Burdens of PBBs, PBDEs, and PCBs in tissues of the cancer patients in the e-waste disassembly sites in Zhejiang, China

This study was conducted to explore the burdens of PBBs, PBDEs, and PCBs among cancer patients living in the e-waste disassembly sites. The contents of 23 PBB congeners, 12 PBDE congeners, and 27 PCB congeners in kidney, liver, and lung samples were measured by GC-MS. The results showed that low-brominated PBBs and PBB153 were the predominant congeners. PBDE47 were the most predominant PBDE congeners. PBDE209 were detected in > 70% of the samples, with geometric means ranging from 64.2 to 113.9 ng g^− 1 lipid. Among the three subfamilies of PHAHs, PCB concentrations were the highest. The detected levels of PHAHs were in the same order of magnitude in the three tissues, which indicated that any of the three tissues could be the suitable indicator for assessing body burdens of PHAHs. PBB contents (181-192 ng g^− 1 lipid) were obviously higher than those reported in the general USA population (3-8 ng g^− 1 lipid). PBDE levels (174.1-182.3 ng g^− 1 lipid) were comparable to those reported in the USA population, but significantly higher than those of the European population. PCBs levels were comparable to those of the European population. The high cancer incidence in the disassembly sites may be related to higher burdens of PBBs, PBDEs, and PCBs in tissues.     

Atmospheric deposition of persistent organic pollutants to the East Rongbuk Glacier in the Himalayas

To assess levels and seasonal trends of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in a high-altitude mountain region, a 2.1 m snowpack sample was collected from the East Rongbuk Glacier at 6572 ma.s.l. on Mt. Everest in September 2005. This snowpack covered a full year period from the fall of 2004 to the summer of 2005 and reflected the major meteorology of the monsoon and non-monsoon seasons. The most abundant compounds detected in the snow samples were γ-hexachlorocyclohexane (γ-HCH) and α-HCH with mean concentrations of 123 pg L^− 1 and 92 pg L^− 1, respectively. This is the first detection of these compounds in recent snow samples from the Himalayas. Backward air trajectory analysis indicated that the Himalayas could be influenced by the major HCH source regions in both India and China. Among the seven marker PCB congeners (PCB 28, 52, 101, 118, 138, 153, and 180) quantified, PCB 28 and PCB 52 were the only dominant PCB congeners detected, with mean concentrations of 17 pg L^− 1 and 6 pg L^− 1, respectively. In addition, DDT metabolites, p,p′-DDE and p,p′-DDD were detected in some snow samples and mean concentrations of DDTs were 24 pg L^− 1. Seasonal differences were observed for α- and γ-HCH concentrations increasing from the non-monsoon season to the monsoon season. Meanwhile, PCB 28 and HCB showed uniform variations with peak concentrations resulting from an effective scavenging by snowfalls between the monsoon and non-monsoon interval. Compared to other high mountain areas, the levels of POPs deposited into the East Rongbuk Glacier were relatively low, resulting from the highest altitude and remoteness from source regions.     

Bioaccumulation of polychlorinated dibenzo-p-dioxins, dibenzofurans, and dioxin-like polychlorinated biphenyls in fishes from the Tittabawassee and Saginaw Rivers, Michigan, USA

Characterizing biological factors associated with species-specific accumulation of contaminants is one of the major focuses in ecotoxicology and environmental chemistry studies. In this study, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and non- and mono-ortho-substituted polychlorinated biphenyl (PCB) congeners were analyzed in various fish species from the Tittabawassee and Saginaw Rivers (12 fish species; n = 314 individuals), Michigan, USA. Due to their migratory habits, greater δ¹³C stable isotope values were found in walleye and white sucker among 12 fish species. Meanwhile, the δ¹⁵N values indicated that the trophic status was least in carp and greatest in largemouth bass. The greatest total concentrations of dioxins were found in fishes with the lowest trophic status (carp (n = 50) followed by channel catfish (n = 49)), and concentrations of ΣPCDD/Fs (20-440 pg/g ww (wet weight)), ΣPCBs (16-690 ng/g ww), and TEQs (6.8-350 pg/g ww) in carp were also greater than the least mean concentrations in other fishes. Contributions of various biological factors to the species accumulation were assessed. Body weight and lipid content were found to be the most significant factors influencing accumulation of ΣPCDD/Fs. Lipid content and trophic level seemed to be dominant factors determining accumulation of ΣPCB and TEQs, but negative correlations between trophic status and concentrations of ΣPCBs and TEQs were observed possibly due to the great concentrations in benthivorous fishes such as carp occupying lower trophic levels. These factors can be used to predict the contaminant levels of dioxins and health risks of the fishes in the river ecosystem.     

The use of muscle burden in rabbitfish Siganus oramin for monitoring polycyclic aromatic hydrocarbons and polychlorinated biphenyls in Victoria Harbour, Hong Kong and potential human health risk

Muscle concentrations of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were determined in rabbitfish Siganus oramin collected from Victoria Harbour and its vicinity, Hong Kong from 2004 to 2007. Spatially, relatively higher levels of ∑PAH (1.05-4.26 μg g^− 1) and ∑PCB (45.1-76.9 ng g^− 1) were determined in the central and western sites inside the harbour. Temporally, upward trend of ∑PAH, accompanied with a proportion shift from high molecular weight to low molecular weight PAHs, was detected during the three-year study period, suggesting a heavier marine traffic in Victoria Harbour and its western region. However, human health risk assessment based on five individual PAHs indicated that PAHs in fish muscles posed minimal health risk through consumption. In contrast, a downward trend of ∑PCB was registered as the open use of PCBs has been banned. Despite this, the level of ∑PCB in fish muscles still posed a health risk on the local people who have a high fish consumption rate. While seasonal influences on ∑PAH/∑PCB accumulation in S. oramin seemed to be negligible, our findings in S. oramin were in line with the established PAH and PCB levels in sediments and/or mussels from the harbour, suggesting S. oramin can be used as a model fish species for monitoring PAHs and PCBs in the region.     

Seasonality of diffusive exchange of polychlorinated biphenyls and hexachlorobenzene across the air-sea interface of Kaohsiung Harbor, Taiwan

Gaseous and dissolved concentrations of polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) were measured in the ambient air and water of Kaohsiung Harbor lagoon, Taiwan, from December 2003 to January 2005. During the rainy season (April to September), gaseous PCB and HCB concentrations were low due to both scavenging by precipitation and dilution by prevailing southwesterly winds blown from the atmosphere of the South China Sea. In contrast, trace precipitation and prevailing northeasterly winds during the dry season (October to March) resulted in higher gaseous PCB and HCB concentrations. Instantaneous air-water exchange fluxes of PCB homologues and HCB were calculated from 22 pairs of air and water samples from Kaohsiung Harbor lagoon. All net fluxes of PCB homologues and HCB in this study are from water to air (net volatilization). The highest net volatile flux observed was + 172 ng m^− 2 day^− 1 (dichlorobiphenyls) in December, 2003 due to the high wind speed and high dissolved concentration. The PCB homologues and HCB fluxes were significantly governed by dissolved concentrations in Kaohsiung Harbor lagoon. For low molecular weight PCBs (LMW PCBs), their fluxes were also significantly correlated with wind speed. The net PCB and HCB fluxes suggest that the annual sums of 69 PCBs and HCB measured in this study were mainly volatile (57.4 × 10³ and 28.3 × 10³ ng m^− 2 yr^− 1, respectively) and estimated yearly, 1.5 kg and 0.76 kg of PCBs and HCB were emitted from the harbor lagoon surface waters to the ambient atmosphere. The average tPCB flux in this study was about one-tenth of tPCB fluxes seen in New York Harbor and in the Delaware River, which are reported to be greatly impacted by PCBs.     

Contaminant blubber burdens in Atlantic bottlenose dolphins (Tursiops truncatus) from two southeastern US estuarine areas: Concentrations and patterns of PCBs, pesticides, PBDEs, PFCs, and PAHs

Polychlorinated biphenyls (PCBs), chlorinated pesticides (i.e., dichlorodiphenyltrichloroethane (DDT) and its metabolites, chlordanes (CHLs), dieldrin, hexachlorobenzene (HCB), and mirex), polybrominated diphenyl ethers (PBDEs), perfluorinated chemicals (PFCs), and polyaromatic hydrocarbons (PAHs) were measured in blubber biopsy samples collected from 139 wild bottlenose dolphins (Tursiops truncatus) during 2003-2005 in Charleston (CHS), SC and the Indian River Lagoon (IRL), FL. Dolphins accumulated a similar suite of contaminants with ∑ PCB dominating (CHS 64%, IRL 72%), followed by ∑ DDT (CHS 20%, IRL 17%), ∑ CHLs (CHS 7%; IRL 7%), ∑ PBDE (CHS 4%, IRL 2%), PAH at 2%, and dieldrin, PFCs and mirex each 1% or less. Together ∑ PCB and ∑ DDT concentrations contributed ∼ 87% of the total POCs measured in blubber of adult males. ∑ PCBs in adult male dolphins exceed the established PCB threshold of 17 mg/kg by a 5-fold order of magnitude with a 15-fold increase for many animals; 88% of the dolphins exceed this threshold. For male dolphins, CHS (93,980 ng/g lipid) had a higher ∑ PCBs geomean compared to the IRL (79,752 ng/g lipid) although not statistically different. In adult males, the PBDE geometric mean concentration was significantly higher in CHS (5920 ng/g lipid) than the IRL (1487 ng/g). Blubber ∑ PFCs concentrations were significantly higher in CHS dolphins. In addition to differences in concentration of PCB congeners, ∑ PBDE, TEQ, ∑ CHLs, mirex, dieldrin, and the ratios ∑ DDE/∑DDT and trans-nonachlor/cis-nonachlor were the most informative for discriminating contaminant loads in these two dolphin populations. Collectively, the current ∑ PCB, ∑ DDT, and ∑ PBDEs blubber concentrations found in CHS dolphins are among the highest reported values in marine mammals. Both dolphin populations, particularly those in CHS, carry a suite of organic chemicals at or above the level where adverse effects have been reported in wildlife, humans, and laboratory animals warranting further examination of the potential adverse effects of these exposures.     

Organochlorines and mercury in livers of great cormorants (Phalacrocorax carbo sinensis) wintering in northeastern Mediterranean wetlands in relation to area, bird age, and gender

Wild birds are exposed to pollutants in their habitats. Top consumers of aquatic environments such as the fish-eating great cormorant (Phalacrocorax carbo sinensis) are especially affected due to the bioaccumulation of toxic substances in their tissues. This study analysed the livers of 80 great cormorants from Greece to estimate the concentration of organochlorines and mercury and to examine their possible toxic effects and origin. The results showed that mercury (geometric mean 8089 ng g⁻¹ dw), p,p′-DDE (2628 ng g⁻¹ dw), ∑ HCHs (47 ng g⁻¹ dw) and HCB (116 ng g⁻¹ dw) concentrations can be considered high compared with those found in great cormorant livers elsewhere except in highly polluted areas, whereas ∑ PCBs occurred in relatively low concentrations (1091 ng g⁻¹ dw). β-HCH was the dominant HCH isomer. Pollutant levels were generally unrelated to area, age and gender. However, p,p′-DDE and p,p′-DDD showed intersite differences, whilst the proportion of PCBs with 8 chlorine atoms were significantly higher in adult than 1st year great cormorants. Pollution did not reflect local patterns but rather these along the Baltic and Black Seas, whilst differences in p,p′-DDE concentration and ∑ DDTs/∑PCBs ratios between Evros, Axios or Amvrakikos, found on common migration route, suggested different bird origins. Most birds had toxic mercury concentrations; 83.7% above 4000 ng g⁻¹ dw and 16% above 17,000 ng g⁻¹ dw. Other pollutant levels were too low to have adverse effects.     

The role of diet on long-term concentration and pattern trends of brominated and chlorinated contaminants in western Hudson Bay polar bears, 1991-2007

Adipose tissue was sampled from the western Hudson Bay (WHB) subpopulation of polar bears at intervals from 1991 to 2007 to examine temporal trends of PCB and OCP levels both on an individual and sum-(∑-)contaminant basis. We also determined levels and temporal trends of emerging polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), polybrominated biphenyls (PBBs) and other current-use brominated flame retardants. Over the 17-year period, ∑ DDT (and p,p′-DDE, p,p′-DDD, p,p′-DDT) decreased (−8.4%/year); α-hexachlorocyclohexane (α-HCH) decreased (−11%/year); β-HCH increased (+ 8.3%/year); and ∑ PCB and ∑ chlordane (CHL), both contaminants at highest concentrations in all years (> 1 ppm), showed no distinct trends even when compared to previous data for this subpopulation dating back to 1968. Some of the less persistent PCB congeners decreased significantly (−1.6%/year to −6.3%/year), whereas CB153 levels tended to increase (+ 3.3%/year). Parent CHLs (c-nonachlor, t-nonachlor) declined, whereas non-monotonic trends were detected for metabolites (heptachlor epoxide, oxychlordane). ∑ chlorobenzene, octachlorostyrene, ∑ mirex, ∑ MeSO₂-PCB and dieldrin did not significantly change. Increasing ∑ PBDE levels (+ 13%/year) matched increases in the four consistently detected congeners, BDE47, BDE99, BDE100 and BDE153. Although no trend was observed, total-(α)-HBCD was only detected post-2000. Levels of the highest concentration brominated contaminant, BB153, showed no temporal change. As long-term ecosystem changes affecting contaminant levels may also affect contaminant patterns, we examined the influence of year (i.e., aging or “weathering” of the contaminant pattern), dietary tracers (carbon stable isotope ratios, fatty acid patterns) and biological (age/sex) group on congener/metabolite profiles. Patterns of PCBs, CHLs and PBDEs were correlated with dietary tracers and biological group, but only PCB and CHL patterns were correlated with year. DDT patterns were not associated with any explanatory variables, possibly related to local DDT sources. Contaminant pattern trends may be useful in distinguishing the possible role of ecological/diet changes on contaminant burdens from expected dynamics due to atmospheric sources and weathering.     

Organochlorine pesticide, polychlorinated biphenyl and heavy metal concentrations in wolves (Canis lupus L. 1758) from north-west Russia

The wolf Canis lupus is a major terrestrial predator in eastern Europe and, as a top carnivore, may be exposed to high concentrations of contaminants that are readily transferred through the food chain. Despite this, there are few published data on pollutant and pesticide levels in wolves. This study utilised tissues from animals legally killed by hunters for other reasons (animals were not killed for the purposes of this study) to carry out the only detailed investigation of contaminants in wolves in Europe and the first in animals from Eastern Europe. The livers of 58 wolves from the Tver and Smoliensk regions of northwest Russia (54°N 31°E to 57°N 35°E) were analysed for seven organochlorine pesticides, 24 PCB congeners, Aroclor 1254-matched summed PCBs (ΣPCBs), total mercury, cadmium and lead. Cadmium, most of the organochlorine pesticides and many PCB congeners were not detectable in any of the wolves. Hexachlorobenzene, alpha-HCH, pp′DDE, PCB congeners 118, 138, 149 and 156 and lead were detected in up to 6% of livers. Dieldrin, PCB congeners 153, 170 and 180, ΣPCBs and mercury were detected more frequently. Contaminant levels were generally low; maximum wet weight concentrations of any of the organochlorine pesticides, ΣPCBs and mercury were less than 0.1, 1 and 0.25 μg g⁻¹, respectively. PCB congeners 153, 170 and 180 accounted for 41% of the ΣPCBs. Dieldrin, ΣPCBs and mercury concentrations did not vary significantly between males and females nor between adult and juvenile (<12 months old) wolves apart from the ΣPCB concentration, which was on average five times higher in adults than juveniles. Liver residues were generally below the level normally associated with adverse effects except for lead levels which exceeded the critical 5 μg g⁻¹ dry wt. concentration in three of the 58 animals examined.     

DDT contamination from indoor residual spraying for malaria control

The insecticide DDT is still used in specific areas of South Africa for indoor residual spray (IRS) to control malaria vectors. Local residents could be exposed to residues of DDT through various pathways including indoor air, dust, soil, food and water. The aims of this study were to determine the levels of DDT contamination, as a result of IRS, in representative homesteads, and to evaluate the possible routes of human exposure. Two villages, exposed (DV) and reference (TV) were selected. Sampling was done two months after the IRS process was completed. Twelve homesteads were selected in DV and nine in TV. Human serum, indoor air, floor dust, outside soil, potable water, leafy vegetables, and chicken samples (muscle, fat and liver) were collected and analyzed for both the o,p′- and p,p′-isomers of DDT, DDD and DDE. DDT was detected in all the media analyzed indicating a combination of potential dietary and non-dietary pathways of uptake. DV had the most samples with detectable levels of DDT and its metabolites, and with the exception of chicken muscle samples, DV also had higher mean levels for all the components analyzed compared to TV. Seventy-nine percent of participants from DV had serum levels of DDT (mean ∑ DDT 7.3 µg g⁻¹ lipid). These residues constituted mainly of p,p′-DDD and p,p′-DDE. ∑ DDT levels were detected in all indoor air (mean ∑ DDT 3900.0 ng m^− 3) and floor dust (mean ∑ DDT 1200.0 µg m^− 2) samples. Levels were also detected in outside soil (mean ∑ DDT 25.0 µg kg^− 1) and potable water (mean ∑ DDT 2.0 µg L^− 1). Vegetable sample composition (mean ∑ DDT 43.0 µg kg^− 1) constituted mainly p,p′-DDT and p,p′-DDD. Chicken samples were highly contaminated with DDT (muscle mean ∑ DDT 700.0 µg kg^− 1, fat mean ∑ DDT 240,000.0 µg kg^− 1, liver mean ∑ DDT 1600.0 µg kg^− 1). The results of the current study raise concerns regarding the potential health effects in residents living in the immediate environment following DDT IRS.     

Characteritization of, and health risks from, polychlorinated dibenzo-p-dioxins/dibenzofurans from incense burned in a temple

Polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) may cause adverse health effects. However, PCDD/F emissions from burning incense in temples have rarely been addressed. This study investigates PCDD/F emissions from burning incense in a temple. The mean total PCDD/F concentrations were 72.4-82.2 pg Nm^− 3 at two indoor sites; their corresponding mean total PCDD/Fs I-TEQ concentrations (0.24-0.27 pg I-TEQ Nm^− 3) were ~ 11 times that at a background location. In air samples collected from burning incense, OCDFs accounted for approximately 90% of total PCDD/Fs at the two indoor sites and an outdoor site near the temple, while the major PCDD/Fs in incense ash were PCDDs. The total PCDD/F content and toxic equivalent value of incense ash were 617 pg g^− 1 and 1.55 pg I-TEQ g^− 1, respectively. At the three sites inside/outside the temple, the air and ash samples contained the same four primary PCDD/Fs-OCDD, 1,2,3,4,6,7,8-HpCDD, OCDF and 1,2,3,4,6,7,8-HpCDF. The Cl⁻ emission factor, which is related to the PCDD/F formation, from burning incense was 0.454 mg g^− 1. The resultant lifetime average daily dose and cancer risk for temple workers were 0.00964 pg I-TEQ day^− 1 kg^− 1 and 9.64 × 10^− 6, respectively, approximately 2 times that for residents near the temple (0.00489 pg I-TEQ day^− 1 kg^− 1 and 4.89 × 10^− 6, respectively). We suggest that the chlorine content in incense must be regulated, and the high risk of PCDD/F exposure from burning incense for temple workers and visitors should be of concern.     

Accumulation of polychlorinated biphenyls and brominated flame retardants in breast milk from women living in Vietnamese e-waste recycling sites

This study investigated the contamination status of PCBs, PBDEs and HBCDs in human and possible exposure pathways in three Vietnamese e-waste recycling sites: Trang Minh (suburb of Hai Phong city), Dong Mai and Bui Dau (Hung Yen province), and one reference site (capital city Hanoi) by analysing human breast milk samples and examining the relationships between contaminant levels and lifestyle factors. Levels of PBDEs, but not PCBs and HBCDs, were significantly higher in Trang Minh and Bui Dau than in the reference site. The recyclers from Bui Dau had the highest levels of PBDEs (20-250 ng g^− 1 lipid wt.), higher than in the reference group by two orders of magnitude and more abundant than PCBs (28-59 ng g^− 1 lipid wt.), and were also the only group with significant exposure to HBCDs (1.4-7.6 ng g^− 1 lipid wt.). A specific accumulation, unrelated to diet, of low-chlorinated PCBs and high-brominated PBDEs was observed in e-waste recyclers, suggesting extensive exposure to these compounds during e-waste recycling activities, possibly through inhalation and ingestion of dust. The estimated infant intake dose of PBDEs from breast milk of some mothers occupationally involved in e-waste recycling were close to or higher than the reference doses issued by the U.S. EPA.     

A comparison of PCB bioaccumulation factors between an arctic and a temperate marine food web

To test how environmental conditions in the Arctic and the resulting ecological adaptations affect accumulation of persistent organic pollutants (POPs) in the marine food web, bioaccumulation of four polychlorinated biphenyls (PCBs) in an arctic (Barents Sea 77 °N-82 °N) and a temperate marine (Baltic Sea 54 °N-62 °N) food web were compared. Three different trophic levels were studied (zooplankton, fish, and seal), representing the span from first-level consumer to top predator. Previously published high-quality data on PCB water concentrations in the two areas were used for calculation of bioaccumulation factors (BAF). BAF was calculated as the ratio of the PCB concentration in the organism ([PCB]_org; pg/kg lipid) to the dissolved water concentration (C_w; pg/L). The BAF_Arctic:BAF_Temperate ratios were above 1 for all four PCB congeners in zooplankton (6.4-13.8) and planktivorous fish (2.9-5.0)), whereas the ratios were below 1 in seal. The mean ratio between arctic and temperate BAFs for all trophic levels and congeners (BAF_Arcti:BAF_Temperate) was 4.8. When the data were corrected for the seawater temperature difference between the two ecosystems, the ratio was 2.0. We conclude that bioaccumulation differences caused by ecological or physiological adaptations of organisms between the two ecosystems were well within a water concentration variability of 50%. Further, our data support the hypothesis that lower seawater temperature lead to a thermodynamically favoured passive partitioning to organic matrices and thus elevated ambient BAFs in the Arctic compared to the Baltic Sea. This would imply that bioaccumulation in the Arctic may be described in the same way as bioaccumulation in temperate regions, e.g. by the use of mechanistic models parameterised for the Arctic.     

Ratio variation of congener profiles of PCDD/Fs and dioxin-like PCBs in human milk during lactation

This study investigates the compositional variations, changes in concentrations and contribution of particular congeners of PCDDs, PCDFs, non-ortho PCBs and mono-ortho PCBs in human milk from two mothers sampled during the 12-month lactation period. Total PCDD/F and dioxin-like PCB concentration in milk sampled from the primiparous mother on day 5 after delivery was 37 pg TEQ/g fat, and this value decreased significantly by 43% at 12 months. In milk sampled from the multiparous mother nursing her second child on day 5 after delivery was 12 pg TEQ/g fat, and this value decreased by 40% at 12 months. The decrease was statistically significant not for PCDD/Fs, but for dioxin-like PCBs. The ratio variance of the congener profiles of PCDD/Fs and dioxin-like PCBs in the milk remained similar during lactation. Moreover, the congener profiles of PCDD/Fs and dioxin-like PCBs in the milk showed similar percentages for both mothers independent of the lactation event and the number of previous births. The mean daily intake of dioxins by the infant nursed by the primiparous mother and the infant nursed by the multiparous mother up to six months of age was 140 and 46 pg TEQ/kg body weight, respectively. From seven to twelve months of age, the mean daily intake was 37 and 13 pg TEQ/kg body weight, respectively. Both values decreased by approximately 70%. The reasons why the mothers' body burden of dioxins decreased by breastfeeding and why the infants' daily intake of human milk per body weight decreased as the infant grows older consequently decreased were considered.     

Biomonitoring of Cd, Cr, Hg and Pb in the Baluarte River basin associated to a mining area (NW Mexico)

With the purpose of knowing seasonal variations of Cd, Cr, Hg and Pb in a river basin with past and present mining activities, elemental concentrations were measured in six fish species and four crustacean species in Baluarte River, from some of the mining sites to the mouth of the river in the Pacific Ocean between May 2005 and March 2006. In fish, highest levels of Cd (0.06 μg g^− 1 dry weight) and Cr (0.01 μg g^− 1) were detected during the dry season in Gobiesox fluviatilis and Agonostomus monticola, respectively; the highest levels of Hg (0.56 μg g^− 1) were detected during the dry season in Guavina guavina and Mugil curema. In relation to Pb, the highest level (1.65 μg g^− 1) was detected in A. monticola during the dry season. In crustaceans, highest levels of Cd (0.05 μg g^− 1) occurred in Macrobrachium occidentale during both seasons; highest concentration of Cr (0.09 μg g^− 1) was also detected in M. occidentale during the dry season. With respect to Hg, highest level (0.20 μg g^− 1) was detected during the rainy season in Macrobrachium americanum; for Pb, the highest concentration (2.4 μg g^− 1) corresponded to Macrobrachium digueti collected in the dry season. Considering average concentrations of trace metals in surficial sediments from all sites, Cd (p < 0.025), Cr (p < 0.10) and Hg (p < 0.15) were significantly higher during the rainy season. Biota sediment accumulation factors above unity were detected mostly in the case of Hg in fish during both seasons. On the basis of the metal levels in fish and crustacean and the provisional tolerable weekly intake of studied elements, people can eat up to 13.99, 0.79 and 2.34 kg of fish in relation to Cd, Hg and Pb, respectively; regarding crustaceans, maximum amounts were 11.33, 2.49 and 2.68 kg of prawns relative to levels of Cd, Hg and Pb, respectively.     

Levels of chlorinated pesticides and polychlorinated biphenyls in Norwegian breast milk (2002-2006), and factors that may predict the level of contamination

In the present study, polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in 423 breast milk samples from women living in Norway. Various predictors for the contaminant levels were also investigated. The samples were collected in six counties, representing South, Central and North Norway in 2002-2006. Initial results showed significantly lower levels of OCPs in breast milk from ethnic Norwegians (N = 377) compared to ethnic non-Norwegians (N = 46). Median concentrations (range) of PCBs, p,p′-DDE, HCB, β-HCH and oxychlordane in breast milk of the Norwegian women, all parities included, were 103 (34-450), 41 (5.4-492), 11 (3.6-24), 4.7 (0.9-37) and 2.8 (0.5-16) ng/g lipid weight, respectively. Results indicated that sum of 18 PCBs, p,p′-DDE and β-HCH are good predictors for monitoring of PCB, DDT and HCH levels in Norwegian breast milk. Multivariable linear regression analyses showed that age was strongly associated with increasing OC levels (P < 0.001), whereas parity was associated with decreasing OC levels (P < 0.001). Smoking was associated with higher levels of PCBs, p,p′-DDE and β-HCH. The models explained from 17 to 35% of the variance. Median levels of OCs in the present Norwegian primparaes seemed to be 29-62% lower than corresponding results found in a Norwegian study from 2000-2002.     

Persistent organic pollutants in fish tissue in the mid-continental great rivers of the United States

Great rivers of the central United States (Upper Mississippi, Missouri, and Ohio rivers) are valuable economic and cultural resources, yet until recently their ecological condition has not been well quantified. In 2004-2005, as part of the Environmental Monitoring and Assessment Program for Great River Ecosystems (EMAP-GRE), we measured legacy organochlorines (OCs) (pesticides and polychlorinated biphenyls, PCBs) and emerging compounds (polybrominated diphenyl ethers, PBDEs) in whole fish to estimate human and wildlife exposure risks from fish consumption. PCBs, PBDEs, chlordane, dieldrin and dichlorodiphenyltrichloroethane (DDT) were detected in most samples across all rivers, and hexachlorobenzene was detected in most Ohio River samples. Concentrations were highest in the Ohio River, followed by the Mississippi and Missouri Rivers, respectively. Dieldrin and PCBs posed the greatest risk to humans. Their concentrations exceeded human screening values for cancer risk in 27-54% and 16-98% of river km, respectively. Chlordane exceeded wildlife risk values for kingfisher in 11-96% of river km. PBDE concentrations were highest in large fish in the Missouri and Ohio Rivers (mean > 1000 ng g^− 1 lipid), with congener 47 most prevalent. OC and PBDE concentrations were positively related to fish size, lipid content, trophic guild, and proximity to urban areas. Contamination of fishes by OCs is widespread among great rivers, although exposure risks appear to be more localized and limited in scope. As an indicator of ecological condition, fish tissue contamination contributes to the overall assessment of great river ecosystems in the U.S.     

Biostrome communities and mercury and selenium bioaccumulation in the Great Salt Lake (Utah, USA)

The Great Salt Lake has a salinity near 150 g/L and is habitat for over 200 species of migratory birds. The diet of many of these birds is dependent on the food web of carbonaceous biostromes (stromatolites) that cover 260 km² of the lake's littoral zone. We investigated the biostrome community to understand their production processes and to assess whether they are a potential vector for bioconcentration of high mercury and selenium levels in the lake. The periphyton community of the biostromes was > 99% colonial cyanobacteria. Periphyton chlorophyll levels averaged 900 mg m⁻² or nine times that of the lake's phytoplankton. Lake-wide estimates of chlorophyll suggest that their production is about 30% of that of the phytoplankton. Brine fly (Ephydra gracilis) larval densities on the biostromes increased from 7000 m⁻² in June to 20000 m⁻² in December. Pupation and adult emergence halted in October and larvae of various instars overwintered at temperatures < 5 °C. Mean total dissolved and dissolved methyl mercury concentrations in water were 5.0 and 1.2 ηg L⁻¹. Total mercury concentrations in the periphyton, fly larvae, pupae, and adults were, respectively, 152, 189, 379 and 659 ηg g⁻¹ dry weight, suggesting that bioconcentration is only moderate in the short food web and through fly developmental stages. However, common goldeneye ducks (Bucephala clangula) that feed primarily on brine fly larvae at the Great Salt Lake had concentrations near 8000 ηg Hg g⁻¹ dry weight in muscle tissue. Data from a previous study indicated that selenium concentrations in periphyton, brine fly larvae and goldeneye liver tissue were high (1700, 1200 and 24,000 ηg g⁻¹, respectively) and Hg:Se molar ratios were < 1.0 in all tissues, suggesting that the high mercury concentration in the ducks may be partially detoxified by combining with selenium. The study demonstrated that the high mercury levels in the Great Salt Lake are routed through the biostrome community resulting in invertebrate prey that may provide health risks for birds and humans that consume them.     

Geography and stage of development affect persistent organic pollutants in stranded and wild-caught harbor seal pups from central California

Persistent organic pollutants have been associated with disease susceptibility and decreased immunity in marine mammals. Concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), polybrominated diphenyl ethers (PBDEs), chlordanes (CHLDs), and hexachlorocyclohexane isomers (HCHs) were evaluated in terms of stage of development and likely exposure routes (in utero, suckling, fasting) in the blubber of 202 stranded and wild-caught, primarily young of the year (n = 177), harbor seals (Phoca vitulina) in the central California coast. This is the first report of HCH concentrations in the blubber of California seals. Lipid normalized concentrations ranged from 200 to 330,000 ng/g for sum PCBs, 320-1,500,000 ng/g for sum DDTs, 23-63,000 ng/g for sum PBDEs, 29-29,000 ng/g for sum CHLDs, and 2-780 ng/g for sum HCHs. The highest concentrations were observed in harbor seal pups that suckled in the wild and then lost mass during the post-weaning fast. Among the pups sampled in the wild and those released from rehabilitation, there were no differences in mass, blubber depth, or percent lipid although contaminant concentrations were significantly higher in the pups which nursed in the wild. When geographic differences were evaluated in a subset of newborn animals collected near their birth locations, the ratio of sum DDTs to sum PCBs was significantly greater in samples from an area with agricultural inputs (Monterey), than one with industrial inputs (San Francisco Bay). A principal components analysis distinguished between seals from San Francisco Bay and Monterey Bay based on specific PCB and PBDE congeners and DDT metabolites. These data illustrate the important influence of life stage, nutritional status, and location on blubber contaminant levels, and thus the need to consider these factors when interpreting single sample measurements in marine mammals.     

Concentration of selected persistent organic pollutants in blood from delivering women in South Africa

Environmental exposure to persistent organic pollutants (POPs) may cause detrimental health effects in the population with the developing foetus and infants being at highest risk. This paper reports on the findings of the pilot study that took place in seven geographical regions of South Africa, 96 pregnant women admitted for delivery participated in the study. The following selected POPs were analysed in maternal plasma: 15 polychlorinated biphenyls (PCBs) congeners (IUPAC No. 28, 52, 99, 101, 105, 118, 138, 149, 153, 156, 170, 180, 183, 187, 194); six DDT metabolites (dichlordiphenyltrichloroethane p,p'-DDT and o,p'-DDT; diphenyldichloroethylene p,p'-DDE and o,p'-DDE, dichlorophenylethane p,p'-DDD o,p'-DDD) and other pesticides such as hexachlorocyclohexanes (α-HCH, β-HCH, γ-HCH), hexachlorobenzene (HCB), heptachlor, chlordanes (t-CD and c-CD), nanochlors (t-NC and c-NC) and mirex.The overall results showed large regional differences with the rural site having the lowest levels for all measured contaminants. The levels of PCB congeners were found to be low in all samples and across all sites. DDT metabolites were detected in most participants of this study and large regional differences were evident. Two malaria endemic sites, where indoor residual spraying (IRS) with DDT takes place to control malaria vector, were included in the study. The highest levels of DDTs were measured in the coastal malaria site (Indian Ocean) with geometric means of 5177 ng/g lipid and 1797 ng/g lipid for p,p'-DDE and p,p'-DDT, and 1966 ng/g lipid and 726 ng/g lipid for p,p'-DDE and p,p'-DDT in inland malaria site. γ-HCH was found to be elevated overall, except for the urban community; the highest levels were measured in the inland and coastal malaria sites. p,p'-DDT and γ-HCH were however not correlated, indicating different sources. The high DDT levels in the malaria spraying regions as well as the elevated γ-HCH levels are of concern and call for extended monitoring of women and children in selected regions.