UW Electrical & Computer Engineering

Electronic Devices

WEEE (e-waste) in Consumer Electronic Devices

Consumer electronic devices play a significant and frequent part in our day to day life. From watching the news to texting friends at the snap of a finger to  using TVs, smartphones, and tablets, consumer electronic devices are an integral part of a more inter-connected globe. But, with their ever-growing popularity comes consequences, particularly at the end of their useful life. Click below to learn more about what is contained in certain consumer electronic devices and how these devices impact both the environment and public health over the long run.

Computers    |    Legacy Televisions    |    Modern Televisions    |    Smartphones


What’s in a Computer?

Available to almost all Americans, the computer, plays an essential role in our day-to-day life. Despite looking very complicated, the internal layout of a computer can be broken into six main components which give it its functionality.


The motherboard is the most essential part of a computer and is akin to the central nervous system in the human body. The motherboard physically connects most computer components together and manages signals that go to and from the other components in a computer.  A motherboard is a printed circuit board containing a variety of discrete components (e.g. resistors, capacitors), integrated circuits, and connectors.  The workhorse or brain of the motherboard is the CPU, a highly integrated circuit which contains billions of transistors and processes the many signals from and to the computer digitally, managing memory, computation, and other critical functions of the computer itself.    The hard drive provides longer term storage of data and is primarily made of aluminum alloy or a mixture of glass and ceramic, while random access memory (or RAM) provides more temporary data storage and faster access to temporary memory, thus allowing the computer to execute commands more efficiently and run faster.  In comparison, the hard drive can store data permanently but cannot be accessed at random, making it slower. RAM is made of silicon integrated circuits which are made primarily of plastic, metals (copper, gold, aluminum), and silicon.   In addition to these components, a variety of other electronics support computation intensive functions of the computer including the graphics and sound card.   Both cards are printed circuit boards like the mother board, but differ from the motherboard in that they carry out dedicated functions.   Many computers, particularly desktop versions, have a CD/DVD-ROM drive which uses a laser that reads data from a CD or DVD (data) and then sends that data to the CPU to be processed. Most of a CD/DVD ROM drive is made of plastic and metal although some electronics are also contained within the drive.  Most general purpose computers, with the exception of tablets and e-readers, also contain a fan which cools the internal electronics down to prevent damage. The fan consists of brushless motor wrapped in copper wires. This motor turns fan blades which cool the electronics. The fan blades, motor, and other supporting components are enclosed in a case, typically made of Rynite plastic.   The monitor in a computer (or screen in a single integrated machine) is similar to televisions and has transitioned from CRT based screens to liquid crystal display screens.  Finally, the housing for most computers is made of steel or aluminum, which can be recycled, or thermoset plastic, which cannot be recycled.  Desktop and larger, heavy duty computers also contain a significant number of insulated copper cables and wires.

How do Computers impact the E-waste Stream?

Close to 84% of all households within the U.S. have a computer; with over 71 million computers sold in the U.S. in 2015 (compared to less than 9 million sold in 1990). This pales in comparison to the over 230 million computers sold worldwide in the same year. Surprisingly, however, global and domestic sales have been slipping since 2011, when global computer sales exceeded 320 million units.


Like many other consumer electronic devices, computers are often discarded carelessly, joining the growing piles of e-waste around the world. The U.S. EPA found that nearly 29.9 million computers were thrown away in 2007, with less than 20% of them being recycled. That number rose to almost 52 million in 2010. However, the good news is that the recycling rate also rose, to 40%!

How do Computers impact the environment?

By virtue of the dense and numerous electronics contained in computers, these devices contain higher toxic materials per volume than many other devices and appliances. The printed circuit boards (PCBs) used to make computers are similar to those used in other appliances and devices and produce similar effects on the environment and on public health when improperly disposed or informally recycled (click here for more information on PCBs and their impact on the environment).


In addition to the impacts of PCBs, improper disposal of computers also represent a waste of high value natural resources such as gold, silver, and ruthenium.  Ruthenium, in particular, is used for high performance hard disks and is incredibly rare. As rare earth materials dwindle, demand for these materials creates growing political tension and conflict in areas of the world where they remain to be mined and extracted.


When informally recycled, the many insulated wires in desktop computers and cables used to connect to peripheral devices pose a significant hazard to human and ecosystem health.  These cables are often covered with polyvinyl chloride (PVC) for safety and insulation, but when burned to recover underlying copper wires, they often release dangerous dioxins and furans.  Inhaling these toxins are very hazardous as they can cause skin disorders (such as chloracne), liver problems, heart disease, and impairment of the immune, endocrine and reproductive systems. Specifically, dioxins are linked with several forms of cancer.  Since they are fat soluble and hydrophobic, they accumulate and remain in the body for a lifetime.


Many plastic computer parts also contain flame retardants; these polybrominated diphenylethers (PBDEs) have endocrine disrupting effects and can be particularly harmful to developing fetuses.  Exposure to PBDEs can also lead to thyroid hormone disruption, delayed onset of puberty, decreased sperm count, permanent learning and memory impairment, loss in hearing and possibly, cancer.


Although computer recycling rates are on the rise, this is not necessarily good news unless recycling is carried out in regulated recycling facilities that avoid the hazards inherent to low temperature burning, unprotected shredded and dismantling, and other practices common in informal or unregulated economies.

Legacy Televisions

What’s in a Legacy Television?

A legacy television is commonly understood as a television that was produced in the year 2000 or before and contains a cathode ray tube (CRT) for generating the image seen on the phosphor coated screen.  The CRT television uses a glass tube whose air has been removed (a vacuum tube) to control three electron beams for each of the three primary colors (red, blue, and green) that generate color and intensity on a screen, using repetitive scanning.   CRT televisions emit X-rays, which are prevented from reaching consumers watching these televisions with a lead glass screen that serves as a barrier to these X-rays.  A typical CRT television can contain up to six pounds of lead and this lead, until recently, has been almost impossible to recycle because it is intertwined with the glass barrier on the front of the television.  In addition to these two major components, the electronic control system includes computer chips, built-in antennas, logic boards and a remote control receiver. Their function is the driving force behind receiving the TV signal (from the air or through cable) and letting the user control the television by changing channels, adjusting volume, and so on.   As with other appliances and consumer electronic devices, most of these electronics are housed on printed circuit boards (PCBs) which contain a wide range of materials are are explored in more detail here.  Finally, the last major component of the television, the exterior housing protects the internal components and tends to made of injection-molded, thermoset plastic which is impossible to recycle and can only be repurposed or repackaged.


Since the turn of the century, CRT or legacy televisions have increasingly been replaced with alternative technologies that use liquid crystal (LCD), plasma, and organic LEDs to generate an image for the television to function properly.  Unfortunately, as consumers have transitioned to these new TV technologies, a large number of legacy televisions have either been illegally dumped or remain in storage across America, awaiting disposal.

How do Legacy Televisions impact the E-Stream?

Many Legacy Televisions have already been dumped in landfills or illegally dumped, creating an impact on the environment through lead and other contamination that will last for generations to come.  Consumers seeking to recycle CRT televisions properly must carefully investigate the companies that claim to recycle these televisions responsibly. Recently, a seemingly credible e-waste reclaim company in Kentucky was caught burying these old televisions in a large hole in their own backyard, entirely contrary to their professed practices and any level of environmental responsibility.


Millions of CRT televisions remain in storage in American homes.  One estimate from the Electronics Recycling Coordination Clearinghouse reports that 5 billion pounds of Legacy Televisions still lurk in American homes.  These heavy and bulky items seem difficult to recycle and Americans often procrastinate in disposing of them.  Thus, even though the technology itself is largely obsolete, Legacy Televisions will continue to impact the e-waste stream for many years into the future.   In the past, it was desirable and lucrative to recycle these televisions as parts could be used to make new CRT televisions and metals in these electronic devices could be recovered for a profit.  However, times have changed, precious metals now cost less, and both incentives to recycle these televisions have dropped drastically, increasing the burden on the consumer to recycle responsibly.

How do Legacy Televisions impact the environment?

The most toxic component in a legacy television is the cathode ray tube and lead glass screen. While most modern televisions don’t contain a CRT anymore, many homes in the US (and across the world) still carry older sets which are based on CRT technology. A CRT and screen can contain over 4-8 pounds of lead and can impact both public and ecosystem health.


When dumped in landfills, many workers break the glass envelope surrounding the CRT and expose themselves to dangerous levels of lead. Lead poisoning is a well known health hazard and is especially harmful to young children.  Click here to learn more about lead and its impact on public health.   Other toxic metals in CRTs include barium and cadmium. Severe barium exposure can lead to kidney problems, respiratory failure, the development of neurodegenerative diseases, and even death. Cadmium, another heavy metal like lead, can lead to acute respiratory problems such as bronchitis and pulmonary irritation. Long term effects include impairment of lung functions, kidney disease, and increased risk of lung cancer.


Lead and other metals, including cadmium, do not break down in the environment and persists for years where they are dumped or leaked.  These metals can contaminate drinking water and food and bioaccumulate up the food chain, affecting a wide range of wildlife in addition to humans.   Fish and seafood are especially vulnerable to heavy metal contamination and the subsequent impact on communities which rely on these foods for subsistence are heavily affected by lead and heavy metal contamination from CRTs and e-waste generated from Legacy Televisions.

Modern Televisions

What’s in a Modern Television?

Modern televisions have similar electronic control systems, exterior housing, and other components to Legacy televisions.   However, modern televisions have drastically different screens and projection systems than legacy televisions. These display technologies and resulting screens are much thinner and also display a much sharper/clearer image.


Modern television displays and screens use three major technologies:  liquid crystal (LCD), plasma, and light emitting diode (LED).  An LCD television uses liquid crystals in a special state, called the nematic state, where all crystals point generally in the same direction.  These liquid crystals are arranged in pixels on the screen and then sub-pixels of red, green, and blue to create a little spot of red, green, or blue light at every sub-pixel that is either on or off.  When the sub-pixel is electrically off, the nematic liquid crystal has an untwisted structure that does not polarize (rotate) light and effectively allows the light in the back of the screen to reach the sub-pixel on the front of the screen (thus turning the pixel on). When the sub-pixel is electrically on, the nematic liquid crystal has a twisted structure that does polarize light and effectively blocks the light in the back of the screen from reaching the sub-pixel at the front of the screen.  A typically LCD television screen has millions of pixels, each containing three sub-pixels of red, green, and blue and each controlled independently to be on and off.  This individual pixel control is vastly different from the Legacy Television which uses electron guns inside a CRT to “paint” the display on the screen.  The liquid crystals in an LCD TV are placed between two pieces of glass, also known as the display glass, which are covered in a layer of silicon dioxide.  Most LCD TVs also contain a fluorescent light in the back of the display which provides light for the liquid crystals to block or transfer the light (allowing the corresponding pixel to be dark or light). Fluorescent lights are made of glass tubes filled with gas and small amounts of mercury. However, because of the pixel based technique and the use of liquid crystals, no x-rays are used to create the TV image and no lead filled glass is needed at the front of the television to block these x-rays.


An LED based TV also operates using pixels and liquid crystals, but uses an LEDs rather than a fluorescent bulb to provide the lighting to the TV display.  There are three main configurations for an LED TV; full array, edge lit and direct lit. In a full array, the LEDs are distributed evenly behind the TV screen, thereby providing excellent contrast differences within images and a high resolution, clear display. In the edge lit LED TV, the LEDs are placed along the perimeter of the TV. While this is the most common of LED televisions, it can also produce cloudy images and spots on the TV that are brighter than others. In the direct lit LED TV, very few LEDs are placed behind the screen compared to full array and edge lit technologies, thereby producing an inferior quality image. However, a direct lit display can also be much bigger in size compared to the edge lit and full array. Regardless of the lighting approach, LEDs themselves are made with semiconductor materials such as gallium arsenide and gallium phosphide. They also use gold and silver compounds, which are enclosed in a transparent plastic.  Overall, LED screens contain much less arsenic and other toxic meals compared to the mercury in conventional LCD screens and the lead in CRT (Legacy television) displays.


Plasma screens also use the pixel based technique, but use tiny fluorescent lamps that are switched on an off to turn each sub-pixel on and off.  These tiny fluorescent lamps are made up of the gases neon and xenon stored between two sheets of glass. The two gases are used to fill hundreds of small pixel cells. Each cell is coated with phosphor chemicals. When electricity flows into the cells, the gas will emit an ultraviolet light, which the phosphor chemicals (often red, blue or green) will turn into visible light that is then projected onto the screen. The more the gas gets excited, the brighter the color will be seen on the screen.  Compared to LCD and LED based displays, plasma screens offer much higher image quality, but are more fragile and consume significantly more power.


How do Modern Televisions impact the E-waste Stream?

Modern televisions have now replaced CRT televisions in sales and usage. In 2016, sales of over 226 million units of LCD televisions are projected, with an average lifespan of 9.5 years. LED televisions are not as popular at just over 17 million units in 2016. However as the technology for LED televisions improves, sales are expected to increase significantly in the near future. As a whole, flat panel televisions (which include LCD, LED and plasma televisions) have experienced a dip in sales during the past few years. In the U.S. alone, sales went from 38.6 million units shipped in 2010 to 34.2 million units in 2015.


Since most modern televisions are very recent and still in use, they are not a huge contributor to the growing piles of e-waste across the world. Many flat panel display TVs purchased in the mid-2000s are just now approaching the end of their lifespan. Through the end of 2015, over 30 million flat panel display televisions(approximately 400,000 kilotons) will have reached the end of their life, with many expected to be disposed of rather than reused.  Another issue is that the prevalence of modern televisions on the market has caused many users to dump out their older legacy (CRT) televisions. The impact of Legacy TVs on the e-waste stream is significant and is described in more detail here.


How do Modern Televisions impact the environment?

Despite significant improvements in the technology used to build televisions, these devices are still not designed for recycling. For example, the mercury found in the fluorescent light sources within LCD televisions is extremely hazardous and can prove fatal even in low doses. Workers are exposed to it when they shred or improperly take apart modern televisions, often near illegal e-waste dumps. Inhaling mercury can lead to a myriad of behavioral and neurological problems such as insomnia, memory loss, tremors, and cognitive dysfunction. It can also affect the kidney, thyroids and lungs. Pregnant woman are especially at risk to the dangers of mercury, as it may harm the brain development of the unborn baby. Excessive or long term exposure to it can lead to death as well. Mercury can also find its way into the local environment through improper disposal of LCD televisions. Similar health effects resulting from exposure to it are seen in fish and other wildlife. Often times, mercury can bioaccumulate and move up the food chain (through eating contaminated animals) until it eventually reaches humans.


Liquid crystals within LCD televisions also present a potential health hazard. While the environmental effects of it are not known in their entirety, it has been demosntrated that the trace amounts of chlorine compounds within liquid crystals may generate dioxins when liquid crystal glass is incinerated, as is typical in many informal e-waste recycling centers. Dioxin exposure has been linked to many serious diseases, including type 2 diabetes, ishemic heart disease, and chloracne. Dioxin exposure can also lead to impairment of the endocrine, immune and reproductive systems as well as alter liver function. People who have inhaled dioxins over a long period of time are also more likely to develop cancer.


The LEDs found in LED televisions also present drawbacks. Expensive metals such as gold and silver are used within LEDs. As production and demand for these televisions increases, the need to use gold and silver will increase as well. As a result of this, the world will face dwindling supplies of these rare metals, potentially leading to political strife over who can control these natural resources. Trace amounts of heavy metals are also found within LEDs. While a single one may not present much environmental impact, thousands of tons of LED television waste can be an issue. Exposure to heavy metals can result in serious health issues. Arsenic (found in LEDs), for example, can induce vomiting, nausea and damage the blood vessels. Long term exposure and inhalation can lead to darkening of the skin and lung cancer. Lead is another heavy metal found in LEDs. Its environmental impact can be found here.


Plasma televisions tend to use a lot more energy compared to their counterparts. In comparing a 55 inch LCD TV with a 55 inch plasma television, the power consumption of the plasma TV (136 watts) will be over double compared that of the LCD TV (67 watts). Since plasma televisions tend to be bigger than televisions that use LCD or LED technology, power consumption per unit will be even greater than double a typical TV using one of these alternative technologies. Increased power consumption in consumer electronic devices has its own impact on the environment through the environmental impacts of electricity production.


Finally, in general, most flat screen televisions contain a greenhouse gas called nitrogen triflouride (NF3). As production, sales and e-waste of these televisions increase in the coming years, emissions of NF3 will increase as well. The potential impact of NF3 is expected to be even greater than that of greenhouse gas (GHG) emissions from coal plants. However, since NF3 is still present in the atmosphere at only small amounts, its full impact is not yet fully understood.


What’s in a Smartphone?

Generally, smartphones tend to consist of a screen, a battery, electronics, and a casing. Many people also choose to use an extra case for protection of the phone from mechanical damage.   An excellent map of the materials used in cell phones is found here.


Most screens are touchscreens which serve a dual purpose of displaying information and accepting user input.  These screens tend to be made from aluminosilicate glass, which is a mixture of aluminum oxide and silicon dioxide, often strengthened by the addition of potassium ions. A transparent and conductive layer of indium tin oxide is placed on the glass so that the screen can function as a touch screen. Mulitple rare earth elements (such as Ytrium, Lanthanum, and Europium) are also used in the screen in small quantities to provide such functions as reducing UV light intrusion into the phone.


Most batteries used in modern smartphones are lithium-ion which use lithium cobalt oxide on one of the battery electrodes and carbon graphite on the other.   Most batteries are encased in aluminum.


Electronics in a smart-phone consist primarily of the motherboard, a graphical processing unit (GPU), and a main microprocessor. The motherboard generally joins all the different parts in a machine together to help it function as one and are usually made of fiberglass and copper. Both the GPU and main microprocessor are made with silicon as is true of other integrated circuits in the phone. Interconnections and other wiring within the phone are usually made of metals such as copper, gold and silver, often joined together with solder (which contains tin and sometimes lead). In more recent times, however, lead-free solder is growing in popularity, in large part due to the European ROHS directive to reduce toxic materials in electronics.


The case or outer housing of a smartphone is composed of metal and/or plastic.  Plastic casings are typically hard or thermoset plastics and cannot be recycled (but in some cases, may be shredded and repackaged).   Metal cases often contain magnesium and nickel (to reduce electromagnetic interference).

How do Smartphones impact the E-waste Stream?

With their popularity skyrocketing, smartphones are an important and concerning part of the e-waste stream. A mind-boggling 19 smartphones are purchased each second around the world and in 2016, there were 207.2 million smartphone users in the US alone. This number is expected to rise more than ten million in the next year


As expected, as the number of smartphone users grows, so does the amount of e-waste generated from smartphone use. In the U.S., over 100 million cell phones are disposed of each year, and worse, over 70%-80% of this waste ends up in landfills, where toxins and chemicals contained in the phone leach into the environment, primarily through the soil and groundwater tables underlying these landfills. A huge part of the problem is that the average user buys a new cell phone every 18 months. Short lifespans of smartphones and many consumer electronics only compound their impact.

How do Smartphones impact the environment?

By far, heavy earth metals in smartphones have the greatest impact to the environment if smartphones are not recycled properly. Although largely present in only trace amounts, heavy metals in smartphones include arsenic, cadmium, lead, and mercury which when combined with thousands of smartphones at e-waste facilities, can result in concerning levels of these toxins.  One such metal is arsenic, which is found in many of the microchips within smartphones. Low-levels of exposure to arsenic can cause skin, liver and respiratory system problems. Another heavy metal is lead, which is used in circuit boards and batteries. Lead can cause damage to the nervous, blood and nervous systems. It is especially harmful to young children and babies, leading to developmental problems such as decreased bone growth and poor muscle coordination. Other toxic heavy metals include mercury, which can produce harmful effects on the kidney, lungs and immune system and cadmium, which can induce bone damage and affect blood pressure. Breaking or simply leaving smartphones in landfills allows many of these toxins to leach into local rivers and soil, where they can contaminate drinking water and food for miles around and years to come.


Humans are exposed to heavy metals through handling of smartphones during recycling and also through soil and water impacted by phone disposal and air impacted by the shredding or burning of these devices.  Most smartphones still impact the environment through improper disposal or through informal (and dangerous) recycling practices. Burning electrical devices (and the plastics they contain) without proper incinerators releases dioxins which cause cancer and are some of the most toxic substances on the planet.


Another less obvious impact of smartphone use (and their fast replacement periods) is the wastage of rare and precious materials, which are used to create smartphones. Every 1 million cell phones thrown away amounts to 750 pounds of silver, 75 pounds of gold, and 35,000 pounds of copper.  Furthermore, smartphones contain at least seven different rare earth materials (Dysprosium, Gadolinium, Europium, Praseodymium, Terbium, Lanthanum, and Yttrium) whose supply cannot possibly support demand over the long term, thus stimulating conflict and political tension around extracting them from the earth.


Smartphones are also the hallmark of tightly integrated and compact devices, which while convenient and appealing to the consumer, are difficult to take apart for proper recycling and recovery of precious materials.  As devices become even more tightly integrated, by their very definition, they will become harder to recycle, creating an imminent need for an alternative to recycling or disposal.

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© 2016 Denise Wilson