The World Health Organization (WHO) has declared the production of electronic waste (e-waste) to be a growing global environmental health problem [1
]. In 2005, annual e-waste generation was estimated at 35 million tons. This figure is increasing, and greater production occurs in developed countries, with later transfer to low- and middle-income countries for reuse or recycling [6
]. E-waste is defined as comprising discarded, nonworking electronic products—e.g., cell phones, computers, and home appliances— and their components, which are no longer considered useful by the owner or manufacturer [7
]. They are a source of hazardous constituents, such as heavy metals, but also valuable materials, including copper, gold, silver, and rare earth metals [1
E-waste recycling occurs in formal and informal settings [2
]. Formal settings involve well-established recycling plants specifically designed for recycling electronics, with at least some proper ventilation and protection for the workers laboring on them. Such facilities recycle between 12% and 35% of all e-waste generated in developed countries [7
]. Informal recycling, on the other hand, tends to involve independent workers, or small groups of workers or families—sometimes including children—who often use hazardous techniques such as cutting, acid baths, heating/smelting, and open burning of materials, without the use of personal protection equipment or engineering controls [2
]. Informal recycling occurs more often in developing countries. Generally, formal recycling of e-waste is considered better for workers and the environment when compared to informal recycling [9
Conditions often present in informal recycling are associated with increased risks to human and environment health, which has heightened awareness in the scientific communities and governmental agencies [1
]. Human exposure to the pollutants of e-waste recycling is not isolated to the occupational setting and can spill into the environment of the general population, which can include vulnerable populations such as children and pregnant women living in or near informal recycling sites [2
]. These exposures have been linked to a range of health effects, including disrupted thyroid function and cellular expression, adverse neonatal effects, and decreased lung function, among others [3
Environmental contamination issues associated with e-waste recycling have been described worldwide [2
], as have e-waste disposal policy options, e-waste reduction strategies, and, to a lesser degree, human health impacts of e-waste [2
]. Studies focusing mainly on informal recyclers have been conducted in middle–lower income countries such as China [10
], Ghana [12
], and Vietnam [14
], and have subsequently found high levels of endocrine disruptors and heavy metals in samples of hair, urine, and blood [2
]. In China, these contaminants have been found at high levels in the surrounding population as well, specifically in samples from human placenta, breast milk, and blood [15
]. On the other hand, among formal recyclers in higher income countries like France [19
], Sweden [9
] and the United States [20
], high levels of heavy metals have been reported in blood, urine, skin, and clothing. While studies have investigated exposures for informal e-waste workers from low-income countries in Asia and Africa, little is known about these exposures in middle- and high-income countries outside the United States and Europe. Very little is known in Latin America, with the exception of a study in Uruguay in a pediatric population [21
]. Additionally, while several studies have assessed contamination or human health impacts, few have examined the association between exposure and health outcomes, and even fewer have evaluated these associations among both informal and formal e-waste recycling workers.
As of 2017, Chile had a population of over 17 million inhabitants. It is highly urbanized (>87%) and centralized, with more than 41% of the total population living in the capital city of Santiago [22
]. The gross domestic product (GDP) has substantially increased in the past fifteen years, reaching US$
247,028 billion in 2016 [23
], promoted by a neoliberal market economy [24
]. The model has positioned Chile as one of the most economically developed countries in the region and a member of the Organization for Economic Cooperation and Development (OECD). However, the Chilean economy is also one of the most unequal in the world, with a Gini coefficient of 0.50 [26
]. Chile’s accelerated growth has boosted the technological sector and demand for new electronics. This has resulted in the highest per capita production of e-waste in Latin America, at 9.9 kg per person per year [27
]. As a consequence, a small, formal recycling industry has emerged, and, since 2016, new e-waste recycling laws have been passed that regulate certification recycling companies and include Extended Producer Responsibility (EPR) requirements [27
Despite the presence of legislation addressing e-waste recycling, informal recyclers operate in the country, though the full extent of their operations is unknown. Informal recycling networks usually include collectors, who collect e-waste from residential areas and companies; recyclers, who dismantle e-waste into their constituent parts and recover valuable materials; scrap dealers, who buy raw materials and products from recyclers and collectors; and repair shops, which use parts salvaged by recyclers to repair broken goods to return them to use. The overall objective of this study is to complete comprehensive health evaluations of e-waste recycling workers in Chile and compare those that work informally (i.e., in independent settings) to those that work formally (i.e., in well-established companies). The nature and location of e-waste activities done by workers in Chile, particularly those in the informal sector, is unknown. Therefore, the first challenge was to identify and recruit informal and formal workers willing to participate. This study was conducted shortly after the passage of e-waste disposal regulations in Chile; therefore, our study represents a baseline comparison between formal and informal e-waste recycling workers.
2.1. Study Design and Sites
A cross-sectional study was conducted from July to August 2017. Since the overall population of informal workers is unknown, this study utilized convenience sampling of workers from two cities of the country where informal recycling was thought to occur at significant levels. The two cities sampled were Santiago, the largest city in the country, and Temuco, a mid-size city of about 300,000 inhabitants [22
] (Figure 1
). To recruit informal workers, in a first step, several network of workers were contacted to identify sections of the cities where recycling activities were usually performed. Then, these sections were visited by field personnel in order to contact individuals for recruitment purposes. On the other hand, formal workers were recruited from a single mid-size formal recycling facility.
2.2. Participant Recruitment
In June and July 2017, informal sites were identified across the two cities at e-waste collection sites, repair shops, public fairs, and flea markets. In July and August 2017, each site was visited and potential participants were identified. Potential participants were then screened to confirm that they fell into one of the recycling activities targeted in our study (i.e., collectors, recyclers, repairers, or scrap dealers). For formal workers, a recycling company was contacted, and authorization was requested from the owner to carry out the study. In both settings, research staff explained the study objectives, procedures, and measurements to potential participants in detail, and interested individuals then signed a Spanish-language consent form.
2.3. Health Assessment
Participant data collection in Santiago, Temuco, and at the formal recycling company took place in August 2017. Since e-waste work is related to several different kinds of exposure (e.g., air pollution, noise, stress, injuries) and many potential health outcomes as shown in previous studies [2
], the questionnaire and exposure assessment was comprehensive. Table 1
summarizes the full set of procedures participants completed in the study. All participants were asked to complete a questionnaire and health assessment, provide blood and urine samples, undergo air sampling and noise monitoring, and complete a daily activity log. This manuscript will focus only on the results from the questionnaire. Four items from the questionnaire were drawn from Cohen’s perceived stress scale; these items addressed the frequency with which participants: felt unable to control important things in life; were confident about personal ability to handle problems; felt things were going their way; and felt they could not overcome difficulties [29
Additionally, a subset of participants also provided surface wipe samples in their homes or workplaces, were filmed for later activity analysis, and participated in focus groups designed to explore particular aspects of informal e-waste recycling. These activities will be described elsewhere.
The study protocol was approved by Health Sciences and Behavioral Sciences Institutional Review Board (IRB-HSBS) of the University of Michigan (Study eResearch ID: HUM00114562), and the Ethics Committee for Research in Human Beings of the Faculty of Medicine, University of Chile (approval 101-2017).
2.4. Data Analysis
An initial exploratory analysis was performed to identify, and correct, typing errors and missing values. Then, descriptive analysis of the variables was carried out using absolute and relative frequencies, for categorical variables, and measures of central tendency and dispersion, for continuous ones. Differences between sites and types of recyclers were explored using chi-squared test (χ2) and analysis of variance (ANOVA), with a significance level of p < 0.05.
While a number of studies of informal e-waste recycling workers have been conducted worldwide [2
], little is known about this industry in middle- and high-income countries outside United States and Europe. Our study of 93 workers appears to be the first study of e-waste recyclers in Chile, and adds to the very sparse literature on e-waste recycling in Latin America [21
]. Informal sector participants in this study worked for more than a decade, on average, suggesting that this industry has emerged relatively recently in Chile. Workers generally reported good overall health status and the prevalence of chronic diseases reported was comparable to national levels. Although workers reported several stressors, insufficient income to support themselves and their families was the most common issue among all participants. The prevalence of injuries was high (an average of three injuries in the past 6 months), and the use of protective equipment was generally low. The most common injuries were cuts and lacerations to the hands that occurred during the dismantling of e-waste products. Beyond visible injuries, participants reported experiencing pain in their hands and muscle soreness often after e-waste recycling work. The majority of workers reported being exposed to high levels of noise at least sometimes. We found few differences between informal and formal recycling workers; formal workers were slightly younger, more likely to work mainly as recyclers, and had less experience working with e-waste than did the informal workers.
Studies of informal e-waste recycling workers have been conducted in Ghana [12
] China [10
], Vietnam [14
], and India [4
]. As with our study, these workers were mostly male, except in Vietnam where workers were mostly female; however, workers in other studies were generally less educated, younger, and had a lower income with longer and more unstable working hours than participants in Chile. Workers in Ghana [32
] worked in e-waste recycling for less time than Chilean workers. E-waste recycling activities most often reported by informal workers in other countries included collecting, dismantling, and scraping, while in Chile there was a high prevalence of repairing and reselling of e-waste as well. Health effects and behaviors also differed between our sample and those conducted on informal e-waste recycling workers outside of Chile. A study conducted in Ghana [32
] suggests that e-waste recycling workers there smoked less in comparison to our sample, but reported more cardiovascular symptoms. The informal workers in our study reported a range of symptoms that is generally consistent with a previous study [4
] that showed informal e-waste recycling work is associated with diseases in the skin, stomach, respiratory tract and other organs. Other existing studies did not report on these conditions and their relation to e-waste recycling.
Studies of formal e-waste recycling workers are uncommon. A handful of such studies have been conducted in the United States [20
], France [19
], and Sweden [9
]. Only the Swedish study characterized its population but did not describe their primary recycling activities. Formal e-waste recycling workers in Chile were mainly involved in recycling activities such as sorting, scraping, dismantling, and baling, which were all activities previously described for other studies of formal workers [9
]. None of these studies had a health history evaluation, so no relevant comparison could be made.
Occupational exposure to stressors among informal e-waste recycling workers assessed in Ghana [32
], reported moderate to high levels of stress, work in unfavorable physical conditions, as well as violence or harassment in their occupational environment, and insufficient income to support themselves for most participants. Chilean informal e-waste recycling workers did not report substantial exposures to occupational stressors, violence, or harassment. However, our Chilean participants did commonly report insufficient income to support themselves and their families. Informal e-waste recyclers in Ghana [32
] reported greater intensity of occupational noise exposure, while Chilean workers reported longer noise exposure times. Difficulty hearing and reported diagnosis of a hearing loss was twice as frequent among Chilean informal e-waste workers as compared to Ghanaians [32
]. We did not identify other studies that quantified occupational injuries among e-waste recycling workers. Overall, it appears that exposure to stressors, and their health impacts, may be lower in Chile than in similar studies performed in developing nations.
There are limitations to our study that may reduce the generalizability of our findings. First, the representativeness of our sample is unknown, as the workforce of Chilean e-waste recyclers is not well understood, especially in the informal sector. We tried to obtain the most representative sample possible by searching for participants in both informal and formal settings and across several cities in Chile. Second, our finding that workers did not report major health problems may simply be a reflection of the healthy worker effect [33
]. Third, our cross-sectional assessment of exposures and health status may not accurately capture changes in these factors that have occurred over time, or the long-term average status and can therefore not prove causality. Finally, it is possible that participant responses were subject to social desirability bias, which could partially explain both the low health risks and the differences found between formal and informal.
Our study is among the first to directly compare exposures and health status among formal and informal e-waste recycling workers anywhere, and the first study of e-waste recyclers in Chile. The results of our questionnaire indicated that e-waste workers in Chile did not present major chronic health effects but rather small effect for injuries and stress, with the latter possibly due to income insecurity. Only a few significant differences, generally of a rather small magnitude, were found between informal and formal workers.
Electronic waste recycling in Chile seems to differ from other studied areas in the methods of reuse as well as the population that participates in the sector. Further research is needed to fully understand and evaluate the long-term impact of both formal and informal sectors in Chile. However, this research, in combination with previously published literature, lends credence to the idea that e-waste recycling differs significantly by country and in each case should be considered a special context. Therefore, to establish country-specific and appropriate policies and safety measures while simultaneously maintaining economic flexibility for those involved, evaluation and understanding of the context should be completed first. Finally, by providing a baseline assessment of exposures and health conditions among informal and formal e-waste recycling workers, we have established a comparison point for subsequent studies both to evaluate the impacts of the new e-waste recycling law in Chile and to compare it with other contexts and countries over time.