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Environment International
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environment
INTtENATIONAL
The formal electronic recycling industry: Challenges and opportunities in occupational and environmental health research
Diana Maria Ceballos *, Zhao Dong
Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA USA
CrossMark
ARTICLE INFO
Article history:
Received 31 May 2016
Received in revised form 17 July 2016
Accepted 20 July 2016
Available online 26 August 2016
Keywords: E-waste
Occupational health Environmental health Formal e-recycling Electronics recycling Chemical hazards
ABSTRACT
Background: E-waste includes electrical and electronic equipment discarded as waste without intent of reuse. Informal e-waste recycling, typically done in smaller, unorganized businesses, can expose workers and communities to serious chemical health hazards. It is unclear if formalization into larger, better-controlled electronics recycling (e-recycling) facilities solves environmental and occupational health problems. Objectives: To systematically review the literature on occupational and environmental health hazards of formal e-recycling facilities and discuss challenges and opportunities to strengthen research in this area. Methods: We identified 37 publications from 4 electronic databases (PubMed, Web of Science, Environmental Index, NIOSHTIC-2) specific to chemical exposures in formal e-recycling facilities.
Discussion: Environmental and occupational exposures depend on the degree of formalization of the facilities but further reduction is needed. Reported worker exposures to metals were often higher than recommended occupational guidelines. Levels of brominated flame-retardants in worker's inhaled air and biological samples were higher than those from reference groups. Air, dust, and soil concentrations of metals, brominated flame-retar-dants, dioxins, furans, polycyclic-aromatic hydrocarbons, or polychlorinated biphenyls found inside or near the facilities were generally higher than reference locations, suggesting transport into the environment. Children of a recycler had blood lead levels higher than public health recommended guidelines.
Conclusions: With mounting e-waste, more workers, their family members, and communities could experience unhealthful exposures to metals and other chemicals. We identified research needs to further assess exposures, health, and improve controls. The long-term solution is manufacturing of electronics without harmful substances and easy-to-disassemble components.
© 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license
(http://creativecommons.org/licenses/by-nc-nd/4.0/).
1. Introduction
The production, commercialization, use, recycle, and disposal of electronics have increased exponentially in the last decades since the creation of the first computer. The rapid increase of new technologies makes electronics obsolete sometimes even within days of purchase. What is most concerning is the amount of electronics that have accumulated as waste worldwide, often called e-waste. It is estimated that the total amount of e-waste generated worldwide in 2014 was 41.8 million metric tons (United Nations University, 2014). E-waste may include electronics (e.g., keyboards, screens, computers, mobile phones), household appliances (e.g., televisions), office equipment (e.g., printer), lamps, personal items (e.g., cameras), and miscellaneous (e.g., photovoltaic panels). In the US, 4.4 million metric tons of e-waste were recycled in US formal electronic recycling (e-recycling) facilities in
» Corresponding author at: 401 Park Drive, PO Box 15677,4th Floor West, Suite 415, Boston, MA 02215, USA.
E-mail address: ceballos@hsph.harvard.edu (D.M. Ceballos).
2011 (ISRI, 2016), which constitute only 25% of all e-waste generated (U.S. EPA, 2011).
Part of the world's e-waste is recycled in informal e-waste sites in developing countries, such as Agbogbloshie in Ghana (Kyere et al., 2016). In the last few years, developing countries like Colombia and China have started to establish formal e-recycling facilities, moving e-waste indoors with varying degrees of protection from hazardous materials. China has recently suspended informal recycling operations in Guiyu, aiming to revamp one of the largest e-waste sites in the world into centralized facilities in an industrial park (Standaert, 2015). In developed countries like US, Canada, and Sweden, formal e-recycling facilities are the norm. We will use the term 'informal e-recycling' when referring to informal recycling operations in e-waste sites, and the term 'formal e-recycling when referring to ideally licensed and permitted facilities that process e-waste indoors with some level of industrial hygiene, worker protection, and pollution controls.
Recycling of electronics can be a source of many toxic chemicals including metals and organic compounds. Metals may include cadmium (e.g., batteries and CRTs), lead (e.g., printed circuit boards, CRTs), mercury (e.g., lamps in older LCD screens), nickel (e.g., batteries), among
http: //dx.doi.org/10.1016/j.envint.2016.07.010
0160-4120/© 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
other metals (Grant et al., 2013; Tsydenova and Bengtsson, 2011). Organic chemical compounds of concern include flame retardants (FRs) (e.g., plastics) and polychlorinated biphenyls (PCBs) (e.g., condensers). If electronics are burned, chemicals such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) may be generated (Grant et al., 2013; Matsukami et al., 2015). A systematic review by Grant et al. (2013) identified plausible health outcomes associated with exposure to chemicals from informal recycling in e-waste sites, including thyroid function changes, adverse neonatal outcomes, and impaired lung function.
Formal e-recycling main processes typically start by sorting, testing, refurbishing, and repairing received electronics. Then, electronics that need recycling are dismantled, sometimes shredded, and materials sorted using automatic machinery and manual labor. In some cases, there are specialized processing of certain electronics, e.g., CRTs (Ceballos et al., 2014b; Ceballos et al., 2015; Tsydenova and Bengtsson, 2011), and many formal e-recycling facilities are distributors to other parties downstream for materials recovery of plastics, glass, and metals. Controls to reduce exposures including ventilation and personal protective equipment (PPE) are common. In contrast, informal recycling is generally much more decentralized and involves fewer, if any, automatic procedures and health protective measures, usually relying on natural ventilation and without PPE. Most common processes in informal e-recycling include manual sorting, dismantling, de-soldering of printed circuit boards over coal grills to release valuable chips (Chan and Wong, 2013), open burning of wires to retrieve copper, and disposal of waste in open fields and water (Matsukami et al., 2015; Song and Li, 2014), and the health consequences of these practices disproportionally affect vulnerable populations (Heacock et al., 2016).
The objectives of this paper were 1) to provide a succinct literature review regarding chemical hazards in the formal e-recycling industry and 2) to propose a research framework to strengthen occupational and environmental health of formal e-recycling facilities based on the current literature and discuss challenges and opportunities to advance research in this area.
2. Methods
Four electronic databases were searched for publications related to chemical exposures during formal e-recycling from 1980 to Feb 2016. Key words used were: NIOSHTIC-2: 'recycling' and other databases: 'electronic,' 'recycling,' 'electronics recycling,' 'waste,' 'e waste,' 'ewaste,' 'e scrap,' 'escrap,' or 'WEEE'. Web of Science search was refined within domain 'science technology' and research areas 'environmental sciences ecology,' 'public environmental occupational health,' or 'toxicology.' Two outside studies were identified through references. Results were combined and duplicates removed to create a database of 1827 articles (Fig. 1).
We included studies in journal articles or government reports in English about formal e-recycling facilities principally engaged in the dismantling and mechanical processing of electronics for the recovery of raw materials. We excluded articles on downstream recycling facilities (i.e., plastic recycler, metallurgical processes), articles on informal or unspecified e-waste sites, cities, areas, or regions (e.g., Guiyu, China; Agbogbloshie, Ghana), and articles on management, life cycle assessment or material flows, economic analysis, new equipment, and other hazards beyond chemicals. We reviewed articles by title and abstract before final inclusion of 37 studies that met the predetermined criteria.
3. Results
3.1. Current literature on occupational health in the formal e-recycling industry (occupational health studies in Table 1)
In the US, several formal e-recycling facilities have been found with deficiencies in handling metal dust contamination (Ceballos et al., 2014a; Page et al., 2015). Inhalable worker overexposures (i.e., air samples above occupational exposure limits or OELs) have been documented during CRT processing for lead or cadmium (Ceballos et al., 2014a), cleaning operations (Almaguer et al., 2008; Page and Sylvain, 2009), and shredding (Ceballos et al., 2014a). Two workers processing CRTs
Fig. 1. Flowchart of a systematic literature review on occupational and environmental health in the formal e-recycling industry.
Table 1
Review of studies related to occupational and environmental health in the formal e recycling industry.
Country Study focus Study design
Number of e-recycling facilities (type)[authors facility description]
Chemicals Type of samples
Main findings
References
China Occupational Cross-sectional health exposure
assessment and risk assessment
Environmental Cross-sectional health exposure
assessment
Cross-sectional
exposure
assessment
1 (TVs)[WEEE recycling Metals and plant in East China with BFRs
two closed workshops using specialized equipment and PPE]
2 (TVs)[licensed and Metals permitted enterprise
located in the industrial zone in Shanghai]
1 (TVs)[specialized PBDEs, PM
factory for WEEE
recycling located in
Pudong District,
Shanghai]
4 (CRTs)[four major Metals formal e-waste recycling workshops and one informal e-waste recycling workshop in Hong Kong]
1 (mobile Metals (Pb,
prototype)[mobile Cd, Cu)
e-waste recycling plant] 1 (printed circuit Metals
boards)[qualified recycling plant located in Jiangsu, China]
1 [dismantling workshop PBDEs at an e-waste recycling plant in Shanghai]
1 [large scale e-waste PCDD/Fs, recycling base in Taizhou PBDD/Fs, with shredder] PBDEs,
chlorinated and parent PAHs
7 [large scale e-waste Metals (Cu, recycling plants in Cr, Cd, Pb,
Taizhou] Zn, Hg, As),
PAHs, PCBs
Cross-sectional exposure assessment and risk assessment
3 [e-waste recycling factories in Taizhou in walled buildings that hired migrant workers]
2 (transformers) [two transformers recycling workshops and vicinity of a large e-waste recycling factory in Taizhou]
Dust and bulk samples
Area air samples
Indoor area air sampling, dust from floor and surface of printed circuit boards and housing plastics
Dust and area air samples
Area air and floor dust when processing CRTs and printed circuit boards Area air and dust samples
Plastic housing of e-recycling, indoor floor dust and outdoor soil, and nearby reference site (1km away)
Facility-floor dust, electronic shredder residues, leaves from trees and shrubs, surface soil from facility ground
Soil samples from the facilities and from small household workshops
Indoor air from facility and houses, and ambient air from main roads; indoor dust at facility and homes of migrant workers and local residents
Air and dust inside homes, offices, private cars, and outdoors near the facility
Dust from production areas had the highest levels of PBDEs, TBBPA, Pb, and Cu. Unlikely non-cancer risk and low-level cancer risk were associated with these exposures. Pb was more enriched in PM2.5 dust and Cu in PM10 dust. Non-cancer levels were above safety guidelines. Cancer risk was highest due to Cr exposures. BDE-209 was mainly released from TV dismantling and plastic crushing process, while lower brominated PBDEs originated from heating of the printed circuit boards. However, printed wire board heating work without respirator would pose a health hazard.
High Pb levels in dismantling and desoldering areas. Pb in air was highest in dismantling areas. Other metals were also detected. Pb was estimated to be above safe guidelines. Cancer risks were present above acceptable range. Hazard index suggests potential non-cancer risk for Pb to the workers, and low cancer risk for Cd. Metals were found in air throughout facility with Pb and Cr highest near automatic crushing and separation processes. Non-cancerous effects might be possible while cancer effects are low risk. PBDEs were detected in the majority of e-recycling and dominated by BDE-209 (>93%), with highest levels found in TV made by Japan; indoor floor dust samples had higher total PBDEs concentrations than soil samples. Total PCDD/Fs, PBDD/Fs, PBDEs and PAHs in soils from facility were higher than soil from reference agricultural sites and a (non-e-recycling) chemical industrial complex. Most metals exceeded soil quality standards in China. PAHs and PCBs in soil were higher than reference site, while levels were lower in large scale recycling plants than small household workshops. PCBs concentrations were found in ambient air in facilities and nearby residential areas. PCBs in indoor dust from facility and houses of migrant workers and local residents were 10-100 times higher than from other cities around the world. Levels in migrant workers houses were significantly higher than neighboring resident houses. Residential areas contained relatively levels of PCBs in ambient air that were linked to facility dust and air, suggesting potential environmental dispersion of PCBs through air.
Deng et al. (2014)
Fang et al. (2013)
Guoetal. (2015)
Lau et al. (2014)
Song et al. (2015) Xueetal. (2012)
Lietal. (2014)
Ma etal. (2008); Ma etal. (2009a); Ma et al. (2009b)
Tang et al. (2010)
Wang etal. (2016)
Xing etal. (2010)
(continued on next page)
Table 1 (continued)
Country Study focus Study design
Number of e-recycling facilities (type)[authors facility description]
Chemicals Type of samples
Main findings
References
Cross-sectional exposure assessment and risk assessment
Canada Environmental Emission and
Finland
France
health
Occupational health
Occupational health
Occupational health
fugacity modeling of dispersion and fate
Longitudinal exposure assessment (2year follow up)
Cross-sectional exposure
1 [e-waste recycling and disposal factory in economic development zone in Shanghai]
1 [state-of-the-art electronics recycling facility in Alberta]
4 [Two commercial recycling sites and a social enterprise site]
9 (CRTs) [recycling sites and workers had access to PPE]
5 (fluorescent lamps) [fluorescent lamp recycling facilities]
Metals (Cr, Ni, Cu, Zn, Cd, Pb)
HBCD (a BFR)
BFRsand
chlorinated
Metals
Soil around the facility
Toxicology assay with mice
Cross-sectional
exposure
assessment
1 (CRT) [e-waste recycling facility with three processing lines set with environmental and worker protection controls]
1 (Battery) [corporation, recovery facility]
3 (CRTs) [electronics recycling program at prison institutions]
Metals
Metals
Industry survey 47 [industry certified] Metals
Cross-sectional exposure
3 (2 processing CRTs) [industry certified]
Metals
Risk assessment
Environmental health
Case study
1 [electronic recycling facility in California]
(Home of e-recycling worker) [industry certified]
Personal air and dust samples
Personal and area air samples, surface and skin wipes, CRT fluorescent dust
Personal and area air samples, skin wipes
Indoor area air
Urine biomonitoring, personal and area air samples
Personal and area air samples, wipes, and bulks. Surface wipes and reviewed existent records of blood and urine biomonitoring
Blood and urine biomonitoring, personal and area air samples, surface and skin wipes
Data on area air
Metals (Pb) Blood biomonitoring
Six metals were elevated in the nearby soil of the e-recycling facility relative to a reference site. Hazard quotients showed different orders among metals in different directions from the facility.
Model indicates that it was possible for HBCD to deposit to soil from air in area east of the facility, where a national park was located.
Two of the four facilities reduced exposures after workplace interventions were implemented (such as improvements in ventilation and its maintenance and changes in cleaning habits). Inhalation overexposures to lead, cadmium, yttrium, and barium found for all different CRT processing stages including dismantling, tube preparation, and CRT glass processing (including splitting of glass and shredding).
Inhalation overexposures to mercury vapors and dust containing lead and yttrium. Metal contamination on skin of workers.
The coarse PM fraction (2.5-10|jm) was 34 times more abundant than the fine/ultrafine PM (<2.5|m) and elicited significant pro-inflammatory responses in the mouse lung at 24h post-exposure compared to fine/ultrafine PM. Overexposures to mercury and central nervous system and respiratory symptoms that may be Hg-related.
Inhalation overexposures to lead and cadmium during filter change-out maintenance operation and CRT processing. Surface metal contamination present but blood levels were below safety guidelines. Wide variety of electronics processed, small to medium size facilities, health and safety programs in place, limited knowledge on how to appropriately deal with metal contaminated dust. Inhalation overexposures to lead during CRT processing and to cadmium during shredding of electronics. Surface and skin metal contamination suggesting potentials for take home. Lead blood levels above safe guideline (>10 |g/dL) for two dismantlers and two CRT processors. Approximate 633-fold increase BFRs exposure estimates in workers compared with the US general population. Lead levels above safe guidelines (>5 ug/dL) in two children due to parental work at an e-recycling facility processing CRTs.
Yangetal. (2013)
Tomko and McDonald (2013)
Rosenberg et al. (2011)
Lecleretal. (2015)
Zimmermann et al. (2014)
Kim etal. (2015)
Reh etal. (2001)
Almaguer et al. (2008a); Almaguer etal. (2008b,2009); Page and Sylvain, (2009)
(Ceballos et al., 2014b; Ceballos et al., 2015)
Beaucham et al. (2014); Ceballos et al., (2014a); Page et al., (2015)
Schecter et al. (2009)
Newman et al. (2015)
assessment
assessment
Table 1 (continued)
Country Study focus Study design
Number of e-recycling facilities (type)[authors facility description]
Chemicals Type of samples
Main findings
References
Sweden
Occupational health
Cross-sectional exposure assessment Cross-sectional and longitudinal (6-month follow up) exposure assessment
Longitudinal exposure assessment (2 year period)
Cross-sectional exposure
Thailand Environmental Cross-sectional health exposure
assessment
1 [electronic recycling BFRs facility in Örebro]
3 (CRTs)[formal recycling Metals facilities]
1 [electronic recycling BFRs facility]
1 [electronics PBDEs
dismantling plant]
1 [electronic recycling FRs plant]
5 (storage)[electronic BFRs waste storage facilities]
Area air samples
Blood/plasma and urine biomonitoring and personal air samples
Personal air samples
Serum biomonitoring
Area air samples
Dust and area air indoor samples. Outdoor air samples.
BFRs measurable in all air samples Julander et al. (highest for PBDE #209 and PBDE (2014) #183).
Significantly higher Julander et al.
biomonitoring results in (2014)
production workers than office workers for 4 (Cr, Pb, In, Hg) of 20 metals measured. Linear correlation of air and biomonitoring levels for 5 (Sb, Pb, In, Hg, V) of 20 metals measured. Dismantlers and those passing by dismantling area had highest PBDEs inhalation levels. Dismantlers had lower exposures when dismantling larger electronics.
PBDEs in serum from workers were significantly higher than from the reference group. FRs measurable in all air samples (BFRs and organophosphate esters). Highest levels found at the vicinity of the shredder. Air samples highest inside e-recycling facility compared to other environments.
Levels of BFRs were highest in Muenhor et al.
personal computer and printer (2010)
waste storage rooms. Levels of
BFRs in air found were lower than
that reported by e-waste site
studies. Levels in dust were
similar to that reported by other
studies for offices and homes.
Pettersson-Julander et al. (2004)
Sjodin etal. (1999) Sjodin et al. (2001)
BFRs = Brominated flame retardants; CRTs = Cathode ray tube from televisions and computer screens; FR = flame retardant; HHE = Health Hazard Evaluation Program; NIOSH = National Institute for Occupational Safety and Health; PBDD/Fs = polybrominated dibenzofurans anddioxins; PBDE = Polybrominated diphenyl ethers; PCB = Polychlorinatedbiphenyls; PPE = Personal protective equipment; TBBPA = tetrabromobisphenol A; TV = television; PAH = polycyclic aromatic hydrocarbons; HBCD = Hexabromocyclododecane; PM = particulate matter; WEEE = Waste Electrical and Electronic Equipment. Studies including personal samples are bolded.
assessment
(Ceballos et al., 2014b) and two workers dismantling electronics (Page et al., 2015) were found with elevated lead levels in their blood, i.e., biological samples above recommended Center for Disease Control and Prevention guidelines given outdated regulatory biological indexes that are not protective of chronic health (NTP, 2012; CDC, 2016). Overexposures to mercury were found during the processing of recycled household-type alkaline batteries, and central nervous system and respiratory symptoms were related to those exposures (Reh et al., 2001).
Worker overexposures to metals in formal e-recycling facilities have been corroborated by studies in France and Sweden. Lecler et al. (2015) documented numerous worker overexposures to barium, cadmium, lead, and yttrium in 9 formal e-recycling facilities processing CRTs in France, and verified CRTs as the source of the exposures. Zimmermann et al. (2014) reported lead and yttrium along with mercury overexposures during the recycling of fluorescent lamps in France. Julander et al. (2014) observed significantly higher biomonitoring results in production workers than office workers for chromium, lead, indium, and mercury during formal e-recycling process in Sweden. They found blood lead levels above the CDC guideline, and that indium was measurable in the blood, urine, and breathing zone air of workers (with air indium levels above NIOSH recommended guidelines for preventing indium lung disease).
Formal e-recycling work also exposes workers to BFRs (Rosenberg et al., 2011; Sjodin et al., 1999), PCBs (Xing et al., 2010), dioxin and furans (Ma et al., 2008). Although there are only a few and outdated OELs available for these organic chemicals to make a safety determination, Sjodin et al. (1999) found significantly higher levels of BFRs in serum from
formal e-recycling workers compared to a reference population. Likewise, Schecter et al. (2009) estimated an increased exposure to BFRs in indoor air at formal e-recycling facilities when compared to the reference dose typical of the US general population. Sjodin et al. (2001) measured BFRs and organophosphate ester FRs in the air of a formal e-recycling facility at levels higher than other workplaces. Further, levels of BFRs in air at two facilities were lowered through implementation of workplace interventions (Rosenberg et al., 2011), suggesting that engineering and administrative controls can achieve a significant reduction in BFR exposures. Metals and BFRs were identified on surfaces in production and non-production areas inside the formal e-recycling facilities in all occupational health studies that collected bulk or wipe samples of the dust.
3.2. Current literature on environmental health in the formal e-recycling industry (environmental health studies in Table 1)
Most studies performed cross-sectional measurement of air, dust, or soil samples within or near a facility, and often found higher concentrations of a group of chemicals including metals (Yang et al., 2013), BFRs (Kim et al., 2015; Li et al., 2014), PCDD/Fs (Ma et al., 2008), PAHs (Ma et al., 2009), and PCBs (Wang et al., 2016; Xing et al., 2010) than reference sites. Highest concentrations were usually detected in floor dust or ground soil within the facility, especially in dust samples (Li et al., 2014; Yang et al., 2013). Concentrations in ambient air or indoor dust in residential areas near the facilities were generally elevated compared to background levels, suggesting potential atmospheric release of
contaminants to the surrounding environment from formal e-recycling facilities (Wang et al., 2016; Xing et al., 2010).
Among the identified studies conducted in China, there were cases in which the facility of interest still utilized primitive recycling techniques such as open burning and generated contaminant levels comparable to those observed in informal e-recycling (Ma et al., 2008), although the facility could be distinguished from an informal e-waste site for being more centralized, partially automated, in a walled building, and on a larger production scale. Therefore, the varying degrees of formalization among formal e-recycling facilities within and across countries may be a key determinant of the potential risk to the surrounding environment and communities.
Major environmental health risks may exist through 'take home' exposures by workers to their family members. For example, a case study (Newman et al., 2015) recognized elevated blood lead levels in two children, due to dust brought home on work clothes of a parent working at a US formal e-recycling facility processing CRTs. In developing countries where formal e-recycling facilities may lack appropriate controls or good enforcement of safety practices, take home pathways may be a larger concern. For example, higher levels of PCBs were found in dust from houses of migrant workers in formal e-recycling facilities than from neighboring houses of local residents (Wang et al., 2016).
4. Discussion
Our review of the literature in the formal e-recycling industry suggests that reported worker exposures are often higher than recommended occupational guidelines for metals and than reference groups for brominated flame-retardants. Air, dust, and soil concentrations of metals and hazardous organic chemicals found inside or near the
facilities are generally higher than reference locations, suggesting transport into the environment. Take-home exposures have been documented for e-recycling workers.
A limitation of our review was the difficulty in discerning if a facility was formal given the different terms used by different authors. Whenever in doubt, we decided against including the publication. It was also difficult to compare the different countries and facilities studied. The US publications documented that facilities were independently certified to an industry standard, but many developing countries do not have certified facilities. Industry certification programs set standards for safer recycling and disposal of electronic waste. Specifically, the Responsible Recycling Practices (R2) and e-Stewards® certification programs include guidelines for responsible and effective e-waste management including environmental and occupational safety and health; the Recycling Industry Operating Standard® (RIOS) defines an integrated quality, environment, health and safety management systems standard for the industry. Lastly, we acknowledge that many variables are at play in strengthening the e-recycling industry. For example, we only touched briefly on the crucial role of economic factors and policies related to e-recycling worldwide since it is beyond the scope of this study.
Improving occupational and environmental health in the new and dynamic formal e-recycling industry requires a two-tier multi-pronged multi-stakeholder research framework with health as a key consideration (Fig. 2, Table 2). Some of the research priorities included in this paper have been discussed in the past when focusing partially or fully on the informal e-recycling sector (Grant et al., 2013; Heacock et al., 2016; Tsydenova and Bengtsson, 2011). However, to our knowledge this is the first publication with research priorities that have been uniquely tailored to the formal e-recycling industry.
Strengthened formal recycling industry that safely processes electronics
tr tr tr tí tr
Tier 2. Improving recycling of electronics
Focus #1:
Assessing exposures to multiple chemicals
Focus #2:
Improving pollution & workplace controls
Focus #3:
Assessing health of workers, families & communities
Production of safer electronics during the entire life cycle
tí tr tí tí tr tr tí
Tier 1. Developing a new generation of electronics
Key Focus: Less hazardous electronic materials and easy-to-disassemble components
Fig. 2. Our proposed research framework to advance occupational and environmental health in the formal e-recycling industry.
Table 2
Research priorities for improving occupational and environmental health in the formal e-recycling industry.
Research priorities
Challenges
Opportunities
Examples of documented advances
TIER 1 - Developing a new generation of electronics
Perform exposure assessment to characterize risk to the surrounding ecosystem and communities from the recycling of electronics.
Perform controlled studies that assess release of chemicals from the recycling of electronics.
Improving controls in formal e-recycling Control emissions inside and outside of the facility.
Assessing health in formal e-recycling Determine toxicology of chemical mixtures from the recycling of electronics.
Perform health studies on formal e-recycling workers.
Perform health studies on the surrounding communities of formal e-recycling facilities.
Smaller and more difficult-to-recycle wearable electronics are entering the marketplace.
Substitute for safer materials while avoiding regrettable substitutions.
TIER 2 - Improving recycling of electronics
Assessing exposures in formal e-recycling Perform worker exposure assessment of complex chemical mixtures from the recycling of electronics.
High cost of chemical analysis for sampling of congener specific analysis. Outdated or non-existent occupational exposure limits for many chemicals present in electronics.
High cost of systematic sampling to generate a large sample size. Lack of environmental regulations to protect ecological health from many chemicals.
Different chemicals may have different transport, speciation, persistence, bioavailability, and toxicity in the environment.
Multitude of changing materials used in the wide variety of types and brands of electronics.
Different and evolving processes and technologies used for recycling electronics.
Lack of processing infrastructure and high capital costs.
Old equipment may be used at some e--recycling facilities and present challenges for controlling emissions in a cost effective manner.
Lack of health and safety expertise typical of small businesses.
The wide variety of electronics being processed at formal electronic recycling facilities makes exposures highly variable.
Dynamic changing industry. Small businesses.
Sometimes low-paid, temporary, and immigrant workforce. Lack of surveillance health data because of not unique industry codes. Facility economic vulnerability, e.g., fluctuating commodities prices, state programs, take back programs. Lack of awareness and data on take-home exposures.
High cost and low incentive to establish a cohort of non-workers.
Consider health in new electronics' life cycle analysis including end-of-life processing.
Design easier-to-disassemble electronics to avoid shredding at the end-of-life processing.
Partnerships of manufacturers, researchers, and recyclers.
Develop real time exposure assessment tools that assess many chemicals simultaneously at low cost. Update/create occupational exposure limits for chemicals that reflect the scientific literature.
Assess risk of end-of-life processing of electronics using personal exposure data from multiple chemicals and routes of exposure. Characterize migration of contaminants from the workplace to homes. Examine environmental compartments beyond air, dust, and soil to include samples of water, biota and human biomarkers.
Compare transition from informal to formal recycling.
Characterize cumulative risk of multiple groups of chemicals. Consider health risks for users, waste disposal workers, and recyclers in the life cycle of electronics.
Test real life exposure scenarios from e-recycling facilities in toxicological models.
Research including key stakeholders. Study the effect of chemical mixtures common to formal e-recycling of electronics on different health outcomes.
Study vulnerable members of the surrounding community such as children and pregnant women. Examine long-term health outcomes from legacy contamination of large abandoned sites.
Electronic prototypes based on biodegradable cellulose (Jung et al., 2015) and green processing of transistors (Portilla et al., 2015).
Risk assessment to metals and BFRs from dust samples (Deng et al., 2014).
Emission and fugacity modeling of the environmental fate and transport of a BFR (Tomko and McDonald, 2013).
Simultaneous assessment of metals, PCBs and PAHs in soil from e-recycling facilities and e-waste site (Tang et al., 2010).
Exposures to nano-particles during recycling of polypropylene composites (Boonruksa et al., 2016).
Potential exposures to BFRs and PBDD/Fs during extruding of plastics (Zennegg et al., 2014).
Increase domestic capacity for end-processing e-recycling. Bridge engineering and public health to discover cost-effective recycling equipment and controls.
Include health and safety in the design of processes.
Assessing reduction of BFRs worker exposures due to workplace interventions at an e-recycling facility (Rosenberg et al., 2011).
Pro-inflammatory response in mice exposed to dust from an e-recycling facility (Kim etal., 2015).
Comparison of PCBs in indoor dust in houses of migrant e-recycling workers and local residents (Wang et al., 2016).
BFR = brominated flame retardants; PBDD/Fs = polybrominated dibenzofurans and dioxins; PAHs = polyaromatic hydrocarbons; PCBs = polycyclic biphenyls.
4.1. Research priority tier 1: developing a new generation of electronics
Substitution of materials in electronics would eliminate hazards from the source, such as electronic prototypes based on biodegradable cellulose (Jung et al., 2015), or green processing of transistors (Portilla et al., 2015). Another example is the European Union legislation (RoHS Directive 2002/95/EC) requiring heavy metals and BFRs to be substituted by safer alternatives. However, legislation efforts of this kind need to be at the global level for them to be truly effective. Further, easier-to-disassemble components in electronics would reduce or eliminate the need for shredding and specialized processing. The production of small wearable electronics is increasing, presenting future challenges for those attempting to recycle and recover them (Elliott, 2016). Health impact evaluations for end-of-life processing of new technologies guided by partnerships between academia, electronic manufacturers, and recyclers are urgently needed.
4.2. Research priority tier 2: improving recycling of electronics
4.2.1. Research priority tier 2.1: assessing exposures informal e-recycling
The influx of various types and brands of e-waste as well as processing technologies may change over time, and can lead to subsequent changes in potential exposures to workers and the environment. The chemicals added to electronic products may also shift in response to change in environmental regulations on those chemicals. For example, concentrations of certain organophosphate FRs, used as alternatives when some BFRs were banned or phased out in some countries, have been increasing in e-waste (Matsukami et al., 2015). In addition, a formal e-recycling facility in the US under regulatory compliance may not necessarily protect workers' health given the failure to test for toxic chemicals in the first place, the outdated regulation for lead, and limited number of occupational limits for most organic chemicals of concern (e.g., FRs, PCBs). These challenges are compounded with the high cost and complexity of sampling and chemical analysis for FRs, PCBs, and other congener-specific chemicals.
There are opportunities for developing new exposure assessment tools and performing risk assessment using human exposure data from multiple chemicals and multiple routes of exposure to workers, worker's families, and local residents. There is also a need to evaluate environmental fate, transport, and health impact of the existing or planned formal e-recycling facilities to nearby residents and surrounding ecosystems.
4.2.2. Research priority tier 2.2: improving controls informal e-recycling
Even though some mechanized and automated processes are performed in formalized facilities, unless appropriate engineering and administrative controls are put in place, PPE itself will not be sufficient to avoid exposures: it is the last line of defense for workers. There are opportunities for bridging engineering and public health to assess and improve the effectiveness of engineering controls to reduce worker exposures and environmental emissions from e-recycling facilities. For moving e-waste sites into buildings, as is the case in China, research is needed to document improvements in occupational and environmental health.
Limited use of pollution controls in the recycling of electronics may sometimes leave behind contaminated sites, for example, after bankruptcy of some formal e-recycling facilities (Elliott and Leif, 2006; Powell, 2006a, 2006b) or mandatory suspension of work at the informal e-recycling site of Guiyu, China. Further, the legacy contamination at former e-recycling sites will continue to pose a health impact on the environment or new businesses using that space (Wu et al., 2015; Zhang et al., 2014), as many of the chemicals are persistent and bio-accumulative. There are opportunities for research to assess decontamination and revitalization of the areas, and the health impact of the legacy contamination.
4.2.3. Research priority tier 2.3: assessing health related to formal e-recycling
Epidemiological studies to assess chronic health concerns in this worker population and potentially affected communities are needed. However, a challenge that may have contributed to the paucity of health studies in the US formal e-recycling industry is the lack of specific North American Industry Classification System (NAICS) codes for this relatively new industry and its unique waste stream. For example, facilities studied in the US were classified with NAICS codes associated with the solid waste industry as a whole (Bastani and Celik, 2015).
Economic vulnerability of the formal e-recycling industry forces many businesses to hire temporary workers, or to close and reopen under a new name while their workforce changes. The Institute for Scrap Recycling Industries (ISRI) reported 45,000 traceable full time jobs in the US formal e-recycling industry (ISRI, 2016), while the actual number may be much larger. Thus, some workers could be followed with an epidemiological study while others may be hard to capture because of their mobility.
5. Conclusion
Electronics will continue to be produced, disposed, and recycled, and it is essential to consider health at the core of creating e-recycling jobs because of the hazardous chemicals inherent in this waste stream. Formal e-recycling facilities provide environmental services to society, and bring enormous benefits to their communities and the world. Recycling of electronics is good for the environment when done in an appropriate manner as it recovers materials for reuse and reduces waste in landfills.
Overall, formalization is a desirable direction for the e-recycling industry. Despite the potential for exposing workers and the surrounding environment to many chemicals, formal e-recycling facilities are expected to have improved occupational (Tsydenova and Bengtsson, 2011) and environmental (Tang et al., 2010) health compared to informal e-recycling. Formal e-recycling facilities typically restrict child labor, separate the workplace and workers' residences, and trigger applicable occupational and environmental health regulations, which vary from country to country. However, the improvements from transitioning informal e-recycling into the formal sector will depend on the degree of formalization.
Even in the high-tech formal e-recycling facilities, challenges still remain in assessing and controlling chemical exposures regularly found in this industry. To strengthen the current formal e-recycling industry around the world, more government and private funding is urgently needed to support a multi-pronged multi-stakeholder research framework, giving priority to developing a new generation of safer electronics, improving processes and controls specific to formal e-recycling, and understanding health in the complexity of chemical mixture exposures typical from recycling of electronics.
Acknowledgements
This work was supported by funds contributed by Ms. Marilyn B. Hoffman.
Diana Ceballos is a JPB Environmental Health Fellow. The JPB Foundation supports the JPB Environmental Health Fellowship Program, which is managed by the Harvard Chan School of Public Health.
We thank the insightful reviews by John Spengler, Gregory Wagner, Robert Herrick, and Joseph Allen at Harvard Chan School of Public Health, Madeleine Scammell at Boston University School of Public Health, and Sarah Westervelt at Basal Action Network.
The authors declare they have no actual or potential competing financial interests.
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