Correct Option
Improper disposal of electronic waste (e-waste) leads to the release of various hazardous substances into the environment. Several heavy metals and chemicals commonly found in electronic components pose environmental and health risks:
- Beryllium: Present in components such as motherboards, connectors, and some ceramic substrates, valued for its strength and electrical properties.
- Cadmium: Used in rechargeable nickel-cadmium batteries, older cathode ray tubes (CRTs), and some resistors and semiconductors.
- Chromium: Hexavalent chromium compounds are utilized in hard drive coatings for corrosion protection and in some decorative finishes.
- Mercury: Found in backlights of older liquid crystal displays (LCDs), fluorescent lamps, and certain switches and relays.
- Lead: A primary component in solder (especially in older electronics), cathode ray tube (CRT) glass, and some batteries.
Incorrect Options
- Heptachlor (4) is an organochlorine pesticide, historically used in agriculture. It is not a constituent material of electronic devices or e-waste.
- Plutonium (7) is a radioactive element primarily associated with nuclear energy and weapons. It is not found in consumer electronics or typical e-waste streams.
- Options 1, 3, and 4 are incorrect because they include Heptachlor (4) and/or Plutonium (7), which are not components released from e-waste. Option 4 is incorrect as it suggests all listed items are released, including the incorrect ones.