Review Article

Waste Prevention As An Investment Opportunity

Henning Wilts*, Susanne Fischer
Research Unit Circular Economy, Wuppertal Institute for Climate, Germany
*Corresponding author:

Henning Wilts, Research Unit Circular Economy, Wuppertal Institute for Climate, Germany, Tel: 49 202 2492 139, Email: henning.wilts@wupperinst.org

Keywords:

Behaviour, Business model, Circular economy, Cost-benefit analysis, Investment, Waste prevention

This paper focuses on waste prevention by putting it in to context with profitability considerations that play a key role in investment decisions for oragainst certain waste management options. Due to the difficult measurability of what is considered as prevented waste, a systematic assessment of costs, benefits and economic profitability with regard to waste prevention is only given to a limited extent. Facing continuously high volumes of waste, it is still imperative to realize waste prevention more effectively and efficiently in the form of respective measures. However, the lack of figures that capture the profitability of these measures hamper needed investments. This becomes more complex as a “waste prevention culture” is a strategic goal, which would have to be carried out in the form of specifically designed behaviour changing measures. Their effectiveness is particularly difficult to measure. Since however profitability is a decisive criterion for or against investments, this lack of data is a fundamental investment barrier. Ireland’s National Waste Prevention Programme, which is analysed in this article is unique because it regularly assesses the effects of its activities and thereby relates waste prevention to economic viability. The signal that can be derived from the Irish experiences is clear: waste prevention is profitable and related investments can cause substantial leverage effects.

With its 2015 Action Plan for a Circular Economy, the European Commission has set the goal to strengthen the competitiveness of the European economy beyond environmental protection by creating an economy that is stronger oriented towards circulating products, materials and resources running in loops: “Such transition is the opportunity to transform our economy and generate new and sustainable competitive advantages for Europe” [1]. In the centre of the discussion around the needed transformation process - from a mostly linear to a future circular economy - are currently higher recycling rates or the increased use of secondary raw materials, which shall make Europe more independent from importing raw materials. Moreover, new business models and services are developed and promoted, for which e.g. the Ellen MacArthur Foundation (2015) [2] estimates very promising cost savings potentials with investment opportunities totalling € 320 billion solely in the European food, mobility and built environment sectors.

Until now, waste prevention as a business model has not yet been considered systematically neither formulated as specific objectives. After decades of deep sleep, waste prevention is currently gaining more importance in public perception: Repair Cafes or Zero Waste Initiatives arise in many places, the issue is discussed at prominent waste management conferences, and contributions to the European Week of Waste Prevention have increased significantly in the past years. This development is driven by the public discussion around individual waste streams, e.g. plastic bags in the sea, waste electrical and electronic equipment being shipped to developing countries, or food waste in households, where the relevance of the waste hierarchy seems very plausible at first sight. Waste should be primarily prevented and only recycled or incinerated, if prevention or reuse, e.g. by repair, is not possible or appropriate. Ecologically considered, individual measures of waste management are not always appropriate with regard to the steps of the waste hierarchy. Fridges that are older than ten years should not be reused due to energy use reasons; paper bags only do less harm to the environment than plastic bags if they are used more than once.

This article does not aim to analyse the interaction between different, more or less important forms of waste management, but rather to consider waste prevention as highest priority that has only received subordinate attention. The focus is on the question, where and how waste prevention is successful and economically appropriate. In addition, it will be analysed how waste prevention can serve as a base for innovative business models and why we know only so little about that.

In order to do so, we will systematically present on which factors innovation and investment, or rather profitability of waste prevention is dependent. In the following chapter, innovative elements and mechanisms of the national waste prevention programme from Ireland are explained. This has, in contrast to many other programmes, based the promotion of waste prevention on feasibility studies, resulting from rarely implemented measurement of waste prevention impacts. The article closes with conclusions for waste prevention in Germany.

The aspect of profitability often plays a leading role for investment decisions. In the area of waste management, building and operating waste treatment plants for sorting, composting, or especially incinerating waste needs investment that, like in the case of the new incineration plant in Copenhagen, can exceed the billion mark. Accordingly, investment decisions are only taken based on a comprehensive cost-benefit analysis. Profitability considerations of both fixed and running costs, as well as potential income sources, belong to the established standards of modern waste management and therefore also consider risk factors, e.g. the “necessary waste generation” that is needed to economically operate plants [3]. Within Environmental Impact Assessments, also externalised effects are included that do not directly influence the profitability of a plant, but have positive (e.g. in form of prevented GHG emissions) or negative (e.g. ground water pollution) effects on society. Table 1 provides an overview of typical cost advantages in form of achieved consequential impacts of waste management measures. Such a comprehensive analysis enables e.g. a municipality to decide if they want to invest shares of their limited financial resources into a new incineration plant, a new biogas plant, or just new collection containers. Most measures do not turn out to be economically profitable and will have to be co-financed through fees - an optimum ratio of costs and benefits is still aimed at.


Consequential impact of waste prevention

Type of effect

Assessment Method

Prevented landfill waste (resource savings)

Direct effect

Long-term marginal costs of landfill sites

 

 

 

Recovery of recyclable materials and production of

Direct effect

Market value, border-crossing price

compost soil (resource savings)

 

 

Energy recovery (resource savings)

Direct effect

Long-term marginal costs of substituted energy

Visual inconveniences, noise and unpleasant odours

Externality

Hedonic price, Indicated preferences

 

 

 

Change in GHG emission

Externality

Shadow price of GHG emissions

 

 

 

Health and environmental hazards (change of air, water

Externality

Shadow price of contaminants

and soil contamination)

 

 

Source: European Commission (2015)

 

 


Table 1 : Typical consequential impacts of waste management investments.

On the level of waste prevention, such cost-benefit analysis is so far in its very early infancy as difficulties arise for all considerable cost dimensions:

• Costs of individual waste prevention measures are not recorded systematically until now. On the municipal level, actions such as media campaigns against dispos-able cups or supporting initiatives against single-use bags often require a high engagement level of indi-vidual employees of environmental administration units, which is barely evaluable in monetary terms. In addition, waste prevention measures are only rarely tendered, in contrast to construction projects, leading to less transparent costs. • On the national level, the different national waste prevention programmes (WPP) only indicate planned or real costs in a limited way [4]. The total costs of waste prevention measures that are distributed across various units and ministries can therefore hardly be determined. • Regulatory or other frame-setting measures that are implemented decentralised, e.g. by the municipalities, are therefore especially complex and hard to identify. The compulsory testing of reparability for waste electri-cal and electronic equipment is probably an important approach to promote re-use networks, as they are worthy of support according to the WPP - related total costs are, however, not quantifiable.

Similar to this, quantifying the specific benefits is also difficult:

• Direct effects of waste prevention should always be reducing waste generation, and hereby preventing e.g. disposal costs. Estimating these cost savings requires another estimation of how much waste would have been generated without this measure. However, for only few of such measures their effects are clearly verifiable, e.g. like the Munich Octoberfest, where prohibiting single-use dishes reduced waste generation by half [5]. • Also for indirect effects various assumptions are nec-essary to measure the contribution of an individual waste prevention measure to resource protection. The effects are strongly dependent on specifically prevented products and their production processes on the one hand, and on the other hand on how the products are treated at the end of their useful life. The “prevention success” would here be dependent on if e.g. a smartphone is disposed of at an illegal waste dump in Ghana or is qualitative highly recycled in Germany.

Despite all these insecurities, a picture has emerged re-garding the economic incentive structures, that is a central barrier for waste prevention: investors and beneficiaries are usually not the same actors; a way larger circle of persons profits from waste prevention than those who really invest time and money. The phenomenon of “split incentives” also occurs for investment in energy efficiency of build-ings. The owner pays, the tenants benefit, so that in total significantly less is invested than it would be economically wise [6]. Therefore, not only the question of cost and benefit level is decisive, but also their distribution along the chain of businesses, households, state sector and waste management companies.

On the European level, the issue of waste prevention is approached differently from one country to another regarding e.g. urgency, actively involved stakeholders and variety of concepts. In the following Ireland is taken as an example for one of the most interesting approaches. In 2004, the Irish Environmental Protection Agency (EPA) initiated a national WPP. Whereas the requirement of such programmes for EU member states according to the European Waste Framework Directive (2008/98/EU) became compulsory just in 2013, Ireland had done pio-neering work with its programme from the beginning of last century. In a European-wide comparison, it is the only national WPP with the longest duration of meanwhile 13 years. The early start can be traced back to enormously high waste generation in the Irish economy and society, which amounted to increasing rates of 10% between 1995 and 2000. In various analyses of the Irish EPA, a lacking (political) focus on waste prevention and absent prioriti-sation over recycling and disposal were identified as the main reasons. As a consequence, financial and human resources dedicated for waste prevention were missing; moreover, there was no administrative structure being able to achieve significant progress in waste prevention. Due to these circumstances, the EPA recommended develop-ing and implementing a programme that should stabilise the increasing waste generation and decouple economic growth from waste generation, which was finally realised through the WPP.

A key element of the programme is implementing sub-programmes, which tackle the challenge of waste prevention through different ways, e.g. by choosing a specific target group, a waste stream or prevention approach. As the human resources of the WPP are limited to approx. 3.5 full time equivalent jobs, the WPP itself is not responsible for the implementation, but rather delegates a realisation contract and appropriate budget to external experts. These experts implement the waste prevention approach given by the WPP in close cooperation with respective municipal administrations and other relevant stakeholders. Potential sub-programmes are selected relatively agile, as reported by Odile Le Bolloch, staff member of the WPP: new ideas that seem promising can be introduced to the programme portfolio quite easily.

The WPP supports the executing external experts in the implementation process by providing further resources, e.g. contacts, a corporate design, as well as consulting and assistance in general that can be based on an experience pool of more than 25 elaborated sub-programmes. Cur-rently, the WPP maintains ten different sub - programmes; Table 2 provides an overview of the history of programme development.


 

‘04

‘05

‘06

‘07

‘08

‘09

‘10

‘11

‘12

‘13

‘14

‘15

€co-Cert

 

 

 

 

 

 

 

x

 

 

 

 

Cleaner Greener Production

 

 

 

 

 

 

 

 

x

 

 

 

Community Re-use Network

 

 

 

 

 

 

 

 

x

x

x

x

Enforcement of the WEEE regula-

 

 

 

 

 

 

 

 

 

 

 

 

tions

 

x

x

 

 

 

 

 

 

 

 

 

Farm Hazardous Waste

 

 

 

 

 

 

 

 

 

x

x

 

Farm Plastic Scheme

 

 

 

 

 

 

 

 

x

x

 

 

Free Trade Ireland

 

 

 

 

 

 

 

 

 

x

x

x

Green Business

 

 

x

x

x

x

x

x

x

x

x

x

Green Enterprise

 

 

 

 

 

 

 

 

 

x

x

x

Green Festivals

 

 

 

 

 

 

 

x

 

 

 

 

Green Healthcare

 

 

 

 

 

 

 

x

x

x

x

x

Green Home

 

 

x

x

x

x

x

x

x

x

x

 

Green Hospitality

 

 

 

 

x

x

x

x

x

x

x

x

Green Public Service

 

 

 

 

x

x

 

 

 

 

 

 

Green Retail

 

 

 

 

 

 

 

x

 

 

 

 

Greening Communities

 

 

 

 

x

x

x

x

x

x

x

 

Hazardous waste

x

x

x

 

 

 

 

 

 

 

 

 

LAPD

x

x

 

 

 

x

 

 

 

 

 

 

LAPN

 

 

 

 

 

 

x

 

 

x

x

x

National strategy on biodegradable

 

 

 

 

 

 

 

 

 

 

 

 

waste

 

x

x

 

 

 

 

 

 

 

 

 

Packaging waste

x

x

x

 

 

 

 

 

x

x

x

 

Print and packaging pilot

 

 

 

 

 

 

 

 

x

 

 

 

Resource efficiency waste audits

x

x

 

 

 

 

 

 

 

 

 

 

Smart Farming

 

 

 

 

 

 

 

 

 

x

x

x

SMILE

 

 

 

 

 

 

 

x

x

x

x

x

Stop Food Waste

 

 

 

 

 

x

x

x

x

x

x

x


Acknowledgements: LAPD: Local Authority Prevention Demonstration, LAPN: Local Authority Prevention Net-work.


Source: Annual EPA Reports 2005-2016


Table 2: Irish WPP history.


For a short overview on the variety of national WPP activities regarding different waste streams, target groups and waste prevention approach, three sub-programmes will be presented.

• In 2008, the initiative “Green Business” was started. It offers a cost-effective, online audit and assessment tool that enables businesses to evaluate their own en-vironmental performance regarding waste and water. In the following years, the initiative has developed further and due to success it has become a “flagship project” [7]. • In the same year, the EPA decided on implementing the sub-programme “Green Healthcare”, a project for improving resource efficiency, prevention and reduc-tion of waste and emissions in healthcare institutions. First samplings have shown a significant potential for prevention and minimization of clinical and food waste. With countries like Portugal and Scotland, interest has also been indicated internationally. • “Stop Food Waste” was initiated in 2009 and should promote food waste prevention and composting in Irish households. Especially consumers should be encouraged to overthink how they buy, store, cook and use leftovers. The initiative has developed to an established and recognized forum for promoting food efficiency and composting in Irish households.

The WPP is financed by an environmental fund that was created for this purpose. It is fed by revenue from regulatory fees on plastic bag sales and landfilling. An-nually, the WPP has a budget of around 2 million € that can be distributed freely to old and new sub-programmes. Distributing the fund to sub-programmes also represents the largest expense share of the annual WPP financial vol-ume; in total, 14 million € of the total budget of 17 million € in the first nine years of running WPP were assigned to this item. Further expenses cover personnel and overhead costs. Table 3 shows how the WPP costs are distributed across chosen sub-programmes.

In the annual reports and annually waste statistics, as well as in the evaluation reports published at greater intervals, the EPA and the WPP give an overview on currently intro-duced and continued sub-programmes, describe achieved implementation success, and publish data on respective waste generation. On basis of the annual reported effects, the AVP decides, which sub-programmes will be funded in the following fiscal year.


 

’04-‘07

‘08

‘09

‘10

‘11

‘12*

Total

Green Business

0.077

0.437

0.406

0.566

0.686

0.572

2.744

 

 

 

 

 

 

 

 

Green Healthcare

-

-

-

0.3

0.2

0.148

0.648

 

 

 

 

 

 

 

 

Green Home

0.088

0.186

0.15

0.173

0.204

0.175

0.976

 

 

 

 

 

 

 

 

Green Hospitality

-

0.4

0.329

0.386

0.452

0.368

1.935

 

 

 

 

 

 

 

 

LAPD/LAPN

0.955

0.842

1.294

0.539

0.772

0.625

5.026

 

 

 

 

 

 

 

 

Packaging Prevention

0.146

0.131

0.029

0.021

0.008

0.01

0.345

 

 

 

 

 

 

 

 

Stop Food Waste

-

-

0.114

0.215

0.192

0.21

0.731

 

 

 

 

 

 

 

 

Other

0.3

0.22

0.183

0.629

0.622

0.46

1.683

 

 

 

 

 

 

 

 

Total

1.566

2.216

2.391

2.614

2.944

2.358

14.088


* Based on estimations of EPA Acknowledgements: Values in million €


Source: Byrne and Derham (2012)


Table 3: Costs of WPP sub-programmes.

In the best case, this decision is made based on specific figures on prevented waste volumes by following from the introduction of a measure. However, the measurement of waste prevention is still a largely unresolved challenge. Data indicating the effectiveness of certain waste preven-tion measures in terms of saved waste amounts is, while looking at all 28 European national waste prevention pro-grammes, only collected by one country - Ireland. Besides other innovative characteristics as presented above, the circumstance of measurement and availability of profit-ability data is the reason why the Irish WPP is presented so prominently in this article.

The collection of waste prevention figures was possi-ble with regard to technically oriented waste prevention measures, e.g. the “Green Business” programme. In such cases, the measurement can be realised comparatively easy by comparing material use and waste generation before and after introducing the measure, although also this method shows its limit when it comes to time delay effects. The combination with data on real or estimated monetary savings potential and investments offers inter-esting insights to waste prevention profitability; Table 4 provides an overview.

Among all these programmes, some are able to demon-strate surprisingly big impact leverage, i.e. they can realise high to very high savings effects with a comparatively low monetary input, like e.g. the sub-programme “Green Healthcare”, which could realise a monetary waste preven-tion potential of 5.29 million € and prevented 5,500 tons of waste stemming from an investment of 148,000 € with a profitability factor of 35 in 2012. Also, while looking at the other WPP sub -programmes, a report published by the Irish EPA states “a remarkable success story” and Ireland will continue trying to reduce its waste generation [1,7].

Nevertheless, even this data is only to be interpreted in a limited way, as e.g. each sub- programme applies its own measurement method or because there is no consideration of time effects. Another important and not yet tackled factor influencing both success and measurability of waste prevention - the circumstance of behavioural change - also leads to missing data in Table 4, and available data will not completely represent the waste prevention potential.


Sub-programme

Investment

Savings potential

Profit

Waste prevention

 

 

Total

Per unit

 

 

Community ReUse

Network

 

 

 

 

2015

70,000

 

 

 

 

2014

 

 

 

 

 

2012

 

 

 

 

175,000 t*

2011

30,000

€ 160,000*

 

5x*

 

€co-Cert

 

 

 

 

 

2015

 

 

 

 

 

2014

 

 

 

 

 

2012

 

 

 

 

 

2011

30,000

160,000

5,000

5x

 

Free Trade Ireland

 

 

 

 

 

2015

40,000

502,500

 

12x

161 t*

2014

40,000

679,000

 

17x

216 t*

2012

 

 

 

 

 

2011

 

 

 

 

 

Green Business

 

 

 

 

 

2015

300,000

€ 1,200,00

41,500

4x

 

2014

320,000

1,380,000

36,000

4x

 

2012

340,000

3,000,000

70,000

9x

 

2011

374,000

4,000,000

40,000

11x

 

Green Healthcare

 

 

 

 

 

2015

 

 

 

 

 

2014

 

 

 

 

 

2012

148,000

5,290,000

 

35x

5,500 t*

2011

150,000

1,600,000

 

11x

2,700 t*

Green Homes

 

 

 

 

 

2015

 

 

 

 

 

2014

 

 

 

 

 

2012

200,000

1,600,000

€ 320*

8x

 

2011

125,000

800,000

€ 320*

6x

 

Green Hospitality

 

 

 

 

 

2015

 

 

 

 

 

2014

 

€ 8,700,000*

70,000

 

8,500 t*

2012

366,000

6,000,000

 

16x

7,000 t*

2011

452,000

5,580,000

 

12x

6,400 t*

Green Retail

 

 

 

 

 

2015

 

 

 

 

 

2014

 

 

 

 

 

2012

 

 

 

 

 

2011

50,000

142,000

 

3x

 

Smart Farming

 

 

 

 

 

2015

100,000

3,250,000

€ 5,000*

32.5x

 

2014

90,000

3,960,000

€ 6,600*

44x

 

2012

 

 

 

 

 

2011

 

 

 

 

 

Smile

 

 

 

 

 

2015

100,000

1,250,000

12x

5,052 t*

2014

140,000

398,000

3x

357 t*

2012

150,000

675,000

4.5x

6,687 t*

2011

106,000

812,000

8x

6,800 t*

Acknowledgement: Savings potential includes real and estimated potential.

 

Source: EPA (2012, 2013, 2015, 2016)

Table 4: Profitability of waste prevention measures.

According to estimates of an Irish EPA evaluation re-port, waste prevention would “still happen” and further annual cost savings of 10 million € would be possible if all sub-programmes were instantly abolished [8]. Why? The measures are dependent on and, in many cases, imply a behavioural change in handling waste and natural re-sources in general - once acquired, procedures and routines are continued, so that resource efficiency potentials are maintained. Although this relation seems at least worth mentioning, as behavioural changes after their adoption are not necessarily maintained and this is not at all a linear process, it still expands the discussion on waste preven-tion and resource efficiency to the dimension that it is not only about institutional, regulatory and technological frameworks. Also, the behaviour of the waste generating, or rather preventing individual is decisive, This must be understood in its respective context and with regard to belonging to social and cultural groups and then trans-formed into policy measures.

Although policy has already recognized the importance of behaviour and behavioural change, the understanding of behaviour within policy instruments is still insufficient and defective, just like the assumption that individuals act rationally as soon as they are informed well enough. This leads to the situation that targeted goals regarding necessary new behavioural patterns might be correct, but are implemented by inappropriate measures. In order to learn and act according to that learning permanently permanently e.g. the right behaviour towards food, infor-mation provided on the European Commission’s website is certainly not very helpful. Instead, according to the Irish EPA, a direct, practical and repeating on-site support and explanation would be much more effective for people to learn how to process food better and more consciously.

The Irish WPP and EPA have recognised the relevance of behaviour and behavioural change for successful waste prevention, and created therefore a scientific job position specifically addressing behavioural change in the different contexts of waste prevention. It hardly comes as a surprise that the relation of waste prevention and behavioural sci-ence still needs further research [9], nevertheless, there is also need for practical implementation.

According to Simon O’Rafferty, behavioural scientist of the WPP, the following aspects of behaviour and be-havioural change are specifically relevant in the context of waste prevention.

• Changing behaviour needs time and does not neces-sarily happen linearly, but dynamically and in loops. • Spill-over effects stemming from behavioural changes in certain contexts a certain context to other contexts are not necessarily given, even if assumed rational consciousness in individual decision-making would suggest that. • Individual behaviour is strongly dependent on respec-tive social contexts and roles to be fulfilled. • Individual behaviour can more easily be changed if the measure targets the individuum’s belonging to a social group and its collective respective behaviour. • A functioning behaviour change mechanism cannot be transferred to another context or object, e.g. due to different cultural values. • Replacement options for the behaviour to be changed must be known and easily accessible, and therefore realisable.

Understanding each of these findings in the waste preven-tion context should especially result in a more effective implementation of waste prevention measures. Hereby, accordingly designed and experimentally tested measures aiming at waste prevention are not only more effective in the long-term, but also more economic than convention-ally developed measures. Although they are more time-consuming during preparation, their expected impact and sustainability is higher. Nevertheless, if the measurability of economic and environmental success of waste prevention measures decides for or against investments, e.g. regard-ing programmes like the Irish WPP, behaviour-oriented approaches face the paradox of being both effective but also difficult to measure in their impact. This complicates investment decisions for waste prevention as a business model and resource protection.

Considering potential economic effects from specific waste prevention measures emphasises the complexity of the issue: prevention does not always lead to immediate and obvious cost savings, which additionally are hardly or difficult to measure in most cases. At the same time, waste prevention measures are related to additional financial and personnel expenses; particularly for the public sector, which usually is the initiator of many measures. However, appropriate and for the longer term planned measures for waste prevention contribute to increased business competi-tiveness in many sectors, they support the labour market and reduce fixed and running costs that are produced by waste treatment. The experience from Ireland shows that a systematic and long-term monitoring of such effects can significantly contribute to waste prevention efficiency. Con-cretely, considering the relation between costs and benefits enables clear hints on where waste prevention saves costs and where it is economically efficient. This does not entail that only prevention measures should be implemented: in some cases, e.g. for hazardous waste, which can have relevant impacts on the environment or human health, it is not a question of profitability of measures, but rather a question of political trade-offs and societal benefits if public funds are used or not.

The broad insecurity and lacking knowledge on such effects also offers opportunities for waste prevention as a business model: with detailed knowledge on potentials and risks the possibility to e.g. offer waste prevention as a contracting service would be provided [10], or to understand waste prevention as a profitable investment opportunity in general. This leads to new options for action, especially for public waste management authorities that are able to recognize and assess changes of waste streams better than other actors.

It is also conceivable that a range of influencing factors will lead to increasing profitability of waste prevention in the future: the debate around plastic bags and food waste prevention illustrates that public appreciation of waste prevention has significantly increased in the past few years, and associated therewith the willingness to invest money in such measures. Currently, the issue is driven by extremely high capacity utilization of waste incineration plants in Germany, leading to considerable increase of incineration prices [11]. The increasing quality requirements for waste management, as described in the EU Circular Economy Action Plan, could also lead to increased waste fees in the medium -term, which would of course foster waste pre-vention. Even more relevant should be the development of raw materials prices: Currently low -price levels, e.g. measured by the HWWI raw material price index, will not be of a permanent nature. Facing increasing material costs, the incentive for businesses to reduce their waste generation continues to rise.

In order to benefit from these opportunities that are associated with waste prevention, further analysis and research is needed; especially regarding the estimation of prevention effects, cost savings and needed for invest-ment [12].

Citation: Wilts H, Fischer S (2017) Waste Prevention As An Investment Opportunity. J Waste Manag Env Issues 1:109.

Published: 23 October 2017

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© 2017 Wilts et al.. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.