Highway motor vehicles as sources of atmospheric particles: Projected Trends 1977 to 2000

Mobile sources of atmospheric polycyclic aromatic hydrocarbons: a roadway tunnel study

“…"Estimates from single-vehicle emission rates and 24-h passenger car/truck and bus counts (ratio of 81:11) for December 17, 1986. Vehicle breakdown as follows: 57.1% light-duty (LD) spark with three-way catalyst; 21.1% LD with no catalyst; 9.3% heavyduty (HD) diesel; 6.3% LD spark with oxidation catalyst; 4.5% LD diesel; and 1.6% HD spark with no catalyst (32).…”

“…A simulated traffic composition for the Tunnel was estimated from total passenger car and trucks/buses counts at the Tunnel for December 17,1986 (sampling for both particle-and vapor-phase PAHs). From the recommendations of Black et al (32), the traffic composition was further defined as 57% light-duty spark-ignition (LDSI) three-way catalyst vehicles, 21% LDSI vehicles without catalysts, 9% heavy-duty diesels, 6% LDSI with oxidation catalyst, 4% light-duty diesels, and 2% heavy-duty spark-ignition vehicles without catalysts. These fractions of the different types of vehicles were multiplied by their respective single-vehicle PAH emission rates (NRC data, ref 31) to yield composite emission rates for comparison with the emission rates estimated from the Tunnel samples (Table VII).…”

Ecohydrological disturbances associated with roads: Current knowledge, research needs, and management concerns with reference to the tropics

“…Heavy metals or other toxic substances, which are more frequently associated with run‐off on urban roads than rural/forest roads, may contaminate sediment, thereby reducing substratum suitable for macroinvertebrate colonization (Forrow & Maltby, ; Perdikaki & Mason, ). Heavy metals are relatively immobile and heterogeneously distributed along roadside areas, including drainage ditches and curb‐side soils (Black, Braddock, Bradow, & Ingalls, ; Hewitt & Rashed, ; Wust, Kern, & Hermann, ). Road run‐off during storms is the primary mechanism moving potentially harmful heavy metals into stream systems, especially lead, zinc, copper, chromium, and cadmium (Brown, ; Gilson et al, ; Kerri, Racin, & Howell, ; Yousef et al, ).…”

Continuous Measurement of Diesel Particulate Emissions

“…Other components, including sulfate and various metal oxides, typically constitute less than 5 percent of the total mass. 7 Adsorption and condensation are temperature and concentration dependent physical processes by which diesel C o emissions become associated with the particulate phase. 8 Normally this association occurs while the exhaust is cooling in the tailpipe and immediately after leaving the tailpipe where rapid dilution and cooling occur.…”