|How do I ensure that
the data I plan to use for analysis are of good quality?
|How do I treat data
below detection? What kinds of data
metrics do I need for subsequent analyses?
(See Preparing Data for Analysis, Section 4)
|How do air toxics
concentrations change spatially and by time of day, day of week, and season?
|Which air toxics
have similar patterns? (See
Characterizing Air Toxics, Section 5)
|Do these air toxics
have common sources? (See
Background, Section 3)
|What are the most
important air toxics in terms of potential risk?
|Are we measuring
them and, if so, are we measuring them well?
Where are they important?
|Which pollutants are
not monitored well enough to characterize their risk or hazard? (See Advanced Analyses, Section 7)
|How do concentration
levels for a given city/area compare to other cities?
comparable? What is the variability of
air toxics concentrations within cities? Do specific cities, states, or
regions experience demonstrably higher or lower concentrations? Do rural and remote sites show demonstrably
lower concentrations? Are there
differences in concentrations associated with geo-political or agency
differences? (See Characterizing
Air Toxics, Section 5)
|Have air toxics
concentrations declined over time in response to emission control
programs? (See Quantifying and
Interpreting Trends in Air Toxics, Section 8)
|How do the most
important air toxics compare with model output (e.g., are ambient
concentrations high in locations not shown by the model)? (See Characterizing Air Toxics,