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Organohalogen compounds in human breast milk from mothers living in Payatas and Malate, the Philippines: Levels, accumulation kinetics and infant health risk Texto completo
2009
Malarvannan, Govindan | Kunisue, Tatsuya | Isobe, Tomohiko | Sudaryanto, Agus | Takahashi, Shin | Prudente, Maricar | Subramanian, Annamalai | Tanabe, Shinsuke
Human breast milk samples (n = 33) from primipara and multipara mothers from Payatas a waste dump site, and Malate a reference site in the Phillipines were collected in 2004 and analyzed for eight organohalogen compounds, viz., PCBs, DDTs, CHLs, HCHs, HCB, TCPMe, PBDEs and HBCDs. DDTs and PCBs were predominant in all the samples. Overall mean concentrations of PBDEs found in our study were higher (7.5 ng/g lipid wt.) than those reported for Japan and many other Asian countries. Primipara mothers had significantly higher levels of DDTs, CHLs and HCHs than multipara mothers, but not PBDEs and HBCDs. A few individuals accumulated CHLs close to or even higher than the tolerable daily intake guidelines proposed by Health Canada. First comprehensive study on organohalogen contaminants in human breast milk from the Philippines.
Mostrar más [+] Menos [-]Soil burdens of persistent organic pollutants – Their levels, fate and risk. Part II. Are there any trends in PCDD/F levels in mountain soils Texto completo
2009
Kukučka, Petr | Klánová, Jana | Sáňka, Milan | Holoubek, Ivan
Good quality data apt for an assessment of temporal trends of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs) in soils are difficult to obtain since there is a general lack of information on their residues in soils. Variability of soil profiles, non-homogeneity of samples, and often also inconsistency of applied sampling procedures further complicate this problem. To assess spatial and temporal trends of contamination, three soil sampling campaigns have been performed over the period of 12 years at the mountain forest sites in the Czech Republic. Relation between the air, needle and soil contaminations was addressed in addition to time-related variability of soil. It has been confirmed that soil is a good matrix for evaluation of spatial distribution of persistent organic pollutants (POPs) but difficult for establishment of temporal trends. A slow rate of the soil-forming processes and their site-specificity was generally the major source of uncertainties. More than a decade of POP monitoring is recommended for successful establishment of temporal trends in forest soils.
Mostrar más [+] Menos [-]Photosynthesis, chloroplast pigments, and antioxidants in Pinus canariensis under free-air ozone fumigation Texto completo
2009
Then, Ch | Herbinger, K. | Luis, V.C. | Heerdt, C. | Matyssek, R. | Wieser, G.
High O3 levels, driving uptake and challenging defense, prevail on the Canary Islands, being associated with the hot and dry summers of the Mediterranean-type climate. Pinus canariensis is an endemic conifer species that forms forests across these islands. We investigated the effects of ozone on photosynthesis and biochemical parameters of P. canariensis seedlings exposed to free-air O3 fumigation at Kranzberg Forest, Germany, where ambient O3 levels were similar to those at forest sites in the Canary Islands. The twice-ambient O3 regime (2xO3) neither caused visible injury-like chlorotic or necrotic spots in the needles nor significantly affected violaxanthin, antheraxanthin and zeaxanthin levels and the de-epoxidation state of the xanthophyll cycle. In parallel, stomatal conductance for water vapour, net photosynthesis, intercellular CO2 concentration, chlorophyll fluorescence parameters, as well as antioxidant levels were hardly affected. It is concluded that presently prevailing O3 levels do not impose severe stress on P. canariensis seedlings.
Mostrar más [+] Menos [-]Bait-lamina assay as a tool to assess the effects of metal contamination in the feeding activity of soil invertebrates within a uranium mine area Texto completo
2009
André, A. | Antunes, S.C. | Gonçalves, F. | Pereira, R.
As part of the tier 2 of a site-specific risk assessment, this study was the first reporting an intensive in situ application of the bait-lamina assay; two exposure periods (7 and 14 days) were tested during four seasons in ten different sites, within a uranium mine area and at two different depths. The most contaminated sites (by deposition of sludge from the effluent treatment pond) were discriminated after 14 days of exposure because extremely low percentages of feeding activity were recorded. Previous sub-lethal ecotoxicological assays, already had demonstrated that the habitat function of these soils is compromised. Nevertheless, seasonality has proved to have a significant influence on responses. Thus to strength conclusions about the impact of contaminants, the in situ bait-lamina assay should be performed on different annual seasons, at least for temperate regions. It was also found that some environmental parameters (e.g. soil moisture and litter) can act as confounding factors in the bait-lamina assay. Bait-lamina assay for in situ evaluation of soil functions under site-specific risk assessments.
Mostrar más [+] Menos [-]Structural and functional responses of benthic invertebrates to imidacloprid in outdoor stream mesocosms Texto completo
2009
Pestana, J.L.T. | Alexander, A.C. | Culp, J.M. | Baird, D.J. | Cessna, A.J. | Soares, A.M.V.M.
Structural and functional responses of a benthic macroinvertebrate assemblage to pulses of the insecticide imidacloprid were assessed in outdoor stream mesocosms. Imidacloprid pulses reduced invertebrate abundance and community diversity in imidacloprid-dosed streams compared to control streams. These results correlated well with effects of imidacloprid on leaf litter decomposition and feeding rates of Pteronarcys comstocki, a stonefly, in artificial streams. Reductions in oxygen consumption of stoneflies exposed to imidacloprid were also observed in laboratory experiments. Our findings suggest that leaf litter degradation and single species responses can be sensitive ecotoxicological endpoints that can be used as early warning indicators and biomonitoring tools for pesticide contamination. The data generated illustrates the value of mesocosm experiments in environmental assessment and how the consideration of functional and structural endpoints of natural communities together with in situ single species bioassays can improve the evaluation and prediction of pesticide effects on stream ecosystems. Combining organism-level responses with community-level processes for the evaluation and prediction of pesticide effects on stream ecosystems.
Mostrar más [+] Menos [-]Accumulation of trace elements in the peripheral and central parts of two species of epiphytic lichens transplanted to a polluted site in Portugal Texto completo
2009
Godinho, R.M. | Verburg, T.G. | Freitas, M.C. | Wolterbeek, H.Th
This paper compares the dynamics, i.e. the rates of change in element concentrations of young and older lichen thallus parts, of one foliose and one fruticose lichen, during a transplant experiment to a polluted site. Both lichen parts respond to environmental changes. Here, differential accumulation suggests that differential constitution leads to differential uptake and release, and/or the overall behaviour is partly due to internal translocation and regulation mechanisms within the whole lichen. For thallus parts, internal translocation should be taken into account as one more factor affecting lichen “memory length”. Young parts of the thallus presented higher rates of change, but different lichen parts accumulate different elements to different extents. Therefore tissue selection in monitoring may depend on the element of interest, and cannot be made into a generalized approach in survey set-ups: the choice depends on the element. Thallus age and type affect the rate of change of element concentrations in lichens as induced by changes in ambient environmental conditions.
Mostrar más [+] Menos [-]Persistent organochlorines in human breast milk from major metropolitan cities in India Texto completo
2009
Devanathan, Gnanasekaran | Subramanian, Annamalai | Someya, Masayuki | Sudaryanto, Agus | Isobe, Tomohiko | Takahashi, Shin | Chakraborty, Paromita | Tanabe, Shinsuke
The present study was carried out to understand the current contamination status of organochlorine compounds (OCs) in human breast milk from three metropolitan cities in India (New Delhi, Mumbai and Kolkata). Among the OCs analyzed, DDTs were predominant followed by HCHs and PCBs. CHLs and HCB levels were much lower. Contamination patterns were different in human milk found in our previous study in Chennai, a metropolitan city in southern India, indicating region specific exposure routes and variable sources. In comparison with previous data, levels of DDTs and HCHs generally declined with time, implying the effect of various bans and restrictions on their usage. No association between concentrations of OCs and demographic characteristics such as parity and age of mothers was observed which might be due to narrow range of mother's age. Estimated daily intake shows that some infants are exposed to OCs to a greater extent, particularly HCHs than the guideline standard. Indian infants may be exposed to relatively high levels of DDTs and HCHs through mothers' milk.
Mostrar más [+] Menos [-]Deposition and solubility of airborne metals to four plant species grown at varying distances from two heavily trafficked roads in London Texto completo
2009
Peachey, C.J. | Sinnett, D. | Wilkinson, M. | Morgan, G.W. | Freer-Smith, P.H. | Hutchings, T.R.
In urban areas, a highly variable mixture of pollutants is deposited as particulate matter. The concentration and bioavailability of individual pollutants within particles need to be characterised to ascertain the risks to ecological receptors. This study, carried out at two urban parks, measured the deposition and water-solubility of metals to four species common to UK urban areas. Foliar Cd, Cr, Cu, Fe, Ni, Pb and Zn concentrations were elevated in at least one species compared with those from a rural control site. Concentrations were, however, only affected by distance to road in nettle and, to a lesser extent, birch leaves. Greater concentrations of metal were observed in these species compared to cypress and maple possibly due to differences in plant morphology and leaf surfaces. Solubility appeared to be linked to the size fraction and, therefore, origin of the metal with those present predominantly in the coarse fraction exhibiting low solubility. High density traffic resulted in elevated metal concentrations on vegetation, which were related to distance from road and plant species.
Mostrar más [+] Menos [-]Responses of herbaceous plants to urban air pollution: Effects on growth, phenology and leaf surface characteristics Texto completo
2009
Honour, Sarah L. | Bell, J. Nigel B. | Ashenden, Trevor W. | Cape, J Neil | Power, Sally A.
Vehicle exhaust emissions are a dominant feature of urban environments and are widely believed to have detrimental effects on plants. The effects of diesel exhaust emissions on 12 herbaceous species were studied with respect to growth, flower development, leaf senescence and leaf surface wax characteristics. A diesel generator was used to produce concentrations of nitrogen oxides (NOx) representative of urban conditions, in solardome chambers. Annual mean NOx concentrations ranged from 77 nl l-l to 98 nl l-1, with NO:NO2 ratios of 1.4-2.2, providing a good experimental simulation of polluted roadside environments. Pollutant exposure resulted in species-specific changes in growth and phenology, with a consistent trend for accelerated senescence and delayed flowering. Leaf surface characteristics were also affected; contact angle measurements indicated changes in surface wax structure following pollutant exposure. The study demonstrated clearly the potential for realistic levels of vehicle exhaust pollution to have direct adverse effects on urban vegetation. Fumigation experiments demonstrate adverse effects of exhaust emissions on urban vegetation.
Mostrar más [+] Menos [-]Influence of titanium dioxide nanoparticles on speciation and bioavailability of arsenite Texto completo
2009
In this study, the influence of the co-existence of TiO2 nanoparticles on the speciation of arsenite [As(III)] was studied by observing its adsorption and valence changing. Moreover, the influence of TiO2 nanoparticles on the bioavailability of As(III) was examined by bioaccumulation test using carp (Cyprinus carpio). The results showed that TiO2 nanoparticles have a significant adsorption capacity for As (III). Equilibrium was established within 30 min, with about 30% of the initial As (III) being adsorbed onto TiO2 nanoparticles. Most of aqueous As (III) was oxidized to As(V) in the presence of TiO2 nanoparticles under sunlight. The carp accumulated considerably more As in the presence of TiO2 nanoparticles than in the absence of TiO2 nanoparticles, and after 25-day exposure, As concentration in carp increased by 44%. Accumulation of As in viscera, gills and muscle of the carp was significantly enhanced by the presence of TiO2 nanoparticles. The co-existence of TiO2 nanoparticles could change the speciation of arsenite by adsorption and photo-oxidation, and enhance its bioaccumulation to carp.
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