PMID- 12269664
OWN - NLM
STAT- MEDLINE
DCOM- 20021008
LR  - 20220330
IS  - 1096-2247 (Print)
IS  - 1096-2247 (Linking)
VI  - 52
IP  - 9
DP  - 2002 Sep
TI  - Concentration and size distribution of ultrafine particles near a major highway.
PG  - 1032-42
AB  - Motor vehicle emissions usually constitute the most significant source of 
      ultrafine particles (diameter <0.1 microm) in an urban environment, yet little is 
      known about the concentration and size distribution of ultrafine particles in the 
      vicinity of major highways. In the present study, particle number concentration 
      and size distribution in the size range from 6 to 220 nm were measured by a 
      condensation particle counter (CPC) and a scanning mobility particle sizer 
      (SMPS), respectively. Measurements were taken 30, 60, 90, 150, and 300 m 
      downwind, and 300 m upwind, from Interstate 405 at the Los Angeles National 
      Cemetery. At each sampling location, concentrations of CO, black carbon (BC), and 
      particle mass were also measured by a Dasibi CO monitor, an aethalometer, and a 
      DataRam, respectively. The range of average concentration of CO, BC, total 
      particle number, and mass concentration at 30 m was 1.7-2.2 ppm, 3.4-10.0 
      microg/m3, 1.3-2.0 x 10(5)/cm3, and 30.2-64.6 microg/m3, respectively. For the 
      conditions of these measurements, relative concentrations of CO, BC, and particle 
      number tracked each other well as distance from the freeway increased. Particle 
      number concentration (6-220 nm) decreased exponentially with downwind distance 
      from the freeway. Data showed that both atmospheric dispersion and coagulation 
      contributed to the rapid decrease in particle number concentration and change in 
      particle size distribution with increasing distance from the freeway. Average 
      traffic flow during the sampling periods was 13,900 vehicles/hr. Ninety-three 
      percent of vehicles were gasoline-powered cars or light trucks. The measured 
      number concentration tracked traffic flow well. Thirty meters downwind from the 
      freeway, three distinct ultrafine modes were observed with geometric mean 
      diameters of 13, 27, and 65 nm. The smallest mode, with a peak concentration of 
      1.6 x 10(5)/cm3, disappeared at distances greater than 90 m from the freeway. 
      Ultrafine particle number concentration measured 300 m downwind from the freeway 
      was indistinguishable from upwind background concentration. These data may be 
      used to estimate exposure to ultrafine particles in the vicinity of major 
      highways.
FAU - Zhu, Yifang
AU  - Zhu Y
AD  - Department of Environmental Health Sciences, University of California, Los 
      Angeles 90095, USA.
FAU - Hinds, William C
AU  - Hinds WC
FAU - Kim, Seongheon
AU  - Kim S
FAU - Sioutas, Constantinos
AU  - Sioutas C
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - J Air Waste Manag Assoc
JT  - Journal of the Air & Waste Management Association (1995)
JID - 9503111
RN  - 0 (Air Pollutants)
RN  - 0 (Vehicle Emissions)
SB  - IM
MH  - Air Movements
MH  - Air Pollutants/*analysis
MH  - *Environmental Monitoring
MH  - Humans
MH  - Particle Size
MH  - Public Health
MH  - Transportation
MH  - Vehicle Emissions/*analysis
EDAT- 2002/09/25 06:00
MHDA- 2002/10/09 04:00
CRDT- 2002/09/25 06:00
PHST- 2002/09/25 06:00 [pubmed]
PHST- 2002/10/09 04:00 [medline]
PHST- 2002/09/25 06:00 [entrez]
AID - 10.1080/10473289.2002.10470842 [doi]
PST - ppublish
SO  - J Air Waste Manag Assoc. 2002 Sep;52(9):1032-42. doi: 
      10.1080/10473289.2002.10470842.