Due to improper/indiscriminate disposal of old 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:
Answer & explanation
Answer: (b) 1, 2, 3, 5 and 6 only
Computers contain the heavy metals beryllium, cadmium, chromium (VI), mercury and lead, and these escape into the environment when old machines are dumped or crudely recycled. Heptachlor is an organochlorine pesticide and plutonium is a radioactive nuclear material. Neither is a computer component. So the answer is (b), and options (a), (c) and (d) are wrong.
- ✓ 1. Beryllium is present in computers. Copper-beryllium alloys are used in electronic connectors that must withstand repeated connection and disconnection.
- ✓ 2. Cadmium is a heavy metal of concern in e-waste. It is found in components such as rechargeable nickel-cadmium batteries.
- ✓ 3. Hexavalent chromium (chromium VI) is used in corrosion-protective coatings on metal parts. It is listed among the heavy metals of concern in e-waste.
- ✗ 4. Heptachlor is an organochlorine pesticide. It is not a constituent of computers or their parts.
- ✓ 5. Mercury is a heavy metal of concern in e-waste. It is found in the backlights of older LCD displays, in switches and in some batteries.
- ✓ 6. Lead is a heavy metal of concern in e-waste. It is used in the solder on circuit boards and in the glass of CRT monitors.
- ✗ 7. Plutonium is a radioactive element used in nuclear reactors and weapons. It is not a component of computers.
Remember · Computer e-waste carries lead, mercury, cadmium, chromium (VI), beryllium and brominated flame retardants. Pesticides like heptachlor and radioactive plutonium are not e-waste constituents.
Sources
- CPCB – Guidelines for Environmentally Sound Management of E-waste (heavy metals of concern) ↗ “heavy metals such as lead, mercury, cadmium and chromium (VI), halogenated substances (e.g. CFCs), polychlorinated biphenyls, plastics and circuit boards that contain brominated flame retardants (BFRs) … Copper beryllium alloys are used in electronic connectors where a capability for repeated connection and disconnection is desired, and thus where solder is not used to make a permanent joint.”
Question: UPSC Civil Services (Preliminary) 2013, General Studies Paper I. Explanation: Minimalist IAS, checked 25 Oct 2026 (how we verify). ·
