Temporal and Spatial Trends in a Long-Term Study of Gas-Phase PCB Concentrations near the Great Lakes

Abstract

Atmospheric concentrations of gas-phase polychlorinated biphenyls (PCBs) were measured at three sites near the Great Lakes as part of the Integrated Atmospheric Deposition Network (IADN). Air samples were collected every 12 days beginning in November 1990. Mean yearly values ranged from 89 to 370 pg/m 3 . Concentrations at the more urban site near Lake Erie (Sturgeon Point) were about two times higher than concentrations at the two more remote sites near Lake Superior (Eagle Harbor) and Lake Michigan (Sleeping Bear Dunes). Multiple regression analysis was used to relate atmospheric PCB concentrations to meteorological conditions. As expected, atmospheric temperature had a very significant effect on gas-phase PCB concentrations. Including wind speed and wind direction in the regression analysis improved the predicted values only slightly. Atmospheric levels of PCBs have remained unchanged as a function of time near Lake Superior but have declined slightly over time near Lakes Michigan and Erie. The rate constants at the latter two sites indicate an environmental half-life in the atmosphere of approximately 6 yr, which agrees well with PCB half-lives in other environmental compartments.

Seasonal Variation and Gas/Particle Partitioning of PCBs in Air from Central Urban Area of an Industrial Base and Coastal City -Tianjin, China

“…For particle PCBs, they were winter (40.02 ± 17.42) > spring (38.29 ± 24.87) > autumn (31.64 ± 19.07) > summer (24.09 ± 9.14). The similar trends for gas PCBs were reported in Great Lakes and Niigata (Hillery et al, 1997;Murayama et al, 2003). with the increasing temperature (R = -0.72, P < 0.05) and showed the strong seasonal variation with winter (43.98%) > spring (21.81%) > autumn (21.09%) > summer (5.93%) ( Fig.…”

“…These physiochemical properties are representative of persistent organic pollutants (POPs) and PCBs can act as their ideal marker compounds for global redistribution of POPs (Hornbuckle et al, 1993;Ockenden et al, 2003). Decades after restrictions, atmospheric PCBs have reached a steady level, and in several areas the PCBs levels were found to decrease only slowly or not at all (Panshin and Hites, 1994;Hillery et al, 1997;Haugen et al, 1999;Hung et al, 2005). The atmosphere is the main transport pathway, major source of PCBs to many aquatic ecosystems and an important media to under the behavior of PCBs (Hoff et al, 1996;Tseng et al, 2014a).…”

Peer Reviewed: The Great Lakes' Integrated Atmospheric Deposition Network

“…Clearly, when PCBs were used in the 1960s, there were substantial inputs into the lakes. Now that PCBs have been banned and the atmospheric concentrations have decreased, the air-water equilibrium has shifted, so the water is releasing its stores of PCBs back into the atmosphere (12).…”

Long-Term Variations of Airborne Cadmium (Cd) Concentrations in Major Urban Areas of Korea between 1991 and 2010

“…To conduct a long-term analysis, annual mean values of Cd obtained from all seven cities were examined by a simple linear regression analysis. The use of such simplified approach has commonly been made to provide a quick view of the general trend of many airborne pollutants (e.g., Hillery et al, 1997). If the long-term trends of Cd concentrations are compared between cities, Cd concentrations in major metropolitan cities experienced gradual reductions throughout the past decades.…”