Due to improper/indiscriminate disposal of hold and used computers or their parts, which of the following are released into the environment as e-waste? 1. Beryllium 2. Cadmium 3. Chromium 4. Heptachlor 5. Mercury 6. Lead 7. Plutonium Select the correct answer using the codes given below:
1, 2, 3, 5 and 6 only
Understanding E-waste Composition and Environmental Risks
Electronic waste, or e-waste, includes discarded electrical or electronic devices. Due to their complex composition, improper disposal of e-waste poses significant environmental and health risks. These discarded electronics often contain valuable materials, but also hazardous substances.
Hazardous Substances Commonly Found in E-waste
Many components within computers and other electronic devices contain materials that are toxic and can contaminate the environment if not handled properly during disposal or recycling. Let's examine the substances listed in the question:
- Beryllium: Used in motherboards and connectors due to its strength and conductivity. It is a toxic substance and can cause lung disease (berylliosis) upon exposure.
- Cadmium: Found in older rechargeable batteries (like NiCd batteries), semiconductors, and some older display technologies. It is highly toxic and accumulates in the human body, affecting kidneys and bones.
- Chromium: Specifically, hexavalent chromium is used in some metal casings and for corrosion protection. It is a known carcinogen and toxic to many organisms.
- Heptachlor: This is an organochlorine insecticide. It is a persistent organic pollutant but is not a typical component used in the manufacturing of computers or electronic parts.
- Mercury: Used in switches, relays, and particularly in the fluorescent lamps used for backlighting older LCD monitors (CCFLs). Mercury is a potent neurotoxin and bioaccumulates in the food chain.
- Lead: A major component in solder (used to connect components on circuit boards), cathode ray tubes (CRTs) in older monitors, and lead-acid batteries. Lead is a neurotoxin and affects the nervous system, particularly in children.
- Plutonium: This is a radioactive element primarily used in nuclear power and weapons. It is not used in the manufacturing of typical consumer electronics like computers.
Analysis of Substances in E-waste Disposal
Based on the common materials used in electronics manufacturing, the following substances from the given list are indeed found in computers and can be released into the environment upon improper disposal:
| Substance | Presence in E-waste | Environmental/Health Risk |
|---|---|---|
| Beryllium | Yes | Toxic, especially upon inhalation |
| Cadmium | Yes | Highly toxic, accumulates in organs |
| Chromium (Hexavalent) | Yes | Toxic, carcinogenic |
| Heptachlor | No | Persistent organic pollutant (not typically found in electronics) |
| Mercury | Yes | Highly toxic neurotoxin, bioaccumulates |
| Lead | Yes | Toxic neurotoxin, affects nervous system |
| Plutonium | No | Radioactive (not typically found in electronics) |
Therefore, the substances from the list that are released into the environment as e-waste due to improper disposal are Beryllium, Cadmium, Chromium, Mercury, and Lead. These correspond to items 1, 2, 3, 5, and 6.
Conclusion
Improper disposal of old and used computers leads to the release of several hazardous materials into the environment. Identifying these substances is crucial for understanding the importance of proper e-waste management and recycling.
The substances from the list that are commonly found in electronics and released upon improper disposal are Beryllium (1), Cadmium (2), Chromium (3), Mercury (5), and Lead (6).
Revision Table: Key E-waste Hazardous Substances
| Substance | Source in Electronics | Hazard |
|---|---|---|
| Beryllium | Connectors, circuit boards | Lung disease |
| Cadmium | Batteries, semiconductors | Kidney damage, bone disease |
| Chromium (Hexavalent) | Metal coatings, corrosion protection | Carcinogen, toxic |
| Mercury | Switches, relays, LCD backlights | Neurotoxin |
| Lead | Solder, CRT glass, batteries | Neurotoxin, developmental issues |
Additional Information: E-waste Management and Impact
E-waste is the fastest-growing waste stream globally. Proper e-waste management involves collection, dismantling, recycling, and disposal processes designed to recover valuable materials and safely handle hazardous components. Informal e-waste recycling methods often involve burning or using acid baths, releasing toxic fumes and chemicals directly into the environment, contaminating soil, water, and air. This poses severe health risks to workers and nearby communities.
Regulations and international conventions, such as the Basel Convention, aim to control the transboundary movement of hazardous waste, including e-waste, to prevent developed countries from simply shipping their e-waste burden to developing countries where informal and unsafe recycling practices are prevalent. Promoting extended producer responsibility (EPR) makes manufacturers responsible for the end-of-life management of their products, encouraging sustainable design and proper recycling infrastructure.
Important Questions from Metals & Non-metals
Recently, there has been a concern over the short supply of a group of elements called 'rare earth metals'. Why?
1. China, which is the largest producer of these elements, has imposed some restrictions on their export.
2. Other than China, Australia, Canada and Chile, these elements are not found in any country.
3. Rare earth metals are essential for the manufacture of various kinds of electronic items and there is a growing demand for these elements.
Which of the statements given above is/are correct?
Which of the following metals CANNOT be cut with a knife?
Which of the following will be formed when dilute hydrochloric acid is added to a beaker having copper oxide ?
Which of the following statement is incorrect regarding metals?
Which of the following metals are mixed with iron to get stainless steel?
