Question

What are the primary sources of Particulate Matter (PM) pollution in urban areas and what are the potential health effects of exposure to PM?

• A. Industrial emissions and vehicular emissions, with potential health effects including respiratory problems and cardiovascular disease
• B. Agricultural activities and natural disasters, with potential health effects including respiratory problems and cancer
• C. Domestic waste and construction activities, with potential health effects including respiratory problems and neurological damage
• D. All of the above

Answer 1

Answer:

A. Industrial emissions and vehicular emissions, with potential health effects including respiratory problems and cardiovascular disease

• Primary Sources in Urban Areas:

  • Vehicular Emissions: This is one of the most significant sources of both primary (directly emitted) and secondary (formed in the atmosphere) Particulate Matter (PM) in cities, including exhaust, brake wear, and tire wear.

  • Industrial Emissions: Power plants, manufacturing facilities, and industrial boilers are major contributors to PM, often emitting precursor gases like sulfur dioxide (SO2​) and nitrogen oxides (NOx​) that form secondary fine particles (PM$_{2.5}$).

  • While other sources like construction (contributing significantly to coarser PM10​) and residential activities (like heating and cooking) are also important, the combination of "Industrial emissions and vehicular emissions" represents the most dominant and pervasive anthropogenic sources of both fine and coarse PM in urban environments.

• Potential Health Effects:

  • Respiratory Problems: Because of their tiny size, especially PM2.5​ (particles less than 2.5 micrometers in diameter), particulate matter can penetrate deep into the lungs and even the bloodstream. This leads to conditions like aggravated asthma, chronic bronchitis, decreased lung function, and increased risk of respiratory infections.

  • Cardiovascular Disease: PM2.5​ is strongly linked to effects on the heart and circulatory system. Exposure can trigger non-fatal heart attacks, irregular heartbeat, and is associated with increased mortality from cardiovascular diseases like stroke and coronary heart disease.

  • Exposure to PM is also associated with lung cancer and other systemic effects, but respiratory and cardiovascular issues are the most immediate and well-established major health effects.