**4. Environmental and human health hazards of electronic waste recycling**

The extent to which many of the other materials found in electronics are hazardous to human health and the environment is increasingly well-known. Electronics often contain toxic elements such as lead (Pb), cadmium (Cd), polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs) and mercury (Hg) as well as other toxic components such as PVC and brominated flame retardants (BFRs) [29]. **Table 3** presents a list of some of the known hazardous components found in the typical desktop computer (with CRT monitor). This table is an adaptation of material presented by the Silicon Valley Toxics Coalition [30] in their report "Poison PC's and Toxic TV's" and toxicity data from Ceballos et al. [31].

Many of the health effects outlined in **Table 3** have been documented in the town of Guiyu, China, where perhaps the greatest portion of the U.S.'s e-waste exports have been deposited historically. Here, almost 80% of children have respiratory problems, and they have an especially high risk of lead poisoning [32]. Neurological, respiratory,


#### **Table 3.**

*A sample of hazardous elements in an older-model PC.*

digestive and bone problems are not uncommon among the workers and their families [32]. In addition to these toxicological threats, which include long-term implications for both health and the environment, the threats posed by the recycling of e-waste are even greater when certain recycling methods are employed [33–36]. For example, the informal recycling practice of burning plastic cables to retrieve the copper inside releases dioxins in the air via the burning PVC in the plastic. In more sophisticated operations (most typically found in Asian countries), a process of leaching printed circuit boards with acids (including nitric acid and hydrochloric acid) in order to maximize the amount of gold recovered can cause burns, respiratory and circulatory problems, pulmonary edema and death [2, 4, 36]. The acid stripping leaves behind a toxic residue that oftentimes is disposed of in waterways where it can acidify water and destroy wildlife and vegetation [36–38]. Heavy metal dust can travel to more populous areas and contaminate food supplies and greater populations [39, 40].

There have also been studies on the occupational health and environmental risks associated with high-tech e-waste recycling, with experts noting that much more research needs to be done in this area in order to gain a more accurate assessment of these risks [41–45]. Many of these studies are based on or informed by field research and experiments that measure concentrations of toxic chemicals in the workers, air, and environment around high-tech recycling facilities. There are indications in these studies that technologies such as the introduction of face masks and improved ventilation do decrease occupational exposures to a number of heavy metals and other hazardous chemicals.

In the U.S., a survey of 276 electronic waste recycling facilities was recently completed by the U.S. National Institutes of Occupational Safety and Health (NIOSH) [31]. It is especially relevant to note that this report finds that "most" of the responding facilities rely on manual dismantling, similar to the approach being applied in new and pilot facilities in less developed countries. It is also worth noting that a majority of the responding facilities were certified as environmentally sound either through the industry standard RiOS, the EPA standard R2 Solutions, or the activist standard e-Stewards. Hence, these facilities are likely to represent the "best

**53**

recycling [47].

**5. Conclusion**

result from e-waste recycling.

**Acknowledgements**

Publishing Fund.

*Electronic Waste Recycling and Disposal: An Overview DOI: http://dx.doi.org/10.5772/intechopen.85983*

case scenario" in electronics recycling. Overall, NIOSH concluded that "e-scrap recycling has the potential for a wide variety of occupational exposures particularly because of the use of manual processes" [31]. One of the primary concerns listed in the report is the potential for exposure to "metal dust" during the process of manual dismantling [31]. Specifically, the report notes that it is unclear whether most facilities have installed proper filtration systems in order to remove metal dust from the air (since the majority of the facilities circulate air within the production area or rely on "natural ventilation"). The report also notes the use of compressed air for cleaning which can heighten exposure to metal dusts. While the initial NIOSH report says that acute exposure to heavy metals such as lead is unlikely, the report notes that "chronic lead poisoning, which is more likely at current occupational exposure levels, may not have symptoms or they may have nonspecific symptoms

that may not be recognized as being associated with lead exposure" [31].

Following the publication of the NIOSH report, additional studies of on-site occupational exposures in formal e-waste recycling facilities have been completed. Researchers reviewed 37 studies of the occupational hazards associated with formal e-waste recycling and concluded that, despite clear improvements to worker and environmental health when compared with informal recycling, "formal e-recycling workers and their families may experience unhealthful exposures to metals" [46]. The authors recommend further research "to reduce chemical exposures from formal e-waste recycling," along with the development of electronics components that are easier to safely disassemble, along with reducing the use of hazardous components in the manufacture of electronics [46]. With e-waste now considered to be the fastest growing stream of hazardous waste in the world, there is an urgent imperative to implement solutions to reduce the risks associated with e-waste

The design, production, sale and use of electronics takes place at the global scale. These initial stages in the life cycle of electronics pose a series of hazards to human health and the environment. Similarly, the disposal and recycling of electronics routinely entails the movement of hazardous materials across national borders. Growing government and industry interest in the recovery of secondary raw materials, such as the rare earth elements from e-waste, is leading towards an increase in the: development of strategies to increase recycling rates (which currently stand at approximately 20% globally), as well as in the development of formal, mechanized processes for recycling e-waste at the end-processing stage. In some cases, this has entailed the development of enabling legislation such as EPR "take-back" laws, and in other cases this has led to pilot projects that promote partnerships between recyclers in the formal and informal sectors. While there are many additional steps that can be taken in order to ensure that recipients of waste are adequately prepared to manage and recycle them in an environmentally sound manner, progress has been made. As these developments unfold, regulation and oversight will play a decisive role in mitigating the myriad risks to human health and the environment that can

This chapter was partially funded by the Boston College Open Access

*Electronic Waste Recycling and Disposal: An Overview DOI: http://dx.doi.org/10.5772/intechopen.85983*

*Assessment and Management of Radioactive and Electronic Wastes*

**Element Main applications Weight** 

shield/CRT, printed wiring board

housing, printed wiring board

phosphor emitter/housing, printed wiring board, CRT

Lead Metal joining, radiation

Mercury Batteries, switches/

Cadmium Battery, blue/green

*A sample of hazardous elements in an older-model PC.*

Plastics (including those containing PVC and BFRs)

*Sources: [30, 31].*

**Table 3.**

digestive and bone problems are not uncommon among the workers and their families [32]. In addition to these toxicological threats, which include long-term implications for both health and the environment, the threats posed by the recycling of e-waste are even greater when certain recycling methods are employed [33–36]. For example, the informal recycling practice of burning plastic cables to retrieve the copper inside releases dioxins in the air via the burning PVC in the plastic. In more sophisticated operations (most typically found in Asian countries), a process of leaching printed circuit boards with acids (including nitric acid and hydrochloric acid) in order to maximize the amount of gold recovered can cause burns, respiratory and circulatory problems, pulmonary edema and death [2, 4, 36]. The acid stripping leaves behind a toxic residue that oftentimes is disposed of in waterways where it can acidify water and destroy wildlife and vegetation [36–38]. Heavy metal dust can travel to more populous areas and contaminate food supplies and greater populations [39, 40]. There have also been studies on the occupational health and environmental risks associated with high-tech e-waste recycling, with experts noting that much more research needs to be done in this area in order to gain a more accurate assessment of these risks [41–45]. Many of these studies are based on or informed by field research and experiments that measure concentrations of toxic chemicals in the workers, air, and environment around high-tech recycling facilities. There are indications in these studies that technologies such as the introduction of face masks and improved ventilation do decrease occupational exposures to a number of heavy

**(per 60 lb)**

Casing, cable coating 22.99 PVC effects: developmental toxin,

**Dangers**

kidney damage. Brain damage and poisoning/death for children Accumulates in the environment

damage and other neurological effects Concentrates through the food chain.

damage to the kidneys

reproductive toxin, endocrine disruptor. Carcinogenic when burned due to production of dioxins BFR effects: endocrine disruptor, neurotoxin, carcinogen (in humans and animals)

3.8 Human effects: neurological, blood,

<0.1 Human effects: long term brain

<0.01 Human effects: acute and chronic

In the U.S., a survey of 276 electronic waste recycling facilities was recently completed by the U.S. National Institutes of Occupational Safety and Health (NIOSH) [31]. It is especially relevant to note that this report finds that "most" of the responding facilities rely on manual dismantling, similar to the approach being applied in new and pilot facilities in less developed countries. It is also worth noting that a majority of the responding facilities were certified as environmentally sound either through the industry standard RiOS, the EPA standard R2 Solutions, or the activist standard e-Stewards. Hence, these facilities are likely to represent the "best

**52**

metals and other hazardous chemicals.

case scenario" in electronics recycling. Overall, NIOSH concluded that "e-scrap recycling has the potential for a wide variety of occupational exposures particularly because of the use of manual processes" [31]. One of the primary concerns listed in the report is the potential for exposure to "metal dust" during the process of manual dismantling [31]. Specifically, the report notes that it is unclear whether most facilities have installed proper filtration systems in order to remove metal dust from the air (since the majority of the facilities circulate air within the production area or rely on "natural ventilation"). The report also notes the use of compressed air for cleaning which can heighten exposure to metal dusts. While the initial NIOSH report says that acute exposure to heavy metals such as lead is unlikely, the report notes that "chronic lead poisoning, which is more likely at current occupational exposure levels, may not have symptoms or they may have nonspecific symptoms that may not be recognized as being associated with lead exposure" [31].

Following the publication of the NIOSH report, additional studies of on-site occupational exposures in formal e-waste recycling facilities have been completed. Researchers reviewed 37 studies of the occupational hazards associated with formal e-waste recycling and concluded that, despite clear improvements to worker and environmental health when compared with informal recycling, "formal e-recycling workers and their families may experience unhealthful exposures to metals" [46]. The authors recommend further research "to reduce chemical exposures from formal e-waste recycling," along with the development of electronics components that are easier to safely disassemble, along with reducing the use of hazardous components in the manufacture of electronics [46]. With e-waste now considered to be the fastest growing stream of hazardous waste in the world, there is an urgent imperative to implement solutions to reduce the risks associated with e-waste recycling [47].
