisory level for PFOA in drinking water of 400 parts per trillion. Health advisories are not binding regulations – they are technical guidelines for state, local and tribal governments, which are primarily responsible for regulating public water systems.

In 2016 the agency dramatically lowered this recommendation to 70 parts per trillion. Some states have set far more protective levels – as low as 8 parts per trillion.

According to a recent estimate by the Environmental Working Group, a public health advocacy organization, up to 110 million Americans could be drinking PFAS-contaminated water. Even with the most advanced treatment processes, it is extremely difficult and costly to remove these chemicals from drinking water. And it’s impossible to clean up lakes, river systems or oceans. Nonetheless, PFAS are largely unregulated by the federal government, although they are gaining increased attention from Congress.

Water treatment tanks
Part of a filtration system designed to remove PFAS from drinking water, Horsham Water and Sewer Authority, Horsham, Pennsylvania.
Bastiaan Slabbers/NurPhoto via Getty Images

Reducing PFAS risks at the source

Given that PFAS pollution is so ubiquitous and hard to remove, many health experts assert that the only way to address it is by reducing PFAS production and use as much as possible.

Educational campaigns and consumer pressure are making a difference. Many forward-thinking companies, including grocers, clothing manufacturers and furniture stores, have removed PFAS from products they use and sell.

[Understand new developments in science, health and technology, each week. Subscribe to The Conversation’s science newsletter.]

State governments have also stepped in. California recently banned PFAS in firefighting foams. Maine and Washington have banned PFAS in food packaging. Other states are considering similar measures.

I am part of a group of scientists from universities, nonprofit organizations and government agencies in the U.S. and Europe that has argued for managing the entire class of PFAS chemicals as a group, instead of one by one. We also support an “essential uses” approach that would restrict their production and use only to products that are critical for health and proper functioning of society, such as medical devices and safety equipment. And we have recommended developing safer non-PFAS alternatives.

As the EPA acknowledges, there is an urgent need for innovative solutions to PFAS pollution. Guided by good science, I believe we can effectively manage PFAS to reduce further harm, while researchers find ways to clean up what has already been released.The Conversation

Carol Kwiatkowski, Adjunct Assistant Professor of Biological Sciences, North Carolina State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

We estimate there are up to 14 million tonnes of microplastics on the seafloor. It’s worse than we thought



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Britta Denise Hardesty, CSIRO; Chris Wilcox, CSIRO, and Justine Barrett, CSIRO

Nowhere, it seems, is immune from plastic pollution: plastic has been reported in the high Arctic oceans, in the sea ice around Antarctica and even in the world’s deepest waters of the Mariana Trench.

But just how bad is the problem? Our new research provides the first global estimate of microplastics on the seafloor — our research suggests there’s a staggering 8-14 million tonnes of it.

This is up to 35 times more than the estimated weight of plastic pollution on the ocean’s surface.

What’s more, plastic production and pollution is expected to increase in coming years, despite increased media, government and scientific attention on how plastic pollution can harm marine ecosystems, wildlife and human health.

These findings are yet another wake-up call. When the plastic we use in our daily lives reaches even the deepest oceans, it’s more urgent than ever to find ways to clean up our mess before it reaches the ocean, or to stop making so much of it in the first place.

Breaking down larger plastic

Our estimate of microplastics on the seafloor is huge, but it’s still a fraction of the amount of plastic dumped into the ocean. Between 4-8 million tonnes of plastic are thought to enter the sea each and every year.




Read more:
Eight million tonnes of plastic are going into the ocean each year


Most of the plastic dumped into the ocean likely ends up on the coasts, not floating around the ocean’s surface or on the seafloor. In fact, three-quarters of the rubbish found along Australia’s coastlines is plastics.

A dead albatross with plastic in its stomach from Midway Atoll
Plastic including toothbrushes, cigarette lighters, bottle caps and other hard plastic fragments are found in the stomachs of many marine species.
Britta Denise Hardesty

The larger pieces of plastic that stay in the ocean can deteriorate and break down from weathering and mechanical forces, such as ocean waves. Eventually, this material turns into microplastics, pieces smaller than 5 millimetres in diameter.

Their tiny size means they can be eaten by a variety of marine wildlife, from plankton to crustaceans and fish. And when microplastics enter the marine food web at low levels, it can move up the food chain as bigger species eat smaller ones.

But the problem isn’t as well documented for microplastics on the seafloor. While plastics, including microplastics, have been found in deep-sea sediments in all ocean basins across the world, samples have been small and scarce. This is where our research comes in.

Collecting samples in the Great Australian Bight

We collected samples using a robotic submarine in a range of sea depths, from 1,655 to 3,062 metres, in the Great Australian Bight, up to 380 kilometres offshore from South Australia. The submarine scooped up 51 samples of sand and sediment from the seafloor and we analysed them in a laboratory.

Sampling of deep sea sediments took place using an underwater robot.
CSIRO, Author provided

We dried the sediment samples, and found between zero and 13.6 plastic particles per gram. This is up to 25 times more microplastics than previous deep-sea studies. And it’s much higher than studies in other regions, including in the Arctic and Indian Oceans.

While our study looked at one general area, we can scale up to calculate a global estimate of microplastics on the seafloor.

Using the estimated size of the entire ocean — 361,132,000 square kilometres — and the average number and size of particles in our sediment samples, we determined the total, global weight as between 8.4 and 14.4 million tonnes. This range takes into account the possible weights of individual microplastics.

How did the plastic get there?

It’s important to note that since our location was remote, far from any urban population centre, this is a conservative estimate. Yet, we were surprised at just how high the microplastic loads were there.

Plastic waste floating in the ocean
Areas with floating rubbish on the ocean’s surface have plastic on the seafloor.
Shutterstock

Few studies have conclusively identified how microplastics travel to their ultimate fate.

Larger pieces of plastic that get broken down to smaller pieces can sink to the seafloor, and ocean currents and the natural movement of sediment along continental shelves can transport them widely.

But not all plastic sinks. A 2016 study suggests interaction with marine organisms is another possible transport method.

Scientists in the US have shown microbial communities, such as bacteria, can inhabit this marine “plastisphere” — a term for the ecosystems that live in plastic environments. The microbes weigh the plastic down so it no longer floats. We also know mussels and other invertebrates may colonise floating plastics, adding weight to make them sink.




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Plastic pollution creates new oceanic microbe ecosystem


The type of rubbish will also determine whether it gets washed up on the beach or sinks to the seafloor.

For example, in a previous study we found cigarette butts, plastic fragments, bottlecaps and food wrappers are common on land, though rare on the seabed. Meanwhile, we found entangling items such fishing line, ropes and plastic bags are common on the seafloor.

Microplastics at the water's edge
We were surprised at just how high the microplastic loads were in such a remote location.
CSIRO

Interestingly, in our new study we also found the number of plastic fragments on the seafloor was generally higher in areas where there was floating rubbish on the ocean’s surface. This suggests surface “hotspots” may be reflected below.

It’s not clear why just yet, but it could be because of the geology and physical features of the seabed, or because local currents, winds and waves result in accumulating zones on the ocean’s surface and the seabed nearby.

Stop using so much plastic

Knowing how much plastic sinks to the ocean floor is an important addition to our understanding of the plastic pollution crisis. But stemming the rising tide of plastic pollution starts with individuals, communities and governments – we all have a role to play.

Reusing, refusing and recycling are good places to start. Seek alternatives and support programs, such as Clean Up Australia Day, to stop plastic waste from entering our environment in the first place, ensuring it doesn’t then become embedded in our precious oceans.




Read more:
The oceans are full of our plastic – here’s what we can do about it


The Conversation


Britta Denise Hardesty, Principal Research Scientist, Oceans and Atmosphere Flagship, CSIRO; Chris Wilcox, Senior Principal Research Scientist, CSIRO, and Justine Barrett, Research assistant, CSIRO

This article is republished from The Conversation under a Creative Commons license. Read the original article.

A brutal war and rivers poisoned with every rainfall: how one mine destroyed an island



Locals living downstream of the abandoned mine pan for gold in mine waste.
Matthew Allen, Author provided

Matthew G. Allen, The University of the South Pacific

This week, 156 people from the Autonomous Region of Bougainville, in Papua New Guinea, petitioned the Australian government to investigate Rio Tinto over a copper mine that devastated their homeland.

In 1988, disputes around the notorious Panguna mine sparked a lengthy civil war in Bougainville, leading to the deaths of up to 20,000 people. The war is long over and the mine has been closed for 30 years, but its brutal legacy continues.




Read more:
Bougainville has voted to become a new country, but the journey to independence is not yet over


When I conducted research in Bougainville in 2015, I estimated the deposit of the mine’s waste rock (tailings) downstream from the mine to be at least a kilometre wide at its greatest point. Local residents informed me it was tens of metres deep in places.

I spent several nights in a large two-story house built entirely from a single tree dragged out of the tailings — dragged upright, with a tractor. Every new rainfall brought more tailings downstream and changed the course of the waterways, making life especially challenging for the hundreds of people who eke out a precarious existence panning the tailings for remnants of gold.

The petition has brought the plight of these communities back into the media, but calls for Rio Tinto to clean up its mess have been made for decades. Let’s examine what led to the ongoing crisis.

Triggering a civil war

The Panguna mine was developed in the 1960s, when PNG was still an Australian colony, and operated between 1972 and 1989. It was, at the time, one of the world’s largest copper and gold mines.

It was operated by Bougainville Copper Limited, a subsidiary of what is now Rio Tinto, until 2016 when Rio handed its shares to the governments of Bougainville and PNG.

When a large-scale mining project reaches the end of its commercial life, a comprehensive mine closure and rehabilitation plan is usually put in place.




Read more:
PNG marks 40 years of independence, still feeling the effects of Australian colonialism


But Bougainville Copper simply abandoned the site in the face of a landowner rebellion. This was largely triggered by the mine’s environmental and social impacts, including disputes over the sharing of its economic benefits and the impacts of those benefits on predominantly cashless societies.

Following PNG security forces’ heavy-handed intervention — allegedly under strong political pressure from Bougainville Copper — the rebellion quickly escalated into a full-blown separatist conflict that eventually engulfed all parts of the province.

By the time the hostilities ended in 1997, thousands of Bougainvilleans had lost their lives, including from an air and sea blockade the PNG military had imposed, which prevented essential medical supplies reaching the island.

The mine’s gigantic footprint

The Panguna mine’s footprint was gigantic, stretching across the full breadth of the central part of the island.

The disposal of hundreds of millions of tonnes of tailings into the Kawerong-Jaba river system created enormous problems.

Rivers and streams became filled with silt and significantly widened. Water flows were blocked in many places, creating large areas of swampland and disrupting the livelihoods of hundreds of people in communities downstream of the mine. These communities used the rivers for drinking water and the adjacent lands for subsistence food gardening.

Several villages had to be relocated to make way for the mining operations, with around 200 households resettled between 1969 and 1989.

In the absence of any sort of mine closure or “mothballing” arrangements, the environmental and socio-economic impacts of the Panguna mine have only been compounded.

Since the end of mining activities 30 years ago, tailings have continued to move down the rivers and the waterways have never been treated for suspected chemical contamination.




Read more:
Environment Minister Sussan Ley faces a critical test: will she let a mine destroy koala breeding grounds?


Long-suffering communities

The 156 complainants live in communities around and downstream of the mine. Many are from the long-suffering village of Dapera.

In 1975, the people of Dapera were relocated to make way for mining activities. Today, it’s in the immediate vicinity of the abandoned mine pit. As one woman from Dapera told me in 2015:

I have travelled all over Bougainville, and I can say that they [in Dapera] are the poorest of the poor.

They, and others, sent the complaint to the Australian OECD National Contact Point after lodging it with Melbourne’s Human Rights Law Centre.

The complainants say by not ensuring its operations didn’t infringe on the local people’s human rights, Rio Tinto breached OECD guidelines for multinational enterprises.

The Conversation contacted Rio Tinto for comment. A spokesperson said:

We believe the 2016 arrangement provided a platform for the Autonomous Bougainville Government (ABG) and PNG to work together on future options for the resource with all stakeholders.

While it is our belief that from 1990 to 2016 no Rio Tinto personnel had access to the mine site due to on-going security concerns, we are aware of the deterioration of mining infrastructure at the site and surrounding areas, and claims of resulting adverse environmental and social, including human rights, impacts.

We are ready to enter into discussions with the communities that have filed the complaint, along with other relevant parties such as BCL and the governments of ABG and PNG.

A long time coming

This week’s petition comes after a long succession of calls for Rio Tinto to be held to account for the Panguna mine’s legacies and the resulting conflict.

A recent example is when, after Rio Tinto divested from Bougainville Copper in 2016, former Bougainville President John Momis said Rio must take full responsibility for an environmental clean-up.

And in an unsuccessful class action, launched by Bougainvilleans in the United States in 2000, Rio was accused of collaborating with the PNG state to commit human rights abuses during the conflict and was also sued for environmental damages. The case ultimately foundered on jurisdictional grounds.

Two people, one waist-deep in tailings.
Hundreds of millions of tonnes of tailings were deposited in the rivers.
Matthew Allen, Author provided

Taking social responsibility

This highlights the enormous challenges in seeking redress from mining companies for their operations in foreign jurisdictions, and, in this case, for “historical” impacts.

The colonial-era approach to mining when Panguna was developed in the 1960s stands in stark contrast to the corporate social responsibility paradigm supposedly governing the global mining industry today.




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Be worried when fossil fuel lobbyists support current environmental laws


Indeed, Panguna — along with the socially and environmentally disastrous Ok Tedi mine in the western highlands of PNG — are widely credited with forcing the industry to reassess its “social license to operate”.

It’s clear the time has come for Rio to finally take responsibility for cleaning up the mess on Bougainville.The Conversation

Matthew G. Allen, Professor of Development Studies, The University of the South Pacific

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The ocean is swimming in plastic and it’s getting worse – we need connected global policies now



Fotos593 / shutterstock

Steve Fletcher, University of Portsmouth and Keiron Philip Roberts, University of Portsmouth

It seems you cannot go a day without reading about the impact of plastic in our oceans, and for good reason. The equivalent of a garbage truck of plastic waste enters the sea every minute, and this increases every day. If we do nothing, by 2040 the amount of plastic entering the ocean will triple from 13 million tonnes this year, to 29 million tonnes in 2040. That is 50kg of waste plastic entering the ocean for every metre of coastline.

Add to that almost all the plastic that has entered the ocean is still there since it takes centuries to break down. It is either buried or broken down into smaller pieces and potentially passes up the food chain creating further problems.

Despite this, plastic has also been a saviour. During the COVID-19 pandemic plastic used in face masks, testing kits, screens and to protecting food has enabled countries to come out of lockdown during and support social distancing. We still need to use these items until sustainable and “COVID safe” alternatives are available. But we also need to look to the future to reduce our dependence on plastic and its impact on the environment. With plastic in the ocean being a global problem, we need global agreements and policies to reverse the plastic tide.




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Ambitious policies are needed

Environment ministers of the G20 group of the world’s most economically powerful countries and regions met on September 16 to discuss their immediate challenges, with marine plastic pollution a top priority. A key item for discussion was “safeguarding the planet by fostering collective efforts to protect our global commons”. This means working out how we can continue to use the planet’s resources sustainably without harming the environment.

A global analysis of plastics policies over the past two decades found that typical reactions to marine plastic litter were bans or taxes on individual or groups of plastic items within single countries. So far, 43 countries have introduced a ban, tax or levy on plastic bags. Other plastic packaging or single-use plastic products were banned in at least 25 countries, representing a population of almost 2 billion people in 2018.

But plastic waste doesn’t respect land or ocean borders, with mismanaged plastic waste easily migrating from country to country when leaked into the environment. Policies also need to consider the entire plastics life cycle to stand a chance of being effective. For example, the inclusion of easier to recycle plastics in consumer products sounds positive, but their actual recycling rate depends on effective sorting and collection of plastic waste, and appropriate infrastructure being in place.




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Ultimately, a joined up but adaptable set of rules and guidelines are needed so all plastic producers and users can prevent its leakage across all stages of the plastics life cycle.

The G20 has sought to lead action on marine plastic litter through a 2017 Action Plan on Marine Litter which set out areas of concern and possible policy interventions, and through connections to initiatives such as the UN Environment Programme’s Global Partnership on Marine Litter and most recently the Osaka Blue Ocean Vision. The Osaka vision was agreed under the Japanese G20 presidency in 2019 and commits countries to “reduce additional pollution by marine plastic litter to zero by 2050”. Although an agreement led by the G20, it now has the support of 86 countries.

But even with these agreements in place, plastic entering the ocean will still only reduce by 7% by 2040. We need ambitious new agreements as current and emerging policies do not meet the scale of the challenge.

A consensus is forming that the G20 and other global leaders must focus on a systemic change of the plastics economy. This includes focusing on “designing out” plastics, promoting technical and business innovation, immediately scaling up actions known to reduce marine plastic litter, and transitioning to a circular economy in which materials are fully recovered and reused. These actions have the potential to contribute to the G20’s vision of net-zero plastics entering the ocean by 2050, but only if ambitious actions are taken now.The Conversation

Steve Fletcher, Professor of Ocean Policy and Economy, University of Portsmouth and Keiron Philip Roberts, Research Fellow in Clean Carbon Technologies and Resource Management, University of Portsmouth

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How bushfires and rain turned our waterways into ‘cake mix’, and what we can do about it



The Murray River at Gadds Reserve in north east Victoria after Black Summer bushfires.
Paul McInerney, Author provided

Paul McInerney, CSIRO; Anu Kumar, CSIRO; Gavin Rees, CSIRO; Klaus Joehnk, CSIRO, and Tapas Kumar Biswas, CSIRO

As the world watched the Black Summer bushfires in horror, we warned that when it did finally rain, our aquatic ecosystems would be devastated.

Following bushfires, rainfall can wash huge volumes of ash and debris from burnt vegetation and exposed soil into rivers. Fires can also lead to soil “hydrophobia”, where soil refuses to absorb water, which can generate more runoff at higher intensity. Ash and contaminants from the fire, including toxic metals, carbon and fire retardants, can also threaten biodiversity in streams.




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As expected, when heavy rains eventually extinguished many fires, it turned high quality water in our rivers to sludge with the consistency of cake mix.

In the weeks following the first rains, we sampled from these rivers. This is what we saw.

Sampling the upper Murray River

Of particular concern was the upper Murray River on the border between Victoria and NSW, which is critical for water supply. There, the bushfires were particularly intense.

Sludge in Horse Creek near Jingellic following storm activity after the fire.
Paul McInerney/Author Provided

When long-awaited rain eventually came to the upper Murray River catchment, it was in the form of large localised storms. Tonnes of ash, sediment and debris were washed into creeks and the Murray River. Steep terrain within burnt regions of the upper Murray catchment generated a large volume of fast flowing runoff that carried with it sediment and pollutants.

We collected water samples in the upper Murray River in January and February 2020 to assess impacts to riverine plants and animals.

Our water samples were up to 30 times more turbid (cloudy) than normal, with total suspended solids as high as 765 milligrams per litre. Heavy metals such as zinc, arsenic, chromium, nickel, copper and lead were recorded in concentrations well above guideline values for healthy waterways.

Ash and sediment blanketing cobbles in the Murray River.
Paul McInerney/Author Provided

We took the water collected from the Murray River to the laboratory, where we conducted a number of toxicological experiments on duckweed (a floating water plant), water fleas (small aquatic invertebrates) and juvenile freshwater snails.

What we found

During a seven-day exposure to the bushfire affected river water, the growth rate of duckweed was reduced by 30-60%.

The water fleas ingested large amounts of suspended sediments when they were exposed to the affected water for 48 hours. Following the exposure, water flea reproduction was significantly impaired.

And freshwater snail egg sacs were smothered. The ash resulted in complete deaths of snail larvae after 14 days.




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These sad impacts to growth, reproduction and death rates were primarily a result of the combined effects of the ash and contaminants, according to our preliminary investigations.

But they can have longer-term knock-on effects to larger animals like birds and fish that rely on biota like snail eggs, water fleas and duckweed for food.

What happened to the fish?

Immediately following the first pulse of sediment, dead fish (mostly introduced European carp and native Murray Cod) were observed on the bank of River Murray at Burrowye Reserve, Victoria. But what, exactly, was their cause of death?

A dead Murray Cod found on the banks of the Murray River following storms after the bushfires.
Paul McInerney/Author Provided

Our first assumption was that they died from a lack of oxygen in the water. This is because ash and nutrients combined with high summer water temperatures can trigger increased activity of microbes, such as bacteria.

This, in turn can deplete the dissolved oxygen concentration in the water (also known as hypoxia) as the microbes consume oxygen. And wide-spread hypoxia can lead to large scale fish kills.




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But to our surprise, although dissolved oxygen in the Murray River was lower than usual, we did not record it at levels low enough for hypoxia. Instead, we saw the dead fish had large quantities of sediment trapped in their gills. The fish deaths were also quite localised.

In this case, we think fish death was simply caused by the extremely high sediment and ash load in the river that physically clogged their gills, not a lack of dissolved oxygen in the water.

These findings are not unusual, and following the 2003 bushfires in Victoria fish kills were attributed to a combination of low dissolved oxygen and high turbidity.

So how can we prepare for future bushfires?

Preventing sediment being washed into rivers following fires is difficult. Installing sediment barriers and other erosion control measures can protect specific areas. However, at the catchment scale, a more holistic approach is required.




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One way is to increase efforts to re-vegetate stream banks (called riparian zones) to help buffer the runoff. A step further is to consider re-vegetating these zones with native plants that don’t burn easily, such as Blackwood (Acacia melanoxylin).

Streams known to host rare or endangered aquatic species should form the focus of any fire preparation activities. Some species exist only in highly localised areas, such as the endangered native barred galaxias (Galaxias fuscus) in central Victoria. This means an extreme fire event there can lead to the extinction of the whole species.

Ash and dead fish on the banks of the Murray River near Jingellic following Black Summer fires.
Paul McInerney/Author Provided

That’s why reintroducing endangered species to their former ranges in multiple catchments to broaden their distribution is important.

Increasing the connectivity within our streams would also allow animals like fish to evade poor water quality — dams and weirs can prevent this. The removal of such barriers, or installing “fish-ways” may be important to protecting fish populations from bushfire impacts.

However, dams can also be used to benefit animal and plant life (biota). When sediment is washed into large rivers, as we saw in the Murray River after the Black Summer fires, the release of good quality water from dams can be used to dilute poor quality water washed in from fire affected tributaries.




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Citizen scientists can help, too. It can be difficult for researchers to monitor aquatic ecosystems during and immediately following bushfires and unmanned monitoring stations are often damaged or destroyed.

CSIRO is working closely with state authorities and the public to improve citizen science apps such as EyeOnWater to collect water quality data. With more eyes in more areas, these data can improve our understanding of aquatic ecosystem responses to fire and to inform strategic planning for future fires.

These are some simple first steps that can be taken now.

Recent investment in bushfire research has largely centred on how the previous fires have influenced species’ distribution and health. But if we want to avoid wildlife catastrophes, we must also look forward to the mitigation of future bushfire impacts.The Conversation

Paul McInerney, Research scientist, CSIRO; Anu Kumar, Principal Research Scientist, CSIRO; Gavin Rees, Principal Research Scientist, CSIRO; Klaus Joehnk, Principal research scientist, CSIRO, and Tapas Kumar Biswas, Senior scientist, CSIRO

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How Earth’s plastic pollution problem could look by 2040



Rich Carey/Shutterstock

Costas Velis, University of Leeds and Ed Cook, University of Leeds

During a visit to a bookstore a few weeks ago, we couldn’t help but stare at a display unit featuring no fewer than ten books telling you how to rid plastics from your daily life. We’re bombarded by information on the topic of marine litter and plastic pollution, but how much do we really know about the problem?

Think about other planetary challenges, like climate change or ozone layer depletion. Mature areas of research have developed around them, allowing scientists to identify where the gases that cause these problems come from, and how much reaches the atmosphere each year.

But when it comes to plastic pollution, we know close to nothing about how and where plastic waste is generated, managed, treated and disposed of, especially in low and middle income countries. As a result, we’re struggling to limit the amount of litter accumulating in the environment.

Our research published in Science involved a herculean effort to spot, track and model the current and future flows of plastics into the world’s land and waterbodies. We found that plastic entering the marine environment is set to double by 2040 and, unless the world acts, more than 1.3 billion tonnes of plastic waste will be dumped on land and in waterbodies.

By identifying the ways in which this litter is produced and distributed, we’ve also discovered how best to reduce the plastic deluge. In the process, we found the unsung heroes on the frontline fighting the pollution crisis who could be the world’s best hope of stemming the tide.

Discarded face masks on a rocky beach.
Single-use plastic consumption has increased during the pandemic.
Fevziie/Shutterstock

The world’s plastic problem in numbers

We developed a model called Plastic-to-Ocean (P₂O) which combines years of accumulated knowledge on global flows of plastic. It compares our current production, use and management of waste with what is projected in the future.

Do you burn your waste in the garden or in the street? Do you drop it into the river? If you answered no to both of these questions then you are possibly one of the 5.5 billion people whose waste gets collected. If you were among the remaining two billion, what would you do with your uncollected waste? Would you make use of a nearby stream, cliff edge, or perhaps squirrel the odd bag in the woods after dusk?

More often than not, uncollected plastic waste is simply set on fire as a cost-free and effective method of disposal. Our model suggests that cumulatively, more than 2.2 billion tonnes of plastic will be open burned by 2040, far more than the 850 million tonnes that’s anticipated to be dumped on land and the 480 million tonnes in rivers and seas.

Having tracked the sources of plastic items through the supply chain and their fate in the environment, we explored what might help reduce aquatic pollution. We found that the single most effective intervention is to provide a service for the two billion people who currently don’t have their waste collected.

A graph showing how different measures could reduce the flow of plastic into the ocean.

Breaking the Plastic Wave, Author provided

But, of the nine interventions we tested, none solved the problem on their own. Only an integrated approach that in addition to increasing collection coverage includes interventions such as reducing demand for single-use and unrecyclable plastic and improving the business case for mechanical recycling, could be successful. For the countries suffering most from plastic pollution, this knowledge could offer a way forward.

But even in our best-case scenario, in which the world takes the kind of concerted and immediate action proposed in our study, approximately 710 million tonnes of plastic waste will be released into the environment by 2040. That may sound a lot, but it would mean an 80% reduction in the levels of plastic pollution compared to what will happen with no action over the next two decades.




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Could waste pickers save the day?

Our work also cast light on the contributions of 11 million waste pickers in low and middle-income countries. These informal workers collect waste items, including plastics, for recycling, to secure a livelihood for day-to-day survival. The model estimates that they may be responsible for 58% of all plastic waste collected for recycling worldwide – more than the combined formal collection services achieve throughout all the high-income countries put together.

Without this informal waste collection sector, the mass of plastic entering rivers and the ocean would be considerably greater. Their efforts should be integrated into municipal waste management plans, not only to recognise their tremendous contribution but to improve the appalling safety standards that they currently endure.

A man in India peddles a bicycle cart to collect rubbish.
An additional 500,000 people will need to be reached by waste collection services each day until 2040.
EPA-EFE/JAIPAL SINGH

Establishing a comprehensive baseline estimate of sources, stocks and flows of plastic pollution, and then projecting into the future, has been an immense task. When it comes to solid waste, the availability, accuracy and international compatibility of data is notoriously insufficient.

Plastic items occur throughout the world in tens of thousands of shapes, sizes, polymer types and additive combinations. There are also considerable differences in cultural attitudes towards the way waste is managed, how plastic products are consumed, and the types of infrastructure and equipment used to manage it when it becomes waste.

Our modelling effort was a delicate and tedious exercise of simplifying and generalising this complexity. To understand how reliable, accurate, and precise our findings are likely to be, think of the first models that estimated how sensitive the climate is to human influence back in the 1970s.

Hopefully, the strong evidence base we have presented today will inform a global strategy and strong local preventive action. The plastic pollution challenge can be substantially controlled within a generation’s time. So, is anyone ready to act?The Conversation

Costas Velis, Lecturer in Resource Efficiency Systems, University of Leeds and Ed Cook, Research Fellow in Circular Economy Systems, University of Leeds

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How to cut your fuel bill, clear the air and reduce emissions: stop engine idling



shutterstock.

Robin Smit, University of Technology Sydney and Clare Walter, The University of Queensland

The transport sector is Australia’s second-largest polluter, pumping out almost 20% of our total greenhouse gas emissions. But everyday drivers can make a difference.

In particular, the amount of time you let your car engine idle can have a significant impact on emissions and local air quality. Engine idling is when the car engine is running while the vehicle is stationary, such as at a red light.

Opting for a bike is a great way to reduce your carbon footprint.
Shutterstock

A new Transport Energy/Emission Research report found in normal traffic conditions, Australians likely idle more than 20% of their drive time.

This contributes 1% to 8% of total carbon dioxide emissions over the journey, depending on the vehicle type. To put that into perspective, removing idling from the journey would be like removing up to 1.6 million cars from the road.




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Excessive idling (idling for longer than five minutes) could increase this contribution further, particularly for trucks and buses. When you also consider how extensive idling may create pollution hot spots around schools, this isn’t something to take lightly.

Pollution hot spots

Reducing idling doesn’t just lower your carbon footprint, it can also lower your fuel costs up to 10% or more.

Drivers simply have to turn their engines off while parked and wait in their vehicle. Perhaps crack open a window to maintain comfortable conditions, rather than switching on the air conditioner.

Some idling is unavoidable such as waiting for a traffic light or driving in congested conditions, but other idling is unnecessary, such as while parked.




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When many cars are idling in the same location, it can create poor local air quality. For example, idling has been identified overseas as a significant factor in higher pollution levels in and around schools. That’s because parents or school buses don’t turn off their engines when they drop off their kids or wait for them outside.

Parked you car? Turn off the engine.
Shutterstock

Even small reductions in vehicle emissions can have health benefits, such as reducing asthma, allergies and systemic inflammation in Australian children. In 2019, Australian researchers identified that even small increases of exposure to vehicle pollution were associated with an increased risk of childhood asthma and reduced lung function.

Anti-idling campaigns make a difference

Overseas studies show anti-idling campaigns and driver education can help improve air quality around schools, with busses and passenger cars switching off their engines more frequently.

In the US and Canada, local and state governments have enacted voluntary or mandatory anti-idling legislation, to address complaints and reduce fuel use, emissions and noise.

The results have been promising. In California, a range of measures – including anti-idling policies – aimed at reducing school children’s exposure to vehicle emissions were linked to the development of larger, healthier lungs in children.




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But in Australia, we identified almost no anti-idling initiatives or idle reduction legislation, despite calls for them in 2017.

However, “eco-driving”, as well as a promising new campaign called “Idle Off” is poised to roll out to secondary school students in Australia.

What about commercial vehicles?

Commercial vehicles can idle for long periods of time. In the US, typical long-haul trucks idle an estimated 1,800 hours per year when parked at truck stops, although a significant range of between 1,000 and 2,500 hours per year has also been reported.




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Fleet operators and logistics companies are therefore in a good position to roll out idle reduction initiatives and save on operating (fuel) costs while reducing emissions.

In fact, fleet operators overseas have actively sought to reduce idling emissions. This is not surprising as fuel costs are the second-largest expense for fleets, behind driver wages, typically accounting for 20% of a trucking fleet’s total operating costs.

The transport sector contributes 18.8% of Australia’s total emissions.
Shutterstock

Various technologies are available overseas that reduce idling emissions, such as stop-start systems, anti-idling devices (trucks) and battery electric vehicles.

But unlike other developed countries, Australia doesn’t have fuel efficiency or carbon dioxide emission standards. This means vehicle manufacturers have no incentive to include idle reduction technologies (or other fuel-saving technologies) in vehicles sold in Australia.

For example, the use of stop-start systems is rapidly growing overseas, but it’s unclear how many stop-start systems are used in new Australian cars.

Emission reduction technologies also come with extra costs for the vehicle manufacturer, making them less appealing, although cost benefits of reduced fuel use would pass on to consumers. This situation probably won’t change unless mandatory emission standards are implemented.

In any case, it’s easy for drivers to simply turn the key and shut down the engine when suitable. Reducing idling doesn’t require technologies.

Reducing your carbon footprint

If reducing emissions or saving money at the fuel bowser is not enough incentive, then perhaps, in time, exposing children to unnecessary idling emissions will be regarded in the same socially unacceptable light as smoking around children.




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And of course, there are other measures to reduce your transport carbon footprint. Drive a smaller car, and avoid diesel cars. Despite their reputation, Australian diesel cars emit, on average, about 10% more carbon dioxide per kilometre than petrol cars.

Or better yet, where possible, dust off that push bike, or walk.The Conversation

Robin Smit, Adjunct associate professor, University of Technology Sydney and Clare Walter, PhD Candidate, Honorary Research Fellow, Advocacy Consultant., The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

More than 1,200 tonnes of microplastics are dumped into Aussie farmland every year from wastewater sludge


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Abbas Mohajerani, RMIT University

Every year, treated wastewater sludge called “biosolids” is recycled and spread over agricultural land. My recent research discovered this practice dumps thousands of tonnes of microplastics into farmlands around the world. In Australia, we estimate this amount as at least 1,241 tonnes per year.

Microplastics in soils can threaten land, freshwater and marine ecosystems by changing what they eat and their habitats. This causes some organisms to lose weight and have higher death rates.

But this is only the beginning of the problem. Microplastics are good at absorbing other pollutants – such as cadmium, lead and nickel – and can transfer these heavy metals to soils.

Wastewater treatment plants create biosolids, which are packed full of microplastics and toxic chemicals.
Shutterstock

And while microplastics alone is an enormous issue, other contaminants have also been found in biosolids used for agriculture. This includes pharmaceutical chemicals, personal care products, pesticides and herbicides, surfactants (chemicals used in detergents) and flame retardants.

We must stop using biosolids for farmlands immediately, especially when alternative ways to recycle wastewater sludge already exist.

Where do the microplastics come from?

Biosolids are mainly a mix of water and organic materials.

But many household items that contain microplastics – such as lotions, soaps, facial and body washes, and toothpaste – end up in wastewater, too. Other major sources of microplastics in wastewater are synthetic fibres from clothing, plastics in the manufacturing and processing industries, and the breakdown of larger plastic debris.

Before they’re taken to farmlands, wastewater collection systems carry all, or most, of these microplastics and other chemicals from residential, commercial and industrial sources to wastewater treatment plants.

To determine the weight of microplastics in Australia and other countries, my data analysis used the average minimum and maximum numbers of microplastics particles, per kilogram of biosolids samples, found in Germany, Ireland and the USA.




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Australia produced 371,000 tonnes of biosolids in 2019. And globally, we estimate between 50 to more than 100 million tonnes of biosolids are produced each year.

Why microplastics are harmful

Microplastics in soil can accumulate in the food web. This happens when organisms consume more microplastics than they lose. This means heavy metals attached to the microplastics in soil organisms can progress further up the food chain, increasing the risk of human exposure to toxic heavy metals.

When microplastics accumulate heavy metals, they transfer these contaminants to plants and crops, such as rice and grains, as biosolids are spread over farmland.




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Over time, microplastics break down and become even tinier, creating nanoplastics. Crops have also been shown to absorb nanoplastics and move them to different plant tissues.

Our research results also show that after the wastewater treatment process, the absorption potential of microplastics for metals increases.

The metal cadmium, for example, is particularly susceptible to microplastics in biosolids and can be transported to plant cells. Research from 2018 showed microplastics in biosolids can absorb cadmium ten times more than virgin microplastics (new microplastics that haven’t gone through wastewater treatment).

Biosolids have a cocktail of nasty chemicals

It’s not just plastic – many industrial additives and chemicals have been found in wastewater and biosolids.

This means they may accumulate in soils and affect the equilibrium of biological systems, with negative effects on plant growth. For example, researchers have found pharmaceutical chemicals in particular can reduce plant growth and inhibit root elongation.




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Other chemical contaminants – such as PFCs, PFAS and BPA – have likewise been detected in biosolids.

The effects these chemicals have on plants may lead to problems further down the food chain, such as humans and other animals inadvertently consuming pharmaceuticals and harmful chemicals.

What can we do about it?

Given the cocktail of toxic chemicals, heavy metals and microplastics, using biosolids in agricultural soils must be stopped without delay.

The good news is there’s another way we can recycle the world’s biosolids: turning them into sustainable fired-clay bricks, called “bio-bricks”.

Bricks incorporated with biosolids are a sustainable solution to an environmental problem.
RMIT media, Author provided

My team’s research from last year found bio-bricks a sustainable solution for both the wastewater treatment and brick manufacturing industries.

If 7% of all fired-clay bricks were biosolids, it would redirect all biosolids produced and stockpiled worldwide annually, including the millions of tonnes that currently end up in farmland each year.




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We also found they’d be more energy efficient. The properties of these bio-bricks are very similar to standard bricks, but generally requires 12.5% less energy to make.

And generally, comprehensive life-cycle assessment has shown biosolid bricks are more environmentally friendly than conventional bricks. These bricks will reduce or eliminate a significant source of greenhouse gas emissions from biosolids stockpiles and will save some virgin resources, such as clay soil and water, for the brick industry.

Now, it’s up to the agriculture, wastewater and brick industries, and governments to make this important transition.The Conversation

Abbas Mohajerani, Associate Professor, School of Engineering, RMIT University

This article is republished from The Conversation under a Creative Commons license. Read the original article.