Question

How do aerosols contribute to air quality concerns?

• A. By reducing respiratory diseases
• B. By acting as natural air purifiers
• C. By causing air pollution and respiratory issues
• D. By having no impact on human health

Hint:

• Aerosols, particularly fine particulate matter (PM$_{2.5}$), are major air pollutants.
• They can penetrate deep into the lungs, causing or worsening respiratory problems (asthma, bronchitis) and cardiovascular diseases.
• Aerosols also reduce visibility (haze) and can impact climate.
• They are a significant concern for public health and environmental quality.

Answer 1

The Correct Option is C

Aerosols, especially fine particulate matter (e.g., PM$_{2.5}$ and PM$_{10}$), are significant contributors to air pollution and have well-documented adverse effects on human health and the environment. How aerosols contribute to air quality concerns:

• Respiratory and Cardiovascular Issues: Fine aerosols can penetrate deep into the lungs and even enter the bloodstream. Exposure is linked to a range of health problems, including asthma exacerbation, bronchitis, reduced lung function, heart attacks, strokes, and premature death. This directly contradicts option (a) and (d).
• Reduced Visibility (Haze): Aerosols scatter and absorb light, leading to reduced visibility and the formation of haze, which impacts aesthetics, transportation safety, and tourism.
• Climate Effects: Aerosols can influence climate by scattering or absorbing solar radiation (direct effect) and by modifying cloud properties (indirect effect), such as their brightness, lifetime, and precipitation efficiency.
• Deposition and Ecosystem Damage: Aerosols can deposit onto surfaces, contributing to the soiling of materials and potentially harming ecosystems (e.g., acid deposition if aerosols are acidic).

Option (a) "By reducing respiratory diseases" is incorrect; aerosols generally exacerbate them. Option (b) "By acting as natural air purifiers" is incorrect. While some atmospheric processes can remove certain pollutants, aerosols themselves are often the pollutants or contribute to pollution. Certain types of aerosols can act as condensation nuclei for rain, which can "wash out" pollutants, but this is a complex interaction, and primarily, aerosols are a concern. Option (c) "By causing air pollution and respiratory issues" accurately describes their negative impact. Option (d) "By having no impact on human health" is incorrect. \[ \boxed{\text{By causing air pollution and respiratory issues}} \]