Consider the following statements: 1. Other than those made by humans, nanoparticles do not exist in nature. 2. Nanoparticles of some metallic oxides are used in the manufacture of some cosmetics. 3. Nanoparticles of some commercial products which enter the environment are unsafe for humans. Which of the statements given above is/are correct?

Answer: D. Statements 2 and 3 are correct; Statement 1 is wrong. Statement 1 is WRONG. NANOPARTICLES DO exist NATURALLY in the environment, independently of human activity. Natural sources include: - Volcanic eruptions (ash, sulfate aerosols). - Forest fires (carbon nanoparticles, soot). - Sea spray (sodium chloride and other salt nanoparticles). - Dust storms (mineral nanoparticles). - Biological processes (viruses themselves are nanoscale, ferritin protein cores etc.). So nanoparticles are NOT exclusively anthropogenic. Statement 2 is CORRECT. NANOPARTICLES OF METALLIC OXIDES are widely used in COSMETICS. Examples: - ZINC OXIDE (ZnO) and TITANIUM DIOXIDE (TiO2) nanoparticles in SUNSCREENS provide transparent UV protection. - IRON OXIDE nanoparticles in foundation and pigment-based cosmetics. - SILICON DIOXIDE nanoparticles as anti-caking and smoothing agents. These uses are commercially established and regulated. Statement 3 is CORRECT. SOME NANOPARTICLES from commercial products entering the environment ARE UNSAFE for humans. Concerns: - Inhalation of titanium dioxide nanoparticles linked to respiratory inflammation. - Silver nanoparticles in textiles/cosmetics released into wastewater accumulate in aquatic systems with antimicrobial/toxic effects. - Carbon nanotubes show asbestos-like behaviour in some studies. - Many nanoparticles can cross biological membranes that bulk forms cannot. Regulators (FDA, ECHA, WHO) have flagged nano-safety as an emerging risk area. Source: NCERT Class 12 Chemistry (Surface Chemistry chapter) / WHO and OECD nano-safety reports.