Bioaccumulation of pharmaceuticals and personal care products in the unionid mussel Lasmigona costata in a river receiving wastewater effluent.

Freshwater mussels are frequently found in rivers receiving effluent from wastewater treatment plants (WWTP), and there is strong evidence that poor water quality is deleterious to freshwater mussel populations. WWTPs are among the main sources of pharmaceuticals and personal care products (PPCPs) in surface waters. We monitored 145 PPCPs in wild and caged mussels both upstream and downstream of the Kitchener WWTP in the Grand River, Ontario, as well as 118 PPCPs in water samples. Our objectives were to characterize the seasonal changes in PPCP concentrations in water, to calculate bioaccumulation factors (BAFs) of PPCPs in mussels, and to determine the chemical and physical properties of PPCPs driving the bioaccumulation. Seventy PPCPs were detected in water, and concentrations were highest in the summer or early fall, which corresponded to low river flow. Forty-three PPCPs from many pharmaceutical classes were detected in mussel tissues, including stimulants, a contrasting agent, anti-inflammatory drugs, anti-bacterial agents, antibiotics, antidepressants, antihistamines, progestins, and illicit drugs such as cocaine and amphetamines. The BAFs ranged from 0.66 for metformin to 32,022 for sertraline. Using partial least squares to predict BAFs based upon chemical properties, log KOC, Log KOW, and fugacity ratio (sediment) all had similar and positive loadings with BAFs (R(2)X = 0.70; caged mussels). BAFs of PPCPs in mussels were predictable from fugacity models that estimate bioconcentration factors using log KOW. Our study demonstrated that mussels readily bioaccumulate PPCPs, in a manner consistent with expectations based upon BCF models and the chemical characteristics of each compound.

Determination of perchlorate in selected surface waters in the Great Lakes Basin by HPLC/MS/MS.

Surface water samples were collected from 55 sites in the Great Lakes Basin and analyzed for the presence of perchlorate using HPLC/MS/MS with an isotopically enriched internal standard. Sites included areas impacted by heavy industry, urbanization, agriculture and atmospheric deposition. Perchlorate was detected at several of the sites at concentrations close to the method detection limit (0.2 microg/l). Despite these low concentrations, its presence was confirmed by sample concentration and determination of the isotopic ratio of perchlorate. The presence of perchlorate at two of the sites was related to a fireworks display which had occurred prior to sampling. The other detections of perchlorate were in rivers/creeks draining watersheds which had high density livestock and crop farming activity. We suspect the two are related. To our knowledge, these are the first reported concentrations of perchlorate in Canadian surface waters.

Concentrations of persistent organochlorine contaminants in bowhead whale tissues and other biota from northern Alaska: implications for human exposure from a subsistence diet.

Bowhead whale (Balaena mysticetus; n = 5) blubber, liver, muscle, kidney, heart, diaphragm, tongue, and uncooked maktak (bowhead whale epidermis and blubber) were collected during subsistence hunts at Barrow, AK, USA (1997-1999) to measure concentrations of persistent organochlorine contaminants (OCs). The exposure of humans to OCs via bowhead whales and other biota [fish, ringed (Phoca hispida) and bearded seals (Erignathus barbatus), and beluga whale (Delphinapterus leucas)] as part of a subsistence diet was evaluated. Concentrations of OCs in bowhead whale tissues were correlated with lipid content (P < 0.001) and were less than levels in other marine mammals reported herein, reflecting the lower trophic status of this cetacean. The relative proportions of hexachlorobenzene (HCB) and sum (Sigma) concentrations of chlordane components (SigmaCHL), DDT-related compounds (SigmaDDT), and polychlorinated biphenyls (SigmaPCB) were not statistically different among the tissues analyzed (P < 0.05). However, relatively higher proportions of hexachlorocyclohexane isomers (SigmaHCH), particularly beta-HCH, were observed in bowhead whale heart and diaphragm (P < 0.03). Based on Canadian and World Health Organization daily intake guidelines, "safe" human consumption rates of bowhead whale tissue and other marine biota were calculated. The most restrictive limits (mean value) for daily consumption for bowhead and beluga whale were 302 and 78 g for maktak and maktaaq (beluga whale epidermis and blubber), respectively. The tolerable daily intake limits of dioxin-like compounds from the consumption of bowhead whale blubber and liver were calculated to be 199 g (approximately 600 g for maktak) and 2222 g, respectively. A detailed profile of traditional/country foods consumed by subsistence communities of northern Alaska is required to address chronic exposure in more detail. Overall, bowhead whale tissues and other biota from northern Alaska are safe to consume at, or below, the levels calculated.

Contaminants in the Canadian Arctic: 5 years of progress in understanding sources, occurrence and pathways.

Recent studies of contaminants under the Canadian Northern Contaminants Program (NCP) have substantially enhanced our understanding of the pathways by which contaminants enter Canada's Arctic and move through terrestrial and marine ecosystems there. Building on a previous review (Barrie et al., Arctic contaminants: sources, occurrence and pathways. Sci Total Environ 1992:1-74), we highlight new knowledge developed under the NCP on the sources, occurrence and pathways of contaminants (organochlorines, Hg, Pb and Cd, PAHs, artificial radionuclides). Starting from the global scale, we examine emission histories and sources for selected contaminants focussing especially on the organochlorines. Physical and chemical properties, transport processes in the environment (e.g. winds, currents, partitioning), and models are then used to identify, understand and illustrate the connection between the contaminant sources in industrial and agricultural regions to the south and the eventual arrival of contaminants in remote regions of the Arctic. Within the Arctic, we examine how contaminants impinge on marine and terrestrial pathways and how they are subsequently either removed to sinks or remain where they can enter the biosphere. As a way to focus this synthesis on key concerns of northern residents, a number of special topics are examined including: a mass balance for HCH and toxaphene (CHBs) in the Arctic Ocean; a comparison of PCB sources within Canada's Arctic (Dew Line Sites) with PCBs imported through long-range transport; an evaluation of concerns posed by three priority metals--Hg, Pb and Cd; an evaluation of the risks from artificial radionuclides in the ocean; a review of what is known about new-generation pesticides that are replacing the organochlorines; and a comparison of natural vs. anthropogenic sources of PAH in the Arctic. The research and syntheses provide compelling evidence for close connectivity between the global emission of contaminants from industrial and agricultural activities and the Arctic. For semi-volatile compounds that partition strongly into cold water (e.g. HCH) we have seen an inevitable loading of Arctic aquatic reservoirs. Drastic HCH emission reductions have been rapidly followed by reduced atmospheric burdens with the result that the major reservoir and transport agent has become the ocean. In the Arctic, it will take decades for the upper ocean to clear itself of HCH. For compounds that partition strongly onto particles, and for which the soil reservoir is most important (e.g. PCBs), we have seen a delay in their arrival in the Arctic and some fractionation toward more volatile compounds (e.g. lower-chlorinated PCBs). Despite banning the production of PCB in the 1970s, and despite decreases of PCBs in environmental compartments in temperate regions, the Arctic presently shows little evidence of reduced PCB loadings. We anticipate a delay in PCB reductions in the Arctic and environmental lifetimes measured in decades. Although artificial radionuclides have caused great concern due to their direct disposal on Russian Shelves, they are found to pose little threat to Canadian waters and, indeed, much of the radionuclide inventory can be explained as remnant global fallout, which was sharply curtailed in the 1960s, and waste emissions released under license by the European reprocessing plants. Although Cd poses a human dietary concern both for terrestrial and marine mammals, we find little evidence that Cd in marine systems has been impacted by human activities. There is evidence of contaminant Pb in the Arctic, but loadings appear presently to be decreasing due to source controls (e.g. removal of Pb from gasoline) in Europe and North America. Of the metals, Hg provokes the greatest concern; loadings appear to be increasing in the Arctic due to global human activities, but such loadings are not evenly distributed nor are the pathways by which they enter and move within the Arctic well understood.

Effect of surfactant solubilization on biodegradation of polychlorinated biphenyl congeners by Pseudomonas LB400.

A variety of commercial surfactants were tested to determine their effect on polychlorinated biphenyl (PCB) transformation by Pseudomonas LB400. Initial tests determined that most surfactants were fully or partially able to solubilize the PCB congeners 2,5,2'-chlorobiphenyl (CBP), 2,4,2',4'-CBP, 2,3,5,2',5'-CBP and 2,4,5,2',4',5'-CBP, at concentrations above the surfactants' critical micelle concentration (CMC). Surfactants were also found to have no negative effect on bacterial survival, as cell numbers were the same or higher after incubation in the presence of surfactants than after incubation without surfactants. A comparison of the extent of biotransformation of single PCB congeners by the bacterium revealed that, at surfactant concentrations above the CMC, the presence of an anionic surfactant promoted while nonionic surfactants inhibited PCB transformation, compared to a control with no surfactant. The rates of transformation of PCB congeners were also higher in the presence of the anionic surfactant compared to the control. The inhibitory effects of a nonionic surfactant, Igepal CO-630 at a concentration above its CMC, on transformation of 2,4,5,2',5'-CBP could be eliminated by diluting the surfactant/PCB solution to a concentration close to the surfactant CMC.

Comparison of the degradation patterns of polychlorinated biphenyl congeners in Aroclors by Pseudomonas strain LB400 after growth on various carbon sources.

Resting cells of Pseudomonas strain LB400, grown on biphenyl, transformed 80, 50 and 17% of Aroclor 1242, 1254, and 1260, respectively. Resting cells grown on glucose or glycerol also transformed these polychlorinated biphenyl (PCB) mixtures to the extent of 60, 35, and 9% for Aroclors 1242, 1254, and 1260, respectively. Time courses of the transformation of the separated individual congeners in the Aroclors were plotted and used to determine the transformation rate constants (k). By analysis of the rate constants, it was concluded that the order of degradation of the different congeners in an Aroclor were similar regardless of the growth substrate. In general, k values for the conversion of a particular congener were lower for cells grown on glucose or glycerol compared with cells grown on biphenyl. Generally, k values for the transformation of the same congener in different Aroclors were not the same: rate constants had highest values for the congener in Aroclor 1242 and lowest values in Aroclor 1260. The data allowed congeners to be grouped according to their relative rates of degradation. The ratio of k values for transformation of individual congeners in Aroclors by cells grown on biphenyl and glucose were not constant.