Evidence for Increased Gaseous PCB Fluxes to Lake Michigan from Chicago

Abstract

Urban-industrial areas exhibit atmospheric concentrations of organic contaminants that are often > 5-10× regional background. Increased emissions of PCBs into the urbanindustrial atmosphere leads to enhanced depositional fluxes to proximate waters. In this study, the increased airwater exchange inputs of PCB congeners into southern Lake Michigan driven by elevated atmospheric concentrations emanating from the Chicago, IL/Gary, IN air plume was studied. Intensive experiments were conducted in May and July 1994 and January 1995. The gaseous ΣPCB concentrations at the overlake site 15-km from Chicago ranged from 132 to 1120 pg/m 3 with higher concentrations occurring in warm periods and when winds were from southerly and westerly quadrants. Dissolved phase ΣPCB concentrations ranged from 48 to 302 pg/L with concentrations in winter ∼2.5× higher than summer concentrations. Instantaneous net air-water exchange fluxes ranged from -32 (absorption) to + 59 ng/m 2 -d with absorptive flux highest in summer when winds were from the urban area and gas-phase concentrations were highest. Air and surface water temperatures and wind direction were the dominant factors influencing the magnitude and direction of air-water exchange fluxes. The modeled net air-water exchange flux of ΣPCB in the southern quarter of Lake Michigan was -18 ug/m 2 -yr (net absorption) in 1994, corresponding to 140 kg/yr net input.

Movement and Retention of Polychlorinated Biphenyls in a Paddy Field of WenTai Area in China

“…The gaseous-phase and particle-phase were characterized by congeners with low chlorinated PCBs. The sum of PCB concentrations in the gaseous phase, which ranged from 191 to 640 ng/m 3 , was similar to those recorded in the gaseous uxes for Lake Michigan (Zhang et al, 1999), however the congeners patterns were different from other European measurements in which penta-and hexa-chlorinated biphenyls were observed (Haugen et al, 1999). Particle-phase concentrations of PCBs in this study were very low and PCB ranged between 5 and 35 ng/m 3 .…”

Endocrine disruptors in the environment (IUPAC Technical Report)

“…The absorptive mass flow rate was highest in summer. It was estimated that the mass flow rate of total PCB congeners in the southern quarter of Lake Michigan was -18 mg m -2 (net absorption) in 1994, corresponding to a yearly net input of 140 kg [154]. Sediments in the harbor of New Bedford in the United States have been contaminated during the production of capacitors.…”

Dry deposition fluxes and velocities of polychlorinated biphenyls (PCBs) associated with particles

“…The atmosphere serves as an important pathway for global transport of PCBs. Particle deposition (Zannetti, 1990;Noll et al, 1990), gaseous air-water exchange (Hornbuckle et al, , 1995Jeremiason et al, 1994;Zhang et al, 1999) and wet deposition via rain and snow (Franz 1994;Poster and Baker, 1996) are the major atmospheric removal mechanisms for PCBs.…”

“…Murphy et al (1981) employed filters that were wetted with propane and butanediols as a collection surface. PCBs enter the atmosphere from incinerators, landfills, or soil and air/water exchange (Murphy et al, 1981(Murphy et al, , 1985Hornbuckle et al, 1994Hornbuckle et al, , 1995Jeremiason et al, 1994;Zhang et al, 1999;Franz, 1994;Poster and Baker, 1996;Hsu et al, 2003;Garcia-Alonso and Perez-Pastor, 2003). Since there are some important PCB sources around Chicago, the atmospheric concentrations of PCBs are higher there than many other urban areas (Tasdemir et al, 2004;Green et al, 2000;Simcik et al, 1998;Cotham and Bidleman, 1995).…”