Due to improper/indiscriminate disposal of old and used computers of 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.

Electronic waste (e-waste) contains a variety of hazardous substances that are released into the environment during improper disposal. Key toxic components include Lead, found in glass panels of monitors and solder [1]; Mercury, used in circuit breakers and switches [1]; Cadmium, present in computer batteries and resistors [1]; and Hexavalent Chromium, used as a corrosion-resistant coating on metal parts and circuit boards. Beryllium is also a known constituent of electronic components like motherboards [3]. However, Heptachlor is a persistent organic pollutant primarily used as a pesticide, not a component of computers [2]. Similarly, Plutonium is a radioactive element used in nuclear reactors and weapons, not in consumer electronics. Therefore, the substances released from e-waste among the options are Beryllium, Cadmium, Chromium, Mercury, and Lead (1, 2, 3, 5, and 6).

Sources

1. [1] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 5: Environmental Pollution > s.11. E - WASTE > p. 92
2. [3] https://pmc.ncbi.nlm.nih.gov/articles/PMC4144270/
3. [2] https://pmc.ncbi.nlm.nih.gov/articles/PMC8172693/