A local authority analyst is investigating whether air quality in urban boroughs is linked to pediatric respiratory health. Specifically, they want to conduct a statistical study to examine the correlation between daily average PM2.5\text{PM}_{2.5}PM2.5 particulate concentration levels and the weekly number of childhood asthma consultations at local clinics.
Outline how the analyst could obtain secondary data to use as the measurement of the variable 'daily average PM2.5\text{PM}_{2.5}PM2.5 particulate concentration level' for the boroughs in the study.
