Decabromodiphenyl ether (deca-BDE) commercial mixture components, and other PBDEs, in airborne particles at a UK site

The occurrence of the major components of the decabromodiphenyl ether (deca-BDE) flame retardant and other PBDEs was investigated in daily air particulate samples from 17th April to 20th May 2004 at a semi-rural site in north-west England. BDE-209 was found at between <0.49 and 100 pg m(-3) (median 13 pg m(-3)), and other higher-brominated PBDE congeners were also found, particularly the nona-BDEs (e.g. BDE-207: <0.042-79 pg m(-3), median 2.5 pg m(-3)). Deca- and nona-BDEs dominated the median particulate sample congener profile: 60% BDE-209, 16% BDE-207, 6% BDE-208 and 4% BDE-206. Nona-BDEs were greatly enriched, relative to BDE-209, compared to the deca-BDE commercial mixture, which may suggest degradation of BDE-209 between source and sampling site, or release from older deca-BDE commercial mixtures, which may have contained higher proportions of nona-BDEs. The highest PBDE concentrations occurred when air-masses passed over urban and industrial areas to the SSW-SW, though small local influences may also be seen. PBDE concentrations appear to have been influenced mainly by particle levels: 1-3 microm diameter particles for BDE-153, and 3-10 microm particles for BDEs with 7-10 Br atoms. BDE-153 may either be released from combustion sources, or re-condense onto small particles after emission, whereas BDE-209 and nona-BDEs appear to be associated with larger dust particles from industrial or domestic sources.     

Transfer of 90Sr to rice plants after its acute deposition onto flooded paddy soils

The transfer of 90Sr to rice plants following its acute ground deposition was examined experimentally in a greenhouse. Lysimeters were flooded after being filled with the soil monoliths from 12 paddy fields. A solution of 90Sr was applied to the standing water in the flooded lysimeters at the pre-transplanting stage or booting stage. Applied 90Sr was mixed with the topsoil only after the pre-transplanting application (PTA). The transfer was quantified with the areal transfer factor (TF(a), m2 kg(-1)-dry) defined as the ratio of the plant concentration to the initial ground deposition. In the PTA, the first-year TF(a) values in the 12 soils were in the range of 8.2 x 10(-3) -2.1 x 10(-2) and 1.7 x 10(-4) -3.6 x 10(-4) for the straws and hulled seeds, respectively. The TF(a) values from the booting-stage application (BSA) were higher than those from the PTA by a factor of up to four. The ratios of the seed TF(a) to the straw TF(a) were, on the whole, higher in the BSA. The 90Sr TF(a) in the PTA was negatively correlated with the soil pH and, to a lesser degree, the exchangeable Ca content. In the second year, the TF(a) in the PTA reduced to 53-90% of that in the first year. A more significant reduction, in general, occurred in a sandier soil. Based on the four consecutive years' transfer data, an overall half-time of the 90Sr TF(a) was estimated to be 2.2 years.     

Freshwater crayfish Astacus leptodactylus (Eschscholtz, 1823) accumulates and depurates copper

Cu accumulation and depuration in various tissues of the crayfish Astacus leptodactylus was investigated. Adult specimens were exposed to 0.5, 2.5 and 5.0 mg Cu/L under static conditions for three weeks. At the end of the 3rd week the specimens were divided into three groups and left in dechlorinated water for either 1, 2 or 3 weeks for depuration. After 7, 14 and 21 days, four crayfish from each group were instantaneously sacrificed. All crayfish were dissected into their hepatopancreas, gill, abdominal muscle and exoskeleton tissues for evaluation of Cu accumulation in each. The following accumulation pattern was obtained in decreasing order; hepatopancreas > gills > exoskeleton > abdominal muscles with values of 94.13, 84.86, 66.13 and 11.43 mg/L, respectively. The observed Cu depuration throughout the study was found to be time-dependent. Based on the present work we conclude that crayfish has a great potential for rapid accumulation and depuration of Cu in fresh water.     

Effect of UV radiation and temperature on mineralization and volatilization of coumaphos in water

This study was undertaken to determine the dissipation and degradation of coumaphos [O-(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl) O,O-diethyl phosphorothioate] under different sunlight conditions and at different temperatures. The effect of the ultra violet (UV) component of solar radiation was also studied using quartz tubes in addition to other radiation in the visible range using glass tubes and the results were compared with those obtained under the dark light conditions. Water suspensions of coumaphos were incubated at three temperatures viz. 22 degrees C, 37 degrees C and 53 degrees C in closed systems to study the effect of temperature. Volatilization, mineralization and degradation of coumaphos increased with an increase in temperature and exposure to solar radiation, particularly under the UV component of the solar radiation. Major loss of the pesticide occurred through volatilization. The optimum temperature for the degradation of coumaphos was found to be at 37 degrees C. The data obtained from the mineralization and degradation studies indicated that 53 degrees C crosses the biological range for suitable growth of microorganism. UV radiation exposure along with maintaining temperature at 37 degrees C may prove useful in the dissipation and/or degradation of coumaphos prior to its disposal as waste from cattle dipping vats.     

Do national advisories serve local consumers: an assessment of mercury in economically important North Carolina fish

Consumption of marine fish provides both benefits (lean protein, omega-3 fatty acids and essential nutrients) and risks (main source of mercury (Hg) exposure for humans). Mercury is a potent neurotoxin and the source of more fish advisories nationwide than any other toxicant. Despite the widespread nature of Hg, it is unknown whether local Hg contamination reflects national and regional levels often used as bases to inform consumers of potential fish consumption risk. Thus, the objectives of our study were to examine Hg levels of six commonly consumed marine species harvested locally off the North Carolina coast and to compare our results to published regional (Monterey Bay Aquarium's Seafood Watch List) and national (Environmental Protection Agency, EPA, and Food and Drug Administration, FDA) Hg averages, action levels, and guidelines. We found significant differences in Hg concentrations among collected species, and we identified correlations between Hg concentration and fish length and trophic levels. Collected mahi mahi and triggerfish were below the EPA fish tissue action level (0.3ppm). Wahoo and grouper exceeded the EPA action level but were below the FDA action level (1.0ppm). King mackerel had the highest Hg concentration among targeted species, exceeding both EPA and FDA action levels. Further, our local results were not always consistent with calculated averages from EPA and FDA databases for the same species, and although many of our findings were consistent with Monterey Bay Aquarium's Seafood Watch List (southeast region), recommendations based on Hg levels would conflict with recommendations they provide based on sustainability. We find regional and national averages are not always reflective of local Hg contamination and suggest local data may be needed to accurately assess consumer risk.     

The impact of vehicular fallout on the Pra estuary of Ghana (a case study of the impact of platinum group metals (PGMs) on the marine ecosystem)

It is increasingly being recognised and environmental measurements have demonstrated that Platinum (Pt) (and potentially Rhodium (Rh) and Palladium (Pd)) is released with the ageing of catalytic converters. Platinum is a particular concern as it has a known mutagenic and toxic effect, even at exceedingly low concentrations, in urban air (affecting human health) and urban water (affecting ecosystem health). In the context given above and given the still keen lack of reliable experimental data on the levels of Pd, Pt and Rh in water and sediment, this study determined the concentration of such elements in water and sediment of the Pra estuary in the Western Region of Ghana where it is estimated that more than two thousand cars pass over the bridge under which the river flows to join the sea each day. Elevated concentrations of platinum (Pt), palladium (Pd) and Rhodium (Rh) were found to be associated with water and soils from areas of high traffic densities (Beposo) suggesting that vehicles also contribute heavy metals (PGMs) to the environment. The result showed elevated levels of these metals in river bank, waterbed and in the water. There is therefore the tendency of possible accumulation of these metals in plant and animals along these areas.     

Environmental estrogenic effects and gonadal development in wild goldfish (Carassius auratus)

Serum vitellogenin (VTG) contents of wild goldfish (Carassius auratus) were investigated as a sensitive biomarker for artificial estrogenic compounds in aquatic environments. Goldfish was sampled from a pristine area, a river situated 5 km downstream from a sewage treatment works (STW), and also from the Young-San River in Korea. The female yolk precursor protein VTG was not detected when gonadosomatic index (GSI) was less than 0.85%, while VTG levels of >10 microg/ml were found in males whose GSI was less than 1.53%. In male goldfish sampled from STW and the Young-San River, the higher VTG corresponded to lower GSI. This study suggested a trend that gonad development was connected to VTG levels in both sexes, and the application of GSI and histological analysis provide an attractive possibility that it could be included in the panel of markers used for estrogenic activity investigation of aquatic environments.     

Inhibition kinetics of certain enzymes in the nervous tissue of vector snail Lymnaea acuminata by active molluscicidal components of Sapindus mukorossi and Terminalia chebula

Effect of active molluscicidal components of Sapindus mukorossi and Terminalia chebula on the acetylcholinesterase (AChE), acid and alkaline phosphatase (ACP/ALP) activity in the nervous tissue of freshwater snail Lymnaea acuminata were studied. In vivo and in vitro exposure of saponin (active component of S. mukorossi pericarp) and tannic acid (active component of T. chebula) significantly inhibited the AChE, ACP and ALP activity in the nervous tissue of L. acuminata. The inhibition kinetics of these enzymes indicate that saponin and tannic acid caused competitive and competitive-non-competitive inhibition of AChE, respectively. Saponin also caused competitive and competitive-non-competitive inhibition of ACP and ALP, respectively, whereas tannic acid caused competitive-non-competitive inhibition of ACP and ALP. Thus the inhibition of AChE, ACP and ALP by saponin and tannic acid in the nervous tissue of L. acuminata may be the cause of molluscicidal activity of S. mukorossi and T. chebula.     

'All hazards approach' to disaster management: the role of information and knowledge management, Boyd's OODA Loop, and network-centricity

The ever-increasing complexity of disasters demands utilisation of knowledge that exists outside domains traditionally drawn upon in disaster management. To be operationally useful, such knowledge must he extracted, combined with information generated by the disaster itself, and transformed into actionable knowledge. The process, though, is hampered by existing, business-oriented approaches to knowledge management, by technical issues related to access to relevant, multi-domain information/knowledge, and by executive decision-making processes based predominantly on historical knowledge. Consequently, as shown by many recent incidents, the management of large-scale (mega) disasters is often inefficient and exceedingly costly. This paper demonstrates that the integration of modified information and knowledge management into the concepts of network-centric operations and network-enabled capabilities, and the employment of Boyd's OODA (Observe, Orient, Decide, and Act) Loop-based decision-making in unpredictable and dynamically changing environments, may address some of these problems.     

Nitrate reductase, arginine deaminase, urease and dehydrogenase activities in natural soil (ridges with forest) and in cotton soil after acetamiprid treatments

Soil enzymes are indicators of microbial activities in soil and are often considered as an indicator of soil health and fertility. They are very sensitive to the agricultural practices, pH of the soil, nutrients, inhibitors and weather conditions. To understand the effect of an insecticide, acetamiprid (IUPAC Name: (E)-N1-[(6-chloro-3-pyridyl) methyl]-N2-cyano-N1-methyl acetamidine) on different soil enzyme activities, the experiments were conducted for three consecutive years (2003--2005) at control and cotton experimental fields of Indian Agricultural Research Institute (IARI) and natural area (ridges with forest) in Delhi. The combined results for all three years were presented here to understand the impact of acetamiprid on soil enzyme activities. Acetamiprid was applied three times in one crop season after 41, 48 and 73 days of sowing, to control the pest. Soil of treated fields was analyzed for insecticide residues immediately after first insecticide treatment and thereafter at definite period. The residues of acetamiprid in experimental soil was varied from 0.30+/-0.13 to 22.67+/-0.2 microg g(-1)d.wt. soil, during the crop period of 2003. The insecticide residues for 2004 ranged between 0.59+/-0.38 and 13.42+/-0.71 microg g(-1)d.wt. soil and for 2005 it ranged between 0.48+/-0.22 and 19.81+/-0.33 microg g(-1)d.wt. soil. An average half life of acetamiprid in our treated field was 11.2+/-1.7 days for all three years. Similarly, the soil from natural area and control were also tested for insecticide residues. No detectable insecticide residues had been found. Soil from three localities i.e. natural, control and experimental fields were tested for different enzyme activities. Nitrate reductase, arginine deaminase, urease and dehydrogenase activities were high in natural soil in comparison to control soil and insecticide treated soil in all three experimental years. At the same time, nitrate reductase activity was all time low in acetamiprid treated soil. Acetamiprid had inhibitory effects on nitrate reductase, arginine deaminase and urease activities. After first treatment (43 days after crop sowing), nitrate reductase (41%), arginine deaminase (22%) and urease (35%) activities were declined. Dehydrogenase activity increased to 22% after first insecticide application. Enzyme activities were recovered at the end of each crop season. Therefore, it can be attributed that agricultural practices, weather conditions and use of acetamiprid might be responsible for the different level of enzyme activities in soil.