Critical Pathway Analysis and Pollution Control Strategies

Critical Pathway Analysis (CPA) is a crucial tool in Environmental Science A Level Questions for predicting pollutant routes and assessing pollution risks. It considers pollutant properties and environmental features to monitor discharges effectively.

Definition: Critical Pathway Analysis (CPA) is the prediction of routes that an effluent will take in the environment to assess pollution risk.

Key aspects of CPA include:

• Pollutant properties: state of matter, density, solubility, and chemical stability
• Environmental features: wind/water currents, geology, pH, oxygen availability, and temperature

CPA is primarily used for monitoring:

• Radioactive materials
• Heavy metals
• Persistent organic pollutants (e.g., chlorinated organic compounds)

Highlight: CPA allows environmental monitoring to focus on sites most at risk of pollution, eliminating the need for sampling other sites.

Critical Group Monitoring (CGM) is another important method used to identify members of the public most at risk from pollutants, particularly radioactive discharges and heavy metals.

Emission control strategies include:

1. Location control:

   • Avoiding releases in valleys
   • Using marine discharges for dilution and dispersion
   • Emitting downwind of urban areas
   • Avoiding discharge onto permeable rock above aquifers

2. Timing control:

   • Coordinating with tidal cycles for river emissions
   • Considering temperature inversions for atmospheric emissions

Example: Emissions into tidal rivers are timed when the tide is going out to carry pollutants out to sea for dispersion.