GPS tracking methods for spatiotemporal air pollution exposure assessment: comparison and challenges in study...

Area of Science:

• Environmental Health
• Epidemiology
• Exposure Science

Background:

• Traditional epidemiological studies often overlook personal activity patterns, focusing solely on residential locations for air pollution exposure assessment.
• This oversight limits understanding of total exposure to pollutants like nitrogen dioxide (NO2) and fine particulate matter (PM2.5).
• This study compares residential-only versus mobility-integrated exposure assessments using tracking data.

Purpose of the Study:

• To evaluate the effectiveness of GPS devices and smartphone apps in capturing personal exposure to air pollution.
• To compare recruitment strategies for personal tracking studies.
• To analyze the impact of activity patterns on exposure assessment for NO2 and PM2.5.

Main Methods:

• Two tracking campaigns were conducted in Switzerland and the Netherlands.
• Participants used a GPS device (SODAQ) and a smartphone app for time-activity diaries and GPS tracking.
• Collected tracking data was integrated with air pollution surfaces to quantify NO2 and PM2.5 exposure based on activities.

Main Results:

• Smartphone app and SODAQ device data showed moderate to high correlations for total NO2 exposure (R2 > 0.57) and activity-specific exposures (0.43-0.63).
• PM2.5 correlations were moderate to high in Switzerland but lower in the Netherlands (R2 = 0.28-0.58).
• Recruitment success varied significantly, with targeted strategies and incentives improving participation rates.

Conclusions:

• Both mobile apps and dedicated GPS devices are viable for personal air pollution exposure tracking.
• Low-frequency GPS data from apps can suffice for long-term exposure assessment, while dedicated devices offer finer-scale readings.
• Effective recruitment strategies, including leveraging existing cohorts and offering incentives, are crucial for successful tracking studies.