MASTERTHESIS
Master's Programme in Applied Environmental Science, 60 credits
Towards the development of an indicator system for environmental risk assessment of electronic waste
A preliminary study focusing on mobile phones
WANG Tianyi
Master Thesis in Applied Environmental Science, 15 credits
2017-08-22
Abstract
Nowadays, large quantities of waste mobile phones are generated each year due to the large consumption and fast updating speed of this electronic product. This has become a rapidly growing pollution problem as mobile phones contain many harmful substances and these substances will be released to the environment if waste mobile phones are treated improperly. Therefore, it is necessary to develop risk assessment methods to determine the contamination degree of this waste to the environment and then take effective measures to reduce the pollution. Considering the complexity of risk assessment procedure, an indicator system for waste mobile phones is here established instead, consisting of totally 30 indicators. The system is developed as a hierarchy structure and has four layers including object layer, factor layer, indicator layer and sub-indicator layer.
Keywords: waste mobile phones, indicators, indicator system, pollution
Abbreviations
CO2 Carbon dioxide
SO2 Sulfur dioxide
NOx Nitrogen oxides
Pb Lead
As Arsenic
Cu Copper
Ni Nickel
Hg Mercury
PM Particulate matter
Content
1. Introduction... 1
1.1 Aim and research questions...3
1.2 Limitations... 3
2. Background...4
2.1 Characterization of waste mobile phones... 4
2.1.1 Composition... 4
2.1.2 Potential value...5
2.2 Material flow of waste mobile phones... 6
2.3 Environmental risk of waste mobile phones... 7
2.3.1 Collection, transportation and storage...7
2.3.2 Recycling... 7
2.3.3 Disposal...8
2.4 General framework of an indicator system... 9
3. Methodology...10
3.1 DPSIR framework...10
3.2 The Criteria of indicator selection... 11
4. The establishment of the risk assessment indicator system...12
4.1 Agreeing on a story-the story of waste mobile phones...12
4.2 The list of questions...13
4.3 Indicator selection and interpretation...13
4.4 The structure of indicator system... 17
5. Conclusion...17
6. Future needs and challenges...18
Acknowledgement... 18
References...20
1. Introduction
Due to rapid economic development, advanced technologies and frequently updating electronic products, the quantities of electronic waste (e-waste) have increased significantly since 1990s (Zeng et al., 2013), becoming one of the most rapidly growing pollution problems worldwide (Kiddee et al., 2013). As small and portable electronic products, waste mobile phones contribute largely to this e-waste stream because mobile phones are very important communication tools in people’s daily life and consumers change their phones very frequently. Presently, the replacing frequency is less than 2 years in developed countries and less than 3 years in developing countries (Sarath et al., 2015). It is estimated that there will be more than 7 billion mobile phone users in the world by the end of 2015(Sarath et al., 2015), and 400 million waste mobile phones are produced each year globally (Xu et al., 2016).
Waste mobile phones contain various kinds of toxic and harmful substances such as heavy metals and brominated flame retardants, and improper disposal of them will cause serious pollution to the environment and potentially affect human health (Lim and Schoenung, 2010, Xu et al., 2016). However, there are also many valuable materials such as gold, silver and copper contained in waste mobile phones which can be recycled for reuse and resale, and recycling these useful materials can both benefit economy and environment (Tan et al., 2017, Xu et al., 2016). However, without effective measures controlling the pollution, the recycling process can also cause harm to the environment and human health.
E-waste refers to electronic products which are nearing the end of their life or just discarded due to the availability of new and advanced products in the market (Devika, 2010). Waste mobile phones are considered as e-waste and considering the amount of it produced and the potential hazard of the waste if not properly handled and recycled, different legislation and initiatives has been taken to manage this kind of waste(Yin et al., 2014, Xu et al., 2016). In the European Union, the Directive on waste electrical and electronic equipment (WEEE Directive) and the RoHS Directive are important legislations. The WEEE Directive gives much information on the definition and
classification of WEEE, the responsibility of producers on taking back their products, collection and recycling target and so on in order to promote the management of WEEE. The RoHS Directive restricts the use of certain hazardous substances in electrical and electronic equipment and requires the use of safer substances as substitutes. These two directives were put into force in 2003 and revised in 2012 and 2011 respectively(European Commission, 2016). Moreover, an international initiative named Solving the E-waste Problem (StEP) is developed to seek effective solutions by providing a forum for discussion among stakeholders and sharing various useful information actively (StEP Initiative, 2017). In addition, there is an initiative specifically developed for mobile phones that is called Mobile Phone Partnership Initiative (MPPI). This initiative was launched in 2002 and its aim is to provide guidance on the whole life cycle of used and end-of-life mobile phones and promote their management(Osibanjo and Nnorom, 2008).
Environmental and health risk assessments have been conducted for e-waste in some regions(Yekeen et al., 2016, Daso et al., 2016, Pradhan and Kumar, 2014)but there is none for waste mobile phones specifically. The risk assessment can determine contamination degree to the environment and serve as decision support for risk managers to find scientifically based risk reduction strategies. The development of a risk assessment process for waste mobile phones, which contain many components and compounds with worldwide distribution, is regarded as a complex and difficult issue with high uncertainty. Therefore, it seems a better approach to establish a risk assessment indicator system to quantify the risk level as it can simplify the risk assessment procedure (Li et al., 2012) and help to guide better management of waste mobile phones. An indicator is a single measure of a characteristic and a good indicator can effectively translate complex data or phenomena into simple and understandable information to assess achievement, change, and performance, which makes it accessible to a wider, non-expert audience (Hák et al., 2010, Lee and Chan, 2009). An indicator system is the combination of different indicators in a set covering multi dimensions of a problem (EEA, 2014) and therefore it can be applied to many aspects and issues.
1.1 Aim and research questions
The aim of this study is to establish an indicator system for risk assessment by using a set of appropriate indicators in order to quantify the environmental risk caused by e-waste using mobile phones as the product of focus. The following research questions were developed to help guide this paper’s structure based on the objective of this study:
Question 1: Which environmental risks are involved in the whole life cycle of waste mobile phones?
Question 2: How can a general indicator system be constructed to assess complex environmental risks for waste mobile phones?
Question 3: Which criteria are important when selecting indicators?
Question 4: Which data can be used to create indicators for mobile phones?
Question 5: Which are the future needs and challenges for the development of a science based, user-friendly and robust indicator system for determining the environmental risk of waste mobile phones?
1.2 Limitations
The focus of this study is the establishment of an assessment indicator system and this system is limited to assess the risk of waste mobile phones at regional level. The development of a complete and tested indicator system is considered too time consuming for a thesis work expending 10 weeks therefore this study should be seen as a preliminary study. Also, an indicator itself can have some limitations although its simplicity makes it easy to understand and useful. Indicators cannot explain a problem from a very comprehensive perspective, and they will not necessarily tell the reason why things happened although they display changes over time. The combination of different indicators in a set to form an indicator system can make up for some deficiency as it covers multi-angle analysis of an issue (EEA, 2014). However, it is difficult to include all the relevant indicators in an indicator system because too many indicators will increase the complexity of operation and interpretation. Moreover, when selecting indicators it is important to consider data availability, but data
availability is not everything as a highly related indicator may have limited available data while a less related indicator may have more data which is easily available(EEA, 2014).
2. Background
2.1 Characterization of waste mobile phones
2.1.1 Composition
A typical mobile phone mainly consists of a battery, a housing case, a display screen, a printed circuit board, a charger and some other accessories (Osibanjo and Nnorom, 2008). The substance composition of mobile phones can be a little different due to different brands, models, producers and functions, but generally the components in all the mobile phones are similar and they are similar to other electronic equipment (Osibanjo and Nnorom, 2008, Navazo et al., 2014, Basel Convention, 2009a). These components include plastics, glass, ceramics and metals(Osibanjo and Nnorom, 2008, Sarath et al., 2015). Plastics and metals are the main constituents in mobile phones and more than 20 metallic elements make up 35-40% of the total weight (Tan et al., 2017, Wu et al., 2008). The following table lists the constituents in a mobile phone, as described in Table 1.
Table 1
Constituents in a mobile phone
Primary Constituents (typical % content)
Location in a mobile phone
Minor Constituents (typically 0.1-1%)
Location in a mobile phone
Micro or Trace Constituents (typically
< 0.1%)
Location in a mobile phone
Plastics (~40%)
Case, circuit board
Bromine Circuit board Antimony Case, circuit board Glass, ceramics
(~20%)
LCD screen, chips
Cadmium NiCd battery Arsenic Gallium
arsenide LED Copper,
compounds (~10%)
Circuit board, wires, connectors, batteries
Chromium Case, frame Barium Circuit board
Nickel, compounds
NiCd or NiMH batteries
Lead Circuit board Beryllium Connectors
(~2-10%a) Potassium hydroxide (<5%a)
Battery, NiCd, NiMH
Liquid crystal polymer
LCD screen Bismuth Circuit board
Cobalt (1-5%a) Lithium-ion Battery
Lithium Lithium-ion battery
Calcium Circuit board Carbon (<5%) Batteries Manganese Circuit board Fluorine Lithium-ion
Battery Aluminum
(~3%b)
Case, frame, batteries
Silver Circuit board, keypad
Gallium Gallium arsenide LED Steel,
ferrous metal (~10%)
Case, frame, charger, batteries
Tantalum Circuit board Gold Connectors, circuit board Tin (~1%) Circuit board Titanium Case, frame Magnesiumc Case
Tungsten Circuit board Palladium Circuit board Zinc Circuit board Ruthenium Circuit board Strontium Circuit board Sulfur Circuit board Yttrium Circuit board Zirconium Circuit board
aonly if these battery types are used, otherwise they are minor or micro constituent
bif aluminum is used for phone case, content would be ~20%
cif magnesium is used for phone case, content would be ~20%
Adapted from(Basel Convention, 2009a) 2.1.2 Potential value
There are various kinds of valuable materials contained in waste mobile phones, which can be recycled for reuse and further production. For example, according to StEP, one ton of mobile phones contains about 340g gold, 3.5kg silver, 140g palladium and 130kg copper, so given enough volume the quantities and value of the materials can be significant (Robbins et al., 2013). In addition, plastics from waste mobile phones can also be useful. They may be utilized as heat sources, reducing agents or substitutes of hydrocarbon fuels in the metal recovery process (Basel Convention, 2009a). Moreover, polymers can be recovered for reuse as their mechanical performance can be comparable to virgin materials (Sarath et al., 2015).
However, recovering plastics is still in an early stage due to the difficulty of sorting plastics efficiently. With the continuous research, wide plastic recovery may be feasible in the future(Sarath et al., 2015, Basel Convention, 2009a).
2.2 Material flow of waste mobile phones
There are several directions of flow for waste mobile phones, as described in Fig.1.
Consumers may give their phones to parents, relatives and friends or donate to others.
In this way, the lifespan of mobile phones can be extended as they can be reused(Yin et al., 2014). Most consumers store their old and unused mobile phones at home according to surveys performed in China, Korea and Finland (Yin et al., 2014, Xu et al., 2016, Ylä-Mella et al., 2015) while a small part of the consumers just lose or discard their phones. Both of these latter two pathways may cause mobile phones to end up in municipal solid waste, which will pose a large risk to the environment.
Some other consumers may sell their phones to peddlers and second hand markets for resale or return to sellers and recycling centers. In addition, peddlers may pick up lost or discarded mobile phones and they can sell the phones to second hand markets. The mobile phones from peddlers, sellers or recycling centers can be either repaired and refurbished for resale and reuse, or recycled. The valuable materials recycled from mobile phones can be resold and reused while the remaining waste will be sent for incineration or landfilling.
Fig.1 Possible material flow of waste mobile phones.
Based on(Yin et al., 2014, Jang and Kim, 2010, Xu et al., 2016, Ylä-Mella et al., 2015)
2.3 Environmental risk of waste mobile phones
2.3.1 Collection, transportation and storage
In the collection process, if loose batteries have not been identified and managed properly, they may cause short circuits and fires as they retain electrical charge to some extent (Basel Convention, 2009b). The environmental risk in the transportation process is related to weather conditions and the way of transportation. If the devices are subjected to high temperature, they may explode and cause fires, which will release toxic substances such as dioxins and furans. For water transport, if the devices are packaged improperly or come into bad weather, they may scatter into the water and cause water pollution. During storage process, the waste equipment will also cause environmental problems such as fires if they are exposed to sunshine or high temperature (Basel Convention, 2009b), soil and underground water pollution when exposed to rain because the rain may carry some soluble chemicals and metal ions into the soil and underground.
2.3.2 Recycling
Before recycling, waste mobile phones should be disassembled by either manual dismantling, mechanical shredding or their combination (Navazo et al., 2014). This process will generate noise and dust particles, which may carry any substances contained in mobile phones. Moreover, short circuits and fires may happen, and caustic chemicals will be released if batteries are not removed before the shredding process (Basel Convention, 2009a). The following process is a separation operation, which aims to separate materials according to their different physical properties and this step will create dust particles. The next step is smelting process which is a high temperature operation aimed to separate copper from other metals and materials.
Plastics contained in mobile phones can be burned here to provide energy and act as a reducing agent (Navazo et al., 2014, Basel Convention, 2009a). After this smelting process, refining processes are required to upgrade and refine individual metals(Basel Convention, 2009a). Pyrometallurgical and hydrometallurgical processes are typical two types of refining process. Pyrometallurgical processes involve heating and melting the materials in furnaces at very high temperature to recover the targeted
metal while hydrometallurgical processes involve using leaching solutions such as sulfuric acid and nitric acid to dissolve the metal and then recovering it by precipitation or electrolysis (Navazo et al., 2014, Iannicelli-Zubiani et al., 2017). All these smelting and refining processes will cause contamination to the environment.
2.3.3 Disposal
Incineration and landfill are the final two options of waste disposal. Plastics and other constituents of hydrocarbons which contained in waste mobile phones may be incompletely oxidized and combine with halogens to generate halogenated hydrocarbons during incineration if incineration temperature is not sufficiently high and the incineration time is too short (Basel Convention, 2009a). For some metals, contained in mobile phones, which have relatively low melting temperatures such as lead and cadmium, they may melt during incineration and form tiny metal oxide particles or fumes, which will be released to the air. For those metals that have not melted during incineration, they end up in the bottom ash(Basel Convention, 2009a).
Dust, fly and bottom ash, waste-acid, slag or some other hazardous substances produced in the recycling process need to be disposed in landfill and if without effective measures preventing leakage, the hazardous substances will leach out into groundwater and soils and thus cause pollution.
A summary of the possible pollutants involved in the life cycle of waste mobile phones is presented in Table 2. There is very limited information available for specific pollutants and their transfer to soil. This may because the pollutants produced in the life cycle of waste mobile phones can be directly released into the air and water while they only enter into soil through precipitation and migration from the other compartments (i.e. air and water). Based on life cycle impact assessment results of some studies, the environmental impact categories can be classified into the following aspects: acidification/nitrification, ecotoxicity, aquatic eutrophication, global warming, ozone layer depletion and photochemical oxidation (Iannicelli-Zubiani et al., 2017, Bian et al., 2016, Soo and Doolan, 2014).
Table 2
The possible pollution involved in the life cycle of waste mobile phones
Possible pollutants to air Possible pollutants to water Possible pollutants to soil Particulate matter Solid particles Metals
Dust Metals Metalloids
Nitrogen oxides, sulfur dioxide, sulfur trioxide, carbon dioxide, carbon monoxide
Cyanide, sulphide, fluoride,
chloride Oil (unspecified)
Polycyclic
aromatic hydrocarbon, Polychlorinated biphenyls
Phenol
Total organic carbon Free chlorine Metal fume and metal
oxide particulate Oil & grease Hydrochloric acid, sulfuric
acid, hydrogen cyanide, hydrogen fluoride, hydrogen bromide
Sulphate, phosphate, nitrate
Chlorine, Bromine Formaldehyde Volatile
organic compounds Ammoniacal Nitrogen Halogenated hydrocarbons
including dioxins and furans
Metalloids
Fly and bottom ash Detergents
Phosphorus Hydrocarbons
Isocyanates
Based on (Navazo et al., 2014, Basel Convention, 2009a, Bian et al., 2016, Soo and Doolan, 2014, Scharnhorst et al., 2005)
2.4 General framework of an indicator system
Generally, a table or a picture can describe an indicator system. Zhu et al. (2015) established an evaluation indicator system for brownfield redevelopment projects that contains one goal, six factors and further criteria for each factor, and displayed these indicators in a table (Zhu et al., 2015). Moreover, in order to identify environmental risk sources causing water eutrophication in rural regions, Huang et al. (2013) proposed multi-angle indicators system also by using a table to display the indicators (Huang et al., 2013). An indicator system is often described by using a picture instead of a table and it is established as a three-level hierarchy structure more frequently, which consists of goal/target/object level, factor/criteria level and
indicator/sub-criteria level (Chen, 2016, Ma et al., 2010, Parekh et al., 2015). The hierarchy structure can make the indicator system more transparent and understandable. In addition, the indicator system can also be built as a hierarchy structure containing four levels if needed. For example, Shi et al. (2014) constructed an evaluation indicator system to determine the optimum treatment and disposal technique for a chemical contamination accident(Shi et al., 2014).
3. Methodology
In this study, four steps are used to build indicators, as described in Fig.2. This indicator development process begins with (1) agreement on a story that means a description of the waste problem and this is based on literature reading. This step is followed by (2) listing questions that can help to think what indicators can be selected.
The next step is to (3) select indicators which should be based on the criteria of indicator selection. A DPSIR framework can be used here to help guide the development of indicators, as described in Fig.3. Once the indicators are selected, it is necessary to (4) interpret indicators, explaining why they are chosen. More detailed information by reading relevant literature will be given here. Finally, the indicator system will be formed by the combination of selected indicators.
Fig.2 Four steps of indicator building (Adapted from(Hák et al., 2010))
3.1 DPSIR framework
The DPSIR (driving force, pressure, state, impact and response) framework developed by European Environmental Agency for reporting on environmental problems is used
to identify indicators (Hák et al., 2010). In this framework, social developments and economic activities are driving forces (D) which drive changes that exert the pressure (P) on the environment. As a result, the changes have influence on the environmental state (S), leading to the impacts (I) on the function of ecosystem and human health (EEA, 2014). Finally, responses (R) such as policies and targets are made to affect and improve the other four parts. Through thinking about these five aspects, indicators can be considered more easily.
Fig.3 DPSIR framework (Source: European Environmental Agency)
3.2 The Criteria of indicator selection
Generally, the selection of indicators should be based on the following principles:
(1) Science-based and accuracy: The indicators selected should be well founded theoretically and reflect the actual situations.
(2) Comprehensiveness: It is difficult to merely use a single indicator to assess the risk as the assessment process involves many factors. Therefore, it is necessary to take into account various influencing indicators comprehensively.
(3) Operability and universality: The indicators selected should be easy to understand, interpret and can be applied generally. Moreover, they should be responsive to human activities and changes occurring in the environment(EEA, 2014).
(4) Measurability: The indicators should be expressed in a quantitative way as much as possible so that they can be clear and more easily understand. Furthermore, the data
Driving
forces Responses
Pressures
State
Impacts
used for indicators should be easily available and can be compared to a reference value.
(5) Validity: The selected indicators should be representative as it is difficult to select all the involved indicators and too many indicators will increase the complexity of the indicator system. Moreover, every indicator should be independent without overlap (Chen, 2016, Li et al., 2012).
4. The establishment of the risk assessment indicator system 4.1 Agreeing on a story-the story of waste mobile phones
By linking to the five aspects of DPSIR framework, a whole story of waste mobile phones can be formed. Rapid economic development, advanced technologies and large market demands drive (D) the production and update of mobile phones. The frequent update and short life span make this waste increase sharply and improper treatment of this waste generates various kinds of pollutants, exerting much pressure (P) on the environment. As described in 2.3 part, environmental risk exists in every process of the whole life cycle of waste mobile phones. The toxic and harmful substances released especially heavy metals will cause air, water and soil contamination, making the state (S) of the environment become unstable and the quality of the environment become worse and worse. As a result, this will cause negative impacts (I) on the function of ecosystem and potentially affect human health.
In addition, recycling of waste mobile phones has become very popular in lots of countries because there are many useful materials contained in waste mobile phones that can be reused or resold. However, if not recycled in a proper manner, the recycling process will also cause much hazards to the environment and workers, and this problem might be more prevalent in developing countries. Therefore, a variety of relevant legislations, policies and initiatives has been developed as the responses (R) to the requirement of promoting the management of e-waste, but these actions are still not enough, as many regions have not met the requirements such as collection and recycling targets. More specific and effective measures should be taken to improve the current state according to practical conditions of different regions.
4.2 The list of questions
When a clear story of waste mobile phones is formed, the relevant questions that can help think about indicators should be made explicit. There should be a balance in the questions related to causes, impacts and solutions to the waste problem ideally(Hák et al., 2010). According to the storyline, the following questions are developed:
1. How frequently do people change their mobile phones?
2. How waste mobile phones are treated?
3. Which kind of harmful substances generated from treating waste mobile phones are common and representative?
4. Are existing legislation or regulations effective for the management of this waste?
5. What measures can be taken to reduce the risk?
4.3 Indicator selection and interpretation
Based on the criteria of indicator selection, five influencing factors are selected here to assess the environmental risk of waste mobile phones including weather conditions, consumer behaviors, harmful substance emissions, infrastructure conditions and management measures.
As described in the above 2.3.1 part, weather conditions including high temperature and precipitation will influence the transportation and storage process. Moreover, continuous heavy rain can damage waste containers and liner system of landfill causing leachate to migrate into groundwater. It is said that precipitation is a major factor influencing the amount of leachate generation and annual average precipitation is used to represent climate condition according to a study(Li et al., 2012). Therefore, annual average precipitation is selected and similarly annual average days of high temperature is selected for the factor of weather conditions. The definition of high temperature varies from region to region. For example, high temperature is defined as more than 35℃ in China while it maybe 25 ℃ in Sweden. The data for these two specific indicators should be easily available from statistical data of government sector.
Consumers are easily affected by fashion trends and attracted by new functions of
mobile phones, and this results in a short service life of phones and hence generates a large amount of waste mobile phones (Tan et al., 2017). As can be seen in Fig.1, consumers can treat waste mobile phones in many different ways. These different treatment ways will lead to different risk degree to the environment. Hence, consumer behaviors can largely affect the generation and fate of waste mobile phones.
Considering this phenomenon, consumer behaviors are represented by two indicators:
the frequency of changing mobile phones and the treatment way of waste mobile phones. The data used for these indicators can be obtained by consumer surveys.
There are lots of harmful substance emissions from the whole life cycle process of waste mobile phones as can be seen in Table 1. It is impossible to select all potentially released toxic substances, because not only too many indicators will increase the complexity of indicator system, but also not all substances have available monitoring data. Hence, six kinds of substances including CO2, SO2, NOx, heavy metals, dioxins and particulate matters are selected as indicators in this study as they are more common and representative. CO2is the main greenhouse gas causing global warming.
SO2, NOx, and particulate matters are very common air pollutants generated from the recycling process of waste mobile phones and their amounts are relatively higher than other detected chemical substances according to some studies (Navazo et al., 2014, Bian et al., 2016, Soo and Doolan, 2014). In addition, according to different diameters, particulate matters are classified into PM>10μm, PM2.5-10μm and PM<2.5μm.
Dioxins are very toxic chemical substances released under incomplete combustion or smelting operations in the presence of halogens such as fluorine and bromine contained in mobile phones(Basel Convention, 2009a).
Heavy metals are very representative as more than 20 metallic elements are contained in mobile phones. They can be taken up by plants when they are released to air, water or soil and accumulated in their tissues(Pradhan and Kumar, 2014). Moreover, people can also take up the heavy metals through inhalation, skin contact or by eating vegetables and meat which are contaminated by heavy metals (Yekeen et al., 2016).
Pb, As, Cu, Hg and Ni are selected to represent heavy metal emissions because these five metals were reported to be major contributors to toxicity potentials from waste
mobile phones according to some studies (Lim and Schoenung, 2010, Woo et al., 2016). Moreover, Pb, Cu and Ni from mobile phone parts exceeded the criteria of different leaching test procedures in the leachability tests which are used to simulate landfill condition for metal leaching (Lincoln et al., 2007, Yadav and Yadav, 2014, Yadav et al., 2014), meaning that the priority of concern should be given to these heavy metals.
Pb contained in mobile phones is of small quantities and commonly used in tin-lead solder. Although lead based solder has been banned in Europe, this heavy metal is still of potential concern because old phones contain this substance and it is a cumulative neurological poison and a suspected carcinogen which has high toxicity (Basel Convention, 2009a). Studies have revealed that Pb concentration in children’s blood is related to the alteration of their temperaments and the decline of their intelligence (Babayemi et al., 2014). As is regarded as a dangerous substance having significant hazards to human health and it has been classified as a carcinogen by Environmental Protection Agency of the United States (Wu et al., 2008, Basel Convention, 2009a).
The content of it in a mobile phone is much lower than the Pb content, but it was reported to have even higher cancer toxicity potential for water than Pb (Lim and Schoenung, 2010) and the concentration limit for As in drinking water set by Environmental Protection Agency of the United States is 10μg/L while for Pb is 15μ g/L (Basel Convention, 2009a). Cu is a metal of highest content in a mobile phone.
Although it is not a carcinogen and important for the functioning and health of living organisms, it can cause liver and kidney damage in very high doses (Basel Convention, 2009a, Babayemi et al., 2014). Since the use of Hg in products is restricted by RoHS Directive, no current use of it is known in mobile phones, but certain old phones contain this heavy metal. Hg is not classified as a carcinogen, but it has very high toxicity (Basel Convention, 2009a). It will be deposited in water and soil when it enters into the environment, and elemental mercury can be transformed into methyl mercury in nature by microorganisms. Methyl mercury is a highly toxic substance and it can be bioaccumulated in the fatty tissues of living organisms especially fish (Basel Convention, 2009a, Clean Up Australia, 2007). Hence, it is still
of potential concern. The consumption of vegetables can make people or animals exposed to Ni as this metal can be accumulated in the plants. Ni is an essential nutrient at low levels, but it can cause hazards to human health at high concentrations such as dizziness and birth defects (Babayemi et al., 2014). Furthermore, it is a probable human carcinogen, and has negative effects on respiratory tract and cause lung and nasal cancers(Wu et al., 2008).
In terms of infrastructure conditions, the main consideration in this study is some aspects of landfill construction. The generation of leachate from landfill can cause contamination to the groundwater even well designed and constructed(Li et al., 2012).
Many factors are involved in the environmental impacts of a landfill such as leakage prevention system, landfill size, landfill service time, waste type, leachate properties, the dumping mode and leachate collection system(Li et al., 2012, Zhang et al., 2016).
In this study, four indicators including leakage prevention system, leachate collection system, landfill service time and landfill size are considered due to data availability.
For the first two qualitative indicators, they can be quantified by being divided into several conditions and each condition will be given a risk value. For example, leakage prevention system can be classified into double-layer structure, single-layer structure, natural silt layer and natural gravel layer, and their risk values are given as 0.1,0.3,0.5 and 1 respectively (Zhang et al., 2016). For the latter two indicators, the data can be obtained from landfill basic information easily.
For management measures, two indicators are selected: producer responsibility and legal regulation. They are selected because these two factors are very important to reduce the risk of waste mobile phones. Legal regulation is a kind of mandatory approach that is necessary to normalize the treatment of waste mobile phones.
Extended producer responsibility (EPR) is one of the most valid principles which requires producers to take back their products and responsible for their recycling and final disposal(Yin et al., 2014, Nnorom and Osibanjo, 2008). These two indicators are also qualitative indicators that can be made to be measurable. For example, legal regulation can be divided into three conditions including no existing legal regulation, existing legal regulation with operational flexibility and existing legal regulation with
no operational flexibility (Widmer et al., 2005). Each condition will be given a value so that it can be expressed in a quantitative way.
4.4 The structure of indicator system
In this study, the framework of the indicator system for risk assessment of waste mobile phones is developed as a hierarchy structure, as described in Fig.4. This system has four layers: object layer, factor layer, indicator layer and sub-indicator layer. The object layer has only one element that is the assessing goal. The factor layer has five elements which are factors affecting the environmental risk level of waste mobile phones. Totally 16 specific indicators are developed on the indicator layer to describe factors and 8 indicators are on the sub-indicator layer.
Fig.4 The developed indicator system for risk assessment of waste mobile phones
5. Conclusion
Finally, an indicator system for risk assessment of waste mobile phones consisting of totally 30 indicators was established by combining indicators from different aspects.
The DPSIR framework is a good approach used for identifying indicators as it can
describe an environmental problem from a comprehensive perspective through five aspects. All the literature used for collecting information are from scientific journals or official websites that are reliable. Although the system has been based on science and data availability, it is just a preliminary indicator system due to the limit of time, which requires to improve indicators by consulting experts and considering practical conditions. Moreover, there would be some problems when it is considered to be applied. For example, it is a time consuming work when conducting surveys for consumer behaviors as the target is common people. Despite this is a preliminary study, it should be a beneficial attempt for further research. And for future application, the improved indicator system may be used to assess the environmental risk level of waste mobile phones in a certain region and therefore help to guide and improve the management of that region.
6. Future needs and challenges
Since this is a preliminary study, to develop a good and sound assessment indicator system for quantifying the environmental risks of waste mobile phones, it is necessary to further verify the indicators to make them more reasonable and valid. After the verification, data collection for the indicators is needed when this indicator system is applied to a certain region. Furthermore, the data used for the indicators should be compared with a reference value and it is important to determine the weight of each indicator since indicators have differences on the importance degree, so that the risk can be quantified to a value and then it is easier and more visualized to find the loophole and promote the management.
Acknowledgement
At first, I want to express my thanks to my supervisor Sylvia waara without whose help I can not finish this thesis. She is a very warmhearted and helpful teacher with extensive professional knowledge who guided me to develop my thesis step by step.
Moreover, she helped me contact the director of the recycling company Stena and drove me to visit this place and a recycling center which will contribute a lot to my further study. I am very grateful for her help.
Secondly, I would like to extend my gratitude to the director who is professional and patient to answer my questions and show us around the recycling section for e-waste.
Without her help, I can not go further with my study.
Last but not least, I want to thank my roommate and my parents who give me much mental support from the beginning to the end of my study.
References:
BABAYEMI, J. O., OSIBANJO, O. & WEBER, R. (2014), "Assessment of Use, Reuse, and End-of-Life Disposal and X-Ray Fluorescence Analysis Screening of Waste Mobile Phones in Nigeria", Environmental Quality Management, Vol. 23 No. 4, pp. 1-12.
Basel Convention (2009a) Mobile Phone Partnership Initiative (MPPI)-project 3.1. Guideline on Material Recovery and Recycling of End-of-Life Mobile Phones. Geneva, Switzerland.
Basel Convention (2009b) Mobile Phone Partnership Initiative (MPPI)-project 2.1. Guideline on the Collection of Used Mobile Phones. Geneva, Switzerland.
BIAN, J., BAI, H., LI, W., YIN, J. & XU, H. (2016), "Comparative environmental life cycle assessment of waste mobile phone recycling in China", Journal of Cleaner Production, Vol.
131209-218.
CHEN, Y. (2016), "Conceptual Framework for the Development of an Indicator System for the Assessment of Regional Land Subsidence Disaster Vulnerability", Sustainability, Vol. 8, pp. 757.
Clean Up Australia (2007) Mobile Phones and the Environment. Australia.
DASO, A. P., AKORTIA, E. & OKONKWO, J. O. (2016), "Concentration profiles, source apportionment and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in dumpsite soils from Agbogbloshie e-waste dismantling site, Accra, Ghana", Environmental Science and Pollution Research, Vol. 23 No. 11, pp. 10883–10894.
DEVIKA, S. (2010), "Environmental impact of improper disposal of electronic waste", in Recent Advances in Space Technology Services and Climate Change 2010 (RSTS & CC-2010), pp. 29-31.
EEA (2014) Digest of EEA indicators., European Environmental Agency.
European Commission (2016) Waste Electrical & Electronic Equipment (WEEE)..
HÁK, T., MOLDAN, B. & DAHL, A. L. (2010), Sustainability indicators: a scientific assessment, Island Press.
HUANG, L., BAN, J., HAN, Y. T., YANG, J. & BI, J. (2013), "Multi-angle Indicators System of Non-point Pollution Source Assessment in Rural Areas: A Case Study Near Taihu Lake", Environmental Management, Vol. 51 No. 4, pp. 939–950.
IANNICELLI-ZUBIANI, E. M., GIANI, M. I., RECANATI, F., DOTELLI, G., PURICELLI, S. &
CRISTIANI, C. (2017), "Environmental impacts of a hydrometallurgical process for electronic waste treatment: A life cycle assessment case study", Journal of Cleaner Production, Vol. 140, Part 3,pp.
1204-1216.
JANG, Y. & KIM, M. (2010), "Management of used & end-of-life mobile phones in Korea: A review", Resources, Conservation and Recycling, Vol. 55 No. 1, pp. 11-19.
KIDDEE, P., NAIDU, R. & MING, H. W. (2013), "Electronic waste management approaches: An overview", Waste Management, Vol. 33 No. 5, pp. 1237-1250.
LEE, G. K. L. & CHAN, E. H. W. (2009), "Indicators for evaluating environmental performance of the Hong Kong urban renewal projects", Facilities, Vol. 27 No. 13/14, pp. 515-530.
LI, Y., LI, J., CHEN, S. & DIAO, W. (2012), "Establishing indices for groundwater contamination risk assessment in the vicinity of hazardous waste landfills in China", Environmental Pollution, Vol. 165 No.
6, pp. 77-90.
LIM, S. & SCHOENUNG, J. M. (2010), "Toxicity potentials from waste cellular phones, and a waste management policy integrating consumer, corporate, and government responsibilities", Waste Management, Vol. 30 No. 8–9, pp. 1653-1660.
LINCOLN, J. D., OGUNSEITAN, O. A., SHAPIRO, A. A. & SAPHORES, J. D. (2007), "Leaching assessments of hazardous materials in cellular telephones", Environmental Science & Technology, Vol.
41 No. 7, pp. 2572-2578.
MA, S., TONG, W., GU, L., QIAN, S. & JIE, P. (2010), "The Establishment on Performance Evaluation Indicator System of Government Financial Resource Integration and the Verification with Reliability and Validity", in International Conference on E-Business and E-Government, pp. 600-603.
NAVAZO, J. M. V., MÉNDEZ, G. V. & PEIRÓ, L. T. (2014), "Material flow analysis and energy requirements of mobile phone material recovery processes", The International Journal of Life Cycle Assessment, Vol. 19 No. 3, pp. 567–579.
NNOROM, I. C. & OSIBANJO, O. (2008), "Overview of electronic waste (e-waste) management practices and legislations, and their poor applications in the developing countries", Resources, Conservation and Recycling, Vol. 52 No. 6, pp. 843-858.
OSIBANJO, O. & NNOROM, I. C. (2008), "Material flows of mobile phones and accessories in Nigeria: Environmental implications and sound end-of-life management options", Environmental Impact Assessment Review, Vol. 28 No. 2-3, pp. 198-213.
PAREKH, H., YADAV, K., YADAV, S. & SHAH, N. (2015), "Identification and assigning weight of indicator influencing performance of municipal solid waste management using AHP", KSCE Journal of Civil Engineering, Vol. 19 No. 1, pp. 36-45.
PRADHAN, J. K. & KUMAR, S. (2014), "Informal e-waste recycling: environmental risk assessment of heavy metal contamination in Mandoli industrial area, Delhi, India", Environmental Science and Pollution Research, Vol. 21 No. 13, pp. 7913–7928.
ROBBINS, P., HINTZ, J. & MOORE, S. A. (2013), Environment and Society, Somerset, John Wiley &
Sons, Incorporated.
SARATH, P., BONDA, S., MOHANTY, S. & NAYAK, S. K. (2015), "Mobile phone waste management and recycling: Views and trends", Waste Management, Vol. 46536-545.
SCHARNHORST, W., ALTHAUS, H. R., CLASSEN, M., JOLLIET, O. & HILTY, L. M. (2005), "The end of life treatment of second generation mobile phone networks: Strategies to reduce the environmental impact", Environmental Impact Assessment Review, Vol. 25 No. 5, pp. 540-566.
SHI, S., CAO, J., FENG, L., LIANG, W. & ZHANG, L. (2014), "Construction of a technique plan repository and evaluation system based on AHP group decision-making for emergency treatment and disposal in chemical pollution accidents", Journal of Hazardous Materials, Vol. 276 No. 9, pp.
200-206.
SOO, V. K. & DOOLAN, M. (2014), "Recycling Mobile Phone Impact on Life Cycle Assessment ☆", Procedia Cirp, Vol. 15 No. 15, pp. 263–271.
StEP Initiative (2017) Step stands for solving the e-waste problem..
TAN, Q., DONG, Q., LIU, L., SONG, Q., LIANG, Y. & LI, J. (2017), "Potential recycling availability and capacity assessment on typical metals in waste mobile phones: A current research study in China", Journal of Cleaner Production, Vol. 148509-517.
WIDMER, R., OSWALD-KRAPF, H., SINHA-KHETRIWAL, D., SCHNELLMANN, M. & BÖNI, H.
(2005), "Global perspectives on e-waste", Environmental Impact Assessment Review, Vol. 25 No. 5, pp.
436-458.
WOO, S. H., LEE, D. S. & LIM, S. R. (2016), "Potential resource and toxicity impacts from metals in waste electronic devices", Integrated Environmental Assessment & Management, Vol. 12 No. 2, pp.
364.
WU, B. Y., CHAN, Y. C., MIDDENDORF, A., GU, X. & ZHONG, H. W. (2008), "Assessment of toxicity potential of metallic elements in discarded electronics: A case study of mobile phones in China", Journal of Environmental Sciences, Vol. 20 No. 11, pp. 1403-1408.
XU, C., ZHANG, W., HE, W., LI, G. & HUANG, J. (2016), "The situation of waste mobile phone management in developed countries and development status in China", Waste Management, Vol.
58341-347.
YADAV, S. & YADAV, S. (2014), "Investigations of metal leaching from mobile phone parts using TCLP and WET methods", Journal of Environmental Management, Vol. 144 No. 21, pp. 101-107.
YADAV, S., YADAV, S. & KUMAR, P. (2014), "Metal toxicity assessment of mobile phone parts using Milli Q water", Waste Management, Vol. 34 No. 7, pp. 1274-1278.
YEKEEN, T. A., XU, X., ZHANG, Y., WU, Y., KIM, S., REPONEN, T., DIETRICH, K. N., HO, S., CHEN, A. & HUO, X. (2016), "Assessment of health risk of trace metal pollution in surface soil and road dust from e-waste recycling area in China", Environmental Science and Pollution Research, Vol.
23 No. 17, pp. 17511–17524.
YIN, J., GAO, Y. & XU, H. (2014), "Survey and analysis of consumers' behaviour of waste mobile phone recycling in China", Journal of Cleaner Production, Vol. 65 No. 1, pp. 517-525.
YLÄ-MELLA, J., KEISKI, R. L. & PONGRÁCZ, E. (2015), "Electronic waste recovery in Finland:
Consumers' perceptions towards recycling and re-use of mobile phones", Waste Management, Vol.
45374-384.
ZENG, X., LI, J., STEVELS, A. L. N. & LIU, L. (2013), "Perspective of electronic waste management in China based on a legislation comparison between China and the EU", Journal of Cleaner Production, Vol. 51 No. 14, pp. 80-87.
ZHANG, B., LI, G., CHENG, P., YEH, T. C. J. & HONG, M. (2016), "Landfill Risk Assessment on Groundwater Based on Vulnerability and Pollution Index", Water Resources Management, Vol. 30 No.
4, pp. 1465-1480.
ZHU, Y., HIPEL, K. W., KE, G. Y. & CHEN, Y. (2015), "Establishment and optimization of an evaluation index system for brownfield redevelopment projects: An empirical study", Environmental Modelling & Software, Vol. 74 No. C, pp. 173-182.
PO Box 823, SE-301 18 Halmstad Phone: +35 46 16 71 00
E-mail: registrator@hh.se I am an exchange student coming from Suzhou University of Science and Technology in China
