Related Experiment Videos
Isoprene from expired air inside a private car
S Björkqvist1, A Spetz, O Ramnäs
1Department of Chemical Environmental Science, Chalmers University of Technology, Göteborg, Sweden.
The Science of the Total Environment
|December 16, 1997
Summary
Isoprene, a major hydrocarbon in parked cars, originates from human breath. Driving and ventilation significantly reduce isoprene levels, indicating its primary source is expired air.
Area of Science:
- Environmental Chemistry
- Analytical Chemistry
- Human Physiology
Background:
- Volatile hydrocarbons in indoor environments, particularly vehicles, are a concern for air quality.
- Isoprene is a significant non-methane volatile hydrocarbon, but its primary source within a car cabin is not fully established.
Purpose of the Study:
- To quantify isoprene concentrations in a small car cabin.
- To determine the primary source of isoprene in a vehicle.
- To analyze other traffic-emitted hydrocarbons simultaneously.
Main Methods:
- Air sampling using triple-layer adsorbent cartridges.
- Analysis of volatile hydrocarbons via gas chromatography with thermal desorption.
- Utilized an aluminum oxide column for simultaneous determination of multiple hydrocarbons.
Main Results:
- Isoprene concentration in a parked car with one person was approximately 20 µg/m³.
- Isoprene was the dominant non-methane volatile hydrocarbon, except in highly traffic-polluted areas.
- Driving with moderate ventilation reduced isoprene levels by an order of magnitude.
- Isoprene concentrations were significantly lower in an empty car, supporting expired air as the source.
- Simultaneous detection of traffic-emitted hydrocarbons, including benzene and 1,3-butadiene, was achieved.
Conclusions:
- Expired air is the predominant source of isoprene within a car cabin.
- Vehicle ventilation and driving conditions effectively reduce indoor isoprene levels.
- The analytical method is capable of simultaneously measuring various indoor and traffic-related hydrocarbons.