In-vehicle Exposure to Carbon Monoxide Emissions from Vehicular Exhaust: A Critical Review

Abstract

Vehicle-induced emissions constitute a major source of air pollutants, particularly in urban areas, where heavy traffic is common occurrence. Contaminated air can flow into enclosed micro-environments, including vehicle compartments. Among various exhaust emissions, carbon monoxide (CO) was the first indicator examined in passenger compartments. This paper presents a critical review of worldwide research work conducted to characterize CO exposure inside vehicles. Measurement methodologies for field testing are presented alongside impacts of various factors on in-vehicle CO exposure, including outdoor CO levels, roadway type, ventilation mode, weather conditions, and vehicle characteristics. Results of in-vehicle CO exposure measurements in various cities are compared. Modeling efforts to characterize in-vehicle CO exposure and relate it to potential explanatory factors are also discussed. Based on the review findings, limitations and future needs are defined.

KEY WORDS:

• in-vehicle exposure
• carbon monoxide
• air quality monitoring

Notes

∗MDL = method detection limit.

^†ASTM = American Society for Testing and Materials.

∗Car features (make, model, and volume) and wind speed data were also reported by Park et al., 1998 ⁶⁴ , and Fletcher and Saunders, 1994, ³⁷ being potential influencing factors.

∗Cited by Flachsbart, 1999a. ³⁵ The study was conducted on an urban highway near San Jose, California.

^†Mean.

^‡Range.

∗ Mean;

^† range.