Direct and Indirect Atmospheric Deposition of PCBs to the Delaware River Watershed

Abstract

Atmospheric deposition can be an important source of PCBs to aquatic ecosystems. To develop the total maximum daily load (TMDL) for polychlorinated biphenyls (PCBs) for the tidal Delaware River (water-quality Zones 2-5), estimates of the loading of PCBs to the river from atmospheric deposition were generated from seven air-monitoring sites along the river. This paper presents the atmospheric PCB data from these sites, estimates direct atmospheric deposition fluxes, and assesses the importance of atmospheric deposition relative to other sources of PCBs to the river. Also, the relationship between indirect atmospheric deposition and PCB loads from minor tributaries to the Delaware River is discussed. Data from these sites revealed high atmospheric PCB concentrations in the Philadelphia/Camden urban area and lower regional background concentrations in the more remote areas. Wet, dry particle, and gaseous absorption deposition are estimated to contribute about 0.6, 1.8, and 6.5 kg year-(-1) sigmaPCBs to the River, respectively, exceeding the TMDL of 0.139 kg year(-1) by more than an order of magnitude. Penta-PCB watershed fluxes were obtained by dividing the tributary loads by the watershed area. The lowest of these watershed fluxes are less than approximately 1 ng m(-2) day(-1) for penta-PCB and probably indicates pristine watersheds in which PCB loads are dominated by atmospheric deposition. In these watersheds, the pass-through efficiency of PCBs is estimated to be on the order of 1%.

Atmospheric concentrations and potential sources of PCBs, PBDEs, and pesticides to Acadia National Park

“…OCP concentrations measured in this study were found to be generally lower than those measured in long-term monitoring programs of the Integrated Atmospheric Deposition Network, the New Jersey Atmospheric Deposition Network, and the Lake Ontario Atmospheric Deposition Study (see Table 2) (Pagano, 2005;Sun et al, 2007;Totten et al, 2006). Acadia National Park's distance from large-scale current or historical use of agricultural pesticides in comparison to other site locations may explain the relatively low contaminant levels reported in this study.…”

Global Distribution and Local Impacts of Inadvertently Generated Polychlorinated Biphenyls in Pigments

“…28,29 These data sets were all therefore collected under a Quality Assurance Project Plan (QAPP) approved by the US EPA and using EPA method 1668A. 7 Atmospheric PCBs were measured by active 30 (Figure 1). 8 PCB 11 levels in these products are many orders of magnitude lower than the levels of ΣPCBs found in carbonless copy paper in 1972, when PCB concentrations were reported as high as 64.7 mg g −1 .…”

POP and PAH in Bizerte Lagoon, Tunisia

“…PCBs are an industrial product; there are no known natural sources. Atmospheric depositions, runoff from the land, and food chain transport (Morrison et al, 2002;Totten et al, 2006;Davis et al, 2007) have been regarded as the major sources of PCBs in aquatic environments. Urban runoff from local watersheds is a particularly significant pathway for PCB entry into the lagoon.…”