Particle exposure and inhaled dose while commuting in Lisbon.

Area of Science:

• Environmental Health
• Occupational Health
• Urban Air Quality

Background:

• Urban commuters are exposed to elevated concentrations of air pollutants during travel.
• Exposure to particulate matter (PM) and other pollutants can lead to adverse health outcomes.
• Understanding transport-specific exposures is crucial for public health interventions.

Purpose of the Study:

• To assess commuter exposure to particulate matter (PM2.5, PM10), black carbon (BC), and particle number (PN0.01-1) across different transport modes in Lisbon.
• To investigate factors influencing indoor air quality in vehicles, such as ventilation.
• To compare inhaled doses of pollutants across car, bicycle, metro, and bus travel.

Main Methods:

• Field study measuring PM2.5, PM10, BC, and PN0.01-1 concentrations in various transport modes (car, bicycle, metro, bus) in Lisbon.
• Analysis of indoor versus outdoor concentrations and the impact of vehicle ventilation systems.
• Calculation of inhaled pollutant doses based on measured concentrations, travel time, and inhalation rates.

Main Results:

• Metro travel exhibited higher mass concentrations of PM2.5 and PM10.
• Car and bus travel showed the highest average concentrations for black carbon (BC) and particle number (PN0.01-1), respectively.
• In cars, ventilation use decreased PM2.5/PM10 but increased BC; bicycle journeys resulted in the highest inhaled doses due to prolonged exposure and high physical activity.

Conclusions:

• Transport mode significantly influences commuter exposure to urban air pollutants.
• Bicycle commuters may experience the highest inhaled pollutant doses despite lower ambient concentrations, due to physical exertion.
• Vehicle ventilation strategies can modify indoor pollutant profiles, highlighting the complexity of exposure assessment.