Dynamics of atmospheric polychlorinated biphenyl concentrations in the northeastern United States

Atmospheric concentrations of polychlorinated biphenyls (PCBs) were measured in coastal New Jersey in 1997–99. ΣPCB concentrations at the suburban site varied from 86 to 2,300 pg m−3 and from 84 to 1,100 pg m−3 at the coastal site. Temperature explained ∼50% of the total variability in ln [PCB] at both sites. Atmospheric concentrations generally increased when winds blew from east-northeast, while increased wind speeds led to a slight dilution. Temporal variations suggested that 3 to 5 Cl-biphenyls are removed by hydroxyl radical with estimated half-lives of 0.7 to 1.8 years.; Simultaneous measurements of polychlorinated biphenyls (PCBs) in the air and water over the NY–NJ Harbor Estuary in July 1998 led to air-water exchange fluxes of +325 (Raritan Bay) and +1490 ngm−2day −1 (NY Harbor). The volatilization fluxes are greater than atmospheric deposition demonstrating that volatilization is an important loss mechanism for PCBs.; In July 1998, day and night air samples were collected at the above sites, and overwater in the Estuary. The highest concentrations were measured over New York Harbor (3610 pg m−3) while the lowest concentration was measured at Raritan Bay (380 pg m−3). Major atmospheric sources were urban-industrial northern New Jersey and New York, along with the contaminated estuary. Identical homologue profiles were observed at all sites suggesting continental air mixed with an impacted urban/industrial atmosphere.; PCBs and particulate organic/elemental carbon (OC/EC) were both elevated in urban Baltimore and over Chesapeake Bay in July 1997. Gas phase ΣPCBs averaged 1180 pg m−3 for Baltimore and 550 pg m −3 for northern Chesapeake Bay. Homologue distributions in the gas phase favored trichlorobiphenyls in Baltimore relative to Chesapeake Bay. Autocorrelation analysis yielded a diurnal cycle for gas phase PCBs at Baltimore with the lowest concentrations during the day. POC and EC constituted 12.4% and 2.8% of total suspended particles in Baltimore, and 15.0% and 5.3% over the Chesapeake Bay, respectively. Variability in PCB concentrations was not related to the variability in OC/EC concentrations. Emissions into the Baltimore atmosphere are major sources to the Bay.; These studies demonstrate that urban-industnal centers are major sources of PCBs and deposition to the Mid-Atlantic estuaries.