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The Science of the total environment [journal]
- Neonatal outcomes of intrauterine nonylphenol exposure-A longitudinal cohort study in Taiwan. [JOURNAL ARTICLE]
- Sci Total Environ 2013 May 13.:367-373.
BACKGROUND:Nonylphenol (NP) is an environmental hormone with proven estrogenic effects. Although its adverse effects on animals are well documented, the effects of NP exposure on humans remain unclear, and those on the human foetus are completely unknown. This study explores the effects of intrauterine NP exposure on neonates.
METHODS:A cohort of pregnant women was established in a medical centre in northern Taiwan. Urine samples from the first, second, and third trimesters of gestation were collected. Urinary NP concentration was measured by high-performance liquid chromatography coupled with fluorescent detection. Neonatal outcomes were evaluated immediately after delivery. A mixed-effects model using a generalised estimating equation was applied to assess the association between gestational age, maternal body weight, and maternal NP concentration throughout the three trimesters. A multivariable regression model was used to determine the association between maternal NP level in urine in each trimester and neonatal outcomes.
RESULTS:In total, 162 singleton pregnant women completed this study through delivery. The geometric mean of creatinine-adjusted urinary NP concentrations were 4.27μg/g, 4.21μg/g, and 4.10μg/g in the first, second, and third trimesters, respectively. Pregnant women whose urinary NP concentrations were above the median in the second trimester had low maternal weight gain (β=-1.55kg, p=0.02) and short neonatal body length (β=-0.47cm, p=0.04). Women with an above-median urinary NP concentration had an odds ratio of having a small for gestational age (SGA) neonate of 7.81 (p<0.05).
CONCLUSIONS:This study indicates that maternal high NP exposure in the second trimester is associated with SGA, decreased foetal body length at birth, and low maternal weight gain. The effects of this endocrine-disrupting substance on pregnant women and foetuses should be a concern during gestation.
- Plasma mercury levels in Hong Kong residents: In relation to fish consumption. [JOURNAL ARTICLE]
- Sci Total Environ 2013 May 13.
Mercury exposure is of particular concern since mercury is a neurotoxin and the developing fetus is most sensitive to its adverse effect. Human blood is routinely used as an indicator for the evaluation of human exposure to Hg. To investigate Hg species in human plasma for Hong Kong residents and the relationship between fish consumption and Hg species in plasma, 151 plasma samples were analyzed for Hg species. The mean values of total Hg (THg) and methyl-mercury (MeHg) concentration in plasma were 0.62 and 0.28μg/L, respectively. No significant differences were observed between females and males as well as among age groups. Fish consumption rate was significantly positively correlated with MeHg concentrations in plasma, which demonstrated that plasma could be a biomarker for human MeHg exposure. Two methods were used to estimate human MeHg exposure. One was based on fish MeHg content and fish consumption rate (EDIFish), another was employed by converting MeHg concentration in blood to MeHg exposure amount (EDIBlood). A significant positive correlation was observed between EDIBlood and EDIFish, and no significant difference was found between EDIBlood and EDIFish. These results demonstrated that fish consumption was the major source of MeHg for humans.
- Interaction between density and Cu toxicity for Enchytraeus crypticus - Comparing first and second generation effects. [JOURNAL ARTICLE]
- Sci Total Environ 2013 May 11.:361-366.
Density of organisms varies considerably in nature depending e.g. on seasonality or food availability. A recent investigation on interaction between Cu and density using Enchytraeus crypticus showed that density itself (5-50 per 20gr dry soil) had an impact on population and individual growth [up to 3000 individuals per test vessel], but the interaction between density and Cu toxicity was not significant. Here, a follow-up study was performed, in which the interactions between density and Cu-exposure were investigated along a two-generation exposure using E. crypticus (three factorial: 1. density (5-50), 2. Cu (0-300mg/kg) and generation (G1-G2)). After G1, the juveniles were retrieved and further exposed under the same conditions along a G2 (using a refined density set - 10 and 50). Results showed an interaction between density and Cu in the reproduction of E. crypticus, this being significant in G2, showing lower toxicity for higher density of organisms whereas in the 1st generation the opposite occurred. Hence, there was an interaction seen along G1 to G2, i.e. animals from density 50 in G1 when further exposed at density 50 in G2 had lower Cu toxicity compared to when further exposed at density 10. Possible explanations include the hydra effect (overcompensation in G2 due to stress in G1) or that for density 50 the organisms are exposed to less Cu than at lower densities, this by e.g. (1) organisms avoid exposure by lumping/clustering which would limit exposure to Cu and (2) there would be less available Cu contaminated soil per individual at high density hence less exposure.
- Decription of a novel viral tool to identify and quantify ovine faecal pollution in the environment. [JOURNAL ARTICLE]
- Sci Total Environ 2013 May 11.:355-360.
Farmed animals such as sheep, cattle, swine and poultry play an important role in microbial contamination of water, crops and food, and introduce large quantities of pathogens into the environment. The ability to determine the origin of faecal pollution in water resources is essential when establishing a robust and efficient water management system. Animal-specific viruses have previously been suggested as microbial source tracking tools, but specific ovine viral markers have not been reported before now. Previous studies have shown that polyomaviruses are host-specific, highly prevalent and are commonly excreted in urine. Furthermore, they have been reported to infect several vertebrate species but not sheep. That situation encouraged the study of a new putative ovine polyomavirus (OPyV) and its use to determine whether faecal pollution originates from ovine faecal/urine contamination. Putative OPyV DNA was amplified from ovine urine and faecal samples using a broad-spectrum nested PCR (nPCR). Specific nested PCR and quantitative PCR assays were developed and applied to faecal and environmental samples, including sheep slurries, slaughterhouse wastewater effluents, urban sewage and river water samples. Successful amplification by PCR was achieved in sheep urine samples, sheep slaughterhouse wastewater and downstream sewage effluents. The assay was specific and was negative in samples of human, bovine, goat, swine and chicken origin. Ovine faecal pollution was detected in river water samples by applying the designed methods. These results provide a quantitative tool for the analysis of OPyV as a suitable viral indicator of sheep faecal contamination that may be present in the environment.
- Evaluating the fate of six common pharmaceuticals using a reactive transport model: Insights from a stream tracer test. [JOURNAL ARTICLE]
- Sci Total Environ 2013 May 10.:344-354.
Quantitative information regarding the capacity of rivers to self-purify pharmaceutical residues is limited. To bridge this knowledge gap, we present a methodology for quantifying the governing processes affecting the fate of pharmaceuticals in streaming waters and, especially, to evaluate their relative significance for tracer observations. A tracer test in Säva Brook, Sweden was evaluated using a coupled physical-biogeochemical model framework containing surface water transport together with a representation of transient storage in slow/immobile zones of the stream, which are presumably important for the retention and attenuation of pharmaceuticals. To assess the key processes affecting the environmental fate of the compounds, we linked the uncertainty estimates of the reaction rate coefficients to the relative influence of transformation and sorption that occurred in different stream environments. The hydrological and biogeochemical contributions to the fate of the pharmaceuticals were decoupled, and the results indicate a moderate hydrological retention in the hyporheic zone as well as in the densely vegetated parts of the stream. Biogeochemical reactions in these transient storage zones further affected the fate of the pharmaceuticals, and we found that sorption was the key process for bezafibrate, metoprolol, and naproxen, while primary transformation was the most important process for clofibric acid and ibuprofen. Conversely, diclofenac was not affected by sorption or transformation.
- The passive control of air pollution exposure in Dublin, Ireland: A combined measurement and modelling case study. [JOURNAL ARTICLE]
- Sci Total Environ 2013 May 10.:331-343.
This study investigates the potential real world application of passive control systems to reduce personal pollutant exposure in an urban street canyon in Dublin, Ireland. The implementation of parked cars and/or low boundary walls as a passive control system has been shown to minimise personal exposure to pollutants on footpaths in previous investigations. However, previous research has been limited to generic numerical modelling studies. This study combines real-time traffic data, meteorological conditions and pollution concentrations, in a real world urban street canyon before and after the implementation of a passive control system. Using a combination of field measurements and numerical modelling this study assessed the potential impact of passive controls on personal exposure to nitric oxide (NO) concentrations in the street canyon in winter conditions. A calibrated numerical model of the urban street canyon was developed, taking into account the variability in traffic and meteorological conditions. The modelling system combined the computational fluid dynamic (CFD) simulations and a semi-empirical equation, and demonstrated a good agreement with measured field data collected in the street canyon. The results indicated that lane distribution, fleet composition and vehicular turbulence all affected pollutant dispersion, in addition to the canyon geometry and local meteorological conditions. The introduction of passive controls displayed mixed results for improvements in air quality on the footpaths for different wind and traffic conditions. Parked cars demonstrated the most comprehensive passive control system with average improvements in air quality of up to 15% on the footpaths. This study highlights the potential of passive controls in a real street canyon to increase dispersion and improve air quality at street level.
- Stabilization by hydrophobic protection as a molecular mechanism for organic carbon sequestration in maize-amended rice paddy soils. [JOURNAL ARTICLE]
- Sci Total Environ 2013 May 9.:319-330.
The hydrophobic components of soil organic matter (SOM) are reckoned to play an important role in the stabilization of soil organic carbon (SOC). The contribution of hydrophobic substances to SOC sequestration was evaluated in four different paddy soils in the South of China, following a 6-month incubation experiment with maize straw amendments. Soil samples included: a well developed paddy soil (TP) derived from clayey lacustrine deposits in the Tai Lake plain of Jiangsu; an acid clayey paddy soil (RP) derived from red earth in the rolling red soil area of Jiangxi; a weakly developed neutral paddy soil (PP) formed on Jurassic purple shale from Chongq; and a calcic Fluvisol (MS) derived from riverine sediments from a wetland along the Yangtze valley of Anhui, China. The SOC molecular composition after 30 and 180days of incubation, was determined by off-line thermochemolysis followed by gas chromatography-mass spectrometry analysis. Lignin, lipids and carbohydrates were the predominant thermochemolysis products released from the treated soils. A selective preservation of hydrophobic OM, including lignin and lipids, was shown in maize amended soils with prolonged incubation. The decomposition of lignin and lipids was significantly slower in the TP and RP soils characterized by a larger content of extractable iron oxyhydrates (Fed) and lower pH. The overall increase in hydrophobic substances in maize incubated samples was correlated, positively, with total content of clay and Fed, and, negatively, with soil pH. Moreover, yields of both lignin and lipid components showed a significant relationship with SOC increase after incubation. These findings showed that the larger the lipid and lignin content of SOM, the greater was the stability of SOC, thereby suggesting that OM hydrophobic components may have an essential role in controlling the processes of OC sequestration in paddy soils of South China.
- Faecal sludge management with the larvae of the black soldier fly (Hermetia illucens) - From a hygiene aspect. [JOURNAL ARTICLE]
- Sci Total Environ 2013 May 10.:312-318.
Inadequate and lacking sanitation and wastewater treatment systems can lead to the spreading of diarrhoeal diseases. One contributing factor in the lack of such treatment systems is the lack of economic incentives for stakeholders throughout the service chain. However, the organic fraction of the waste is high in valuable plant nutrients and could be reused in agriculture and as animal feed. For example, grown larvae of the black soldier fly, Hermetia illucens L. (Diptera: Stratiomyidae), make an excellent protein source in animal feed, while the feeding activity of the larvae substantially reduces the dry mass of the treated material. This study examined the effect of black soldier fly larvae on the concentration of pathogenic microorganisms in human faeces and found a 6 log10 reduction in Salmonella spp. in human faeces in eight days, compared with a <2 log10 reduction in the control. No increased reduction was observed for Enterococcus spp., bacteriophage ΦX174 or Ascaris suum ova.
- A participatory approach for selecting cost-effective measures in the WFD context: The Mar Menor (SE Spain). [JOURNAL ARTICLE]
- Sci Total Environ 2013 May 9.:303-311.
Achieving a good ecological status in water bodies by 2015 is one of the objectives established in the European Water Framework Directive. Cost-effective analysis (CEA) has been applied for selecting measures to achieve this goal, but this appraisal technique requires technical and economic information that is not always available. In addition, there are often local insights that can only be identified by engaging multiple stakeholders in a participatory process. This paper proposes to combine CEA with the active involvement of stakeholders for selecting cost-effective measures. This approach has been applied to the case study of one of the main coastal lagoons in the European Mediterranean Sea, the Mar Menor, which presents eutrophication problems. Firstly, face-to-face interviews were conducted to estimate relative effectiveness and relative impacts of a set of measures by means of the pairwise comparison technique. Secondly, relative effectiveness was used to estimate cost-effectiveness ratios. The most cost-effective measures were the restoration of watercourses that drain into the lagoon and the treatment of polluted groundwater. Although in general the stakeholders approved the former, most of them stated that the latter involved some uncertainties, which must be addressed before implementing it. Stakeholders pointed out that the PoM would have a positive impact not only on water quality, but also on fishing, agriculture and tourism in the area. This approach can be useful to evaluate other programmes, plans or projects related to other European environmental strategies.
- Assessment of pathogenic bacteria in treated graywater and irrigated soils. [JOURNAL ARTICLE]
- Sci Total Environ 2013 May 9.:298-302.
Reuse of graywater (GW) for irrigation is recognized as a sustainable solution for water conservation. One major impediment for reuse of GW is the possible presence of pathogenic microorganisms. The presence and abundance of six pathogens and indicators were investigated in three GW recirculating vertical flow constructed wetland treatment systems and their respective irrigated yard soils. The treated GW and soils were monitored once every two months for six months using real-time quantitative PCR. As a control, samples from four soils irrigated with fresh water (FW) were similarly analyzed for pathogens and indicators. Comparable types of pathogens and fecal indicator bacteria, including Escherichia coli, Klebsiella pneumoniae, Salmonella enterica, Pseudomonas aeruginosa, Enterococcus faecalis, and Shigella spp., were found in the treated GW, their corresponding irrigated soils and the FW-irrigated soils. Moreover, the abundance of these bacteria in the GW- and FW-irrigated soils was of the same order of magnitude, suggesting that the source of the pathogens cannot be established. Our results suggest that GW irrigation has no effect on the diversity and abundance of the tested pathogens and indicators in yard soils.