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February, 2016:

OECD calls for urgent research into risks from nanomaterials in household waste

In a new report on nanomaterials and waste, the OECD has expressed concern that too little is being done to control the rapidly expanding presence of nanomaterials in the waste stream.

The dramatic increase in the number of products containing nanomaterials has resulted in a significant increase in the quantities of nanomaterials entering the waste system. Waste treatment methods and facilities are not generally able to remove these nanomaterials and they are ending up in our water and soil.

Many of these nanomaterials, such as titanium dioxide, are known to be toxic to aquatic organisms. Some, such as nanosilver, which kills microbes, can accumulate in soil. Others can be taken up by food plants and enter the food chain.

The OECD report sees the use of wastewater sludge on agricultural lands as the most alarming issue because of likely effects on soil and plant health.

This is an urgent issue and both State and Federal Governments need to respond. In Australia, where nanomaterials are virtually unregulated, nanomaterials can now be found in food, cosmetics, paints, toothpaste, tennis rackets, baby bottles, appliances…in fact, in almost any consumer product. We don’t know which nanomaterials are being used in what products, what quantities are entering the waste stream, where those materials are ending up – or what impact they are already having on the environment and human health.

While far too little research has been done on the environmental impacts of nanomaterials, we know enough regarding the risks associated with nanomaterials to be able to say that allowing the unregulated and unrestricted release of nanomaterials into the environment needs to stop.

The first step is a mandatory register of nanomaterials. We also need an immediate investigation by the Federal Department of the Environment to determine the scale of the pollution, the impacts to date and the regulations and technologies that are necessary to protect the environment from adverse impacts.

Zero waste press conference against landfill in Debagoiena, Basque Country

A group of citizens from Debagoiena held a press conference on February 16 in front of the Community of Debagoiena with the slogan “Landfill no!”. Among people who took part were members of Zero Waste Gipuzkoa (Zero Zabor).

They emphasized that Debagoiena is separately collecting 80% of their waste, while the rest of the municipalities reach under 50% separate collection, this is why they have underlined that they will start speaking about “solidarity” when “others start to be responsible”.

They will not accept receiving mixed waste in Debagoiena and they demand Debagoiena municipality refuses the landfill project in Epele. Their aim is to create a regional proponent to work in order to fulfil these goals.

In the press conference, they have said the following:

“Most of the waste which is not recycled or composted in Gipuzkoa is going to be thrown without any treatment in Debagoiena. 100,000 tons of mixed waste will be brought to our region, while within Debagoiena we are generating only 5,000 tons of waste.

We know that these kind of landfills create many problems, both in terms of health and environment: bad smells, an increase of rats and scavenger birds, the coming and goings of large lorries, methane, large amounts of land taken over, pollution of streams and aquifers due to leaching…

The solution is not to build an expensive and polluting infrastructure, the example of Debagoiena is a role model for a healthy solution. Our region is doing things well, important organisations have congratulated us and we have become a reference point in Europe because we have recycled 78% of our waste. But we haven’t got this results out of respect for the environment.

We have got it due to compulsory separate collection (with containers in some places and with cubes in others) and we think the results are improvable. If only Gipuzkoa would recycle the same percentage, things would be completely different and we would not need toxic incinerators or polluter landfills.”

Croatian municipalities adopt ‘Zero Waste 2020’ strategy

Since 2006 the seven municipalities of the lower Međimurje (The City of Prelog and the municipalities of Kotoriba, Donja Dubrava, Donji Vidovec, Sveta Marija, Goričan and Donji Kraljevec) have been developing a joint waste management system. Organised by the municipally owned company Pre-Kom, waste has been separately collected in the region since 2007. With the region currently ranked top in terms of separate collection within Croatia, it seemed the next logical step was the creation of a society without waste, or the implementation of a ‘Zero Waste Strategy’.

Zero Waste 2020 commitments

By the adoption of a ‘Zero Waste Strategy’ the municipalities of the region have committed to meeting the following waste management conditions by 2020:

  • 70% of useful waste to be extracted, processed and recovered (recycling, composting, anaerobic processing, or other acceptable means of useful waste recovery) through separate waste collection.
  • The amount of bulky waste and combined waste will be reduced from the current (2015) level of 98.8 kilograms per capita per year to 50 kilograms per capita per year by 2020.
  • The priorities in the field of waste management (prevention of waste, reuse and recycling) will be reinforced to the fullest extent, waste incineration will be avoided, the amount of waste deposited on landfills will be reduced to the lowest possible level.
  • An analysis of useless waste will be conducted yearly, and an operative strategy and campaigns for further improvement in waste management will be defined based on the results of the analysis.

In addition to the initiated activities in waste management, and according to Waste management plans of municipalities of lower Međimurje, the municipalities commit to start and take part in the following activities:

  • Organising educational sessions related to sustainable development and waste management and to promote the zero waste development strategy.
  • Work on projects related to reuse of the collected waste (clothing, shoes, etc.).
  • Promote separate waste collection of biodegradable communal waste and the composting of it.
  • Promote the use of compost given back to users.
  • Promote increasing the amount of households included in the waste management system.
  • Introduce a billing system based on the volume of collected waste.
  • Start projects on all levels of development, or public and private initiatives in order to secure improvement of living standards and sustainable development in their areas.
  • Encourage green construction using environmentally friendly materials.
  • Take part in sustainable mobility (car sharing, walking, bus transport, etc.).
  • Promote new lifestyles (tourism, catering, Fair trade commerce, etc.).

In order to track their progress, the municipalities have formed the ‘Council for Waste Management in Lower Međimurje’ which will track the fulfilment of the goals of the international strategy for “Zero waste”, this council will consist of:

  • The Mayor and municipality heads of ULGs
  • The Director of PRE-KOM.
  • A representative of Zero Waste Europe / Zelena akcija

The president of the Council is a Director of PRE-KOM, and the council will meet at least once every six months.

In adopting a ‘Zero Waste Strategy’ the region of Lower Međimurje will join an international community of municipalities moving towards zero waste. This community includes; New Zealand (the first country in the world to include the Strategy in its national legislation), New Scotia, British Columbia in Canada, Buenos Aires in Argentina, San Francisco in California, Canberra in Australia and many other local communities, regions and cities across the EU.

The municipalities of lower Međimurje are becoming a key example of good practice in waste management, and an exemplary model for other local communities in Croatia and around the world in the struggle towards a zero waste society.

Current waste management practices & infrastructure

In the area of lower Mešimurje, mixed communal waste is collected in black containers, biodegradable communal waste is collected in brown containers, bulky waste is collected after a phone call, paper and carton are collected in blue containers or bags, plastics in yellow containers or bags and metal and glass are collected in free bags. Aside from the gathering infrastructure, Pre-Kom. manages a composting plant, a sorting plant and a recycling yard.

Amounts of bulky and mixed communal waste disposed on a landfill per household:

  • 2011 2,888 t — 424 kilograms per household (128.5 kg per capita)
  • 2012 2,801 t — 409 kilograms per household (123.9 kg per capita)
  • 2013 2,794 t — 407 kilograms per household (123.9 kg per capita)
  • 2014 2,862 t — 412 kilograms per household (124.8 kg per capita)
  • 2015 2,299 t — 326 kilograms per household (98.9 kg per capita)

Amount of separately collected, processed and recovered waste:

  • 2011 16.93 %
  • 2012 19.04 %
  • 2013 19.63 %
  • 2014 22.39 %
  • 2015 49.58 %

By completion of the separate waste collection system and by introducing containers for biodegradable waste, Pre-Kom. has already significantly increased the amount of separately collected waste in 2015, compared to 2014. Analysis show an increase in other materials collected separately door-to-door. In 2015, 49,58% of waste has been collected and processed separately, which is a better than EU average of 43%. The results weren’t achieved quickly, they were achieved by continual investments and upgrades to the waste management system.

Considering what has already been achieved, municipalities of lower Međimurje aspire to demonstrate some of the best waste management practices in the world and to lead the way a zero waste society.

Still looking at artificial islands plan

I refer to the article by Dr Martin Williams (“Extreme folly of reclamation amid rising sea levels”, February 4). I would like to provide relevant information for reference to your readers.

Hong Kong is committed to working together with the international community to combat the challenge of climate change. Among the measures, the Civil Engineering and Development Department is updating the existing design guidelines for coastal structures including reclamation works, making reference to the latest assessment -reports published by the Intergovernmental Panel on Climate Change to take into account the predicted sea level rise.

Reclamation is a recognised major source of land formation for coastal cities worldwide. In 2013, the government conducted a public engagement exercise on the enhanced land supply strategy and identified the central waters between Lantau and Hong Kong Island as having good potential for development of artificial islands for accommodating populations and as a new core business district.

Against this background, the government has proposed to carry out technical studies to determine the feasibility and suitability of the reclamation.

While no position has been taken on the proposal at this stage, the works departments reckon that purely on the technical ground of coastal defence against severe weather conditions, there is no reason to regard the construction of artificial islands as “folly”.

The design standards and technology for reclamation works and coastal defence structures will take into consideration the probable severe weather conditions, including storm surges.

Paul C. K. Chu, senior engineer/public relations, Civil Engineering and Development Department
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New HK$43.7bn Kowloon highway project to cost 3.4 times more than expected

The financial budget unveiled on Wednesday revealed that the latest estimates for the new Central Kowloon route highway project stand at HK$43.7 billion. The sum is 3.4 times more than original the amount tabled in 2002.

The infrastructure project is set to commence during the next financial year. According to the Highways Department website, the highway will extend for 4.7km from Yau Ma Tei through to the Kai Tak Development and Kowloon Bay. It is expected to relieve traffic congestion in Central Kowloon and includes a 3.9km long tunnel.

It is predicted that the construction of the highway will take seven years and could be online by 2023.

Proposed Central Kowloon route. Photo: GovHK.

Proposed Central Kowloon route. Photo: GovHK.

The cost of the project was adjusted in 2002, when it was proposed that the highway could carry three lanes instead of two. It was then predicted that the project will cost HK$10 billion. Now, at HK$43.7 billion, each kilometre averages HK$9.2 billion, much higher than the high-speed rail’s average cost at HK$3.2 billion per kilometre, Ming Pao reported.

The Executive Council authorised the project last month, but no price was stated in the gazette, RTHK reported.

Proposed Central Kowloon route. Photo:

Proposed Central Kowloon route. Photo:

The Professional Commons convenor Albert Lai Kwong-tak said that it was unreasonable for the project to have a threefold increase in cost and said the government could be overestimating the cost of the project due to pressure surrounding over expenditure in projects in recent years.

“It’s a self-defence mechanism – better to overestimate than underestimate,” he said.

The Highways Department has yet to respond to media inquiries by RTHK and Ming Pao.

Big business wins again in John Tsang’s budget for Hong Kong

Philip Bowring says the financial secretary has again presented a budget that coddles the rich and powerful while offering mere crumbs to SMEs and disadvantaged groups

Financial Secretary John Tsang Chun-wah may be “distressed and angry” at recent evidence of social conflict, but his highly political budget speech did not suggest an understanding of the “why”.

That surely includes an unrepresentative government comprised of lifetime bureaucrats turned politicians who find it hard to think outside their own little 1970s-designed boxes.

Our fiscal reserves have become a fetish designed to limit spending on social needs

Tsang has been in the job for nine years, but he has yet to make any progress in resolving what the government itself has long admitted is a serious fiscal flaw – the dependence on land price inflation and volatile stamp duty revenue. Broadening the tax base has long been a stated goal. Yet, again, he has made the problem worse by reducing the reach of salaries tax, and by a rates waiver.

Salaries tax now accounts for a pitiful 12 per cent of revenue as the government becomes ever more reliant on less stable sources, including profits tax (28 per cent) – which is now vulnerable to foreign or mainland crackdowns on tax avoidance through transfer pricing. For sure, the cuts are supposed to be temporary, but he will have a hard time reversing the salaries tax concession next year, particularly if the economy continues to face stiff headwinds. As it is, he says the local economy is “laden with risks “ for the coming year.

The claim that his tax concessions will boost the economy by 1 per cent hides the fact that the government has been a contractionary force on the economy for the past year (and beyond) through its accumulation of reserves. If Tsang’s budget forecasts are correct, the government will at best be neutral. He also vastly overstates the impact that a slew of little measures to help tourism, small and medium-sized enterprises, IT and robotics industry development and the like can have in an open economy. Nor should government be involved in promoting events like the Rugby Sevens tournament – which is always sold out anyway! Government exists to facilitate, not subsidise.

The surplus for 2015/16 was actually bigger than it first appears, as Tsang continued the policy of squirrelling away yet more revenue into special, hard-to-reach reserve funds. For the second year running, almost all the income from investment of the reserves has been credited not, as was and should be the case, to operating revenue but transferred to the Housing Reserve.

This kind of manipulation of the accounts both to conceal surpluses and make them harder to access in future is, Tsang should consider, one reason for distrust of government. As it is, the Future Fund was created with the express purpose of not being touchable for at least 10 years and now comprises HK$219 billion of the fiscal reserves. The fund is supposed to invest longer term, but no details of its performance are available.

Meanwhile, the return on the other reserves are estimated at a miserable 3.3 per cent for 2016 and 2.6 per cent to 3.5 per cent average for 2017 to 2020 – barely above the projected rate of consumer price inflation (2.5 per cent). Clearly these funds would be better invested if distributed to the public for their pension plans.

Tsang again misleads by stating that the fiscal reserves “are all we have at our disposal”, conveniently forgetting the HK$600 billion retained profits of the Monetary Authority, which is an arm of government and does not need these for exchange rate management. As for the statement that “our fiscal reserves are the mainstay of our economy”, this can only be described as arrogant nonsense. They have become a fetish designed to limit spending on social needs. Meanwhile, lavish spending on capital projects with little or no financial or economic return steams ahead to satisfy “one country” or local vested-interest demands.

Tsang peppered his speech with references to the increasing burdens of an ageing society. Future belt-tightening was called for to avoid resulting deficits. Yet Tsang’s own forecasts for the coming five years show capital spending rising by 50 per cent, to HK$132 billion, while operating spending rises just 25 per cent. So, clearly, we are going to have to pay for more mega projects with minimal returns while health, welfare and education are squeezed.

Tsang did not go into specifics other than mention a desalination plant, a bizarre project for which no economic case has been made and for which there is surely no political justification.

The budget does contain a number of small measures to help the elderly but these are minor compared with tax cuts. And with all the emphasis on an ageing society, why not some real effort to raise the extraordinarily low fertility level by reducing the opportunity costs of raising children? Tsang’s idea of investing in the future is clearly one of pouring concrete, not investing in a new generation through childcare facilities, job protection for nursing mothers and other relatively low-cost ways of addressing this aspect of the ageing problem.

The government talks a lot about the problem of income disparities. These are clearly most visible among the elderly and young, low-income families. Yet this budget will, if anything, make matters worse. Nor will any amount of hand-wringing over riots, or budget crumbs for SMEs, counter the widespread public view that big business, whether property, construction or retailing, is always favoured by government policies.

Philip Bowring is a Hong Kong-based journalist and commentator

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Hong Kong needs a bolder action plan to protect its environmental legacy

Michael Lau and Gavin Edwards say the government has let Hongkongers down with its safe and ineffective framework for public discussion on a strategy to safeguard our amazing biodiversity
Hong Kong’s subtropical climate and unique position at the mouth of the Pearl River mean the city is blessed with an amazing diversity of plant and animal life. The need to protect the diversity of life on earth is enshrined in the UN Convention on Biological Diversity, which also extends to Hong Kong.

In his 2013 policy address, Chief Executive Leung Chun-ying committed to develop a biodiversity strategy and action plan [1] to help implement the convention locally. Unusually for Hong Kong, a participatory approach was embraced, with academics, environmental NGOs, professionals and other stakeholders invited to develop a set of recommendations for Hong Kong’s first biodiversity strategy for 2016-2020.

After more than a year of intense work by more than 100 experts and stakeholders, over 400 recommendations have been produced and grouped into 33 draft key actions. They are aimed at strengthening conservation across the territory, to find a better balance between urban development and environmental protection. A public consultation is being held until April 7 [2], after which the government will produce a final action plan.

However, most of the 400 recommendations have been omitted from the consultation document, and most of the 33 draft key actions have not been directly incorporated. Instead, there are 25 pages summarising previous or ongoing initiatives to conserve biodiversity, and only 17 pages on an action plan.

A closer inspection of the consultation document reveals a mixture of vague “possible actions” and restating of existing government commitments, such as implementing ongoing species action plans even though they are falling short – for example, in relation to the decline of the Chinese white dolphin. This is in stark contrast to the call by the UN convention for an effective and practical action plan.

There is also a danger that the government will be tempted to take the easy route in formulating its action plan, by prioritising research and awareness-raising, with less emphasis on new direct conservation action. This takes responsibility away from government – for example, research can be undertaken by academics and non-governmental organisations, whereas only the government can lead on specific policies.

Also, research, while an essential component of conservation, won’t directly result in an improvement in our natural environment. Such an approach is also contrary to the UN convention’s “precautionary principle”, which states that “where there is a threat of significant reduction or loss of biological diversity, then lack of full scientific certainty should not be used as a reason for postponing measures to avoid or minimise such a threat”.

More worryingly, the consultation document emphasises enhancing existing conservation measures, implying that the government has no interest in introducing new measures to protect our natural heritage.

So, what more should the action plan contain? The answers lie within those 400 specific recommendations. For example, less than 2 per cent of our seas now receive some form of protection and are under increasing threat from reclamation, contaminated mud deposits, pollution and unsustainable fisheries.

Governments around the world have identified marine conservation as lagging behind, and have adopted a specific target to ensure at least 10 per cent of the marine environment should be protected globally by 2020. Such a target could easily be achieved for Hong Kong.

Another priority is more coordinated preservation of the Inner Deep Bay wetlands, which are of international importance to the tens of thousands of migratory water birds. A growing number of wetland reserves are being created as mitigation of urban development around Deep Bay. A statutory Wetland Trust needs to be set up, to ensure their long-term conservation, and a holistic management plan developed.

Effective species action plans are urgently needed to halt and reverse the decline of species such as the Chinese white dolphin. A comprehensive list of threatened species should be produced. It is also important to address Hong Kong’s impact on global biodiversity, which is considerable due to the unsustainable consumption of shark fin and Bluefin tuna.

There is no reason why the government cannot adopt these and other measures into the biodiversity strategy while continuing to develop the city; Hong Kong has a history of doing just that.

For example, we can draw inspiration from the previous success in turning a treeless landscape into a recognised biodiversity hot spot. Accounts from visitors arriving in Hong Kong in the 1800s described the place as “barren” and “sterile”. During the Japanese occupation in the second world war, nearly all the plantations and regenerated forests were cut down for firewood.

We can draw inspiration from the previous success in turning a treeless landscape into a recognised biodiversity hot spot

Since then, a dedicated effort involving decades of reforestation and protection and allowing natural regeneration and recolonisation has resulted in a flourishing landscape, with over 1,900 species of flowering plants (over 5 per cent of China’s total) and over 500 bird species recorded (some 40 per cent of China’s total). This demonstrates that, when the government pursues dedicated conservation efforts by working with nature, biodiversity decline can be reversed.

Previous governments have left a legacy of a world-class country park system, afforested our barren hillsides and protected an internationally important wetland. What legacy will the current government leave for the plants, animals and 7 million citizens that inhabit Hong Kong?

Dr Michael Lau is assistant director, conservation, at WWF-Hong Kong. Gavin Edwards is director, conservation, at WWF–Hong Kong
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Zero Waste speeds up in Croatia after Zelena akcija

On Wednesday 24 February, representatives of the city of Prelog and six surrounding municipalities signed the European “Zero Waste 2020” strategy at a conference in Prelog organised by NGO Zelena akcija / Friends of the Earth Croatia and the communal waste company PRE-KOM. In signing the strategy, the local authorities – which are already leaders in sustainable waste management in Croatia – have committed to meet the ambitious goal of 70% separately collected waste by 2020.

Attendees at the conference included Minister of Environmental and Nature Protection Slaven Dobrović, Assistant Minister Lidija Runko Luttenberger, head of the Environmental Protection and Energy Efficiency Fund Sven Muller, the Assistant Minister for Enterprise and Trade, the Head of Međimurje County, relevant Mayors, Heads of Districts, communal companies and representative of Zero Waste Europe. 18 NGOs from the Zero Waste Croatia* network were also present. After the conference the NGOs met with Assistant Minister Luttenberger on the topic of advancing sustainable waste management in Croatia.

The seven local authorities in Lower Međimurje for whom Zelena akcija / FoE Croatia drew up recommendations (the city of Prelog, and the districts of Goričan, Donji Kraljevec, Sveta Marija, Donji Vidovec, Donja Dubrava and Kotoriba, with altogether more than 25 000 inhabitants) managed to separately collect more than 50% of waste in 2015. As this moved them to the top of the league tables for separate waste collection and recycling in Croatia, signing on to the international Zero Waste 2020 strategy was a logical next step.

Siniša Radiković, Director of PRE-KOM commented:

“Our wish, by accepting this strategy and implementing Zelena akcija’s recommendations, is to separately collect and treat 70% of useful waste by 2020, landfill less than 30%, and reduce the amount of landfilled waste to less than 50 kg per inhabitant per year, which is in the range of the most successful cities and districts in the world”.

“Thank you for making our task easier, and that is to continue changing waste management policy in the Republic of Croatia. Until now the policy has been to mix and burn waste – thank you because you have shown that another way is possible”.

“According to the experience of many zero waste communities in the world, three ingredients are needed for success: political support, good management and commitment to meeting ever higher targets. The town of Prelog and the surrounding districts have shown that they have all these ingredients. I hope that other communities in Croatia will soon join them, to the benefit of their inhabitants and the environment.”

“Lower Međimurje has shown that in a relatively short period of time it is possible to create a good quality waste management system and become a good example for others. I’m proud that Zelena akcija contributed to this success with its analysis. This shows that NGOs have relevant knowledge and that when the authorities are ready to listen to well-argued recommendations, significant results can be achieved”.

In order to enable the commitments in the Strategy, the Lower Međimurje Waste Management Council was formed, which will include the local waste management companies along with Zelena akcija. Together with Zero Waste Europe, Zelena akcija will monitor progress towards the targets and assist with implementation of the measures to prevent, re-use and recycle waste.

At the meeting of the Zero Waste Croatia network with Assistant Minister, Marko Košak, Waste Managament Programme coordinator in Zelena akcija and Zero Waste Croatia network presented the current situation with waste management in Croatia. Erika Oblak from Zero Waste Europe presented the Zero Waste Europe network and successes by particular cities and districts. Ms Luttenberger presented the priorities of the Ministry for Environment and Nature Protection with regard to implementing a good quality waste management system. The NGOs provided comments on problems with the system and suggestions for the planned new national Waste Management Plan for the period until 2021.

The main message from the NGOs was that the new plan needs to ensure a long-awaited shift from mixing and burning waste to reducing, re-using, separating and recycling waste, as done by Prelog and neighbouring districts. The Assistant Minister clearly stated that the Ministry will ensure that the system is changed for the benefit of people and the environment, and that environmental organizations will have an important role in this process. A similar sentiment was expressed by Minister Dobrović during the conference “The problem in Croatia is large and I therefore welcome NGOs which actively work on the promotion of the zero waste concept. We all have a common task and even if it has not been like that until now, from now on problems will be resolved by sitting together around the table and all suggestions will be examined.”

Zelena akcija believes that the city of Prelog will achieve its ambitious targets by 2020 with the implementation of the proposed measures. We hope that other communal waste companies, with expert assistance from NGOs and support from the Ministry and Fund for Environmental Protection and Energy Efficiency, will also advance their waste management systems according to Lower Međimurje’s example and satisfy the needs of both residents and the environment.

THE 2016-17 BUDGET

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Meet the Scientist Connecting the Dots Between Air Pollution and Dementia

At first blush, you might not think air quality is related to brain health. But what if the two are connected? Air pollution continues to worsen in the developing world, especially in rapidly developing countries like China and India; at the same time, our global population is aging, and dementia rates are expected to rise accordingly. Increasingly, research suggests a link between air pollution exposure and the risk of diseases like Alzheimer’s and Parkinson’s. How might this relationship be possible, and what might it mean for what the world is — or isn’t — prepared to handle in the coming decades?

Aaron Reuben is a science writer, recovering policy wonk, and neuropsychologist-in-training who’s exploring just these questions. A PhD student at Duke, Reuben’s journalistic endeavors include an eye-opening feature for Mother Jones (cross-posted at Grist) that draws attention to the connection between dementia and dirty air.

Driving Reuben’s work is the notion that the countries that will see the most aging in the coming years are the same countries that are going to have the most polluted air — and the same places that have some of the least developed infrastructure for diagnosing and treating brain disease. I caught up with Reuben to chat about the state of the science, the justice issues at stake, and the difficulties of communicating the invisible.

Q: What do we know about the links between air pollution and dementia?

A. There are two branches of relevant science here. The first body of research studies people in older age brackets and maps their health outcomes onto possible air pollution exposures generated from regional pollution monitoring data. When you do that, you find that people who are exposed to more air pollution, particularly fine particles, show an increased risk for dementia and pre-dementia, called mild cognitive impairment. A study that came out of Taiwan, for example, drew on a cohort of nearly 100,000 people and showed that for every unit increase in exposure to particle pollution, the risk of developing Alzheimer’s went up by more than 100 percent.

Of course, before we can say that one causes the other, one of the things that needs to happen is data to arrive from longitudinal studies in which you follow people from day one, categorize their exposures, follow their outcomes, and control for things you’d like to control for, like exposures to other toxins like lead. But every month and every year, more and more studies are coming out, and the fact that they’re all finding the same thing is very compelling.

The other kinds of studies that are contributing to the evidence base are animal studies. You can’t sit someone down and expose them to air pollution and watch their brains degenerate in real time. But you can do that in mice. There are a lot of studies coming out now on changes in cell dynamics and epigenetics in mice exposed to air pollution, and you see that many of the changes are in the direction of Alzheimer’s disease and heavily related to dementia outcomes. Something that’s really sexy that hasn’t been published yet are studies using transgenic mice that have been engineered to develop Alzheimer’s-type pathology. If you expose generations of these mice to air pollution and that changes the development of pathology, then you can make a call that in this particular animal, the exposure to fine particles fostered the disease. So far the mouse studies are pointing in the same direction as the cohort studies.

Q: So are we at smoking-causes-lung-cancer levels of evidence?

A. No, we’re not there yet. But when people ask me this, I also ask them how long it took to get there for lung cancer. How long did we think cigarettes caused cancer before we were finally willing to say ‘we know’? It took decades. I don’t think anyone thinks the evidence is going to start weighing against this trend. It’s a matter of how long new research needs to pile up before people are willing to make a bold statement.

Q: And what do we know about how pollution might contribute to dementia?

A. There are a couple ways we think it works. One is by nature of the fact that some of the particles are very small. Your sense of smell is a very potent sense, and there is a direct connection from the nose to the brain via the nasal nerve. That means that once you get something in your nose, if it’s small enough, it can pass into the nerve and make its way all the way to the brain.

Keep in mind that pollution particles typically bring in a host of other nasty things with them, including heavy metals: things that can directly kill neurons. The end result is a disruption of the brain’s homegrown immune system. Microglia cells — which clear waste, trim away dead neurons, improve synaptic connections, and clear pathogens — end up performing an unsuccessful process. They continue to release oxidative chemicals that are designed to kill pathogens, but instead of killing anything, the chemicals just accumulate and disrupt neural activity. The damage this causes looks a lot like what you see in Alzheimer’s and Parkinson’s patients.

Another mechanism comes via the lungs. When pollution particles are inhaled into the lungs, they tend to be small enough to make it past the body’s defenses and end up in the deepest tissue, where they then pass into the bloodstream. When they do that, they trigger an immune reaction that circulates molecules related to inflammation, cytokines, in the bloodstream — the kind of thing that seems to cause chronic low-level inflammation wherever the particles go. We’re not sure if the particles can enter the brain through the blood directly or if the chemicals they trigger actually reach the brain, but there’s evidence that they interact with the blood-brain barrier and damage it somehow. It’s all about low-level inflammation that turns into long-term damage. Particles that enter through the nose will cause neuroinflammation directly, and particles that enter through the lungs will also cause neuroinflammation indirectly.

Q: You’ve suggested we’re past the tipping point at which this theory is going to be wholly refuted, but you’ve also cited overly cautious scientists who are wary of overstating the evidence. Why do you think this hesitance exists?

A. I think in all of science there’s a tendency to be as precise as possible. It’s never unusual for scientists to hedge their bets. But the other thing I think is going on here is that there’s been a sort of history of jumping the gun on Alzheimer’s. We’ve been talking about one cause, but there are many ways to brain disease. The brain is uniquely susceptible to damage. Air pollution isn’t causing all the dementia we see around us. There’s pesticide exposure, there are concussions — there’s not just one way to get this disease. And it’s also a function of your cumulative exposures and your genetic predisposition.

There’s a lot to fear when it comes to dementia. It comes out of nowhere, there’s no cure, it erases everything about you. If you can point to something that’s causing it, people are going to take you seriously. That’s what happened with the aluminum scare in the 1980s, which led to sensationalist headlines and people worrying about their pans and the things they were drinking. The studies that found unusually large aluminum deposits in the brains of Alzheimer’s patients were real, but that didn’t mean that your personal exposure to aluminum actually influenced your dementia risk. The field of gerontology remembers this and is going to be slow to embrace air pollution. Especially because it’s something that everyone is exposed to, unlike, say, a concussion.

Q: I’m interested in what you just said about air pollution being something that everyone is exposed to. There are obviously inherent justice questions at stake here given the inequities of air pollution exposure. How does environmental justice enter the conversation for you?

A. I think there are two things going on, and neither of them are good. The same communities that are reliably exposed to the most air pollution are the same communities that have the fewest resources to defend themselves or compensate for the effects.

Something you see time and again is that high-income, high-resourced individuals not only can buffer themselves against exposure to air pollution — they live in the nice parts of town, they don’t live by busy roads, they live by a lot of greenery, which we know can reduce pollution levels — but they also have the resources to respond to the kinds of cognitive impairments that we’re predicting. Researchers at the University of Southern California have found that air pollution levels are linked to developmental disorders. We know that if your child has a developmental disorder, there are plenty of services and activities you can do to improve their cognitive abilities. These are the kinds of things that aren’t always available to low-income communities, who are also at greater risk.

Another thing that people are talking about are the synergistic stressors at play. It’s not just that you’re living in a neighborhood that has higher levels of air pollution, it’s that there might also be more violence in your social environment. You might have an incarcerated family member. These are many forms of adversity that, on their own, modify the way the brain develops and modify a slew of risk factors. When you put them all together, these effects may be magnified.

Q: What if I buy your story about air pollution and dementia but can’t move out of my heavily polluted neighborhood? What are my options?

A. Something we used to study in my old lab was called cognitive reserve. The basic idea is that there are some things you can do that appear to make you more resilient against showing symptoms of disease or brain injury. It’s based on old evidence of people who had died and, once an autopsy of their brain was done, appeared to have had Alzheimer’s-like pathology — but there was no evidence they had Alzheimer’s when they were alive. And it seems to be the case that they were compensating somehow to the brain damage.

There are certain things we know lead to good cognitive reserve. Yes, a lot of them are associated with your socioeconomic status, but some of them aren’t. If you have a higher IQ, it seems you’re buffered a bit against insults to your brain. For every year of education you get, your risk of presenting Alzheimer’s goes down — not because you’re immune to the disease, but because if you start to get early damage, you’re more able to deal with the damage in a way that maintains your cognitive function. More physical activity is another one.

With respect to age, young people and old people are the most vulnerable. Young people’s brains are still developing; old people have brains that are less likely to bounce back and repair themselves after injury. As a society, we can choose to design better communities around some of this knowledge. In California, there’s a law that says you can’t put an elementary school on a busy road.

But no, we can’t all move. In Beijing, if you wanted to move, you’d have to change your whole life. You can’t escape the pollution.

Q: I feel like there’s a certain paradox here when you mention a place like Beijing. We’re building these factories in the name of progress, but for whom? If people’s brains are atrophying because of exposure to air pollution, there’s a pretty abysmal vicious circle going on.

A. It’s not just that we’re going to die younger or age more poorly. There’s lots of evidence that you’re stopping people at the start of their lives. Studies have found that kids drop IQ points for every unit of air pollution exposure. Or look at what’s happening in Flint. There’s a whole generation of kids getting set at a disadvantage from day one. We’re doing the damage to ourselves.

Q: Something like climate change is already so slow and abstract. Something like air quality isn’t always something you can see. When you combine these kinds of things with mental health or brain health — which are already siloed off from the rest of the health spectrum — there’s a lot of abstraction going on in one place. That must make these effects particularly difficult to communicate. Does this ever leave you frustrated?

A. This actually reminds me of something I’m working on now, which is trying to look at the long-term effects of exposure to positive things like parks and green spaces — improved environments. I think of it as the flipside of these stressors. Almost everyone you talk to can speak at a personal level to the benefit of green spaces. Trying to find that effect in data and trying to make that data compelling is hard. There are a lot of things that are going to contribute to how well or how poorly you live. Something like your environment is just one of them. Trying to pull out the influence of that one factor is really hard, both scientifically and with respect to communication.

But we do know the places where people are getting older. In a lot of those places, we can reliably say there are going to be greater rates of dementia than there should be. A lot of those places don’t have infrastructure yet for diagnosing or treating these things, and I think it’s time we started thinking about the resources that need to be put into place in the areas where the air is bad. At some point we’re going to have to start paving the way to dealing with the brain health crisis that’s coming. Of course, it’d be great to clean up the air in these places, and we know how to clean up the air, but we’re not going to be able to do it right away. In the meantime, we know who the people are at risk, and we know pretty well what’s going to happen. Can we start getting ready for that in a real way?