Electrolytic debromination of PBDEs in DE-83 technical decabromodiphenyl ether

Electrochemical debromination of the commercial decabromodiphenyl ether flame retardant DE-83 in partly aqueous tetrahydrofuran (THF) solution gave lower brominated congeners by sequential loss of bromine atoms. Hydrodebromination was most facile for the most heavily brominated congeners. It involves initial electron transfer and proton transfer from water, rather than hydrogen atom abstraction from THF, as shown by experiments with deuterated water. The product distribution from electrolysis involves preferential loss of bromine meta- and para- to the ether linkage, comparable with the products of metabolism of BDE-209 in various organisms. Significantly, the environmentally relevant congeners BDE-47, BDE-99, and BDE-154 were not major products of debromination of BDE-209 by the electron transfer mechanism.     

Seasonal variations of Rn concentrations in the air of a tunnel located in Nagano city

The seasonal variation of 222Rn concentrations in the air of tunnels constructed during World War II at Nagano City has been investigated. The determination of 222Rn concentrations in tunnel air was performed using a solid-state nuclear track detector technique. The monthly radon concentrations changed smoothly, decreasing towards winter and increasing towards summer, and it was found that the concentrations strongly correlate with the temperature difference between the inside and the outside of the tunnel. In the innermost areas of the tunnel, the maximum concentration was observed in July, its value being about 6500 Bq m (-3). The concentrations of radon in the tunnel air decrease exponentially towards the openings of the tunnel, which indicates that the radon concentration in the tunnel is basically governed by diffusion and mixing of radon gas with air. These observations lead to the conclusion that the seasonal variation of the radon concentration in the tunnel air is mainly caused by a convection current due to a stack effect induced by the temperature difference between the tunnel air and the outside air.     

Neighborhood influences on the diffusion of residential photovoltaic systems in Kyoto City,Japan

Environmental Economics and Policy Studies - This study investigates the factors influencing the diffusion of residential photovoltaic systems. Factors examined are related to social attributes,...     

Database of PCDD/PCDF levels in ambient air and in samples related to the pulp and paper industry

A literature and questionnaire survey has been carried out in order that a database be developed for PCDD/PCDF levels in ambient air. The data received to date and entered into the database indicates that standardization in methodologies and reporting is required. The overall response to the survey, even with reminders, was disappointing.     

Improved application of recombinant yeast assays on environmental samples by size exclusion chromatography

The utility of HPLC with a size exclusion chromatography (SEC) column for the fractionation of environmental samples was examined to expand the applicability of recombinant yeast assays (RYAs) for the measurement of estrogenic activity in environmental samples. The elution of steroidal hormone standards through SEC was tested, and river water and sediment samples were subjected to SEC fractionation. The retention times of all estrogen standards were longer than those of the major components with absorbance at 230 nm of the environmental sample matrix. The estrogenic activity of SEC fractions of environmental samples from highly polluted sites was measured using RYA and revealed the existence of estrogenic compounds that could not be detected or quantified in extracted samples before fractionation. The fractions from environmental samples that corresponded to the retention time of estrone, 17[small beta]-estradiol, and estriol were analyzed with LC/MS/MS. These three estrogens were separated into three different fractions, and the concentration of estrone coincided with the estrogenic activity of the fraction in which it was detected. The profile of estrogenic activity of SEC fractions indicated the molecular size of the estrogenic compounds and the yeast growth inhibitors in samples.     

Preliminary report: Dioxins and furans in prescribed burns

The Ontario Ministry of Environment (MOE) recently participated in a joint Canadian/U.S. program to monitor the behavior and environmental impact of prescribed fires. Air, soil and ash samples were collected at the burn sites and analyzed for chlorinated dibenzo-p-dioxins (CDD) and dibenzofurans (CDF). Preliminary results indicated that larger air sample volumes were required.     

Characterization of mass-labeled [13C14]-decabromodiphenylethane and its use as a surrogate standard in the analysis of sewage sludge samples

Very little data is available about the presence of the brominated flame retardant, DBDPE, in the environment. This study reports the characterization of [(13)C(14)]-decabromodiphenylethane and the use of this surrogate standard to positively identify and quantify the presence of DBDPE in sewage sludge samples. The large difference in response factors between BDE-209 and DBDPE predicates the use of [(13)C(14)]-decabromodiphenylethane as a surrogate standard to improve the accuracy when determining the levels of DBDPE in environmental samples.     

Biological monitoring of chlorinated dibenzo-dioxins in the Rainy River using introduced mussels ( )

Mussels from an uncontaminated site were exposed in the Rainy River for 21 days. Polychlorinated dibenzo-p-dioxins (PCDDs) which accumulated in mussel tissues indicated that they are sensitive biomonitors of PCDDs. Several sources of PCDDs were identified including two Kraft pulp and paper mills, a wood waste disposal site and a sewage treatment plant.     

Atmospheric NO2 and CO concentration in Lima,Peru

The atmospheric concentration of NO2 in Lima, Peru was measured through 1 year using passive samplers. The concentration was stable and evident seasonal change was not observed. Also, the distribution of NO2 concentration in entire Lima was monitored twice in different seasons. The average NO2 concentrations at 33 and 27 sites of these monitoring were 17.1 and 15.3 ppb, respectively. NO2 distribution was high in the downtown area and decreased gradually with distance from there. The wind that almost always blew from the ocean had a great influence on it. High NO2 level and the change of CO concentration suggest that the residential area in the northeast side forms a topological channel among hills to blow out the pollutants from the downtown area.     

Seasonal variations of 222Rn concentrations in the air of a tunnel located in Nagano city

The seasonal variation of 222Rn concentrations in the air of tunnels constructed during World War II at Nagano City has been investigated. The determination of 222Rn concentrations in tunnel air was performed using a solid-state nuclear track detector technique. The monthly radon concentrations changed smoothly, decreasing towards winter and increasing towards summer, and it was found that the concentrations strongly correlate with the temperature difference between the inside and the outside of the tunnel. In the innermost areas of the tunnel, the maximum concentration was observed in July, its value being about 6500 Bq m (-3). The concentrations of radon in the tunnel air decrease exponentially towards the openings of the tunnel, which indicates that the radon concentration in the tunnel is basically governed by diffusion and mixing of radon gas with air. These observations lead to the conclusion that the seasonal variation of the radon concentration in the tunnel air is mainly caused by a convection current due to a stack effect induced by the temperature difference between the tunnel air and the outside air.