Variability in background levels of surface soil radionuclides in the vicinity of the US DOE waste isolation pilot plant

Concentrations of radionuclides were measured in soils from a grid of locations surrounding the US Department of Energy Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico and from a grid on a reference site approximately 20 km southeast of the WIPP site. Each of the two grids has 16 sampling locations (grid nodes) systematically distributed within an area of 16.580 ha. Sampling was conducted prior to the arrival of the first waste shipment at WIPP. Thus, the 137Cs and 23,240Pu in the soil are expected to have been deposited as global fallout, although the Gnome Site, 8.8 km southwest of the WIPP, is also a potential source of 239,240Pu and fission products. The reference grid has significantly higher concentrations of fallout and natural radionuclides than the WIPP grid. Up to 80% of the total variability in radionuclide concentrations across the two grids is attributable to differences between grid nodes. Differences between replicates within a location account for 44-50% of the variability in concentrations of the uranium isotopes, but only 11-17% of the variability in the concentrations of the other radionuclides. Samples having similar abundance of radionuclides were spatially aggregated across the terrain. The activity concentrations of the radionuclides were strongly correlated with the concentrations of Al and Pb, and with the percentages of sand, silt and clay in the soil. Normalizing radionuclide concentrations to the concentration of Al or percent fine particles can help adjust for differences in soil textures among samples and facilitate the detection of gradients or temporal changes in soil concentrations.     

Weathering of radiocaesium contamination on urban streets,walls and roofs

Recent investigations in Russia have emphasised the significance of dose contributions from contamination on urban streets and roof pavings, and, typically to a lesser extent, walls in the urban environment. The crucial factor determining the magnitude of these contributions is the retention of the contamination by the different types of urban surface. Since the Chernobyl accident, a series of long-term field studies has been carried out on urban streets, walls and roofs, to examine the weathering processes of 137Cs on the various surface types. The derived time-functions are applied to estimate resultant long-term doses to inhabitants of an urban centre. The paper highlights the effect on caesium retention of surface material characteristics.     

Synthesis of polychlorinated biphenyls (PCBs) using the Suzuki-coupling

An improved synthesis of polychlorinated biphenyls (PCBs) utilizing a palladium-catalyzed cross-coupling reaction (Suzuki-coupling) is described. The coupling of (chlorinated) aryl boronic acids 1-3 with bromochlorobenzenes 4 using the standard conditions of the Suzuki-coupling gave the desired PCB congeners 5-7 in good to excellent yields. The self-coupling product of the aryl boronic acids is the major impurity of this reaction. 3,4,5-trichlorophenyl derivatives such as 10 can be synthesized by coupling of an aryl boronic acid with the corresponding bromochloroaniline 8. The approach offers the advantage of high selectivity and good yields compared to conventional methods such as the Cadogan reaction and allows the use of less toxic starting materials.     

Genotoxic damage in free-living Algerian mouse (Mus spretus) after the Coto Doñana ecological disaster

The Do?ana National Park (Spain), one of the most important wildlife sites in the West of Europe, was affected (25 April 1998) by the spill of acidic waste rich in toxic metals (mainly zinc, lead, copper, etc.), arsenic and aromatic amines from the Aznalcollar mine accident. Micronuclei test with May Grunwald-Giemsa and with CREST-antikinetocore staining using DAPI as counter-staining were performed on peripheral blood erythrocytes from Algerian mice to evaluate genotoxic damage. Animals were collected in four locations each differently affected by the disaster. Higher frequencies of micronuclei and CREST-positive micronuclei were observed in the sites, which were reached by toxic sludge and contaminated water in comparison with those located within the park. The results obtained applying the two methods indicate that DAPI staining is more sensitive in detecting micronuclei. Genotoxic biomonitoring should be further carried out in the area to control the mutagenetic level in natural populations.     

Immunotoxicity risks associated with land-treatment of petrochemical wastes revealed using an in situ rodent model

Land-treatment of petrochemical wastes is a widely used method to dispose of hazardous and non-hazardous waste by biodegradation. However, no comprehensive assessment of the impact of such disposal techniques on terrestrial ecosystems has been conducted. Despite the presence of suspected immunotoxicants in the soil, wild rodents frequently reside on these waste sites after closure or abandonment. We explored the seasonal sensitivity of the immune system of the hispid cotton rat (Sigmodon hispidus) to in situ exposures on sites land-treated with petrochemical wastes. Animals were monitored on five contaminated land-treatment sites and five ecologically matched-reference sites in Oklahoma, USA, over two seasons (summer and winter). Most hematological parameters were not adversely affected by land-treatment; however, platelet counts were 26% greater in cotton rats from land-treatment sites compared to reference sites in winter. Significant treatment-related differences were observed in total serum protein concentrations, organ mass and organ cellularity, but these differences were not consistent across the five land-treatment units. Lymphoproliferative responses of cotton rat splenocytes stimulated in vitro were elevated for a T-cell mitogen and depressed for a B-cell mitogen in animals from land-treatment compared to reference sites. The ability of splenocytes to proliferate in response to interleukin-2 receptor-binding was not influenced by treatment. Total yields of peritoneal cells, yield of peritoneal macrophages, and yield of peritoneal lymphocytes were influenced to varying degrees by land-treatment. Functionally, in vitro metabolic activity of peritoneal macrophages was 114% greater in cotton rats from land-treatment sites compared to reference sites during summer. These results indicate that petrochemical wastes applied to soils on these five land-treatment sites had variable immunomodulatory effects in resident cotton rats. Immune alterations for some assays were indicative of enhancement on some land-treatment sites while suppressive on other land-treatment sites, which could have been a function of type and concentration of immunotoxicants present on each site and highlights the uniqueness of each land-treatment site.     

Comparison among air pollutants, meteorological conditions and some chemical parameters in the transplanted lichen Usnea amblyoclada

The response of Usnea amblyoclada (Müll. Arg.) Zahlbr. to real concentrations of atmospheric pollutants measured by two automatic monitoring stations, was studied in Córdoba City, Argentina. The influence of different weather conditions on the biomonitor's response was also assessed. The concentration of chlorophyll a, chlorophyll b, hydroperoxy-conjugated dienes, and malondialdehyde were quantified in lichen thalli collected from a clean area and in transplanted thalli after 1 month of exposure in an urban area, from April to October, 1996. The dry weight/fresh weight, chlorophyll b/chlorophyll a and phaeophytin a/chlorophyll a ratios were also calculated. Data sets were evaluated by two-way analysis of variance and correlation analysis. It was observed that hydroperoxy-conjugated dienes, malondialdehyde, chlorophylls, and pigment degradation increase during winter-time, when higher levels of suspended particles, non-methane hydrocarbons, hydrogen sulfide and ozone were also measured. These findings would be connected mainly with meteorological conditions, as most pollutants did not exceed prescribed threshold levels.     

Air pollution modeling for an industrial complex and model performance evaluation

Jamshedpur, the steel city of India situated in the eastern part of India is affected by increasing air pollution levels as a result of concentrated industrial activities. The impact of NOx emissions resulting from various air pollution sources, viz. industries, vehicles and domestic, was estimated using Industrial Source Complex Short-Term gaussian dispersion model. The contribution of NOx concentration from industrial, vehicular and domestic sources was found to be 53, 40 and 7%. Further statistical analysis was carried out to evaluate the model performance by comparing measured and predicted NOx concentrations. The model performance was found good with an accuracy of about 68%.     

Cadmium,chromium and lead contamination of Athene noctua,the little owl,of Bologna and Parma,Italy

A study was conducted to determine cadmium, chromium and lead concentrations in liver and brain of 52 little owls (Athene noctua) from two provinces of Emilia Romagna region, with the aim of furnishing indirect information concerning contamination of their habitat, also considering possible environmental dispersion of the metals. Metal analysis was performed by atomic absorption spectrophotometry with graphite furnace. Variance analysis with sampling area, gender and age shows that no statistical difference was found for gender, while a significant difference (P<0.05) was found for cadmium and lead, but not for chromium, when sampling areas and age were of concern. For all metals highest mean concentrations were found in liver (170 ppb for cadmium, 297 ppb for chromium and 312 ppb for lead). These levels can be considered as indicative of chronic exposure to low and "background" amounts of pollutants and they are of no toxicological concern, as they are always well below the toxic thresholds defined for each metal. The present study can be considered as a starting point for further analyses, aimed to the definition of any possible subtle effect (e.g. effects on enzymes activity) and of any possible correlation between levels of pollutants and appearance of possible adverse effects. It also furnished useful data for diagnostic cases and potentially for monitoring local contamination.     

Future directions of meteorology related to air-quality research

Meteorology is one of the major factors contributing to air-pollution episodes. More accurate representation of meteorological fields has been possible in recent years through the use of remote sensing systems, high-speed computers and fine-mesh meteorological models. Over the next 5-20 years, better meteorological inputs for air quality studies will depend on making better use of a wealth of new remotely sensed observations in more advanced data assimilation systems. However, for fine mesh models to be successful, parameterizations used to represent physical processes must be redesigned to be more precise and better adapted for the scales at which they will be applied. Candidates for significant overhaul include schemes to represent turbulence, deep convection, shallow clouds, and land-surface processes. Improvements in the meteorological observing systems, data assimilation and modeling, coupled with advancements in air-chemistry modeling, will soon lead to operational forecasting of air quality in the US. Predictive capabilities can be expected to grow rapidly over the next decade. This will open the way for a number of valuable new services and strategies, including better warnings of unhealthy atmospheric conditions, event-dependent emissions restrictions, and now casting support for homeland security in the event of toxic releases into the atmosphere.     

Air quality in the 21st century: community outreach in North Central Texas

Public education campaigns, to be successful, must repeat simple, consistent messages over time, using various sources and media. During the 2000, 2001, and 2002 ozone seasons, the North Central Texas Council of Governments (NCTCOG) employed a four-pronged, multimedia approach to educate the public about air quality in the Dallas/Fort Worth (DFW) region. The four-pronged approach included several varied information sources:The new Air Pollution Watch/Warning system based on public health and designed using standard meteorological terminology with notices delivered via e-mail, over the radio, during TV weather forecasts, and on electronic road signs.A revamped Web page, including information about current air quality, ozone exceedances, clean air public meetings, and how to "Do Your Share for Cleaner Air".A PowerPoint presentation used to explain the basics of ozone air pollution, the new Air Pollution Watch/Warning system, and the new Dallas/Fort Worth Clean Air Plan to a variety of constituencies, including the media, scientific/technical/academic groups, elected officials, and community/civic organizations.Newsletter updates, published in the Environmental Resources Department's InsidER (with a circulation of around 1500), to educate and keep the public up-to-date about various air quality issues.This paper provides details about the four-pronged approach, and how it incorporates principles of successful public education campaigns.