Question 1: Particulates are tiny solid particles suspended in the atmosphere, originating from sources such as vehicle emissions, industrial processes, and natural events like wildfires. These particles can affect air quality and human health.

Answer: Particulates are tiny solid particles suspended in the atmosphere, coming from sources like vehicles, industry, and wildfires, impacting air quality and health.

Question 1: Define 'particulates' in the context of atmospheric pollution.

Answer: Tiny solid particles suspended in the air that can originate from natural or human sources.

Question 2: Explain two ways in which particulates can affect human health.

Answer: Particulates can cause respiratory problems, aggravate asthma, and lead to cardiovascular diseases by entering the lungs and bloodstream.

Question 1: A city measures the concentration of particulates in the air as 150 micrograms per cubic metre (μg/m³). If the allowable safety limit is 40 μg/m³, by what factor does the current pollution exceed the safe limit?

Answer: 3.75

Question 2: Calculate the mass of particulates in 10 cubic metres of air if the concentration is 200 μg/m³. (Show your working)

Answer: Mass = concentration × volume = 200 μg/m³ × 10 m³ = 2000 μg = 2 mg

Question 1: Describe a simple experimental method to measure particulate concentration in the air. Include the safety precautions that should be taken.

Answer: Use a filter paper attached to a sampling device exposed to the air for a fixed period. Weigh the filter before and after exposure to determine particulate mass. Safety precautions include avoiding inhalation of dust, wearing gloves and masks, and working in a well-ventilated area.

Question 1: A report states that during winter, particulate levels in a city increase by 50% compared to summer levels. If the summer level is 80 μg/m³, what is the winter level? Explain the possible reasons for this increase.

Answer: Winter level = 80 μg/m³ + (50% of 80 μg/m³) = 80 + 40 = 120 μg/m³. Reasons may include increased heating, reduced atmospheric dispersion, and weather conditions trapping pollutants.

Question 1: Suggest two methods industries can implement to reduce particulate emissions from their factories.

Answer: Use electrostatic precipitators and install filters on emission stacks.

Question 2: Explain how the use of cleaner fuels can help reduce atmospheric particulates.

Answer: Cleaner fuels produce fewer solid particles when burned, reducing the amount of particulates released into the atmosphere and improving air quality.

Question 1: Discuss the environmental and health impacts of high particulate levels in urban areas. (6 marks)

Answer: High particulate levels can cause respiratory and cardiovascular diseases, reduce air quality, harm ecosystems, and contribute to smog formation, affecting overall public health and environment.