The Los Angeles International Airport as a source of ultrafine particles and other pollutants to nearby communities

Air monitoring was performed in the vicinity of the Los Angeles International Airport (LAX) during the spring of 2003. The purpose of this monitoring was to determine the extent of airport emissions on downwind ambient air in a mixed use neighborhood that includes residences. A mobile air monitoring platform was developed and deployed to measure ultrafine particle numbers (UFP), size distributions, particle length, black carbon (BC), oxides of nitrogen (NOx), and particle-phase polycyclic aromatic hydrocarbons (PM-PAH).Pollutant levels were low at a coastal site upwind of the airport, with UFP ranging between 580 and 3800 counts cm−3, oxides of nitrogen (NOx) from 4 to 22 ppb, black carbon from 0.2 to 0.6 μg m−3, and PM-PAH ranged from 18 to 36 ng m−3. Markedly higher UFP counts, with average counts of approximately 50,000 cm−3, were observed at a site 500 m downwind of the airport, which was strongly influenced by aircraft landings and where the community interfaced with airport facilities. Black carbon, PM-PAH, and NOx levels were elevated to a lesser extent at downwind locations. Transient peaks in UFP corresponding to aircraft landings and takeoffs were evident. A maximum UFP count reached 4.8 million particles cm−3 downwind of a runway used by jet aircraft for takeoffs. Particle size distributions differed substantially between upwind and downwind locations. The particle numbers at the upwind site were dominated by particles of approximately 90 nm diameter while downwind sites were dominated by particles peaking at approximately 10–15 nm. Additional data obtained from a study of UFP levels conducted subsequently by a co-author indicates that aircraft-generated UFP persist up to 900 m from an LAX runway [Biswas, S., Fine, P.M., Geller, M.D., Hering, S.V., Sioutas, C., 2005. Performance evaluation of a recently developed water-based condensation particle counter. Aerosol Science and Technology 39, 419–427]. Considered together, these observations suggest that airport operations are associated with elevated levels of UFP much further downwind in the neighboring community than would have been predicted by prior studies of UFP from roadway-traffic.