E-waste and its effect on health and the environment

Transcription

1 E-waste and its effect on health and the environment E-waste cannot be considered or treated like any kind of waste, because it contains hazardous and toxic substances such as lead, mercury, cadmium or others such as dioxins and furans, bromined flame retardants (produced when e-waste is incinerated). For instance, lead represents 6% of the total weight of a computer monitor. Another example: nearly 36 chemical elements are incorporated in electronic equipment. This data further demonstrates the unsustainability of irresponsible electronic equipment disposal, its negative effect on the environment and the need to implement management regulations which include actions like refurbishment and recycling. Even though in the last years recycling has become a regular practice almost everywhere in the world, some e-waste components present difficulties when they are recycled mainly because of their complexity and the lack of methods. Such is the case of plastics used in electronic equipment which contain flame retardants that impede the recycling process. In order to amplify the information submitted in the web page We Recylce following is a more detailed description of electronic equipment components effects on human health and the environment.

2 Polychlorinated Biphenyl (PCB) Humans are exposed through contaminated food consumption or direct contact at their workplace, (e.g inadequate disassembly of electronic Can be present in condensers and transformers of old electronic equipment because of its properties as cooler, lubricant and its resistance to high temperatures. TBBA is a flame-retardant which is used in computer motherboards. This compound represents 50% of all bromined flame-retardants produced worldwide. 96% of all motherboards use this chemical compound which represents 1 to 2% of their weight. equipment). Exposure to this compound can cause anemia, damages to the skin, liver, stomach and thyroid. Contamination of pregnant women is very risky and research results show that it can be carcinogen This chemical compound could drip through subsurface layers reaching water and contaminating it if buried in landfills. Because it is poorly soluble, it is very dangerous when it enters water currents as it could contaminate the chain of production of some foods. Tetra Bromo Bisphenol-A (TBBPA) It has not been proved that it can cause mutations or carcinogen effects on human beings. Nevertheless, it has been proved that TBBA may interfere in the transport and metabolism of some hormones. A technical study has demonstrated that there is a direct correlation between TBBA in the blood flow and in the air. TBBA is toxic to aquatic organisms Unlike other flame-retardants, TBBA when used as a reactive, bounds chemically to plastic or polymers for protection. This impedes its liberation into the environment. It is biodegradable but one of the products of this biodegradation is bisphenol which can cause damages to the endocrine system. The fact that TBBA dissolves poorly in water and tends to adhere to soil, where it can reach food, has created great concern because TBBA levels magnify while passing through the food chain from 20 to 3200 times. Polybrominated Biphenyls (PBB) Exposure to this substance can damage kidneys, PBB dissolves poorly in water but can liver and thyroids. Fetuses that were exposed to adhere strongly to soil, through which it PBB had endocrinal problems. Likewise it is could reach food. It keeps magnifying while suspected that PBB is carcinogen passing along the food chain. Originally, this substance was added to plastics of electronic equipment for inflammability reduction. Nevertheless, PBB production in the US was stopped in 1976 and in the world in 2000.

3 Polybrominated Diphenyl Ethers (PBDE) Since its was tested for the first time in 1970, PDBE is easily liberated into the PBDE was found in numerous samples of human environment and, like other flameretardants, tissue, and with increasing concentrations of factor dissolves poorly in water and 100 in the last 30 years. Exposure can occur the strongly adheres to soil, crossing to moment that plastics containing this substance are organisms, animals, and food. This PBDE is another brominated flameretardant with its number of bromine atoms varying up to 209 times. Three types are sold for commercial use referreded to as penta, octa and deca, two of them used in electronic equipment: octa, used in high impact housings, and deca used in wire insulation. Even though the production of this compound has decreased since 1999 its presence in the environment is increasing, becoming a global problem. CFC are used in aerosol propellants, cleansing agents, foaming agents, and other packaging materials like solvents and refrigerants. In 1987, a prohibition campaign was initiated reaching its objective in 1996, an objective that developing countries aim to reach in recycled. Concerns for human health arise because PBDE containing 4 to 6 brominated molecules that can act as thyroxin, damaging the endocrine system. Exposed children show thyroid damages and neurological anomalies. crossing depends on the brominated concentration level; the lower it is, the more toxic PDBE gets (for example when exposed to UV Light). This compound is almost omnipresent, as it is found both in sea and fresh water organisms, mammals, birds and water and soil samples. When PBDE is incinerated, it produces dioxins and furans. Chlorofluorocarbons (CFC) There are no significant impacts on human health. Nevertheless there are indirect negative effects. Fir example, the release of CFC attacks levels of the atmosphere When in contact with the ozone layer, CFC destroys it. One chlorine atom is responsible for the destruction of ozone molecules. The ozone layer protects earth from radiation which causes skin cancer and blindness in living beings. Polyvinyl chloride (PVC) PVC plastic is used as an insulator in In the amounts present in the environment, there is This compound is disseminated in the certain types of wiring in electronic no proof that DEHP causes damage to humans environment because of its extended equipment. Risks arise from vinyl beings but it been proven that it can damage to lab usage, being soluble in water if oils or chloride since this compound is toxic animal kidneys. Recent debates about this grease are present. Bonds easily with soil

4 and the DEHP used to soften PVC carries great risks to human health compound suggest that it can cause endocrine and gender anomalies in embryos. but also degrades easily in contact with oxygen. Arsenic (As) GaAs is carcinogen and causes skin and lung Gallium Arsenide is an inorganic compound cancers. The most common means of exposure is with low water solubility. It is transformed direct contact with dust containing this compound into an organic compound when bioaccumulated especially by workers of semiconductor in fish and crustaceans. manufacturers. Arsenic is present in small amounts in electronic equipment in forms such as Gallium Arsenide GaAs, which has semiconductor properties and can be found in electronic equipment diodes. Barium (Ba) Barium compounds toxicity is linked to its solubility Its impact on the environment depends on in water. Some of these compounds produced in its solubility. Barium compounds that are monitors are extremely soluble. Intake of these highly soluble in water are very mobile and compounds can cause gastrointestinal disorders tend to cumulate in aquatic organisms. and muscle weakness. Higher doses can cause changes in heart beat rate, paralysis and death. Direct contact with dust containing barium can cause eye and skin irritation. Barium is generally used in cathode ray tubes (CRT) in computer monitors. When functioning in the monitor this metal reacts with CO, CO2, N2, O2, H2O y H2 which produces a series of barium compounds including oxides, hydroxides and carbonates. Beryllium (Be) Beryllium is only dangerous if inhaled, as dust or This metal doesn t dissolve in water and it fumes, which could occur when electronic remains into soil. equipment is disassembled, burned or crushed. Its inhalation can cause pneumonia, respiratory inflammation (chronic illness of Beryllium) and can raise the risk of lung cancer. Beryllium is a metal that generally forms alloys with copper to increase its endurance, conductivity and elasticity. Initially, Beryllium was used in the production of motherboards but its major usage is in contact circuits, relays and in some laser printer mechanisms. Cadmium (Cd) Cadmium is a heavy metal included in Cadmium exposure commonly occurs through Cadmium enters the environment through

5 many electronic components, such as contact plates, switches, or used to prevent corrosion. Cadmium is particularly found in chip resistors, infrared detectors, and semiconductors. Old monitors contain around 5 to 10 grams of Cadmium and some batteries are made of Nickel Cadmium. It is added as a plastic stabilizer and pigment to wiring, motherboards, pcs, monitors and printed circuit boards. Chromium VI, i.e. chromium ions with a charge of +6, is chromium s only toxic form. Its presence is small in electronic equipment where it is used as a plastic hardener and protection layer for some metal components. When electronic components are burned, 99% of Chromium VI stays in residuals and ashes, contaminating soil in a toxic way, which could reach water currents with significant higher risk. inhalation and ingestion of food or contaminated water. Inhaling large amounts of Cadmium can cause lung damage and death. Exposure to small amounts over a long period of time can cause high pressure and kidney damage. This metal is carcinogen. water and soil that is absorbed by plants. Low concentrations can cause alterations in the ecology and balance of soil nutrients. This metal can bio-accumulate in mushrooms, oysters, shrimps, mussels and fish. Chromium VI (Cr+6) The effect of this compound on humans depends Chromium VI is hardly found in nature. Its on the type of exposure. For example, inhalation presence in the environment (air) is can cause catarrh, nose bleeding, ulcers and sinus attributed to industrial plant emissions, fuel perforations. Ingestion of contaminated water and combustion in commercial and residential food can damage the stomach, kidneys, liver and zones. cause ulcers, convulsions and even death. If there is a direct contact with skin it can cause ulcers. This metal is carcinogen only when inhaled. Lead (Pb) Humans are exposed to this metal by particle The chemical structure of this metal is inhalation and through contaminated foods. The directly affected by its ph but most lead first effects and symptoms of lead exposure are compounds are insoluble in water and anorexia, muscle pain, malaise and headache but remain in that state. They are difficultly an extended exposure can cause a decrease in accumulated in plants or transferred to nervous system performance, weakness, brain food. Lead doesn t bio-accumulate in fish Lead is found in many electronic equipment components. For example, in a PC, the largest amount of this metal is found in the CRT of the monitor: 0 to 3% in the panel, 70% in the frit, 24% in the funnel and 30% in

6 the neck. Lead is also present in weldings (40%), motherboards, circuits and wiring plastic. Lithium is present in computer batteries and modern electronic equipment. Typically batteries contain an anode of lithium or lithium oxide, a magnesium dioxide (magnesium oxide and carbon) cathode and lithium salt dissolved in an organic solvent. This type of batteries replaces alkaline and NiCd batteries. It is environmentally more sustainable than its predecessors. damage and even death. Likewise, it can affect the reproductive system both in men and women and is considered carcinogen. Lithium (Li) but it does in other seafood. If broken or incinerated to the environment, particles will be transmitted by air and soil. Lithium doesn t cause toxicological problems as Not many studies about the effects of lead, cadmium or mercury do. But, a great risk lithium on the environment have been exists for workers that have a direct contact. published. These compounds tend to stay Lithium is classified as a corrosive alkali that can dissolved in water and they aren t easily burn skin, eyes and, if inhaled, lungs. To avoid absorbed through soil. these risks lithium batteries must not be exposed to hot environments or broken, factors that can cause the battery to explode. Mercury (Hg) Mercury is found in three specific All forms of mercury represent a risk to human The impact of mercury on the environment places in a computer. The largest health, but mercury in metal form that is not has been thoroughly studied. Mercury in amount is found in LCD screen combined with other components and organic pure form is extremely volatile and mining, fluorescent light, computer or monitor methyl mercury are the ones that possess the incineration and manufacture release this switches, which enable them to shut greater risk, especially to the nervous system. compound to the atmosphere. When down while idle, and finally in batteries. Short-term exposures to this compound cause lung mercury, in any of its forms, gets in contact Mercury is very volatile and easily damage, nausea, vomiting, diarrhea, high with water or soil, turns into organic methyl liberated by incineration or breaking, pressure, and, skin and eye irritation. Long or mercury by bacteria action. In organic form which could liberate up to 90% of the mercury is more accessible to living mercury contained in screen, for example. the monitor permanent exposure might cause permanent damages to the brain, kidneys and fetus development, besides neurological changes, irritability, tremors, short-sightedness, deafness, memory problems, delirium, hallucinations and suicidal tendencies. Níckel (Ni) organisms and food. Many studies have shown mercury presence in fish, causing great concern in many regions worldwide.

7 Nickel causes skin damages and asthma symptoms in about 10 to 20% of the population that has direct contact. Workers that are exposed to dust containing nickel suffer bronchitis and lung Nickel is present in the batteries of some electronic equipment (NiCd), which are being gradually replaced with lithium batteries. Likewise, nickel is used in CRT of computer monitors. damages. There is evidence that many nickel Nickel generally enters the environment through air. These particles are then placed in water and soil, especially if they contain magnesium and steel. Nevertheless, this compound does not bio-accumulate in living compounds such as nickel hydroxide are organisms. carcinogen. Antimony (Sb) Antimony is present in electronic equipment in small quantities. Antimony trioxide is added to plastic as a flame-retardant. This compound is also used in the CRT glass of monitors and wire welding. Zinc Sulfide is mixed with other metals to create a phosphor coating, which is used in the inside of the monitor glass. Exposure to this compound happens when the monitor breaks. Elevated exposure to antimony via electronic equipment is unlikely. Experiments in animals have demonstrated that short-term exposure can cause eye and skin irritation, hair loss, lung and heart damages, and fertility problems. Antimony trioxide is considered as possibly carcinogen. Antimony released into the environment is commonly found in soil and sediments. Its mobility greatly depends on soil structure, the form which it takes, and its ph. This element is better absorbed in soils containing steel, magnesium or aluminum. Zinc Sulfide (ZnS) This element is corrosive to the skin and lungs and Zinc is one of the most common minerals in its ingestion can be very harmful because it forms nature. a toxic gas (hydrogen sulfide) within the stomach