Patterns and concentration levels of polybrominated diphenyl ethers (PBDEs) in placental tissue of women in Denmark

The levels and congener patterns of PBDEs were investigated in human placental samples in Denmark. The median concentrations of ∑PBDE_tri-hepta and BDE-209 in the 50 samples were 1.22 and 1.14 ng g⁻¹ lw, respectively, with the total sum ranging from 0.51 to 17.1 ng g⁻¹ lw, which is similar to previous placental studies. The PBDE content in placental tissue was dominated by BDE-209, which accounted for approximately 50% of the total amount of PBDEs. BDE-47, -99, and -153 were detected in all samples. Approximately equal amounts of BDE-47 and BDE-153 were observed in the placental tissue, which is in agreement with previous European studies of human serum. Principal Component Analysis (PCA) was performed to analyze congener patterns within and between mothers. The loading plot showed groupings of the measured PBDE variables in three groups, representative of Penta-, Octa- and Deca-BDE technical mixtures. Congeners representing the individual technical mixtures were close to orthogonal or inversely correlated, indicating variation in the congener patterns of internal exposure corresponding to the patterns of technical mixtures used in products. Visualisation of the participant objects according to body mass index (BMI), revealed inherent congener patterns (19% X-variance) showing increased frequency for participants within the highest BMI group to have elevated concentrations of BDE-209 in the placental tissue.     

Parsing participation: models of engagement for outcomes monitoring in urban stewardship

Few urban environmental stewardship, or civic ecology, practices monitor their impacts on local communities and ecosystems. This lack of monitoring prevents lay stewards from adapting their practices based on outcomes. For those that do collect data on their practices, we see different forms of practitioner engagement in outcomes monitoring. We categorise these different forms of engagement according to five published models of public participation in scientific research, revealing different strategies for collecting and analysing data towards adaptive co-management in urban ecosystems. We propose two broad strategies for expanding outcomes monitoring in these contexts: creating openly accessible tools and protocols for do-it-yourself inquiry and supporting more resource-intensive partnerships between practitioners and scientists for more complex forms of outcomes monitoring.     

Oxidation of a PAH polluted soil using modified Fenton reaction in unsaturated condition affects biological and physico-chemical properties

A batch experiment was conducted to assess the impact of chemical oxidation using modified Fenton reaction on PAH content and on physico-chemical and biological parameters of an industrial PAH contaminated soil in unsaturated condition. Two levels of oxidant (H₂O₂, 6 and 65 g kg⁻¹) and FeSO₄ were applied. Agronomic parameters, bacterial and fungal density, microbial activity, seed germination and ryegrass growth were assessed. Partial removal of PAHs (14% and 22%) was obtained with the addition of oxidant. The impact of chemical oxidation on PAH removal and soil physico-chemical and biological parameters differed depending on the level of reagent. The treatment with the highest concentration of oxidant decreased soil pH, cation exchange capacity and extractable phosphorus content. Bacterial, fungal, and PAH degrading bacteria densities were also lower in oxidized soil. However a rebound of microbial populations and an increased microbial activity in oxidized soil were measured after 5 weeks of incubation. Plant growth on soil treated by the highest level of oxidant was negatively affected.     

Air Pollutant Emissions from Coal-Fired Power Plants,Report No. 2

The Public Health Service and the Bureau of Mines are conducting a joint study to evaluate a number of flue-gas-stream components from coal-burning power plants. Emissions of fly ash, sulfur oxides, nitrogen oxides, polynuclear hydrocarbons, total gaseous hydrocarbons, formaldehyde, certain metals, and carbon dioxide are determined. A previous paper covered air pollutant emissions from vertical-fired and front-wall-fired power plant boilers. This paper includes a comparative evaluation of emissions from a tangential-fired and a turbo-fired power plant boiler.     

Uncertainty Requirements in Radiative Forcing of Climate Change

Abstract

The continuing increase in atmospheric carbon dioxide (CO₂) makes it essential that climate sensitivity, the equilibrium change in global mean surface temperature that would result from a given radiative forcing, be quantified with known uncertainty. Present estimates are quite uncertain, 3 ± 1.5 K for doubling of CO₂. Model studies examining climate response to forcing by greenhouse gases and aerosols exhibit large differences in sensitivities and imposed aerosol forcings that raise questions regarding claims of their having reproduced observed large-scale changes in surface temperature over the 20th century. Present uncertainty in forcing, caused largely by uncertainty in forcing by aerosols, precludes meaningful model evaluation by comparison with observed global temperature change or empirical determination of climate sensitivity. Uncertainty in aerosol forcing must be reduced at least three-fold for uncertaintyin climate sensitivity to be meaningfully reduced and bounded.     

Temporal variation and persistence of bacteria in streams

Better understanding of bacterial fate and transport in watersheds is necessary for improved regulatory management of impaired streams. Novel statistical time series analyses of coliform data can be a useful tool for evaluating the dynamics of temporal variation and persistence of bacteria within a watershed. For this study, daily total coliform data for the Little River in East Tennessee from 1 Oct. 2000 to 31 Dec. 2005 were evaluated using novel time series techniques. The objective of this study was to analyze the total coliform concentration data to: (i) evaluate the temporal variation of the total coliform, and (ii) determine whether the total coliform concentration data demonstrated any long-term or short-term persistence. For robust analysis and comparison, both time domain and frequency domain approaches were used for the analysis. In the time domain, an autoregressive moving average approach was used; whereas in the frequency domain, spectral analysis was applied. As expected, the analyses showed that total coliform concentrations were higher in summer months and lower in winter months. However, the more interesting results showed that the total coliform concentration exhibited short-term as well as long-term persistence ranging from about 4 wk to approximately 1 yr, respectively. Comparison of the total coliform data to hydrologic data indicated both runoff and baseflow are responsible for the persistence.     

Screening of seaweeds in the East China Sea as potential bio-monitors of heavy metals

Environmental Science and Pollution Research - Seaweeds are good bio-monitors of heavy metal pollution and have been included in European coastal monitoring programs. However, data for seaweed...     

Laboratory-scale application of fiber optic transflection dip probe (FOTDP) for in situ monitoring of gas phase ozone in unsaturated porous media

A fiber optic transflection dip probe (FOTDP) system was developed for in situ and real-time monitoring of the transport of gas phase ozone in unsaturated porous media. A unique property of this system is the employment of a dip probe, which is inserted within the porous media. At the probe's tip, incoming light interacts with gas phase ozone and is partially reflected back into the probe by a mirror attached to the tip. Calibration of the FOTDP system was successfully carried out with various ozone concentrations using a column packed with glass beads. The ozone breakthrough curves (BTCs) were obtained by converting normalized UV intensities into gas phase ozone concentrations. The FOTDP system worked well for in situ monitoring of gas phase ozone using a column packed with sand under various water saturations in the presence of SOM and reflected the ideal transport phenomena of gas phase ozone for various flow rates.     

Primary organic pollutants in New Zealand urban aerosol in winter during high PM10 episodes

In the two biggest New Zealand cities, Auckland and Christchurch, the mass concentration of the PM10 atmospheric aerosol can exceed the 50 microg m(-3) 24 h health guideline in winter. This high pollution level is thought to be caused mainly by old-fashioned domestic heating systems based on wood combustion. Therefore the chemistry of the carbonaceous aerosol has been investigated in several high-pollution level urban situations in order to assess the origin of the pollution. All the high concentration organic tracers, including levoglucosan and dehydroabietic acid, were characteristic for biomass burning. The findings have confirmed via advanced chemical analytical methods that domestic heating can be the main contributor to the high level of wintertime pollution, especially in Christchurch. The results are of great importance in supporting the ambition of authorities and environmental associations to change the domestic heating regimes.