Why is it important to characterize particulate matter by size?

Correct Answer: A

Rationale: The correct answer is A because particulate matter size determines where it deposits in the respiratory system, affecting the potential health impacts. Larger particles may get trapped in the upper airways, while smaller particles can reach deeper into the lungs. This is crucial for understanding the health risks associated with different sizes of particulate matter. Choices B, C, and D are incorrect because the question specifically focuses on the importance of size in relation to health effects, not chemical composition, exposure categories, or respiratory protection needs.

Correct Answer: B

Rationale: The correct answer is B: Landfill. Landfill is the major method of dealing with solid waste in the United States because it involves burying waste in designated areas. Landfills are designed to contain waste and prevent environmental contamination. Recycling (A) and composting (C) are also important methods, but they are not as widely used or as comprehensive as landfills. Burning (D) can be used for waste-to-energy purposes, but it is not the primary method for managing solid waste in the U.S. Landfills remain the most common and effective way to handle solid waste on a large scale.

Correct Answer: D

Rationale: The correct answer is D: Microorganisms. Microorganisms, such as bacteria and fungi, produce volatile organic compounds (VOCs) as a byproduct of their metabolic processes. VOCs are released into the air and can have various effects on health and the environment. Feces (A) do not produce VOCs directly, gasoline (B) is a chemical compound, not a biological organism, and bleach (C) is a chemical disinfectant that does not produce VOCs in the same way as microorganisms do. Therefore, the correct answer is D because microorganisms are a known source of VOCs.

Correct Answer: B

Rationale: The correct answer is B because silicosis is a lung disease caused by inhaling crystalline silica dust found in materials like sand, quartz, and granite. The dust particles scar and inflame the lungs, leading to breathing difficulties. Choice A is incorrect as silicosis is not associated with breast implants. Choice C is incorrect as silicosis is not a mental disorder. Choice D is incorrect as silicosis does not involve the replacement of oxygen by silicon in the blood.

Correct Answer: D

Rationale: The correct answer is D: The National Institute for Occupational Safety and Health (NIOSH) because NIOSH is specifically tasked with conducting research and making recommendations for the prevention of work-related illnesses and injuries. They establish exposure limits through rigorous scientific research and collaboration with experts in the field. The other choices are incorrect because: A: The Environmental Protection Agency regulates environmental standards, not specifically occupational exposure limits. B: The Centers for Disease Control focuses on public health and disease prevention, not occupational exposure limits. C: The National Institute for Environmental Health Science focuses on environmental health research but does not set specific occupational exposure limits.