Lead concentrations in blood from incubating common eiders (Somateria mollissima) in the Baltic Sea.

Here we investigate if lead may be a contributing factor to the observed population decline in a Baltic colony of incubating eiders (Somateria mollissima). Body mass and blood samples were obtained from 50 incubating female eiders at the Baltic breeding colony on Christiansø during spring 2017 (n = 27) and 2018 (n = 23). All the females were sampled twice during early (day 4) and late (day 24) incubation. The full blood was analysed for lead to investigate if the concentrations exceeded toxic thresholds or changed over the incubation period due to remobilisation from bones and liver tissue. Body mass, hatch date and number of chicks were also analysed with respect to lead concentrations. The body mass (mean ± SD g) increased significantly in the order: day 24 in 2018 (1561 ± 154 g) < day 24 in 2017 (1618 ± 156 g) < day 4 in 2018 (2183 ± 140 g) < day 4 in 2017 (2359 ± 167 g) (all p < 0.001). The lead concentrations increased significantly in the opposite order i.e. day 4 in 2017 (41.7 ± 67.1 µg/L) < day 24 in 2017 (55.4 ± 66.8 µg/L) < day 4 in 2018 (177 ± 196 µg/L) < day 24 in 2018 (258 ± 243) (all p < 0.001). From day 4 to 24, the eider females had a 1.33-fold increase in blood lead concentrations in 2017 and a 1.46-fold increase in 2018. Three of the birds (13%) sampled in 2018 had lead concentrations that exceeded concentrations of clinical poisoning (500 µg/L) and eleven (48%) had concentrations that exceeded the threshold for subclinical poisoning (200 µg/L). In 2017, none of the birds exceeded the high toxic threshold of clinical poisoning while only one (4%) exceeded the lower threshold for subclinical poisoning. Three of the birds (6%) sampled in 2018 had lead concentrations that exceeded those of clinical poisoning while 12 birds (24%) resampled in both years exceeded the threshold for subclinical poisoning. In addition, lead concentrations and body mass on day 4 affected hatch date positively in 2018 (both p < 0.03) but not in 2017. These results show that bioavailable lead in bone and liver tissue pose a threat to the health of about 25% of the incubating eiders sampled. This is particularly critical because eiders are largely capital breeding which means that incubating eiders are in an energetically stressed state. The origin of lead in incubating eiders in the Christiansø colony is unknown and it remains an urgent priority to establish the source, prevalence and mechanism for uptake. The increase in lead from day 4 to day 24 is due to bone and liver remobilization; however, the additional lead source(s) on the breeding grounds needs to be identified. Continued investigations should determine the origin, uptake mechanisms and degree of exposure to lead for individual birds. Such research should include necropsies, x-ray, lead isotope and stable C and N isotope analyses to find the lead sources(s) in the course of the annual cycle and how it may affect the population dynamics of the Christiansø colony which reflects the ecology of the Baltic eiders being suitable for biomonitoring the overall flyway.

Determinants of serum concentrations of perfluoroalkyl acids (PFAAs) in school children and the contribution of low-level PFAA-contaminated drinking water.

Little is known about the demographic/life-style/physiological determinants explaining the variation of serum perfluoroalkyl acid (PFAA) concentrations in children. We identified significant determinants in children and investigated the influence of low-level PFAA-contaminated drinking water (DW) (<10 ng L-1 of single PFAAs) on serum concentrations. Four perfluorosulfonic acids (PFSAs) and 11 perfluorocarboxylic acids (PFCAs) were analyzed in serum from 5th grade children from 11 Swedish schools (N = 200; average age: 12 years) using liquid chromatography-tandem-mass-spectrometry. Data on demography and life-style/physiological factors were obtained by questionnaires. PFAA concentrations in raw and drinking water (DW) were obtained from the water works supplying DW to the schools. In multiple regression analyses school was the determinant contributing most to the variation in PFAA concentrations, with the lowest contribution for PFHpA (10%) and the highest for PFHxS (81%). Girls had lower adjusted mean concentrations of PFHxS, PFOS, PFNA and PFDA than boys, but a higher concentration of PFHxA. Girls reporting onset of menstruation had lower PFHxS and PFOA concentrations than other girls, suggesting menstrual bleeding elimination. Children born by mothers from less industrialized countries had lower mean concentrations of both PFSAs and PFCAs than children with mothers from highly industrialized countries, suggesting differences in early-life exposure. Life-style factors associated with paternal education levels appeared to influence PFAA concentrations differently than maternal education level. Already at an average DW PFHxS concentration of 2 ng L-1, children had a significantly higher adjusted mean serum PFHxS concentration than at an average DW concentration of <1.6 ng PFHxS L-1. Similar results were observed for PFOS and PFOA. The DW variable explained 16% (PFOA) to 78% (PFHxS) of the variation in serum PFAA concentrations, suggesting that low-level-contaminated DW is a significant source of exposure for children in Sweden. Although some of the associations, especially those with menstruation and maternal birth country, should be interpreted with extra caution due to the small size of the study, the results contribute to future work on identifying populations of children at risk of elevated PFAA exposures.

Possible maternal offloading of metals in the plasma, uterine and capsule fluid of pregnant ragged-tooth sharks (Carcharias taurus) on the east coast of South Africa.

We studied the possible metal offloading onto the progeny of three pregnant female ragged-tooth sharks (Carcharias taurus) (C. taurus). The presences of five metals, i.e. aluminium (Al), arsenic (As), cadmium (Cd), lead (Pb) and selenium (Se) were validated by mass spectrometry in the maternal plasma as well as the intracapsular and uterine fluids (UF) in which embryos develop. Metals were ranked in a decreasing concentration as follows: Plasma: As > Al > Se > Pb > Cd; ICF: As > Se > Al > Cd > Pb and UF: As > Se > Al > Cd > Pb. As was present in the highest concentration in all three sharks. Al, Pb and Cd were found to be the highest within the plasma, while concentrations of Se were similar in all three fluids. These results indicate that C. taurus embryos are exposed to metals during early development, but the impact of this exposure remains unknown. To the best of our knowledge, this is the first investigation to confirm the presence of metals in the fluids that surround the developing C. taurus embryos, a species that is already listed as vulnerable.

Geographic and temporal patterns of variation in total mercury concentrations in blood of harlequin ducks and blue mussels from Alaska.

We compared total mercury (Hg) concentrations in whole blood of harlequin ducks (Histrionicus histrionicus) sampled within and among two geographically distinct locations and across three years in southwest Alaska. Blue mussels were collected to assess correlation between Hg concentrations in locally available forage and birds. Mercury concentrations in harlequin duck blood were significantly higher at Unalaska Island (0.31±0.19 mean±SD, µg/g blood) than Kodiak Island (0.04±0.02 mean±SD, µg/g blood). We found no evidence for annual variation in blood Hg concentration between years at Unalaska Island. However, blood Hg concentration did vary among specific sampling locations (i.e., bays) at Unalaska Island. Findings from this study demonstrate harlequin ducks are exposed to environmental sources of Hg, and whole blood Hg concentrations are associated with their local food source.

A competitive immunoassay for ultrasensitive detection of Hg(2+) in water, human serum and urine samples using immunochromatographic test based on surface-enhanced Raman scattering.

An immunochromatographic test (ICT) strip was developed for ultrasensitive competitive immunoassay of Hg(2+). This strategy was achieved by combining the easy-operation and rapidity of ICT with the high sensitivity of surface-enhanced Raman scattering (SERS). Monoclonal antibody (mAb) against Hg(2+) and Raman active substance 4-mercaptobenzoic acid (MBA) dual labelled gold nanoparticles (GNPs) were prepared as an immunoprobe. The Raman scattering intensity of MBA on the test line of the ICT strip was measured for quantitative determination of Hg(2+). The ICT was able to directly detect Hg(2+) without complexing due to the specific recognition of the mAb with Hg(2+). The IC50 and limit of detection (LOD) of the assay for Hg(2+) detection were 0.12 ng mL(-1) and 0.45 pg mL(-1), respectively. There was no cross-reactivity (CR) of the assay with other nineteen ions and the ICT strips could be kept for 5 weeks without loss of activity. The recoveries of the assay for water, human serum and urine samples spiked with Hg(2+) were in range of 88.3-107.3% with the relative standard deviations (RSD) of 1.5-9.5% (n = 3). The proposed ICT was used for the detection of Hg(2+) in urine samples collected from Occupational Disease Hospital and the results were confirmed by cold-vapor atomic fluorescence spectroscopy (CV-AFS). The assay exhibited high sensitivity, selectivity, stability, precision and accuracy, demonstrating a promising method for the detection of trace amount of Hg(2+) in environmental water samples and biological serum and urine samples.

Blood cadmium concentration of residents living near abandoned metal mines in Korea.

The purpose of this study was to investigate demographic and lifestyle variables and blood cadmium concentrations in residents living near abandoned metal mines in Korea. Blood cadmium concentrations were measured in 15,161 subjects living around abandoned metal mines (exposed group, n = 14,464) and compared with those living in designated control areas (control group, n = 697). A questionnaire was provided to all subjects to determine age, gender, mine working history, times of residence, smoking habits and dietary water type. The geometric mean (95% confidence intervals) of blood cadmium concentration (1.25 [1.24-1.27] µg/L) in the exposed group was significantly higher than in the control group (1.17 [1.13-1.22] µg/L). Mean residence time and mine working history in the exposed group were significantly higher than in the control group. Blood cadmium concentrations increased with increasing age, and residence time in both groups, and blood cadmium concentrations were higher in current-smokers than in non-smokers in both groups. This study shows the geometric mean of blood cadmium concentration in abandoned mining areas are higher than in non-mining areas in the general adult Korean population.

Blood Cadmium Concentration of Residents Living near Abandoned Metal Mines in Korea

The purpose of this study was to investigate demographic and lifestyle variables and blood cadmium concentrations in residents living near abandoned metal mines in Korea. Blood cadmium concentrations were measured in 15,161 subjects living around abandoned metal mines (exposed group, n = 14,464) and compared with those living in designated control areas (control group, n = 697). A questionnaire was provided to all subjects to determine age, gender, mine working history, times of residence, smoking habits and dietary water type. The geometric mean (95% confidence intervals) of blood cadmium concentration (1.25 [1.24-1.27] microg/L) in the exposed group was significantly higher than in the control group (1.17 [1.13-1.22] microg/L). Mean residence time and mine working history in the exposed group were significantly higher than in the control group. Blood cadmium concentrations increased with increasing age, and residence time in both groups, and blood cadmium concentrations were higher in current-smokers than in non-smokers in both groups. This study shows the geometric mean of blood cadmium concentration in abandoned mining areas are higher than in non-mining areas in the general adult Korean population.

Association of osteoarthritis with serum levels of the environmental contaminants perfluorooctanoate and perfluorooctane sulfonate in a large Appalachian population.

Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) are persistent environmental contaminants that affect metabolic regulation, inflammation, and other factors implicated in the pathogenesis of osteoarthritis (OA). However, the link between these compounds and OA remains unknown. In this study, the authors investigated the association of OA with PFOA and PFOS in a population of 49,432 adults from 6 PFOA-contaminated water districts in the mid-Ohio Valley (2005-2006). Participants completed a comprehensive health survey; serum levels of PFOA, PFOS, and a range of other blood markers were also measured. Medical history, including physician diagnosis of osteoarthritis, was assessed via self-report. Analyses included adjustment for demographic and lifestyle characteristics, body mass index, and other potential confounders. Reported OA showed a significant positive association with PFOA serum levels (for highest quartile of PFOA vs. lowest, adjusted odds ratio = 1.3, 95% confidence interval: 1.2, 1.5; P-trend = 0.00001) and a significant inverse association with PFOS (for highest quartile vs. lowest, adjusted odds ratio = 0.8, 95% confidence interval: 0.7, 0.9; P-trend = 0.00005). The relation between PFOA and OA was significantly stronger in younger and nonobese adults. Although the cross-sectional nature of this large, population-based study limits causal inference, the observed strong, divergent associations of reported OA with PFOA and PFOS may have important public health and etiologic implications and warrant further investigation.

PCB and PBDE levels in wild common carp (Cyprinus carpio) from eastern Lake Erie.

Male common carp (Cyprinus carpio) from eastern Lake Erie, which is greatly effected by urbanization, agriculture, and industry, were analyzed for PCB and PBDE concentrations in plasma, muscle, and liver to evaluate exposure to these chemicals through habitat interactions. Additional male carp from two nearby relatively clean lakes (Bear Lake and Hemlock Lake, NY) were also sampled as controls. While PCBs were detected in muscle, liver, and plasma of Lake Erie carp, the largest concentrations were found in muscle, which also had the most number of congeners. The dominant congeners were PCB 138 and PCB 153. Concentrations of PCB 153 in the muscle were correlated with fish length, total weight, and age. Therefore, larger (and generally older) carp had the highest concentrations of PCB 153. In contrast, PBDEs were found only in muscle with the predominant congener being PBDE 47. The total PCB concentrations in muscle of male carp from eastern Lake Erie (ranging from nd to 15,000 ng g(-1) lipid) were 100-fold higher than the total PBDE observed (1.5-100 ng g(-1) lipid), indicating a higher level of contamination of PCBs in Lake Erie. The high PCB levels in carp points to PCB resistance to metabolic degradation.

Cytochrome P4501A1 expression, polychlorinated biphenyls and hydroxylated metabolites, and adipocyte size of bottlenose dolphins from the Southeast United States.

Persistent organic pollutants (POPs) bioaccumulate in blubber of marine mammals. Therefore, it is important to understand the structure and dynamics of blubber layers and how they affect the accumulation of POPs and subsequent biochemical responses. We used established histological and immunohistochemical methods to document the structure of bottlenose dolphin (Tursiops truncatus) blubber and to assess the expression of cytochrome P4501A1 (CYP1A1) in skin-blubber biopsies of dolphins sampled in the waters off Charleston, SC (CHS) (N=38), and Indian River Lagoon, FL (IRL) (N=36). CYP1A1 expression was strongest and most frequent in capillary endothelial cells and was stratified in blubber; the greatest CYP1A1 staining was in the deepest layer. CYP1A1 expression in deep blubber and 2,3,7,8-TCDD Toxic Equivalents measured in the entire blubber were significantly higher in dolphins from CHS as compared to those from IRL. Adipocyte size was associated with the extent of CYP1A1 expression. Male dolphins with smaller adipocytes from CHS and IRL had higher levels of CYP1A1 expression in deep blubber. In CHS females, CYP1A1 expression in vascular endothelial cells varied with reproductive status. CYP1A1 expression in the deep layer was highest in simultaneously pregnant-lactating dolphins, and these dolphins had the smallest adipocytes in deep blubber. In all dolphins, CYP1A1 expression in the deep blubber layer was positively related to concentrations of hydroxylated PCBs (OH-PCBs) in plasma. In summary, redistribution of AHR agonists from blubber into the circulatory system may enhance PCB metabolism and production of OH-PCBs by induction of CYP1A1 in hepatocytes and, possibly, by induction of CYP1A1 in endothelial cells of the deep blubber. The OH-PCBs thus formed have the potential to interfere with thyroid hormone homeostasis.

Cadmium dietary intake and biomarker data in French high seafood consumers.

Seafood and especially mollusks are known to be a rich source of cadmium (Cd), but little data are available concerning French seafood contamination and Cd exposure of French populations. The objective was then to assess food intake and biological level of Cd in high consumers of seafood, and to determine the impact of the consumption of self-fished mollusks on urinary Cd. Seafood consumption levels of 80 products were assessed for 1011 high consumers aged 18 and over in four French coastal areas, thanks to a validated food frequency questionnaire (FFQ). According to a total diet study approach, seafood samples were collected taking into account preservation methods and supply habits. Food samples were analyzed for Cd. Exposure was assessed by crossing consumption data with contamination data. Total blood and urine samples were collected from 380 subjects of the cohort and analyzed for Cd. The impact of the self-collected mollusks consumption on the Cd biological level adjusted for creatinine was assessed by a multivariate linear regression model. The mean dietary intake of Cd is 2.44+/-3.34 microg/kg bw/wk and the mean urinary Cd (U-Cd) level is 0.65+/-0.45 microg/g creatinine, and is significantly higher in women than in men (P<0.05). The consumption of self-fished mollusks is significantly negatively associated with U-Cd (r=-0.11 [-0.185, -0.009], P=0.03). The results of this study indicate that the biological Cd levels remain below the standards, and also suggest a protective effect of self-fishing, which inspires confidence about the high consumer health safety in terms of Cd exposure.

Changes in blood lead levels associated with use of chloramines in water treatment systems.

BACKGROUND: More municipal water treatment plants are using chloramines as a disinfectant in order to reduce carcinogenic by-products. In some instances, this has coincided with an increase in lead levels in drinking water in those systems. Lead in drinking water can be a significant health risk. OBJECTIVES: We sought to test the potential effect of switching to chloramines for disinfection in water treatment systems on childhood blood lead levels using data from Wayne County, located in the central Coastal Plain of North Carolina. METHODS: We constructed a unified geographic information system (GIS) that links blood lead screening data with age of housing, drinking water source, and census data for 7,270 records. The data were analyzed using both exploratory methods and more formal multivariate techniques. RESULTS: The analysis indicates that the change to chloramine disinfection may lead to an increase in blood lead levels, the impact of which is progressively mitigated in newer housing. CONCLUSIONS: Introducing chloramines to reduce carcinogenic by-products may increase exposure to lead in drinking water. Our research provides guidance on adjustments in the local childhood lead poisoning prevention program that should accompany changes in water treatment. As similar research is conducted in other areas, and the underlying environmental chemistry is clarified, water treatment strategies can be optimized across the multiple objectives that municipalities face in providing high quality drinking water to local residents.

Mercury and other contaminants in common loons breeding in Atlantic Canada.

Common loons (Gavia immer) were studied to assess the biomagnification of persistent contaminants in lake ecosystems in Atlantic Canada. Forty-two breeding adults and 20 juvenile loons were captured in August, 1995-1997 on lakes in four areas of southern New Brunswick (Lepreau and Fundy National Park) and Nova Scotia (Halifax and Kejimkujik National Park). Blood samples were collected for analysis of mercury, methylmercury, lead, and selenium. Plasma samples from adult loons were analyzed for PCB congeners and organochlorine pesticides. Secondary flight feathers were collected from adult loons for mercury analysis. Kejimkujik loons had significantly higher geometric mean concentrations of mercury in blood (adults: 5.5 microg/g, wet wt) and feathers (adults: 15 microg/g, fresh wt), and higher levels of PCBs, DDE, oxychlordane, trans-nonachlor, mirex and hexachlorobenzene than loons at Halifax or Lepreau. Blood selenium levels were lowest in Kejimkujik loons. Selenium and mercury concentrations were negatively related in blood of adults across all sites. Adult males had higher concentrations of mercury in blood and feathers and PCBs, DDE, and oxychlordane in plasma, and lower levels of selenium in blood, than adult females. Juvenile loons had lower blood mercury and selenium concentrations than adults. Several contaminants showed significant inter-lake variation within the study sites. Mean blood mercury concentrations in Kejimkujik loons are the highest found in breeding common loons across North America. Of adult loons at Kejimkujik, 92% had blood mercury levels > 4 microg/g (wet wt), which have been associated with impaired reproduction, elevated corticosterone levels, asymmetry in plumage development, and altered breeding behavior in loons there and elsewhere.

Monitoring mercury in the loggerhead sea turtle, Caretta caretta.

The validity of using blood samples and keratinized scutes for nonlethal routine monitoring of mercury (Hg) in loggerhead sea turtles, Caretta caretta, is evaluated in the context of how effectively these matrixes predict internal tissue Hg burdens and the different temporal scales of exposure they represent. Total Hg (THg) was measured in blood and scutes collected from live captures (n = 34) and liver, kidney, muscle, spinal cord, blood, and scutes collected from freshly stranded loggerhead turtles (n = 6) along the coast of the southeastern United States. Linear regressions between monitoring compartments and internal tissues from stranded animals were all statistically significant (r2 > 0.805, p < 0.015) but varied in their utility as a predictive tool depending on which tissues were paired. Blood was an effective predictor of THg in muscle (r2 = 0.988, p < 0.0001) and spinal cord (r2 = 0.988, p < 0.0001), while scute was the most accurate predictor of THg in liver (r2 = 0.948, p = 0.0010). The strength of the relationship between tissues types is believed to reflect the similarity in the temporal scales they represent and the variability in the fraction of methylmercury present. The stability of Hg in the scute matrix makes this tissue preferable for approximating long-term exposure, while blood Hg levels can be affected by recent changes in Hg intake. THg levels in blood and scutes from live captures were highly correlated (linear regression r2 = 0.926, p < 0.0001) and increased significantly with body mass (r2 = 0.173, p = 0.016 and r2 = 0.187, p = 0.012 respectively), further supporting thatthere is a component reflecting long-term accumulation of Hg in these matrixes. We also present a novel technique using the residuals from the blood-scute regression as an index of recent exposure (IRE). The interpretation of this value is derived from the comparison between the most recent Hg intake (which contributes to the Hg measured in the blood) relative to the average past intake (which is recorded in the scute). A stepwise multiple regression revealed a significant positive relationship between the IRE and the proximity of the capture site to the nearest major industrial river mouth (p = 0.0102). This suggests that there is an elevation of bioavailable Hg in nearshore habitats where terrestrial influences and anthropogenic impacts are high. Seasonal foraging site fidelity and the variability in environmental Hg may explain the high intraspecific variability and occasional highly contaminated turtle seen in this and previous studies.

Contaminants in molting long-tailed ducks and nesting common eiders in the Beaufort Sea.

In 2000, we collected blood from long-tailed ducks (Clangula hyemalis) and blood and eggs from common eiders (Somateria mollissima) at near-shore islands in the vicinity of Prudhoe Bay, Alaska, and at a reference area east of Prudhoe Bay. Blood was analyzed for trace elements and egg contents were analyzed for trace elements, organochlorine pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons. Except for Se (mean=36.1 microg/g dry weight (dw) in common eiders and 48.8 microg/g dw in long-tailed ducks), concentrations of trace elements in blood were low and, although several trace elements differed between areas, they were not consistently higher at one location. In long-tailed ducks, Se in blood was positively correlated with activities of two serum enzymes, suggestive of an adverse effect of increasing Se levels on the liver. Although common eiders had high Se concentrations in their blood, Se residues in eggs were low (mean=2.28 microg/g dw). Strontium and Ni were higher in eggs near Prudhoe Bay than at the reference area, but none of the other trace elements or organic contaminants in eggs differed between locations. Concentrations of Ca, Sr, Mg, and Ni differed among eggs having no visible development, early-stage embryos, or late-stage embryos. Residues of 4,4'-DDE, cis-nonachlor, dieldrin, hexachlorobenzene, oxychlordane, and trans-nonachlor were found in 100% of the common eider eggs, but at low concentrations (means of 2.35-7.45 microg/kg wet weight (ww)). The mean total PCB concentration in eggs was 15.12 microg/kg ww. Of PAHs tested for, residues of 1- and 2-methylnaphthalene and naphthalene were found in 100% of the eggs, at mean concentrations of 0.36-0.89 microg/kg ww.

Concentrations of cadmium, mercury and selenium in blood, liver and kidney of common eider ducks from the Canadian arctic.

We determined concentrations of selected trace elements in livers, kidneys and blood samples from common eiders (Somateria mollissima borealis) from the eastern Canadian arctic during 1997 and 1998. Concentrations of total mercury and organic mercury were generally low in the livers of these birds (less than 6 and 4 microg g(-1) dry wt, respectively). Selenium ranged between 11-47 microg g(-1) in livers. Renal cadmium concentrations were among the highest ever published for this species (range: 47-281 microg g(-1)). The regressions of log-transformed concentrations of these trace elements in blood samples on those in liver or kidney were significant (all P-values < 0.05) and positive. However, except for organic mercury (R2 = 0.83), the co-efficients of determination were low to moderate (range of R2: 0.26-0.52), suggesting poor to moderate predictive capability. Furthermore, the relationships between total mercury in blood and liver changed between 1997 and 1998, suggesting that it would not be possible to predict consistently, concentrations of mercury in blood from those in liver based on samples taken in one year. Blood samples can be used to determine concentrations of these trace elements in common eiders (and probably other sea duck species as well). The use of blood samples is especially warranted when it is undesirable to kill the animal such as when working with rare or endangered sea duck species or when the objective is to relate trace element exposure to annual survival rates. However, the predictive equations developed here should not be used to predict expected concentrations in one type of tissue from those in the other.

Modulation of human polymorphonuclear leukocyte adherence by cyanopeptide toxins.

The oligopeptides microcystins and nodularins are the most common and abundant cyanotoxins present in diverse water systems. They cause different illnesses in animal and humans, sometimes leading to death, and are responsible for severe environmental problems. Here we demonstrate that both microcystin-LR and N. spumigena nodularin (Nod) significantly enhance the early spontaneous adherence of peripheral polymorphonuclear leukocytes (PMNs) over the concentration range 10(-11)-10(-9) M. However, neither of them affect significantly the late spontaneous adherence or the early or late PMN-stimulated adherence (when cells are treated with formyl-methionyl-leucyl-phenylalanine). Since PMN adherence is a key step in the immune response, our data clearly indicate for the first time the immunomodulatory capacity of cyanopeptide toxins. The low concentrations at which the adherence modulation occurs are similar to the physiological concentrations for natural mammalian peptide hormones. Such concentrations are well below those recommended by other authors and World Health Organization in terms of risk assessment as safe for drinking water (8x10(-10) to 10(-9) M).

Developmental toxicity of lead-contaminated sediment in Canada geese (Branta canadensis).

Sediment ingestion has recently been identified as an important exposure route for toxicants in waterfowl. The effects of lead-contaminated sediment from the Coeur d'Alene River Basin (CDARB) in Idaho on posthatching development of Canada geese (Branta canadensis) were examined for 6 wk. Day-old goslings received either untreated control diet, clean sediment (48%) supplemented control diet, or CDARB sediment (3449 microg/g lead) supplemented diets at 12%, 24%, or 48%. The 12% CDARB diet resulted in a geometric mean blood lead concentration of 0.68 ppm (ww), with over 90% depression of red blood cell ALAD activity and over fourfold elevation of free erythrocyte protoporphyrin concentration. The 24% CDARB diet resulted in blood lead of 1.61 ppm with decreased hematocrit, hemoglobin, and plasma protein in addition to the effects just described. The 48% CDARB diet resulted in blood lead of 2.52 ppm with 22% mortality, decreased growth, and elevated plasma lactate dehydrogenase-L (LDH-L) activity. In this group the liver lead concentration was 6.57 ppm (ww), with twofold increases in hepatic lipid peroxidation (thiobarbituric acid-reactive substances, TBARS) and in reduced glutathione concentration; associated effects included elevated glutathione reductase activity but lower protein-bound thiols concentration and glucose-6-phosphate dehydrogenase (G-6-PDH) activity. The kidney lead concentration in this group was 14.93 ppm with subacute renal tubular nephrosis in one of the surviving goslings. Three other geese in this treatment group exhibited calcified areas of marrow, and one of these displayed severe chronic fibrosing pancreatitis. Lead from CDARB sediment accumulated less readily in gosling blood and tissues than reported in ducklings but at given concentrations was generally more toxic to goslings. Many of these effects were similar to those reported in wild geese and mallards within the Coeur d'Alene River Basin.