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Emissions from an international airport increase particle number concentrations 4-fold at 10 km downwind.

Hudda N, Gould T, Hartin K, Larson TV, Fruin SA - Environ. Sci. Technol. (2014)

Bottom Line: The total freeway length in Los Angeles is 1500 km.These results suggest that airport emissions are a major source of PN in Los Angeles that are of the same general magnitude as the entire urban freeway network.They also indicate that the air quality impact areas of major airports may have been seriously underestimated.

View Article: PubMed Central - PubMed

Affiliation: Keck School of Medicine, Department of Preventive Medicine, University of Southern California , Los Angeles, California 90089, United States.

ABSTRACT
We measured the spatial pattern of particle number (PN) concentrations downwind from the Los Angeles International Airport (LAX) with an instrumented vehicle that enabled us to cover larger areas than allowed by traditional stationary measurements. LAX emissions adversely impacted air quality much farther than reported in previous airport studies. We measured at least a 2-fold increase in PN concentrations over unimpacted baseline PN concentrations during most hours of the day in an area of about 60 km(2) that extended to 16 km (10 miles) downwind and a 4- to 5-fold increase to 8-10 km (5-6 miles) downwind. Locations of maximum PN concentrations were aligned to eastern, downwind jet trajectories during prevailing westerly winds and to 8 km downwind concentrations exceeded 75 000 particles/cm(3), more than the average freeway PN concentration in Los Angeles. During infrequent northerly winds, the impact area remained large but shifted to south of the airport. The freeway length that would cause an impact equivalent to that measured in this study (i.e., PN concentration increases weighted by the area impacted) was estimated to be 280-790 km. The total freeway length in Los Angeles is 1500 km. These results suggest that airport emissions are a major source of PN in Los Angeles that are of the same general magnitude as the entire urban freeway network. They also indicate that the air quality impact areas of major airports may have been seriously underestimated.

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Related in: MedlinePlus

Change in location of impact due to shift in wind direction.Winddirection during monitoring is shown in insets on bottom left. PNconcentrations are classified and colored by deciles.
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fig4: Change in location of impact due to shift in wind direction.Winddirection during monitoring is shown in insets on bottom left. PNconcentrations are classified and colored by deciles.

Mentions: Thedownwind location of the impact changed with shifts in the prevailingwind direction, although significant shifts in wind direction duringthe daytime are not typical of this area of Los Angeles.12 Figure 4(a) and (b) illustrateone such change in impacted locations due to a shift in wind directionon a gusty day with frontal weather that also resulted in cleanerupwind baseline PN concentrations of less than 5000 particles/cm3. The impacted locations were aligned along the NE directionduring 2000–2220 h when winds were from W to WSW (250–280°).The impact then moved southwards between 2220–0000 h as windsturned more W to WNW (280–330°). During this shift, theimpact centerline moved by 5.5 km on transects 8–10 km eastof LAX.


Emissions from an international airport increase particle number concentrations 4-fold at 10 km downwind.

Hudda N, Gould T, Hartin K, Larson TV, Fruin SA - Environ. Sci. Technol. (2014)

Change in location of impact due to shift in wind direction.Winddirection during monitoring is shown in insets on bottom left. PNconcentrations are classified and colored by deciles.
© Copyright Policy - editor-choice
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4215878&req=5

fig4: Change in location of impact due to shift in wind direction.Winddirection during monitoring is shown in insets on bottom left. PNconcentrations are classified and colored by deciles.
Mentions: Thedownwind location of the impact changed with shifts in the prevailingwind direction, although significant shifts in wind direction duringthe daytime are not typical of this area of Los Angeles.12 Figure 4(a) and (b) illustrateone such change in impacted locations due to a shift in wind directionon a gusty day with frontal weather that also resulted in cleanerupwind baseline PN concentrations of less than 5000 particles/cm3. The impacted locations were aligned along the NE directionduring 2000–2220 h when winds were from W to WSW (250–280°).The impact then moved southwards between 2220–0000 h as windsturned more W to WNW (280–330°). During this shift, theimpact centerline moved by 5.5 km on transects 8–10 km eastof LAX.

Bottom Line: The total freeway length in Los Angeles is 1500 km.These results suggest that airport emissions are a major source of PN in Los Angeles that are of the same general magnitude as the entire urban freeway network.They also indicate that the air quality impact areas of major airports may have been seriously underestimated.

View Article: PubMed Central - PubMed

Affiliation: Keck School of Medicine, Department of Preventive Medicine, University of Southern California , Los Angeles, California 90089, United States.

ABSTRACT
We measured the spatial pattern of particle number (PN) concentrations downwind from the Los Angeles International Airport (LAX) with an instrumented vehicle that enabled us to cover larger areas than allowed by traditional stationary measurements. LAX emissions adversely impacted air quality much farther than reported in previous airport studies. We measured at least a 2-fold increase in PN concentrations over unimpacted baseline PN concentrations during most hours of the day in an area of about 60 km(2) that extended to 16 km (10 miles) downwind and a 4- to 5-fold increase to 8-10 km (5-6 miles) downwind. Locations of maximum PN concentrations were aligned to eastern, downwind jet trajectories during prevailing westerly winds and to 8 km downwind concentrations exceeded 75 000 particles/cm(3), more than the average freeway PN concentration in Los Angeles. During infrequent northerly winds, the impact area remained large but shifted to south of the airport. The freeway length that would cause an impact equivalent to that measured in this study (i.e., PN concentration increases weighted by the area impacted) was estimated to be 280-790 km. The total freeway length in Los Angeles is 1500 km. These results suggest that airport emissions are a major source of PN in Los Angeles that are of the same general magnitude as the entire urban freeway network. They also indicate that the air quality impact areas of major airports may have been seriously underestimated.

Show MeSH
Related in: MedlinePlus