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A series of experiments were conducted to measure the rate of volatile loss of PCBs from subaqueous quartz sand spiked with Aroclors 1242, 1248, 1254, and 1260 under laboratory conditions (20 °C, 25% relative humidity). Volatilized PCBs were trapped on Florisil columns attached to a 1.5-L evaporation chamber through which 1.2 L/min of filtered air was drawn for a 24-h period. PCB losses ranged from 20 to 65% and were inversely correlated with the chlorine percentage of the aroclors (R  2 = 0.97). Congeners with the fewest number of chlorines in each aroclor were preferentially lost. In comparison, sediment from a Federal Superfund site along the St. Lawrence River, originally contaminated with Aroclor 1248, lost 19% of its PCB total during a similar experiment. Several orthochlorinated congeners, produced by anaerobic biodegradation, were preferentially lost, and four of these (2/2; 2/6; 2; 26/2) accounted for >55% of the total loss. This work suggests that under certain conditions the volatile loss of PCBs and other hydrophobic compounds from wet soils and sedi ments may be rapid and substantial. Further work is needed to elucidate the implications for analytical procedures, remedial actions, and the global mass balance of PCBs.

Our observations suggest that atmospheric transport of PCBs contributes to levels in the Yupik people, but that the abandoned military site at the NEC may also contribute to the human body burden in those individuals who have either spent substantial time or consumed food from there.

ObjectivesThis article synthesizes discussion of collaborative research results, interventions and policy engagement for St Lawrence Island (SLI), Alaska, during the years 2000–2012.MethodsAs part of on-going community-based participatory research (CBPR) studies on SLI, 5 discrete exposure-assessment projects were conducted: (a) a biomonitoring study of human blood serum; (b–d) 3 investigations of levels of contaminants in environmental media at an abandoned military site at Northeast Cape – using sediment cores and plants, semi-permeable membrane devices and blackfish, respectively; and (e) a study of traditional foods.ResultsBlood serum in residents of SLI showed elevated levels of polychlorinated biphenyls (PCBs) with higher levels among those exposed to the military site at Northeast Cape, an important traditional subsistence-use area. Environmental studies at the military site demonstrated that the site is a continuing source of PCBs to a major watershed, and that clean-up operations at the military site generated PCB-contaminated dust on plants in the region. Important traditional foods eaten by the people of SLI showed elevated concentrations of PCBs, which are primarily derived from the long-range transport of persistent pollutants that are transported by atmospheric and marine currents from more southerly latitudes to the north.InterventionsAn important task for all CBPR projects is to conduct intervention strategies as needed in response to research results. Because of the findings of the CBPR projects on SLI, the CBPR team and the people of the Island are actively engaging in interventions to ensure cleanup of the formerly used military sites; reform chemicals policy on a national level; and eliminate persistent pollutants internationally. The goal is to make the Island and other northern/Arctic communities safe for themselves and future generations.ConclusionsAs part of the CBPR projects conducted from 2000 to 2012, a series of exposure assessments demonstrate that the leaders of SLI have reason to be concerned about the health of people due to the presence of carcinogenic chemicals as measured in biomonitoring and environmental samples and important traditional foods.

This study was conducted in order to determine if the source of contaminants at formerly used defense sites (FUDS) in Alaska were deposited as a result of military occupancy or from long-­-distance transport. This determination largely influences whether remediation will occur, and, if so, to what extent. For this reason, plant samples (rinsed and unrinsed) and sediment cores were collected at military and remote sites on St. Lawrence Island (SLI) and Norton Sound, Alaska during the summers of 2002, 2006, and 2007 and analyzed for persistent organic pollutants. On St. Lawrence Island sediment core samples were collected at the Northeast Cape FUDS, also a traditional fishing/hunting camp, and were sectioned and analyzed for concentrations of Polychlorinated biphenyl (PCB) congeners, Mirex, Dichlorodiphenyldichloroethylene (DDE), Hexachlorobenzene (HCB), Mercury and Cesium-­-137 (137Cs). Differences in the total concentrations and distributions of PCB congeners, Mirex, DDE and Mercury in sediment cores and in plants collected from the two SLI and three Norton Sound mainland formerly used defense sites indicate the majority of the contaminants found can be temporally related to releases during military occupancy and subsequent redistribution of contaminants. Contaminants in plant samples at the SLI sites are elevated relative to the two remote sites located on St. Lawrence Island and the three mainland Norton Sound FUDS at Elim, Unalakleet, and Wales. The concentrations, lateral and vertical distribution of the total PCBs, and congener-­-specific differences in sediments and plants readily differentiate locally derived from globally transported contaminants. The relative contaminant concentrations in sediment cores and between rinsed and unrinsed plants collected from the NEC FUDS indicate contaminants were remobilized and redistributed during recent site remediation activities