خيارات البحث
النتائج 331 - 340 من 4,044
Manganese concentrations in drinking water from villages near banana plantations with aerial mancozeb spraying in Costa Rica: Results from the Infants' Environmental Health Study (ISA) النص الكامل
2016
van Wendel de Joode, Berna | Barbeau, Benoit | Bouchard, Maryse F. | Mora, Ana María | Skytt, Åsa | Córdoba, Leonel | Quesada, Rosario | Lundh, Thomas | Lindh, Christian H. | Mergler, Donna
Elevated manganese (Mn) in drinking water has been reported worldwide. While, naturally occurring Mn in groundwater is generally the major source, anthropogenic contamination by Mn-containing fungicides such as mancozeb may also occur. The main objective of this study was to examine factors associated with Mn and ethylenethiourea (ETU), a degradation product of mancozeb, in drinking water samples from villages situated near banana plantations with aerial spraying of mancozeb. Drinking water samples (n = 126) were obtained from 124 homes of women participating in the Infants' Environmental Health Study (ISA, for its acronym in Spanish), living nearby large-scale banana plantations. Concentrations of Mn, iron (Fe), arsenic (As), lead (Pb), cadmium (Cd) and ethylenethiourea (ETU), a degradation product of mancozeb, were measured in water samples. Only six percent of samples had detectable ETU concentrations (limit of detection (LOD) = 0.15 μg/L), whereas 94% of the samples had detectable Mn (LOD = 0.05 μg/L). Mn concentrations were higher than 100 and 500 μg/L in 22% and 7% of the samples, respectively. Mn was highest in samples from private and banana farm wells. Distance from a banana plantation was inversely associated with Mn concentrations, with a 61.5% decrease (95% CI: −97.0, −26.0) in Mn concentrations for each km increase in distance. Mn concentrations in water transported with trucks from one village to another were almost 1000 times higher than Mn in water obtained from taps in houses supplied by the same well but not transported, indicating environmental Mn contamination. Elevated Mn in drinking water may be partly explained by aerial spraying of mancozeb; however, naturally occurring Mn in groundwater, and intensive agriculture may also contribute. Drinking water risk assessment for mancozeb should consider Mn as a health hazard. The findings of this study evidence the need for health-based World Health Organization (WHO) guidelines on Mn in drinking water.
اظهر المزيد [+] اقل [-]Distribution of polychlorinated biphenyls, phthalic acid esters, polycyclic aromatic hydrocarbons and organochlorine substances in the Moscow River, Russia النص الكامل
2016
Eremina, Natalia | Paschke, Albrecht | Mazlova, Elena A. | Schüürmann, Gerrit
The purpose of this study was to investigate the levels of polychlorinated biphenyl (PCB), phthalic acid esters (PAE), polycyclic aromatic hydrocarbons (PAH) and organochlorine substances (OCP) in the Moscow River water. Some studies have reported the occurrence of these substances in the soil of the Moscow region; however, no study has yet established an overview for these compounds in the Moscow River water. In this study the Moscow River water contamination with PAEs, PAHs and OCPs was determined. Obtained results were associated with the resident area located on the river bank, and the possible contamination sources were considered. The obtained data were compared with the data on the contamination of the different world-wide rivers. This research indicates the further study necessity of the Moscow region to cover more contaminated sites and environmental compartments.
اظهر المزيد [+] اقل [-]Historical anthropogenic contributions to mercury accumulation recorded by a peat core from Dajiuhu montane mire, central China النص الكامل
2016
Li, Yuanping | Ma, Chunmei | Zhu, Cheng | Huang, Run | Zheng, Chaogui
Mercury (Hg) accumulation records spanning the last 16,000 years before present (yr BP, relative to AD 1950) were derived from a peat core collected from Dajiuhu mire, central China. The natural Hg concentration and accumulation rate (free from anthropogenic influence) were 135.5 ± 53.9 ng g−1 and 6.5 ± 4.5 μg m−2 yr−1, respectively. The increase in Hg flux that started from a core depth of 96.5 cm (3358 cal yr BP) is independent of soil erosion and organic matter content. We attribute this to an increase in atmospheric Hg deposition derived from regional anthropogenic activities. Anthropogenic Hg accumulation rates (Hg-ARA) in the pre-industrial period peaked during the Ming and the early Qing dynasties (582–100 cal yr BP), with Hg-ARA of 9.9–24.6 and 10.7–24.4 μg m−2 yr−1, respectively. In the industrial interval (post∼1850 AD), Hg-ARA increased progressively and reached 32.7 μg m−2 yr−1 at the top of the core. Our results indicate the existence of regional atmospheric Hg pollution spanning the past ∼3400 years, and place recent Hg enrichment in central China in a broader historical context.
اظهر المزيد [+] اقل [-]Impacts of the Deepwater Horizon oil spill on the salt marsh vegetation of Louisiana النص الكامل
2016
Hester, Mark W. | Willis, Jonathan M. | Rouhani, Shahrokh | Steinhoff, Marla A. | M. C. B. (Mary C. Baker),
The coastal wetland vegetation component of the Deepwater Horizon oil spill Natural Resource Damage Assessment documented significant injury to the plant production and health of Louisiana salt marshes exposed to oiling. Specifically, marsh sites experiencing trace or greater vertical oiling of plant tissues displayed reductions in cover and peak standing crop relative to reference (no oiling), particularly in the marsh edge zone, for the majority of this four year study. Similarly, elevated chlorosis of plant tissue, as estimated by a vegetation health index, was detected for marsh sites with trace or greater vertical oiling in the first two years of the study. Key environmental factors, such as hydrologic regime, elevation, and soil characteristics, were generally similar across plant oiling classes (including reference), indicating that the observed injury to plant production and health was the result of plant oiling and not potential differences in environmental setting. Although fewer significant impacts to plant production and health were detected in the latter years of the study, this is due in part to decreased sample size occurring as a result of erosion (shoreline retreat) and resultant loss of plots, and should not be misconstrued as indicating full recovery of the ecosystem.
اظهر المزيد [+] اقل [-]Sedimentary records of polycyclic aromatic hydrocarbons (PAHs) in remote lakes across the Tibetan Plateau النص الكامل
2016
Yang, Ruiqiang | Sun, Chloe Tse | Li, An | Yang, Handong | Turner, Simon | Wu, Guangjian | Jing, Chuanyong
Sediment cores from five lakes across the Tibetan Plateau were used as natural archives to study the time trends of polycyclic aromatic hydrocarbons (PAHs). The depositional flux of PAHs generally showed an increasing trend from the deeper layers towards the upper layer sediments. The fluxes of PAHs were low with little variability before the 1950s, and then gradually increased to the late 1980s, with a faster increasing rate after the 1990s. This temporal pattern is clearly different compared with those remote lakes across the European mountains when PAHs started to decrease during the period 1960s–1980s. The difference of the temporal trend was attributed to differences in the economic development stages and energy structure between these regions. PAHs are dominated by the lighter 2&3-ring homologues with the averaged percentage over 87%, while it is notable that the percentage of heavier 4–6 ring PAHs generally increased in recent years, which suggests the contribution of local high-temperature combustion sources becoming more predominant.
اظهر المزيد [+] اقل [-]Spatial variability of heavy metals in estuarine, mangrove and coastal ecosystems along Parangipettai, Southeast coast of India النص الكامل
2016
Sundaramanickam, Arumugam | Shanmugam, Nadanasabesan | Cholan, Shanmugam | Kumaresan, Saravanan | Madeswaran, Perumal | Balasubramanian, Thangavel
An elaborate survey on the contamination of heavy metals was carried out in surface sediments of different ecosystems such as Vellar-Coleroon estuarine, Pichavaram mangrove and coastal region of Parangipettai, Southeast coast of India. The study was intended since, the coal based thermal power plant and oil refinery plant are proposed to set up along this coast and aquaculture industries and dredging activities are developing. The parameters such as soil texture, pH, total organic carbon (TOC) and heavy metal (Fe, Mn, Cu, Cd, Zn and Ni) concentrations were analyzed for the surface sediments during pre and postmonsoon seasons. Among the metals analyzed, Fe and Mn were found to have dominant as the levels were recorded as 11,804 μg g−1 and 845.2 μg g−1 respectively. A significant correlation was observed between total organic carbon (TOC) and heavy metals. In the mangrove ecosystem, the levels of heavy metals found to be maximum indicating that the rich organic matter acts as an efficient binding agent for metals. The overall finding of the present study indicated that the sediments from the entire Vellar-Coleroon estuarine and Pichavaram mangrove ecosystems were found moderately polluted with cadmium metal. The result of cluster analysis indicated disparity in accumulation of heavy metals in sediments of different ecosystems due to the variations in organic matter. The heavy metals were transported from land to coastal through flood during monsoon season reflecting the variations in their levels in different ecosystems at postmonsoon season.
اظهر المزيد [+] اقل [-]Spatial variability of mercury and polyunsaturated fatty acids in the European perch (Perca fluviatilis) – Implications for risk-benefit analyses of fish consumption النص الكامل
2016
Strandberg, Ursula | Palviainen, Marjo | Eronen, Aslak | Piirainen, Sirpa | Laurén, Ari | Akkanen, Jarkko | Kankaala, Paula
Spatial variability of mercury and polyunsaturated fatty acids in the European perch (Perca fluviatilis) – Implications for risk-benefit analyses of fish consumption النص الكامل
2016
Strandberg, Ursula | Palviainen, Marjo | Eronen, Aslak | Piirainen, Sirpa | Laurén, Ari | Akkanen, Jarkko | Kankaala, Paula
This study evaluated the spatial variability of risks and benefits of consuming fish from humic and clear lakes. Mercury in fish is a potential risk for human health, but risk assessment may be confounded by selenium, which has been suggested to counterbalance mercury toxicity. In addition to the risks, fish are also rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are known to be beneficial for cardiovascular health and brain cognitive function in humans.We found that the concentrations of EPA + DHA and mercury in European perch (Perca fluviatilis) vary spatially and are connected with lake water chemistry and catchment characteristics. The highest mercury concentrations and the lowest EPA + DHA concentrations were found in perch from humic lakes with high proportion of peatland (30–50%) in the catchment. In addition, the ratio of selenium to mercury in perch muscle was ≥1 suggesting that selenium may counterbalance mercury toxicity.The observed variation in mercury and EPA + DHA content in perch from different lakes indicate that the risks and benefits of fish consumption vary spatially, and are connected with lake water chemistry and catchment characteristics. In general, consumption of perch from humic lakes exposed humans to greater risks (higher concentrations of mercury), but provided less benefits (lower concentrations of EPA + DHA) than consumption of perch from clear lakes.
اظهر المزيد [+] اقل [-]Spatial variability of mercury and polyunsaturated fatty acids in the European perch (Perca fluviatilis) - Implications for risk-benefit analyses of fish consumption النص الكامل
2016
Strandberg, Ursula | Palviainen, Marjo | Eronen, Aslak | Piirainen, Sirpa | Laurén, Ari | Akkanen, Jarkko | Kankaala, Paula | University of Eastern Finland | University of Helsinki | Luke / Luonnonvarat ja biotuotanto / Ympäristövaikutukset / Ilmastonmuutoksen hillintä ja sopeutuminen (4100100411) | Luke / Luonnonvarat ja biotuotanto / Ympäristövaikutukset / Vesitalous ja vesistökuormitus (4100100412) | 4100100411 | 4100100412
Integrative transcriptomic and protein analysis of human bronchial BEAS-2B exposed to seasonal urban particulate matter النص الكامل
2016
Longhin, Eleonora | Capasso, Laura | Battaglia, Cristina | Proverbio, Maria Carla | Cosentino, Cristina | Cifola, Ingrid | Mangano, Eleonora | Camatini, Marina | Gualtieri, M. (Maurizio)
Exposure to particulate matter (PM) is associated with various health effects. Physico-chemical properties influence the toxicological impact of PM, nonetheless the mechanisms underlying PM-induced effects are not completely understood.Human bronchial epithelial cells were used to analyse the pathways activated after exposure to summer and winter urban PM and to identify possible markers of exposure.BEAS-2B cells were exposed for 24 h to 10 μg/cm² of winter PM2.5 (wPM) and summer PM10 (sPM) sampled in Milan. A microarray technology was used to profile the cells gene expression. Genes and microRNAs were analyzed by bioinformatics technique to identify pathways involved in cellular responses. Selected genes and pathways were validated at protein level (western blot, membrane protein arrays and ELISA).The molecular networks activated by the two PM evidenced a correlation among oxidative stress, inflammation and DNA damage responses. sPM induced the release of pro-inflammatory mediators, although miR-146a and genes related to inflammation resulted up-regulated by both PM. Moreover both PM affected a set of genes, proteins and miRNAs related to antioxidant responses, cancer development, extracellular matrix remodeling and cytoskeleton organization, while miR-29c, implicated in epigenetic modification, resulted up-regulated only by wPM. sPM effects may be related to biological and inorganic components, while wPM apparently related to the high content of organic compounds.These results may be helpful for the individuation of biomarkers for PM exposure, linked to the specific PM physico-chemical properties.
اظهر المزيد [+] اقل [-]The effect of drinking water salinity on blood pressure in young adults of coastal Bangladesh النص الكامل
2016
Talukder, Mohammad Radwanur Rahman | Rutherford, Shannon | Phùng, Dũng | Islam, Mohammad Zahirul | Chu, Cordia
More than 35 million people in coastal Bangladesh are vulnerable to increasing freshwater salinization. This will continue to affect more people and to a greater extent as climate change projections are realised in this area in the future. However the evidence for health effects of consuming high salinity water is limited. This research examined the association between drinking water salinity and blood pressure in young adults in coastal Bangladesh. We conducted a cross-sectional study during May-June 2014 in a rural coastal sub-district of Bangladesh. Data on blood pressure (BP) and salinity of potable water sources was collected from 253 participants aged 19–25 years. A linear regression method was used to examine the association between water salinity exposure categories and systolic BP (SBP) and diastolic BP (DBP) level. Sixty five percent of the study population were exposed to highly saline drinking water above the Bangladesh standard (600 mg/L and above). Multivariable linear regression analyses identified that compared to the low water salinity exposure category (<600 mg/L), those in the high water salinity category (>600 mg/L), had statistically significantly higher SBP (B 3.46, 95% CI 0.75, 6.17; p = 0.01) and DBP (B 2.77, 95% CI 0.31, 5.24; p = 0.03). Our research shows that elevated salinity in drinking water is associated with higher BP in young coastal populations. Blood pressure is an important risk factor of hypertension and cardiovascular diseases. Given the extent of salinization of freshwater in many low-lying countries including in Bangladesh, and the likely exacerbation related to climate change-induced sea level rise, implementation of preventative strategies through dietary interventions along with promotion of low saline drinking water must be a priority in these settings.
اظهر المزيد [+] اقل [-]The Egyptian Red Sea coastal microbiome: A study revealing differential microbial responses to diverse anthropogenic pollutants النص الكامل
2016
Mustafa, Ghada A. | Abd-Elgawad, Amr | Ouf, Amged | Siam, Rania
The Red Sea is considered one of the youngest oceanic systems, with unique physical, geochemical and biological characteristics. Tourism, industrialization, extensive fishing, oil processing and shipping are extensive sources of pollution in the Red Sea. We analyzed the geochemical characteristics and microbial community of sediments along the Egyptian coast of the Red Sea. Our sites mainly included 1) four ports used for shipping aluminum, ilmenite and phosphate; 2) a site previously reported to have suffered extensive oil spills; and 3) a site impacted by tourism. Two major datasets for the sediment of ten Red Sea coastal sites were generated; i) a chemical dataset included measurements of carbon, hydrogen, nitrogen and sulfur, metals and selected semi-volatile oil; and ii) a 16S rRNA Pyrotags bacterial metagenomic dataset. Based on the taxonomic assignments of the 16S rRNA Pyrotags to major bacterial groups, we report 30 taxa constituting an Egyptian Red Sea Coastal Microbiome. Bacteria that degrade hydrocarbons were predominant in the majority of the sites, particularly in two ports where they reached up to 76% of the total identified genera. In contrast, sulfate-reducing and sulfate-oxidizing bacteria dominated two lakes at the expense of other hydrocarbon metabolizers. Despite the reported “Egyptian Red Sea Coastal Microbiome,” sites with similar anthropogenic pollutants showed unique microbial community abundances. This suggests that the abundance of a specific bacterial community is an evolutionary mechanism induced in response to selected anthropogenic pollutants.
اظهر المزيد [+] اقل [-]