Archives: Air quality (in vehicles)

 

Riediker 2004 - "Particulate Matter Exposure in Cars is Associated with Cardiovascular Effects in Healthy Young Men"

Riediker, Michael; Cascio, Wayne; et al.
"Particulate Matter Exposure in Cars is Associated with Cardiovascular Effects in Healthy Young Men"
American Journal of Respiratory and Critical Care Medicine
April 15, 2004; v.168, n.8; pp.934-940
On the Web
Relevance: medium-low

Part of a larger research project measuring air quality in cars, the authors measured the effects of exposure to PM2.5 on the cardiovascular functions of nine young, healthy patrol officers in North Carolina. They concluded that in-vehicle PM2.5 negatively affected inflammation, coagulation, and cardiac rhythm in slight but significant amounts. However, they also measured PM2.5 concentrations to be lower in the vehicles than on the side of the road or at the ambient location.

This study suggests to me that even a small amount of PM2.5 from vehicles is bad.

 

Chang 2000 - "Hourly Personal Exposures to Fine Particles and Gaseous Pollutants--Results from Baltimore, Maryland"

Chang, Li-Te; Koutrakis, Petros; et al
"Hourly Personal Exposures to Fine Particles and Gaseous Pollutants--Results from Baltimore, Maryland"
Journal of the Air and Waste Management Association
July 2000; v.50, n.7; pp.1223-1235
On the Web
Relevance: medium

The authors measured personal VOC exposure in a variety of microenvironments that older adults generally encounter. PM 2.5 concentrations were highest in the food court, while walking and driving, and in a kitchen and TV room at home. Ozone levels were elevated while walking at noon and while driving. Carbon monoxide levels were elevated i the middle of the day and while driving.

Ambient concentrations of PM 2.5 seem to be fairly well with personal exposure (r>.6 for all but one case). Ambient concentrations of ozone were also highly correlated with personal exposure for outdoor and in-vehicle microenvironments, less so for indoor environments, and barely at all for homes. There seems to be little correlation between ambient BTEX levels and personal exposures in homes and cars (except for benzene in homes), which suggests to me that personal exposure in those places comes mostly from personal activities (cooking, cleaning, and driving).

 

Chan 1991 - "Commuter Exposure to VOCs in Boston, Massachusetts"

Chan, Chang-Chuan; Spengler, John D; et al.
"Commuter Exposure to VOCs in Boston, Massachusetts"
Journal of the Air and Waste Management Association
December 1991; v.41, n.12; pp.1594-1600
On the Web
Relevance: high

The authors measured VOC exposure for four commuting methods (car, subway, walking, biking) plus concentrations in homes, offices, and on the sidewalk in Boston. They found that concentrations were generally highest in cars and lowest in homes/offices. "For most VOCs, the concentrations in homes and offices were about three to five times lower than the VOC concentrations during commuting." Around 10-20% of daily VOC exposure for car and subway commuters occurred during the commute.

Driving on urban roads was correlated with higher VOC concentrations (1.5 times higher) than driving on interstates.  Using the heater also increased VOC levels. On the other hand, the age of the car or country of origin (US vs. imported) did not seem to make a difference.

More notes...

 

Riediker 2003 - "Exposure to Particulate Matter, Volatile Organic Compounds, and Other Air Pollutants Inside Patrol Cars"

Riediker, Michael; Williams, Ronald; et al.
"Exposure to Particulate Matter, Volatile Organic Compounds, and Other Air Pollutants Inside Patrol Cars"
Environmental Science and Technology
2003; v.37 n.10; pp.2084-2093
On the Web
Relevance: high

The authors measured PM and VOCs in patrol cars, roadsides, and a remote (ambient) site in North Carolina. They found that BTEX levels were significantly higher in the cars; elemental carbon levels were higher in the cars; but NO2 and PM2.5 levels were a little higher in at the ambient site; and ozone levels were nearly twice as high at the ambient site.

 

Levy 2000 - "Particle Concentrations in Urban Microenvironments"

Levy, Jonathan I; Houseman, E. Andres; et al.
"Particle Concentrations in Urban Microenvironments"
Environmental Health Perspectives
November 2000; v.108, n.11; pp.1051-1057.
On the Web
Relevance: medium

The authors measured particulate matter indoors and outdoors in seven microenvironments (subway, bus, restaurant, hospital, gymnasium, museum, store) in Boston. Particle counts for PM 0.3-0.5 were generally higher inside the subway and bus than outdoors, but lower inside the store, hospital, and museum. Particle counts overall were higher inside the subway and bus than outside.

 

Leung 1998 - "Evaluation of Personal Exposure to Monoaromatic Hydrocarbons"

Leung, Pei-Ling; Harrison, Roy M
"Evaluation of Personal Exposure to Monoaromatic Hydrocarbons"
Occupational and Environmental Medicine
April 1998; v.55, n.4; pp. 249-257
On the Web
Relevance: high

The authors measured the exposure of 50 volunteers in the UK to various monoaromatic hydrocarbons (MAHs) over the course of 12 hour days. They found that urban volunteers were exposed to more MAHs than non-urban volunteers. Most of the total exposure is from the home, despite low concentrations, due to the vast amount of time spent there. Although little time is spent driving, the high concentration of MAHs in vehicles made it a noticeable contributor for office workers (5% of total exposure) 

More notes...

 

Allen 2004 - "Estimated Hourly Personal Exposures to Ambient and Nonambient Particulate Matter Among Sensitive Populations in Seattle"

Allen, Ryan; Wallace, Lance; et al.
"Estimated Hourly Personal Exposures to Ambient and Nonambient Particulate Matter Among Sensitive Populations in Seattle"
Journal of Air and Waste Management
September 2004; v.54; n.9; pp.1197-1411
On the Web
Relevance: High

The authors measured the concentration of particulate matter in various mircoenvironments (home indoors, home outdoors, work, school, in transit, other outdoors, other indoors) and the average exposure for 38 subjects in Seattle. The subjects selected were "sensetive populations" with asthma, coronary heart disease, or advanced age. The major findings were:

  • The best air was indoors at home; the worst air was at work, followed by outdoors and in transit.
  • Because subjects spend so much time at home, most of their exposure (79%) occured there.
  • There was a low correlation between ambient and personal exposures (0.43) compared to findings from other studies. This means that localized sources highly affect personal exposure (i.e. cooking fumes vs.general air quality)

More notes...

 

Kingham 1998 - "Assessment of Exposure to Traffic-Related Fumes During the Journey to Work"

Kingham, Simon; Meaton, Julia; et al.
"Assessment of Exposure to Traffic-Related Fumes During the Journey to Work"
Transportation Research, Part D
July 1998; v.3, n.4; pp.271-274
On the Web
Relevance: medium-low

In a pilot study, the authors measured commuter's exposure to benzene and particulates using different modes (car, bus, train, road cyclist, path cyclist) but along similar routes(?). Findings include:

  • The car driver had the highest mean exposure to benzene (108.3 micrograms/m^3) a factor of at least 4 and also the highest mean exposure to particulates (7.6 absorbance), but by a much smaller margin.
  • Train riders had the lowest benzene exposure (12.9) and path cyclists had the lowest particulate exposure (2.7).
  • The bus was slightly better than the road bike
  • The exposure ratios for the car driver to the road cyclist were 4.05 for benzene and 1.26 for particulates.
  • The exposure ratios for the road cyclist to the path cyclist were 1.73 for benzene and 2.41 for particulates.

 

Adams 2002 - "Assessment of Road Users' Elemental Carbon Personal Exposure Levels, London, UK"

Adams, HS; Nieuwenhuijsen, MJ; Colvile, RN.
"Assessment of Road Users' Elemental Carbon Personal Exposure Levels, London, UK"
Atmospheric Environment
November 2002; v.36, n.34; pp.5335-5342
On the Web
Relevance: low

The authors measured exposure to elemental carbon (EC) a component of diesel exhaust, along various routes, using different modes, and in summer vs. winter.  They found that exposure levels were higher:

  • for cars, followed by buses and bicycles (cyclists may have lower exposure because they don't get stuck in traffic and keep "away from the central road 'tunnel of pollution'.";
  • along the most congested central route, perhaps due to higher traffic density and a street canyon effect;
  • in winter, perhaps due to colder engines and more stable meteorological conditions.

 

Fruin 2004 - "Black Carbon Concentrations in California Vehicles and Estimation of In-Vehicle Diesel Exhaust Particulate Matter Exposures"

Fruin, Scott A; Winer, Arthur M; Rodes, Charles E.
"Black Carbon Concentrations in California Vehicles and Estimation of In-Vehicle Diesel Exhaust Particulate Matter Exposures"
Atmospheric Environment
August 2004; v.38, n.25; pp.4123-4133
On the Web
Relevance: low

The authors measured black carbon (BC) concentrations inside vehicles driven around LA and Sacramento. BC is typically associated with diesel emissions. The authors found that the most important predictor of in-vehicles BC concentrations was the type of vehicle followed, with diesel buses and delivery trucks that had ground-level exhaust pipes being the worst. Following a gasoline powered car did not increase BC concentrations.

The authors also estimate daily exposure to diesel particulate matter (DPM), concluding that compared to earlier models, "in-vehicle DPM exposures appear to make very significant contributions to overall DPM exposures, randing from approximately 30-55% of total DPM exposure on a statewide, population basis.  Thus the in-vehicle microenvironment may be the most important route of overall DPM exposure, though only 1.5h day-1 is spend there, on average."