Block 8: Environmental Issues and Public Health - Air Pollution Chapter 1: Introduction (Continued)

The Essential Elements Of An Air Quality Management System:

An air quality management system needs to address the complexity of the relationship between the sources of air pollution and the exposure of people, crops, vegetation, livestock and physical infrastructure to the air pollutants, and the human health and economic consequences of this exposure. A complex set of factors relates the sources of air pollution, characterised by factors such as the emission rate of each pollutant, and the height, temperature and exit velocity (if a stack) of the pollution plume, to the exposure (measured as time-averaged concentrations) of "receptors" - people, buildings, crops and animals. These factors include the atmospheric processes of dispersion, chemical and physical transformation, and deposition of pollutants onto surfaces.

Key elements of an Air Quality Management System (AQMS) are

• the setting of Ambient Air Quality Standards;
• source Emission Standards (or limits),
• the development of an Emission Inventory,
• Ambient Air Quality Monitoring,
• the gathering appropriate Meteorological Data and,
• Air Quality Modelling.

A coherent and effective regulatory system (AQMS) would include the setting of air quality standards, setting specific time-bound air quality objectives, and would be capable of gathering the necessary air quality information and using the permitting or licensing system and the necessaey technical and legal resources to give effect to regulations.

Questions:

1. Does Figure 4 "prove" that air pollution (SO₂ and smoke) "causes" an increase in daily mortality in the exposed population?
2. Assuming that the population of London was 8.3 million in 1952, calculate the attributable daily mortality apparently due to increased SO₂ and smoke exposure during the 1952 episode.
3. Is it possible to use this estimate of attributable risk to infer or estimate daily winter-time mortality for Soweto, 2004, assuming that the SO₂ and smoke exposures increase to 25% of the London 1952 values during winter? What would the incremental daily mortality be if the risk factor is valid?