Interplay of metals and bromine with dioxin-related compounds concentrated in e-waste open burning soil from Agbogbloshie in Accra, Ghana

Occurrence and ecotoxicological impacts of polybrominated diphenyl ethers (PBDEs) in electronic waste (e-waste) in Africa: Options for sustainable and eco-friendly management strategies

Polybrominated diphenyl ethers (PBDEs) are persistent contaminants used as flame retardants in electronic products. PBDEs are contaminants of concern due to leaching and recalcitrance conferred by the stable and hydrophobic bromide residues. The near absence of legislatures and conscious initiatives to tackle the challenges of PBDEs in Africa has allowed for the indiscriminate use and consequent environmental degradation. Presently, the incidence, ecotoxicity, and remediation of PBDEs in Africa are poorly elucidated. Here, we present a position on the level of contamination, ecotoxicity, and management strategies for PBDEs with regard to Africa. Our review shows that Africa is inundated with PBDEs from the proliferation of e-waste due to factors like the increasing growth in the IT sector worsened by the procurement of second-hand gadgets. An evaluation of the fate of PBDEs in the African environment reveals that the environment is adequately contaminated, although reported in only a few countries like Nigeria and Ghana. Ultrasound-assisted extraction, microwave-assisted extraction, and Soxhlet extraction coupled with specific chromatographic techniques are used in the detection and quantification of PBDEs. Enormous exposure pathways in humans were highlighted with health implications. In terms of the removal of PBDEs, we found a gap in efforts in this direction, as not much success has been reported in Africa. However, we outline eco-friendly methods used elsewhere, including microbial degradation, zerovalent iron, supercritical fluid, and reduce, reuse, recycle, and recovery methods. The need for Africa to make and implement legislatures against PBDEs holds the key to reduced effect on the continent.

A review of heavy metal risks around e-waste sites and comparable municipal dumpsites in major African cities: Recommendations and future perspectives

In Africa, the effects of informal e-waste recycling on the environment are escalating. It is regularly transported from developed to developing nations, where it is disassembled informally in search of precious metals, thus increasing human exposure to harmful compounds. Africa has a serious problem with e-waste, as there are significant facilities in Ghana and Nigeria where imported e-waste is unsafely dismantled. however, because they are in high demand and less expensive than new ones, old electronic and electrical items are imported in large quantities, just like in many developing nations. After that, these objects are frequently scavenged to recover important metals through heating, burning, incubation in acids, and other techniques. Serious health hazards are associated with these activities for workers and individuals close to recycling plants. At e-waste sites in Africa, there have been documented instances of elevated concentrations of hazardous elements, persistent organic pollutants, and heavy metals in dust, soils, and vegetation, including plants consumed as food. Individuals who handle and dispose of e-waste are exposed to highly hazardous chemical substances. This paper examines heavy metal risks around e-waste sites and comparable municipal dumpsites in major African cities. Elevated concentrations of these heavy metals metal in downstream aquatic and marine habitats have resulted in additional environmental impacts. These effects have been associated with unfavourable outcomes in marine ecosystems, such as reduced fish stocks characterized by smaller sizes, increased susceptibility to illness, and decreased population densities. The evidence from the examined studies shows how much e-waste affects human health and the environment in Africa. Sub-Saharan African nations require a regulatory framework that includes specialized laws, facilities, and procedures for the safe recycling and disposal of e-waste.

Informal E-waste recycling practices and environmental pollution in Africa: What is the way forward?

Globally, e-waste is the fastest growing and most valuable waste-stream. While countries worldwide are increasingly acknowledging the e-waste problem and introducing policies and regulations that deal with e-waste, large quantities of e-waste still go undocumented. Much of these global e-wastes are accumulating in open-dumpsites and landfills in African-countries where they are recycled informally resulting in significant environmental and public-health concerns. Although, there is a plethora of studies on e-waste management and disposal, only a few-studies have focused on African-countries who are major recipients of e-waste. Moreover, despite the attempts to mitigate the problem of e-waste in African-countries, e-waste has remained a major-concern and there are currently very limited workable solutions. This study examines informal e-waste recycling, environmental pollution and the extent of environmental and health impacts in major countries of concern including Ghana, Nigeria, Egypt, Kenya and South Africa. The global e-waste Waste Atlas Report, 2020 identified these countries as major recipients of e-waste. To achieve the aims of this research, previous studies from 2005 to 2022 are collected from various databases and analyzed. Accordingly, this study focuses on environmental pollution and public-health impacts resulting from e-waste dumping and informal recycling practices, illegal transboundary shipment of e-waste to the selected countries, and the interventions of governments and international organizations in reducing the impact of e-waste pollution and informal recycling practices in Africa. Based on the outcomes of this study, practical approaches on the way-forward are recommended. The findings of this study contribute to a growing-body of research on informal e-waste recycling practices in Africa to document that individuals working within e-waste sites and residents in nearby communities are exposed to a number of toxic-substances, some at potentially concerning levels.

Pollution Characteristics and Health Risk Assessment of Phthalate Esters in PSW Recycling Sites: A Typical Case Study

The concentrations of six priority phthalate esters (PAEs) in 700 soil samples and 110 sediment samples from an area in China containing plastic solid waste (PSW) recycling sites were determined. The total concentrations of the six PAEs in soil and sediment were not detected - 274 and not detected - 597 mg kg^-1, respectively, and the mean concentrations in soil and sediment were 14.4 and 31.7 mg kg^-1, respectively. The dominant PAEs were di(2-ethylhexyl) phthalate and di-n-butyl phthalate. PAEs were detected in soil collected from the surface to 0.5 m below ground level around the PSW recycling sites, and the concentrations were markedly higher in these areas than at other polluted sites. PSW recycling is an important source of PAEs to soil and sediment. The di(2-ethylhexyl)phthalate concentrations in soil were higher than the relevant concentrations that pose environmental risks for sensitive land uses and non-sensitive land uses (42 and 121 mg kg^-1, respectively), indicating emissions of PAEs from PSW recycling sites may pose environmental risks. The results indicate that PAE pollution at PSW sites needs to be better controlled and managed.

A green slurry electrolysis to recover valuable metals from waste printed circuit board (WPCB) in recyclable pH-neutral ethylene glycol

The continuous growth of e-waste necessitates an efficient method to recover their metal contents to improve their recycling rate. The successful recovery of the metallic component from Waste Electrical and Electronic Equipment (WEEE) can generate great economic benefits to incentivize the industrial recycling effort. In this study, we report the use of slurry electrolysis (SE) in pH-neutral ethylene glycol (EG) electrolyte to extract and recover the metallic component from waste printed circuit broad (WPCB) powder. The system operates at room temperature and atmospheric pressure, and the electrolyte can be recycled multiple times with no signs of chemical degradation. The EG electrolyte system can oxidize the metallic component without triggering anodic gas evolution, which allowed us to incorporate a reticulated vitreous carbon (RVC) foam anode to maximize the capture and oxidation of the metal content. The system demonstrated up to 99.1% Faraday efficiency for the cathodic metal deposition and could recover Cu from the WPCB powder in a selective manner of 59.7% in the presence of 12 other metals. The SE reaction system was also scalable and displayed no compromises on the Cu recovery selectivity. With the ability to leach and recover metallic content from WPCB in a mild and chemically benign condition, the SE system displayed much promise to be adapted for industrial-scale metal recovery from WPCB.

E-Device Purchase and Disposal Behaviours in the UAE: An Exploratory Study

The United Arab Emirates (UAE) is one of the high-income countries in the Middle Eastern region and is vying for sustainable development in every sector. One of the UAE sustainable development goals is to ensure sustainable consumption and production patterns; hence, the emphasis is on circular economy. UAE is one of largest consumers of e-devices, and their proper disposal is of paramount importance. E-waste disposal awareness leads to better disposal behaviors. Therefore, the purpose of the study was to understand the e-device purchase and disposal behaviour among university communities in the UAE. A survey was conducted among the students and staff members of a federally funded university in the UAE, namely Zayed University, and quantitative methodology was adopted to analyze the collected data. The study found that 47.95% of respondents purchased mobile phones, and 65% of the respondents purchased 1–3 electronic devices every year. Through chi-square test, gender of the respondents was found to be related with e-device ownership. Through the analysis of variance (ANOVA), age and field of specialization were found to affect the knowledge about e-waste. Older and the respondents with science specialization were more aware about e-waste. Most of the respondents disposed e-devices, such as batteries, earphones/headphones, and electronic toys, along with the household trash. A very small percentage of respondents disposed e-devices such as laptops, phones, and tablets with the household trash. Mostly, these were either repaired, donated, or sold to second-hand users. Many respondents were neither aware of the government initiatives on e-waste collection nor participated in government-sponsored e-waste recycling. The study further identified that 67% of the respondents were aware of the toxicity of e-waste, and 61% of the respondents were keen to join e-waste recycling drives at university. The findings of the study imply that the policy makers need to incentivize e-waste-disposal systems and develop targeted awareness approaches to enhance e-waste disposal in the UAE.

Assessing data in the informal e-waste sector: The Agbogbloshie Scrapyard

The Old-Fadama-Scrapyard, better known as Agbogbloshie, is located in Accra, Ghana. Over the last 20 years, the area has developed into a large scrapyard, where the informal sector processes mainly electronic waste (e-waste) and scrap metals. However, unsafe treatment methods, such as the open burning of cables and foams, and the spilling of hazardous liquids onto the ground, cause environmental pollution and create health risks by releasing persistent organic pollutants (POPs) and heavy metals. There is a recognized lack in literature of data on e-waste mass and material flows due to the lack of applicable methods to measure e-waste quantities in an informally managed treatment system. However, to establish sustainable e-waste management, e-waste mass and material flow data are crucial prerequisites. Therefore, the material flow analysis (MFA) methodology is proposed as a means for data collection within a limited time frame in the informal e-waste recycling context. In this case study, mass and material flows of e-waste processed at Agbogbloshie were estimated using two different approaches: Firstly, the kind, measures, constitution of load and number of loaded entering and exiting vehicles was observed and documented, and second, to validate the data collected, the mass and material flow of e-waste treatment processes on site were observed and documented. The resulting annual mass flows range between 13,090 t/a and 17,094 t/a of e-waste. Based on the data for Ghana from the Global E-waste Monitor, an average of 15,092 t/a (approximately 39% of the Ghanaian e-waste generation) is treated in Agbogbloshie.

Removal of Bromine from the non-metallic fraction in printed circuit board via its Co-pyrolysis with alumina

The effectiveness of a recycling approach of the printed circuit board (PCBs), and, thus, the quality of polymeric constituents, primarily rests on the capacity to eliminate the bromine content (mainly as HBr). HBr is emitted in appreciable quantities during thermal decomposition of PCB-contained brominated flame retardants (BFRs). The highly corrosive, yet relatively reactive HBr, renders recovery of bromine-free hydrocarbons streams from brominated polymers in PCBs very challenging. Via combined experimental and theoretical frameworks, this study explores the potential of deploying alumina (Al₂O₃) as a debromination agent of Br-containing hydrocarbon fractions in PCBs. A consensus from a wide array of characterization techniques utilized herein (ICP-OES, IC, XRD, FTIR, SEM-EDX, and TGA) clearly demonstrates the transformation of alumina upon its co-pyrolysis with the non-metallic fractions of PCBs, into aluminum bromides and oxy-bromides. ICP-OES measurements disclose the presence of high concentration of Cu in the non-metallic fraction of PCB, along with minor levels of selected valuable metals. Likewise, elemental ionic analysis by IC demonstrates an elevated concentration of bromine in washed alumina-PCBs pyrolysates, especially at 500 °C. The Coats-Redfern model facilitates the derivation of thermo-kinetic parameters underpinning the thermal degradation of alumina-PCB mixtures. Density functional theory calculations (DFT) establish an accessible reaction pathway for the HBr uptake by the alumina surface, thus elucidating chemical reactions governing the observed alumina debromination activity. Findings from this study illustrate the capacity of alumina as a HBr fixation agent during the thermal treatment of e-waste.

E-Waste in Africa: A Serious Threat to the Health of Children

Waste electronic and electrical equipment (e-waste) consists of used and discarded electrical and electronic items ranging from refrigerators to cell phones and printed circuit boards. It is frequently moved from developed countries to developing countries where it is dismantled for valuable metals in informal settings, resulting in significant human exposure to toxic substances. E-waste is a major concern in Africa, with large sites in Ghana and Nigeria where imported e-waste is dismantled under unsafe conditions. However, as in many developing countries, used electronic and electrical devices are imported in large quantities because they are in great demand and are less expensive than new ones. Many of these used products are irreparable and are discarded with other solid waste to local landfills. These items are then often scavenged for the purpose of extracting valuable metals by heating and burning, incubating in acids and other methods. These activities pose significant health risks to workers and residents in communities near recycling sites. E-waste burning and dismantling activities are frequently undertaken at e-waste sites, often in or near homes. As a result, children and people living in the surrounding areas are exposed, even if they are not directly involved in the recycling. While toxic substances are dangerous to individuals at any age, children are more vulnerable as they are going through important developmental processes, and some adverse health impacts may have long-term impacts. We review the e-waste situation in Africa with a focus on threats to children's health.

Comprehensive screening of polybromochlorodibenzo-p-dioxins, dibenzofurans as mixed halogenated compounds in wastewater samples from industrial facilities by GC×GC/ToFMS and post-data processing

An enormous number of pollutants must be investigated to be able to understand which types threaten human health and environmental biota. In this study, we propose a workflow for screening polybromochlorodibenzo-p-dioxins and dibenzofurans (PBCDD/Fs), which are compounds that have thousands of isomers and congeners, by combining measurement of a sample without any in-laboratory-cleanup with the results of comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry and post-data processing. This process can be regarded as "in silico sample cleanup." The post-data processing stage comprises two methods in which the extracted mass spectra are matched to exact mass and isotopic ratios specified as formulae and filtering via mass deficiency. We applied this workflow to wastewater samples from industrial facilities to identify mixtures of halogenated dioxins. As a result, it was estimated that dioxins in an absolute quantity of 10-500 pg could be detected with sufficient accuracy by recovery testing of a standard mixture against sample crude extracts. Tri- to octa-halogenated dioxins were detected in 8 of 13 samples. Leachate from an industrial landfill was found to contain relatively large numbers of PBCDD/Fs, and several congeners were found in wastewater from an industrial fabric facility that handles decabromodiphenyl ether. The workflow, including the post-data processing method developed and applied in this study, has the advantage that additional identifications can be performed at any time from a single set of measurement data. This also enables the screening of substances that have thousands of homologous isomers, such as chlorinated and brominated dioxins, as well as other non-halogenated compounds.

Bromination of Carbon and Formation of PBDD/Fs by Copper Bromide in Oxidative Thermal Process

Brominated aromatic compounds are unintentionally generated during various thermal processes, including municipal solid waste incineration, electric-waste open burning, and secondary copper smelting. Copper (Cu) plays an important role in the formation of brominated aromatic compounds. In the present study, the thermochemical behaviors of Cu and Br in model samples, including copper bromide (CuBr₂) and activated carbon, were studied using in situ X-ray absorption near-edge structure (XANES) and thermogravimetry. Quantification of polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) was also conducted by gas chromatograph-high resolution mass spectrometer. Three key reactions were identified: (i) the reduction of CuBr₂ to CuBr (room temperature to 300 °C), (ii) the generation of Br bonded with aromatic carbon (150-350 °C), and (iii) the oxidation of copper (>350 °C). Maximum amounts of PBDD/Fs were found in residual solid phase after heating at 300 °C. The analytical results indicated the direct bromination of aromatic carbon by the debromination of copper bromides (I, II) and that CuBr and CuO acted as catalysts in the oxidation of the carbon matrix. The bromination mechanisms revealed in this study are essential to the de novo formation of PBDD/Fs and other brominated aromatic compounds.

Formation pathways of polychlorinated dibenzo-p-dioxins and dibenzofurans from burning simulated PVC-coated cable wires

Open burning of PVC-coated cables is a major source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F). In the present study, the formation characteristics of PCDD/F from burning of PVC-based samples with and without metallic copper were evaluated over the dioxin formation temperature window (200-500 °C). This temperature range also inevitably occurs under open burning conditions. The PCDD/F yield from PVC added with Cu increased by factors of 1390 (300 °C), 65 (400 °C) and 17 (500 °C) compared with that from PVC alone, confirming the stimulatory effect of metallic Cu on PCDD/F production. For the first time, a relatively complete isomer-specific analysis is established for PVC acting as source of PCDD/F. Formation pathways of PCDD/F and the reaction mechanisms were investigated using a combined analysis of PCDD/F isomer signatures, thermogravimetric results and Cl K-edge X-ray absorption spectra. De novo synthesis is the major pathway leading to massive production of PCDD/F. Copper extends the temperature range for the concurrence of de(hydro)chlorination of PVC with cross-linking and aromatisation of polyenes and then stimulates cracking of the chlorine-embedded carbon network. Together, these processes contribute to the strongly enhanced formation of PCDD/F via de novo synthesis.

Evaluating critical barriers and pathways to implementation of e-waste formalization management systems in Ghana: a hybrid BWM and fuzzy TOPSIS approach

The majority of developing countries are facing enormous challenges in implementing sustainable waste electrical and electronic equipment (e-waste) management systems. Informal e-waste management practices in Ghana have become a critical challenge to the government and the various stakeholders owing to its environmental and health impacts. However, the effort to implement e-waste formalization management practices has been threatened with many barriers. This study aims to identify and evaluate barriers and pathways to the implementation of e-waste formalization management systems in Ghana. A three-phase methodology consisting of the Delphi method, the hybrid best-worst method and the fuzzy TOPSIS technique is employed. The first phase involves extensive literature review and the use of the Delphi method to identify barriers, pathways, and data collection for e-waste formalization. In the second phase, the best-worst method was employed to analyze the relative weight and ranking of the barriers. The third phase involves the application of fuzzy TOPSIS to rank and prioritize pathways to e-waste formalization systems. Fuzzy logic was applied to handle the subjectivity of decision-makers' preferences. A sensitivity analysis was carried out to check the robustness of the framework and address any effect of bias. The outcome of the study indicates that economic and financial limitations are the most significant barriers to e-waste formalization. "Setting up resourced environmental government agencies for effective monitoring and auditing at the regional levels for appropriate e-waste management practices" is the most prominent pathway. The present study can potentially inform policy makers to develop systematic and strategic policies for the implementation of e-waste formalization management systems.

Co-pyrolysis of polyethylene with products from thermal decomposition of brominated flame retardants

Co-pyrolysis of brominated flame retardants (BFRs) with polymeric materials prevails in scenarios pertinent to thermal recycling of bromine-laden objects; most notably the non-metallic fraction in e-waste. Hydro-dehalogenation of aromatic compounds in a hydrogen-donating medium constitutes a key step in refining pyrolysis oil of BFRs. Chemical reactions underpinning this process are poorly understood. Herein, we utilize accurate density functional theory (DFT) calculations to report thermo-kinetic parameters for the reaction of solid polyethylene, PE, (as a surrogate model for aliphatic polymers) with prime products sourced from thermal decomposition of BFRs, namely, HBr, bromophenols; benzene, and phenyl radical. Facile abstraction of an ethylenic H by Br atoms is expected to contribute to the formation of abundant HBr concentrations in practical systems. Likewise, a relatively low energy barrier for aromatic Br atom abstraction from a 2-bromophenol molecule by an alkyl radical site, concurs with the reported noticeable hydro-debromination capacity of PE. Pathways entailing a PE-induced bromination of a phenoxy radical should be hindered in view of high energy barrier for a Br transfer into the para position of the phenoxy radical. Adsorption of a phenoxy radical onto a Cu(Br) site substituted at the PE chain affords the commonly discussed PBDD/Fs precursor of a surface-bounded bromophenolate adduct. Such scenario arises due to the heterogeneous integration of metals into the bromine-rich carbon matrix in primitive recycling of e-waste and their open burning.

Global occurrence, chemical properties, and ecological impacts of e-wastes (IUPAC Technical Report)

The waste stream of obsolete electronic equipment grows exponentially, creating a worldwide pollution and resource problem. Electrical and electronic waste (e-waste) comprises a heterogeneous mix of glass, plastics (including flame retardants and other additives), metals (including rare Earth elements), and metalloids. The e-waste issue is complex and multi-faceted. In examining the different aspects of e-waste, informal recycling in developing countries has been identified as a primary concern, due to widespread illegal shipments; weak environmental, as well as health and safety, regulations; lack of technology; and inadequate waste treatment structure. For example, Nigeria, Ghana, India, Pakistan, and China have all been identified as hotspots for the disposal of e-waste. This article presents a critical examination on the chemical nature of e-waste and the resulting environmental impacts on, for example, microbial biodiversity, flora, and fauna in e-waste recycling sites around the world. It highlights the different types of risk assessment approaches required when evaluating the ecological impact of e-waste. Additionally, it presents examples of chemistry playing a role in potential solutions. The information presented here will be informative to relevant stakeholders seeking to devise integrated management strategies to tackle this global environmental concern.

Bioaccessibility and human health risk assessment of metal(loid)s in soil from an e-waste open burning site in Agbogbloshie, Accra, Ghana

Environmental pollution and human health issues due to unrestricted electronic waste (e-waste) recycling activities have been reported at a number of locations. Among different e-waste recycling techniques, open burning of e-waste releases diverse metal(loid)s into the environment, which has aroused concern worldwide. In human health risk assessments (HHRAs), oral ingestion of soil can be a major route of exposure to many immobile soil contaminants. In vitro assays are currently being developed and validated to avoid overestimation of pollutants absorbed by the human body when calculating total pollutant concentrations in HHRAs. In this study, Cu, As, Cd, Sb, and Pb bioaccessibility in polluted soils (n = 10) from e-waste open burning sites at Agbogbloshie in Accra, Ghana, was assessed using an in vitro assay, the physiologically based extraction test. A bioaccessibility-corrected HHRA was then conducted to estimate the potential health risks to local inhabitants. The in vitro results (%) varied greatly among the different metal(loid)s (Cu: 1.3-60, As: 1.3-40, Cd: 4.2-67, Sb: 0.7-85, Pb: 4.1-57), and also showed marked variance between the gastric phase and small intestinal phase. The particle sizes of soil samples and chemical forms of metal(loid)s also influenced bioaccessibility values. Using these bioaccessibility values, both the hazard index and carcinogenic risk were calculated. The hazard index was above the threshold value (>1) for 5/10 samples, indicating a potential health risk to local inhabitants.

Using elemental analyses and multivariate statistics to identify the off-site dispersion from informal e-waste processing

Electronic waste (e-waste) is informally processed and recycled in Agbogbloshie in Accra (Ghana), which may be the largest such site in West Africa. This industry can lead to significant environmental contamination. In this study, surface dust samples were collected at a range of sites within Accra to establish the offsite consequences of such activities. Fifty-one samples were collected and analysed for 69 elements by ICP-mass spectrometry after nitric acid digestion. The data indicated a significant enrichment in metals associated with solder and copper wire at the site itself and a downwind dispersion of this source material to a distance of approximately 2.0 km. Chlorine and bromine were also elevated at this site as residues from polyvinyl chloride combustion and flame retardants respectively. The elemental composition indicated that only low technology electrical equipment was being treated this way. Multivariate statistical analyses by principal components analysis and polytopic vector analysis identified three sources contributing to the system; (i) burn site residue dispersing within 2 km from the source site, (ii) marine matter on the beaches alone and (iii) the baseline soil conditions of the city of Accra. Risk ratios and hazard quotients developed from the measured concentrations indicated that copper was providing the greatest risk to inhabitants in most cases although nickel, vanadium, chromium and zinc also contributed.

Quantitative speciation of insoluble chlorine in E-waste open burning soil: Implications of the presence of unidentified aromatic-Cl and insoluble chlorides

Open burning of electronic waste (E-waste) produces numerous organochlorine compounds (OCs). Although the presence of unidentified OCs has been suggested, the mass balance of identified and unidentified OCs in E-waste open burning soils (EOBSs) still remains unknown. In this study, the concentrations of Cl bonded with aromatic carbon (aromatic-Cl) and aliphatic carbon (aliphatic-Cl), and inorganic Cl in EOBSs were determined by focusing on chlorine (Cl) in water-insoluble fractions (insoluble Cl) and applying Cl K-edge X-ray absorption spectroscopy in conjunction with combustion ion chromatography. The concentrations of identified Cl (Cl in five individual OCs: polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, chlorinated polycyclic aromatic hydrocarbons and chlorinated benzenes) were calculated from the concentrations previously reported for the same samples. The proportions of identified Cl were less than 1% to aromatic-Cl, indicating the abundance of unidentified OCs. The concentrations of both aromatic-Cl and identified Cl were highest in the sample collected from the site in Vietnam (VN), where wires and cables were mainly burned, suggesting that unidentified aromatic-Cl were produced through pathways similar to those of identified OCs, and the pathway could be related to burning of wires and cables. Further, insoluble Cu (II) compound, Cu₂(OH)₃Cl were assumed to be present in EOBSs and the concentration was highest in VN, implying that insoluble inorganic chlorides could be related to the formation of aromatic-Cl and identified Cl.

Public Health Burden of E-waste in Africa

BACKGROUND

Environmental impacts from informal e-waste recycling are increasing in Africa. E-waste handling and disposal exposes people to highly toxic cocktails of heavy metals, brominated flame retardants, non-dioxin-like polychlorinated biphenyls (PCB), polycyclic aromatic hydrocarbons (PAH), polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PBDF) and dioxin-like polychlorinated biphenyls (DL-PCB). Most of these compounds are endocrine disrupters, and most are neuro- and immune-toxic as well.

OBJECTIVES

Informal e-waste recycling in African countries is a serious public health threat. The present paper reviews the extent of e-waste exposure in Africa and related impacts on people, animals and the environment.

METHODS

Four electronic databases (PubMed, Science Direct, Scopus, Google Scholar) were searched for publications related to e-waste and human health in Africa. Search terms included 'e-waste in Africa', 'e-waste in developing nations', 'public health and e-waste', 'environment and e-waste', and 'e-waste and health'.

DISCUSSION

Elevated levels of e-waste pollutants in water, air, soil, dust, fish, vegetable, and human matrices (blood, urine, breast milk) indicate that not only are e-waste workers at risk from exposure to e-waste, but the general population and future generations as well. Headache, cough and chest pain, stomach discomfort, miscarriage, abnormal thyroid and reproductive function, reduction of gonadal hormone, and cancer are common complaints of those involved with the processing of e-waste.

CONCLUSIONS

The evidence presented from the reviewed studies illustrates the extent of the human health and environmental risks posed by e-waste in Africa. There is a need for a regulatory framework including specific legislation, infrastructure and protocols to safely recycle and dispose of e-waste in sub-Saharan African countries.

COMPETING INTERESTS

The authors declare no competing financial interests.

A relative risk assessment of the open burning of WEEE

Waste electric and electronic equipment (WEEE) represents a potential secondary source of valuable materials, whose recovery is a growing business activity worldwide. In low-income countries, recycling is carried out under poorly controlled conditions resulting in severe environmental pollution. High concentrations of both metallic and organic pollutants have been confirmed in air, soil, water, and sediments in countries with informal recycling areas. The release of these contaminants into the environment presents a risk to the health of the exposed population that has been widely acknowledged but still needs to be quantified. The aim of this work was to evaluate the relative risk from inhalation associated with the open burning of different kinds of WEEE. The shrinking core model was applied to estimate the concentration of the metals which would be released into the environment during the incineration of different types of WEEE. In addition, the potential generation of dioxins during the same informal practice was estimated, based on the plastic content of the WEEE. The results provided for the first time a comparative analysis of the risk posed from the open burning of WEEE components, proposing a methodology to address the absolute risk assessment to workers from the informal recycling of WEEE.

The state of POPs in Ghana- A review on persistent organic pollutants: Environmental and human exposure

Ghana is one of the top pesticide users and highest persistent organic pollutant (POP) emitters in sub-saharan Africa. Despite recent increases in published data, there is limited information on how POP concentrations have changed, post ratification of the Stockholm Convention. As a result, this review aims to address these knowledge gaps by collating available data that reported POPs in Ghanaian environmental matrices, identify spatial and temporal trends, and establish potential health risks. It is worth noting that Ghana has not developed its own regulatory standards for POPs, but adapts United States Environmental Protection Agency (USEPA) standards. Results obtained showed concentrations in excess of USEPA regulatory standards for per- and poly-fluoroalkyl sulphonates (PFASs) and dichlorodiphenyldichloroethane (DDD) in water, polychlorinated and polybrominated dibenzo-p-dioxins and furans (PCDD/Fs and PBDD/Fs) in e-waste soils, and polybrominated diphenyl ethers in aquatic organisms and dairy products. The published studies do not cover major regions nationwide. The inconsistency in methods and analytes measured, along with data scarcity in some regions, makes it challenging to identify temporal trends. However, the data did indicate decreasing concentrations of some legacy POPs in soil/sediment and aquatic organisms, with increasing concentrations of some POPs in water, fish, fruits and vegetables. Studies that performed health risks assessments were limited although the data indicated risks to e-waste workers, some farmers and vulnerable sub-populations. This review identified potential human health risks from POPs in the Ghanaian environment and the need for more consistent and widespread monitoring program.

Concentrations, spatial distributions, and congener profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans around original plastic solid waste recovery sites in China

The concentrations, profiles, and spatial distributions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in soil and sediment samples from several typical plastic solid waste (PSW) recovery sites (particularly from areas in which PSW is burned openly) in China were investigated. The results showed that burning PSW directly influenced PCDD/F concentrations immediately around the burning area. All of the samples in which soil contained black burning residue, collected from immediately around burning areas, had PCDD/F concentrations (mean 21708 ng kg^-1) and toxic equivalent (TEQ) concentrations (mean 2140 ng I-TEQ kg^-1 or 1877 ng WHO₂₀₀₆-TEQ kg^-1) more than 100 times higher than the concentrations in samples collected away from burning areas (mean 222 ng kg^-1, 8.75 ng I-TEQ kg^-1, 7.96 ng WHO₂₀₀₆-TEQ kg^-1). Principal component analysis and hierarchical cluster analysis indicated that the PCDD/F concentrations in seven soil samples from near PSW burning areas were influenced by PSW burning but that the PCDD/Fs in these soil samples may have had other or multiple sources. PCDD/F distributions at PSW recovery sites have been investigated in few previous studies. The results presented here indicate that appropriate measures should be taken to decrease the ecological risks posed by PSW recovery and to prevent, control, and remediate PCDD/F and other chemical contamination caused by PSW recovery.

Has the question of e-waste opened a Pandora's box? An overview of unpredictable issues and challenges

Despite regulatory efforts and position papers, electrical and electronic waste (e-waste) remains ill-managed as evidenced by the extremely low rates of proper e-waste recycling (e-recycling) worldwide, ongoing illegal shipments to developing countries and constantly reported human health issues and environmental pollution. The objectives of this review are, first, to expose the complexity of e-waste problems, and then to suggest possible upstream and downstream solutions. Exploring e-waste issues is akin to opening a Pandora's box. Thus, a review of prevailing e-waste management practices reveals complex and often intertwined gaps, issues and challenges. These include the absence of any consistent definition of e-waste to date, a prevalent toxic potential still involving already banned or restricted hazardous components such as heavy metals and persistent and bioaccumulative organic compounds, a relentless growth in e-waste volume fueled by planned obsolescence and unsustainable consumption, problematic e-recycling processes, a fragile formal e-recycling sector, sustained and more harmful informal e-recycling practices, and more convoluted and unpredictable patterns of illegal e-waste trade. A close examination of the e-waste legacy contamination reveals critical human health concerns, including significant occupational exposure during both formal and informal e-recycling, and persistent environmental contamination, particularly in some developing countries. However, newly detected e-waste contaminants as well as unexpected sources and environmental fates of contaminants are among the emerging issues that raise concerns. Moreover, scientific knowledge gaps remain regarding the complexity and magnitude of the e-waste legacy contamination, specifically, a comprehensive characterization of e-waste contaminants, information on the scale of legacy contamination in developing countries and on the potential environmental damage in developed countries, and a stronger body of evidence of adverse health effects specifically ascribed to e-waste contaminants. However, the knowledge accumulated to date is sufficient to raise awareness and concern among all stakeholders. Potential solutions to curb e-waste issues should be addressed comprehensively, by focusing on two fronts: upstream and downstream. Potential upstream solutions should focus on more rational and eco-oriented consumer habits in order to decrease e-waste quantities while fostering ethical and sustained commitments from manufacturers, which include a limited usage of hazardous compounds and an optimal increase in e-waste recyclability. At the downstream level, solutions should include suitable and pragmatic actions to progressively reduce the illegal e-waste trade particularly through international cooperation and coordination, better enforcement of domestic laws, and monitoring in both exporting and receiving countries, along with the supervised integration of the informal sector into the recycling system of developing countries and global expansion of formal e-waste collection and recycling activities. Downstream solutions should also introduce stronger reverse logistics, together with upgraded, more affordable, and eco-friendly and worker-friendly e-recycling technologies to ensure that benefits are derived fully and safely from the great economic potential of e-waste.

Reviewing the relevance of dioxin and PCB sources for food from animal origin and the need for their inventory, control and management

BACKGROUND

In the past, cases of PCDD/F and PCB contamination exceeding limits in food from animal origin (eggs, meat or milk) were mainly caused by industrially produced feed. But in the last decade, exceedances of EU limit values were discovered more frequently for PCDD/Fs or dioxin-like(dl)-PCBs from free range chicken, sheep, and beef, often in the absence of any known contamination source.

RESULTS

The German Environment Agency initiated a project to elucidate the entry of PCBs and PCDD/Fs in food related to environmental contamination. This paper summarizes the most important findings. Food products from farm animals sensitive to dioxin/PCB exposure-suckling calves and laying hens housed outdoor-can exceed EU maximum levels at soil concentrations that have previously been considered as safe. Maximum permitted levels can already be exceeded in beef/veal when soil is contaminated around 5 ng PCB-TEQ/kg dry matter (dm). For eggs/broiler, this can occur at a concentration of PCDD/Fs in soil below 5 ng PCDD/F-PCB-TEQ/kg dm. Egg consumers-especially young children-can easily exceed health-based guidance values (TDI). The soil-chicken egg exposure pathway is probably the most sensitive route for human exposure to both dl-PCBs and PCDD/Fs from soil and needs to be considered for soil guidelines. The study also found that calves from suckler cow herds are most prone to the impacts of dl-PCB contamination due to the excretion/accumulation via milk. PCB (and PCDD/F) intake for free-range cattle stems from feed and soil. Daily dl-PCB intake for suckler cow herds must in average be less than 2 ng PCB-TEQ/day. This translates to a maximum concentration in grass of 0.2 ng PCB-TEQ/kg dm which is less than 1/6 of the current EU maximum permitted level. This review compiles sources for PCDD/Fs and PCBs relevant to environmental contamination in respect to food safety. It also includes considerations on assessment of emerging POPs.

CONCLUSIONS

The major sources of PCDD/F and dl-PCB contamination of food of animal origin in Germany are (1) soils contaminated from past PCB and PCDD/F releases; (2) PCBs emitted from buildings and constructions; (3) PCBs present at farms. Impacted areas need to be assessed with respect to potential contamination of food-producing animals. Livestock management techniques can reduce exposure to PCDD/Fs and PCBs. Further research and regulatory action are needed to overcome gaps. Control and reduction measures are recommended for emission sources and new listed and emerging POPs to ensure food safety.

Determination of the Extent of Trace Metals Pollution in Soils, Sediments and Human Hair at e-Waste Recycling Site in Ghana

The concentrations of trace elements (Mg, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Y, Mo, Cd, In, Sn, Sb, Cs, Ba, Tl, Pb, and Bi) in soils, sediment, human hair, and foodstuff collected around the electronic waste (e-waste) recycling sites in Accra, Ghana were detected using inductively coupled plasma-mass spectrometry (ICP-MS). High levels of Cu, Zn, Mo, Cd, In, Sn, Sb, and Pb were observed in soils collected from the e-waste recycling sites. Four sequential extraction procedures were used to evaluate the mobility and bioavailability of metals (Cu, Zn, Cd, Sb, and Pb). Especially, the results showed that Cd and Zn in soils were mostly recovered in exchangeable fraction (respectively 58.9 and 62.8%). Sediment collected from around the site had enrichment of Zn, Sn, Sb, Mo, In, Pb, and Bi. The concentrations of Cu, Mo, Cd, Sb, and Pb in human hair were significantly higher than those collected from the control site (p < 0.01). Additionally, hierarchical cluster analysis reviewed that these elements were derived from e-waste activities. The results of Pb isotopic ratios in the samples indicate that Pb in human hair possibly originated from contaminated soils, fish, and foodstuff.

Occurrence, profiles, and toxic equivalents of chlorinated and brominated polycyclic aromatic hydrocarbons in E-waste open burning soils

We conducted this study to assess the occurrence, profiles, and toxicity of chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs) and brominated polycyclic aromatic hydrocarbons (Br-PAHs) in e-waste open burning soils (EOBS). In this study, concentrations of 15 PAHs, 26 Cl-PAHs and 14 Br-PAHs were analyzed in EOBS samples. We found that e-waste open burning is an important emission source of Cl-PAHs and Br-PAHs as well as PAHs. Concentrations of total Cl-PAHs and Br-PAHs in e-waste open burning soil samples ranged from 21 to 2800 ng/g and from 5.8 to 520 ng/g, respectively. Compared with previous studies, the mean of total Cl-PAH concentrations of the EOBS samples in this study was higher than that of electronic shredder waste, that of bottom ash, and comparable to fly ash from waste incinerators in Korea and Japan. The mean of total Br-PAH concentrations of the EOBS samples was generally three to four orders of magnitude higher than those in incinerator bottom ash and comparable to incinerator fly ash, although the number of Br-PAH congeners measured differed among studies. We also found that the Cl-PAH and Br-PAH profiles were similar among all e-waste open burning soil samples but differed from those in waste incinerator fly ash. The profiles and principal component analysis results suggested a unique mechanism of Cl-PAH and Br-PAH formation in EOBS. In addition, the Cl-PAHs and Br-PAHs showed high toxicities equivalent to PCDD/Fs measured in same EOBS samples when calculated based on their relative potencies to benzo[a]pyrene. Along with chlorinated and brominated dioxins and PAHs, Cl-PAHs and Br-PAHs are important environmental pollutants to investigate in EOBS.

Speciation and leaching of trace metal contaminants from e-waste contaminated soils

Primitive electrical and electronic waste (e-waste) recycling activities have caused serious environmental problems. However, little is known about the speciation and leaching behaviors of metal contaminants at e-waste contaminated sites. This study investigated trace metal speciation/mobilization from e-waste polluted soil through column leaching experiments involving irrigation with rainwater for almost 2.5 years. Over the experimental period, Cu and Zn levels in the porewater were 0.14±0.08mg/L, and 0.16±0.08mg/L, respectively, increasing to 0.33±0.16mg/L, and 0.69±0.28mg/L with plant growth. The amounts of Cu, Zn, and Pb released in surface soil (0-2cm) contributed 43.8%, 22.5%, and 13.8%, respectively, to the original levels. The released Cu and Zn were primarily caused by the mobilization of the carbonate species of metals, including Cu(OH)₂, CuCO₃, and Zn₅(CO₃)₂(OH)₆, and amorphous Fe/Mn oxides associated fractions characterized by sequential extraction coupling with X-ray absorption spectroscopy. During the experiments, trace metals were not detected in the effluent, and the re-sequestration of trace metals was mainly attributed to the adsorption on the abundant Fe/Mn oxides in the sub-layer soil. This study quantitatively elucidated the molecular speciation of Cu and Zn in e-waste contaminated soil during the column leaching process.

Separate screening of brominated and chlorinated dioxins in field samples using in vitro reporter gene assays with rat and mouse hepatoma cell lines

In 2011, a joint World Health Organization (WHO) and United Nations Environment Programme expert panel recommended the use of the WHO toxicity equivalency factor (TEF) scheme for assessment of the human health risks of brominated dioxins which have different sources from chlorinated dioxins. Therefore, WHO toxic equivalents (TEQs) should be determined for both chlorinated and brominated dioxins. As alternative to the conventional but time-consuming dioxin analysis using gas chromatography high-resolution mass spectrometry, we have developed a screening method involving cleanup and separation of brominated dioxins from chlorinated dioxins in field samples and subsequent analysis by CALUX (chemically activated luciferase expression) assays which are in vitro reporter gene assays detecting dioxin-like compounds. Cleanup and separation were accomplished with silica gel columns impregnated with 55% sulfuric acid and with 10% silver nitrate, respectively, and the average recoveries of the major contributors to the WHO-TEQs were approximately 90%. The CALUX 2,3,7,8-TCDD equivalents (CALUX-TEQs) derived from all the dioxin-like compounds in the cleanup fractions of the field samples (n = 24) were measured by means of the CALUX assays, indicating significant positive correlations between the WHO-TEQs and CALUX-TEQs (r ≥ 0.969, P < 0.001). We found that the ratios of the chlorinated dioxin-derived WHO-TEQs to the brominated dioxin-derived WHO-TEQs were strongly positively correlated with the ratios of the CALUX-TEQs derived from the chlorinated dioxin fractions to the CALUX-TEQs derived from the brominated dioxin fractions (r ≥ 0.833, P < 0.001). These results suggest that our method will be useful for estimating the contributions of chlorinated and brominated dioxins to WHO-TEQs.

Comparison of soil heavy metal pollution caused by e-waste recycling activities and traditional industrial operations

The traditional industrial operations are well recognized as an important source of heavy metal pollution, while that caused by the e-waste recycling activities, which have sprouted in some developing countries, is often overlooked. This study was carried out to compare the status of soil heavy metal pollution caused by the traditional industrial operations and the e-waste recycling activities in the Pearl River Delta, and assess whether greater attention should be paid to control the pollution arising from e-waste recycling activities. Both the total contents and the chemical fractionation of major heavy metals (As, Cr, Cd, Ni, Pb, Cu, and Zn) in 50 surface soil samples collected from the e-waste recycling areas and 20 soil samples from the traditional industrial zones were determined. The results show that the soils in the e-waste recycling areas were mainly polluted by Cu, Zn, As, and Cd, while Cu, Zn, As, Cd, and Pb were the major heavy metals in the soils from the traditional industrial zones. Statistical analyses consistently show that Cu, Cd, Pb, and Zn in the surface soils from both types of sites were contributed mostly by human activities, while As, Cr, and Ni in the soils were dominated by natural background. No clear distinction was found on the pollution characteristic of heavy metals in the surface soils between the e-waste recycling areas and traditional industrial zones. The potential ecological risk posed by heavy metals in the surface soils from both types of sites, which was dominated by that from Cd, ranged from low to moderate. Given the much shorter development history of e-waste recycling and its largely unregulated nature, significant efforts should be made to crack down on illegal e-waste recycling and strengthen pollution control for related activities.

Soil concentrations of polybrominated diphenyl ethers and trace metals from an electronic waste dump site in the Greater Accra Region, Ghana: Implications for human exposure

Unregulated electronic waste (e-waste) recycling operations have become a significant environmental issue as well as human health risk in developing countries across the world. The present study evaluated the extent of pollution in Agbogbloshie e-waste recycling site in Accra, Ghana. The concentrations of polybrominated diphenyl ethers (PBDEs) and some selected trace metals were determined using gas chromatography electron impact ionization mass spectrometry and flame atomic absorption spectrophotometry, respectively. The concentrations of ∑ PBDEs ranged from 15.6 to 96.8ngg^-1 dry weight, with an overall mean of 54.8ngg^-1dw. BDE-28 was the dominant congener followed by BDE-209 and BDE-47. The order of mean concentrations of the abundant trace metals was Fe>Cu>Pb≫Mn, with a mean range of .531-289mgkg^-1. Geoaccumulation index suggested that the surface soils deteriorated from moderate to high metal pollution, particularly for Cu, Pb and Fe. Of the trace metals analysed, Fe exhibited the highest concentration ranging from 3.97 to 918mgkg^-1. Correlation and principal component analyses suggested possible interactions between PBDEs and the trace metals analysed, while source assessment suggested that PBDEs and trace metals were mostly derived from inputs from the e-waste recycling activities. Average daily dose (ADD) was estimated using concentrations corresponding to 5th percentile, median and 95th percentile. Hazard quotients of 380 and 862 were obtained for adults and children respectively, for Cu and Pb which is a cause for concern especially for local children.

Toward a More Sustainable Trajectory for E-Waste Policy: A Review of a Decade of E-Waste Research in Accra, Ghana

Global flows of e-waste from the Global North to the Global South continue to damage local environments and harm human health. Weak e-waste regulations and limited use of safety measures for e-waste workers in Accra, Ghana, foster an exploitative environment within the industry, and pose health risks for those working and living near e-waste processing sites. This paper presents an integrated review of over 40 e-waste studies specific to Accra, with particular emphasis on the well-studied e-waste processing site in Agbogbloshie, and synthesizes the existing research base across interdisciplinary themes of human health, environmental health, globalization, trade and informalization, and public policy. Despite significant international attention to Accra’s e-waste problem, loopholes within international environmental regulations and treaties provide few incentives and resources for Ghana to strengthen protections for human and environmental health. After a decade of e-waste research in Accra, the crisis continues to intensify; we present a renewed vision for sustainable e-waste policy reform in Ghana and beyond.