City-Specific Air Quality Warnings for Improved Asthma Self-Management

Area of Science:

• Environmental Health
• Epidemiology
• Public Health

Background:

• Asthma exacerbations are linked to ambient air pollution.
• Existing air quality warnings may not capture city-specific risks for asthma.
• Local data can enhance asthma self-management strategies.

Purpose of the Study:

• To develop and apply a framework for identifying high-risk asthma days using local pollution data.
• To provide supplemental air quality warnings that differ from the EPA Air Quality Index (AQI).
• To improve asthma self-management in Houston, Texas.

Main Methods:

• A four-step framework was used to identify days with increased asthma attack risk.
• A case-crossover study analyzed historical asthma attacks (2004-2016) and air pollutant concentrations in Houston.
• Conditional logistic regression identified associations between pollution levels and asthma attacks.

Main Results:

• Specific thresholds for ozone and nitrogen dioxide were associated with increased asthma attack risk (e.g., RR=1.30 for NO2 >19.3 ppb).
• The framework identified supplemental warning days, adding 12% more days annually compared to AQI warnings.
• These supplemental days capture risks from consecutive poor air quality days and levels below NAAQS.

Conclusions:

• Houston implemented this framework for supplemental air quality warnings to aid asthma self-management.
• Supplemental warnings provide additional risk information beyond standard AQI alerts.
• The study highlights the value of localized data for public health advisories.