细化搜索
结果 1-10 的 32
Air pollution effects on fetal and child development: A cohort comparison in China
2014
Tang, Deliang | Li, Ting Yu | Chow, Judith C. | Kulkarni, Sanasi U. | Watson, John G. | Ho, Steven Sai Hang | Quan, Zhang Y. | Qu, L.R. | Perera, Frederica
In Tongliang, China, a coal-fired power plant was the major pollution source until its shutdown in 2004. We enrolled two cohorts of nonsmoking women and their newborns before and after the shutdown to examine the relationship between prenatal exposure to polycyclic aromatic hydrocarbons (PAHs) and fetal and child growth and development. PAHs were used to measure exposure to air pollution generated by the power plant. Using PAH–DNA adduct levels as biomarkers for the biologically effective dose of PAH exposure, we examined whether PAH–DNA adduct levels were associated with birth outcome, growth rate, and neurodevelopment. Head circumference was greater in children of the second cohort, compared with the first (p = 0.001), consistent with significantly reduced levels of cord blood PAH–DNA adducts in cohort II (p < 0.001) and reduced levels of ambient PAHs (p = 0.01).
显示更多 [+] 显示较少 [-]Pathways of Pb and Mn observed in a 5-year longitudinal investigation in young children and environmental measures from an urban setting
2014
Gulson, Brian | Mizon, Karen | Taylor, Alan | Korsch, Michael | Davis, J Michael | Louie, Honway | Wu, Michael | Gómez, Laura | Antin, Luminita
We monitored 108 children ≤5 years on a 6-month basis for up to 5 years in a major urban setting. Samples (n ∼ 7000) included blood, urine, handwipes (interior, and after exterior playing), 6-day duplicate diet, drinking water, interior house and day care dust-fall accumulation using petri dishes, exterior dust-fall accumulation, exterior dust sweepings, paint, soil and urban air. The geometric mean blood Pb (PbB) was 2.1 μg/dL and blood Mn (MnB) was 10.0 μg/L. Following a path modelling approach, mixed model analyses for a fully adjusted model showed the strongest associations for PbB were with interior house dust and soil; for MnB there were no significant associations with any predictors. Predictor variables only explained 9% of the variance for Pb and 0.7% for Mn. Relationships between environmental measures and PbB in children are not straightforward; soil and dust sweepings contribute only about 1/5th of the amounts to PbB found in other studies.
显示更多 [+] 显示较少 [-]Identification of lead sources in residential environments: Sydney Australia
2014
Laidlaw, M.A.S. | Zahran, S. | Pingitore, N. | Clague, J. | Devlin, G. | Taylor, M.P.
Interior and exterior dust, soil and paint were analysed at five brick urban Sydney homes over 15 months to evaluate temporal variations and discriminate sources of lead (Pb) exposure. Exterior dust gauge Pb loading rates (μg/m2/28 days), interior vacuum dust Pb concentrations (mg/kg) and interior petri-dish Pb loading rates (μg/m2/28 days), were correlated positively with soil Pb concentrations. Exterior dust gauge Pb loading rates and interior vacuum dust Pb concentrations peaked in the summer. Lead isotope and Pb speciation (XAS) were analysed in soil and vacuum dust samples from three of the five houses that had elevated Pb concentrations. Results show that the source of interior dust lead was primarily from soil in two of the three houses and from soil and Pb paint in the third home. IEUBK child blood Pb modelling predicts that children's blood Pb levels could exceed 5 μg/dL in two of the five houses.
显示更多 [+] 显示较少 [-]Dietary mercury exposure to endangered California Clapper Rails in San Francisco Bay
2014
Casazza, Michael L. | Ricca, Mark A. | Overton, Cory T. | Takekawa, John Y. | Merritt, Angela M. | Ackerman, Joshua T.
California Clapper Rails (Rallus longirostris obsoletus) are an endangered waterbird that forage in tidal-marsh habitats that pose risks from mercury exposure. We analyzed total mercury (Hg) in six macro-invertebrate and one fish species representing Clapper Rail diets from four tidal-marshes in San Francisco Bay, California. Mercury concentrations among individual taxa ranged from lowest at Colma Creek (mean range: 0.09–0.2μg/gdw) to highest at Cogswell (0.2–0.7), Laumeister (0.2–0.9) and Arrowhead Marshes (0.3–1.9). These spatial patterns for Hg matched patterns reported previously in Clapper Rail blood from the same four marshes. Over 25% of eastern mudsnails (Ilyanassa obsolete) and staghorn sculpin (Leptocottus armatus) exceeded dietary Hg concentrations (ww) often associated with avian reproductive impairment. Our results indicate that Hg concentrations vary considerably among tidal-marshes and diet taxa, and Hg concentrations of prey may provide an appropriate proxy for relative exposure risk for Clapper Rails.
显示更多 [+] 显示较少 [-]Selenium and mercury concentrations in harbor seals (Phoca vitulina) from central California: Health implications in an urbanized estuary
2014
McHuron, Elizabeth A. | Harvey, James T. | Castellini, J Margaret | Stricker, Craig A. | O’Hara, Todd M.
We measured total selenium and total mercury concentrations ([TSe] and [THg]) in hair (n=138) and blood (n=73) of harbor seals (Phoca vitulina) from California to assess variation by geography and sex, and inferred feeding relationships based on carbon, nitrogen, and sulfur stable isotopes. Harbor seals from Hg-contaminated sites had significantly greater [THg], and lesser [TSe] and TSe:THg molar ratios than seals from a relatively uncontaminated site. Males had significantly greater [THg] than females at all locations. Sulfur stable isotope values explained approximately 25% of the variability in [THg], indicating increased Hg exposure for seals with a greater use of estuarine prey species. Decreased [TSe] in harbor seals from Hg-contaminated regions may indicate a relative Se deficiency to mitigate the toxic effects of Hg. Further investigation into the Se status and the potential negative impact of Hg on harbor seals from Hg-contaminated sites is warranted.
显示更多 [+] 显示较少 [-]Effects of the modified Huanglian Jiedu decoction on the disease resistance in grey mullet (Mugil cephalus) to Lactococcus garvieae
2014
Choi, W.M. | Lam, C.L. | Mo, W.Y. | Cheng, Z. | Mak, N.K. | Bian, Z.X. | Wong, M.H.
Lactococcosis is prevalent on grey mullet (Mugil cephalus) in Hong Kong aquaculture resulting in serious economic loss. A compound formulation of Traditional Chinese Medicines (TCM) (modified Huanglian Jiedu decoction (HLJDD)) comprising Rhizoma coptidis, Radix scutellaria, Cortex phellodendri, Fructus gardeniae, Fructus forsythiae and Flos lonicerae japonicae (in a ratio of 3:2:2:3:3:5) were applied as feed supplements to deal with the disease. The Nitroblue tetrazolium activity in blood, bactericidal activity and total immunoglobulin in plasma were significantly enhanced after feeding 1% of this TCM for 28days. The disease resistances to Lactococcus garvieae in 1% and 2% TCM feeding groups were significantly enhanced. In the in vitro study, the modified HLJDD also activated the plasma bactericidal activities (p<0.01). Based on this study, 1% modified HLJDD feeding for 28days may be an optimal dose to prevent L. garvieae infection and could be used in aquaculture industries.
显示更多 [+] 显示较少 [-]Potential impacts of historical disturbance on green turtle health in the unique & protected marine ecosystem of Palmyra Atoll (Central Pacific)
2014
McFadden, Katherine W. | Gómez, Andrés | Sterling, Eleanor J. | Naro-Maciel, Eugenia
Palmyra Atoll, in the Central Pacific, is a unique marine ecosystem because of its remarkably intact food web and limited anthropogenic stressors. However during World War II the atoll was structurally reconfigured into a military installation and questions remain whether this may have impacted the health of the atoll’s ecosystems and species. To address the issue we assessed green sea turtle (n=157) health and exposure to contaminants at this foraging ground from 2008 to 2012. Physical exams were performed and blood was sampled for testosterone analysis, plasma biochemistry analysis, hematology and heavy metal exposure. Hematological and plasma chemistries were consistent with concentrations reported for healthy green turtles. Heavy metal screenings revealed low concentrations of most metals, except for high concentrations of iron and aluminum. Body condition indices showed that <1% of turtles had poor body condition. In this study, we provide the first published blood values for a markedly healthy sea turtle population at a remote Central Pacific Atoll.
显示更多 [+] 显示较少 [-]Isolation and characterization of biosurfactant producing bacteria from Persian Gulf (Bushehr provenance)
2014
Hassanshahian, Mehdi
Biosurfactants are surface active materials that are produced by some microorganisms. These molecules increase biodegradation of insoluble pollutants. In this study sediments and seawater samples were collected from the coastline of Bushehr provenance in the Persian Gulf and their biosurfactant producing bacteria were isolated. Biosurfactant producing bacteria were isolated by using an enrichment method in Bushnell-Hass medium with diesel oil as the sole carbon source. Five screening tests were used for selection of Biosurfactant producing bacteria: hemolysis in blood agar, oil spreading, drop collapse, emulsification activity and Bacterial Adhesion to Hydrocarbon test (BATH). These bacteria were identified using biochemical and molecular methods. Eighty different colonies were isolated from the collected samples. The most biosurfactant producing isolates related to petrochemical plants of Khark Island. Fourteen biosurfactant producing bacteria were selected between these isolates and 7 isolates were screened as these were predominant producers that belong to Shewanella alga, Shewanella upenei, Vibrio furnissii, Gallaecimonas pentaromativorans, Brevibacterium epidermidis, Psychrobacter namhaensis and Pseudomonas fluorescens. The largest clear zone diameters in oil spreading were observed for G. pentaromativorans strain O15. Also, this strain has the best emulsification activity and reduction of surface tension, suggesting it is the best of thee isolated strains. The results of this study confirmed that there is high diversity of biosurfactant producing bacteria in marine ecosystem of Iran and by application of these bacteria in petrochemical waste water environmental problems can be assisted.
显示更多 [+] 显示较少 [-]Molecular biomarkers in grey seals (Halichoerus grypus) to evaluate pollutant exposure, health and immune status
2014
Lehnert, K. | Muller, S. | Weirup, L. | Ronnenberg, K. | Pawliczka, I. | Rosenberger, T. | Siebert, U.
Grey seals as top-predators bioaccumulate contaminants and can be considered as sentinels of eco-system health. Pups are weaned after a short nursing period, characterised by an enormous lipid transfer and exposure to contaminants. This study established molecular biomarkers of the xenobiotic metabolism and immune system to help assess health and immune status. mRNA transcription of AHR, ARNT, PPARα and cytokine IL-2 and heat-shock-protein HSP70 was measured in blood of grey seal pups and adults in rehabilitation and permanent care using RT-qPCR and compared to rehabilitating harbour seal pups and haematology values. In pups highest levels at admission in xenobiotic biomarker, HSP70 and cytokine transcription may show contaminant exposure via lactation, stress during abandonment and dehydration. The significant decrease may be linked to diet, health improvement and adaptation. Adults showed higher levels and more variation in biomarker transcription and clear species-specific differences between harbour and grey seal pups were found.
显示更多 [+] 显示较少 [-]Metals and metalloids in whole blood and tissues of Olive Ridley turtles (Lepidochelys olivacea) from La Escobilla Beach (Oaxaca, Mexico)
2014
Cortés-Gómez, Adriana A. | Fuentes-Mascorro, Gisela | Romero, Diego
Concentrations of eight metals and metalloids (Pb, Cd, Cu, Zn, Mn, Se, Ni and As) were evaluated from 41 nesting females (blood) and 13 dead (tissues) Olive Ridley turtles (Lepidochelys olivacea), a species classified as vulnerable and also listed in Appendix I of the Convention of International Trade in Endangered Species (CITES). The mean blood, liver and kidney lead concentration were 0.02±0.01, 0.11±0.08 and 0.06±0.03μgg−1 ww respectively, values lower than other turtle species and locations, which it could be due to the gradual disuse of leaded gasoline in Mexico and Central America since the 1990s. Mean concentration of cadmium was 0.17±0.08 (blood), 82.88±36.65 (liver) and 150.88±110.99μgg−1 (kidney). To our knowledge, the mean renal cadmium levels found is the highest ever reported worldwide for any sea turtle species, while other six elements showed a concentration similar to other studies in sea turtles.
显示更多 [+] 显示较少 [-]