Bioaccumulation of toxic metals (Cr, Cd, Pb and Cu) by seeds of Euryale ferox Salisb. (Makhana) W

The level of toxic metals Cr, Cd, Pb and Cu was determined in seeds, water and sediments collected from nine closed waterbodies of Darbhanga, north Bihar, used for cultivation of the edible aquatic macrophyte Euryaleferox Salisb. during harvesting season of the crop for two successive years (1996 and 1997). Seeds bioconcentrated appreciable amount of these toxic metals in the order Pb > Cr > Cu > Cd. The increased load of metal pollution due to domestic and municipal discharges threatened the habitats of the plant. The toxic metal contents in seeds were found positively correlated with the ambient concentration of metals in water and sediments. The importance of these findings has been discussed for national water resource economy of the country and human health perspectives.     

Regiospecific dechlorination of spiked tetra- and trichlorodibenzo-p-dioxins by anaerobic bacteria from PCDD/F-contaminated Spittelwasser sediments

Samples were taken from sediment of the River Spittelwasser (district Bitterfeld, Germany), which is highly polluted with PCDD/Fs and other chloroorganic compounds. The sediment cores were separated into 10-20 cm thick layers, spiked with 50 microM of 1,2,3,4-tetrachlorodibenzo-p-dioxin and incubated for 8 months under anaerobic conditions in the presence of cosubstrates. Reductive dechlorination of the tetrachlorinated congener and formation of tri- and dichlorinated products were observed in all biologically active incubations. Analysis of subcultures spiked with 1,2,3- and 1,2,4-trichlorodibenzo-p-dioxin, respectively, revealed two different dechlorination pathways within the sediment cores. Pathway M was characterized by the simultaneous dechlorination of peri- and lateralchlorine atoms, whereas sequence SP was restricted to the dechlorination at positions flanked by chlorine atoms on both sides.     

Some heavy metals, essential elements, and chlorinated hydrocarbons in polar bear (Ursus maritimus) at Svalbard

During the period 1978-1989, samples of liver, kidney and subcutaneous fat from 24 polar bears, Ursus maritimus, from Svalbard were analysed for mercury, cadmium, lead, copper, zinc, selenium, arsenic, HCB, DDE, PCBs (as Aroclor 1260 or Phenoclor DP6). In a selected number of liver (seven) and fat (three) samples, the composition of individual PCB congeners was studied by comparison with 23 individual PCB congeners (IUPAC nos 28, 52, 74, 101, 99, 110, 149, 118, 114, 105, 153, 141, 138, 187, 128, 183, 156, 157, 180, 170, 194, 206 and 209). In the seven liver samples, the concentrations of o,p'- and p,p'-isomers of DDT, TDE, DDE, alpha-, beta- and gamma-HCH, oxychlordane, heptachlor, heptachlorepoxide, aldrin and dieldrin were also determined. The hepatic concentrations of mercury, cadmium and lead in animals of all ages were 0.4-6.0, <0.1-1.2, and <0.5-1.6 microg g(-1), respectively. This indicates a moderate exposure. Concentrations of mercury and selenium were correlated (r=0.80). The levels of copper and zinc represented normal physiological concentrations. The concentrations of HCB, DDE and PCBs in fat were <0.05-1.5, <0.1-3.4 and 2.9-90 microg g(-1), respectively. The corresponding results for liver were <0.01-0.11, <0.1-0.5 and 0.1-78 microg g(-1), respectively. Six PCB congeners, PCB-99, -153, -138, -180, -170, and, -194 accounted for about 99 and 87% of the total PCB content (sum of the 12 congeners, nos. 28, 99, 153, 138, 128 + 187, 156, 157, 180, 170, 194, 206 and 209) in liver and fat, respectively. PCB-153 represented 37+/-3 30+/-16% of the sum PCB (sum of 12 congeners) in liver and fat, respectively. The range of the hepatic concentration of oxychlordane was 5-19 microg g(-1). Quantifiable concentrations of heptachlor, heptachlorepoxide, beta-HCH and dieldrin were also found in all the liver samples analysed. Low concentrations of p,p'- and o,p'-DDT were found in two of seven liver and two of two fat samples. Comparisons are made with investigations from Canada and Greenland. Possible effects of PCBs, especially on reproduction, cannot be excluded. Ringed seal, Foca hispida, and to some extent bearded seal, Erignathus barbatus, are the main food of the polar bear. It is therefore likely that the exposure to environmental pollutants occurs via the consumption of these two species.     

Simultaneous sampling of PCDD/PCDF inside the combustion chamber and on four boiler levels of a waste incineration plant

At a MSWI (municipal solid waste incinerator) plant PCDD/PCDF samples (gasphase and particulates) were taken simultaneously be a shock-freezing method in the incinerator combustion chamber at approx. 800°C and in four sampling sections in the boiler at about 490°C, 370°C, 330°C and 270°C. In this way PCDD/PCDF-formation in the flow through the boiler was determined. Two data sets were evaluated. A considerable PCDD/PCDF-formation had occurred already at boiler temperatures of about 490°C; the highest concentration, however, was found at the end of the boiler at about 300°C. The accompanying measuring program of plant parameters made the calculation of the PCDD/PCDF mass flows possible, which allowed the inclusion of the PCDD/PCDF-content in the ESP dust in the mass flow calculations.     

Evaluation of a respirometric test method to determine the heterotrophic yield coefficient of activated sludge bacteria

The heterotrophic yield coefficient of activated sludge bacteria is an important parameter in the field of wastewater degradation kinetics and the determination of degradation kinetics of defined chemicals. With the help of easily biodegradable organic compounds like glucose and acetate the respiration kinetics of degrading activated sludge bacteria was studied. The results of the respiration analysis were transformed to examine the degradation and respiration kinetics of municipal wastewaters at different food to microorganism ratios (F/M ratios). It was proved that the heterotrophic yield coefficient of aerobically degrading activated sludge bacteria could reliably be determined and that the heterotrophic yield coefficient was independent of the F/M ratio over a wide range.     

Temporal trends of organochlorines in Northern Europe, 1967-1995. Relation to global fractionation, leakage from sediments and international measures

The time trend monitoring of organochlorine pollution was carried out in Sweden since the late 1960s. This report presents data on concentrations of DDT, PCB, HCHs and HCB in biota samples collected and analysed annually. All the matrices and compounds studied show a significant decrease over time. The data cover severely polluted Swedish marine and fresh water in southern Sweden as well as locally unpolluted waters in remote northern Arctic regions of Sweden. A total of 13 time series representing different locations and species are presented for the different pollutants. The period studied covers the time when pollution was serious as well as the time of recovery. All monitoring activities were carried out at the same laboratories over the entire study period, which means that comparability over time is good in the sets of data presented. The various time trends show a convincing agreement with trends and annual change over time, although the concentrations differ between the species and locations investigated, the highest concentrations being in the south. Since the annual changes are normally similar regardless of locations and species, spatial variations in concentrations remain over time, although concentrations are lower today. The onset of changes in concentrations over time can be related to international measures or other circumstances that lowered releases into the environment. Similarities in the annual changes, as well as the time when changes began, are discussed with respect to suggested hypotheses on the fate of the investigated organochlorines. It was not possible to verify that the oxygenation of anoxic sediments mobilised old pollution in Baltic sediments. Neither was it possible to conclude that eutrophication has caused a measurable effect on the rate and timing of the decreases. Finally, long-range transport to Arctic regions seems to be due more to a one step transport than to the 'Grass-hopper' effect. The comprehensive database used, clearly shows how important it is to have datasets big enough to describe between-year variation before attempting to evaluate the time trend. In addition, if between-year variation is not known, it is then also difficult to evaluate spatial variation on the basis of single year observations.     

Edaphological characteristics of unweathered and weathered fly ashes from Gondwana and lignite coal

Naturally weathered and unweathered samples of fly ashes produced from Gondwana and lignite coals were characterized for their edaphological properties. The particle size distribution in these fly ashes varied widely, and the percentage of [Formula: see text] size particles governed their water holding capacity. All fly ashes were noncoherent in the dry state and had lower particle density than quartz and mulite. The fly ashes were low in available N, but were sufficient in available P, K, Ca, Mg, S, Cu, Fe, Mn, Zn and B. Among the fly ashes, unweathered lignite fly ash was the richest source of K, Ca, Mg, S and Fe, while weathered lignite fly ash had the highest amounts of Mn, Zn and B. The pH of the fly ashes was closely related to the ratio of exchangeable Ca to exchangeable Al. The fly ashes were high in soluble salt, but were poor in cation exchange capacity. As an amendment to correct soil pH, the fly ashes had a poor buffering capacity. Weathering decreased the total Fe, available S and exchangeable Na percentages, but increased the organic C content of the fly ashes. Invariably, an excess of soluble salts and exchangeable Na could limit plant growth on fly ash dumps. Toxic levels of B and Al existed in only some fly ashes.     

Organochlorines in polar bears (Ursus maritimus) at Svalbard

A comprehensive survey on organochlorine (OC) contaminants in polar bears at Svalbard has been undertaken. Subcutaneous tissue, blood and milk have been sampled from anesthetized free-ranging bears of both sexes and different ages in the period from 1990 to 1994. A number of sexually mature females have been fitted with satellite transmitters which make it possible to follow their reproductive behaviour pattern. We report on contamination levels and pattern of PCB congeners, chlordanes, DDT-compounds, HCB and HCH-isomers in the various tissues. The relation of age, sex and reproductive status to OC contamination has been described, and the capacity of polar bears in metabolising OCs has been discussed from the isomer/metabolite composition of residues. Finally, the possible association between OC contamination and reproduction success has been assessed. The PCB levels present in polar bears at Svalbard are extremely high. Especially high levels of higher chlorinated PCBs are found, and they accumulate with age, particularly in males. With females, considerable amounts of OCs are transferred to the offspring via milk. However, more efficient OC transfer between subcutaneous depot lipid and circulatory lipids than from the circulatory system to milk is found particularly for the most lipophilic compounds. The OC pattern in suckling yearlings reflects the low transfer of the highest chlorinated PCBs into maternal milk. The levels of most other OCs, however, are higher in depot lipid of yearlings than in that of their mothers. The polar bears have high capacity to metabolise several OCs. This may protect them against toxic action of the contaminants. No relation between OC levels in females and their ability to get pregnant is found in this preliminary investigation on OC effects on the polar bears at Svalbard.     

Risk assessment of PBDEs and PAHs in house dust in Kocaeli,Turkey: levels and sources

Indoor dust samples were collected from 40 homes in Kocaeli, Turkey and were analyzed simultaneously for 14 polybrominated diphenyl ethers (PBDEs) and 16 poly aromatic hydrocarbons (PAHs) isomers. The total concentrations of PBDEs (Σ₁₄PBDEs) ranged from 29.32 to 4790 ng g^?1, with a median of 316.1 ng g^?1, while the total indoor dust concentrations of 16 PAHs (Σ₁₆PAHs) extending over three to four orders of magnitude ranged from 85.91 to 40,359 ng g^?1 with a median value of 2489 ng g^?1. Although deca-PBDE products (BDE-209) were the principal source of PBDEs contamination in the homes (median, 138.3 ng g^?1), the correlation in the homes was indicative of similar sources for both the commercial penta and deca-PBDE formulas. The PAHs diagnostic ratios indicated that the main sources of PAHs measured in the indoor samples could be coal/biomass combustion, smoking, and cooking emissions. For children and adults, the contributions to ∑₁₄PBDEs exposure were approximately 93 and 25 % for the ingestion of indoor dust, and 7 and 75 % for dermal contact. Exposure to ∑₁₆PAHs through dermal contact was the dominant route for both children (90.6 %) and adults (99.7 %). For both groups, exposure by way of inhalation of indoor dust contaminated with PBDEs and PAHs was negligible. The hazard index (HI) values for BDE-47, BDE-99, BDE-153, and BDE-209 were lower than the safe limit of 1, and this result suggested that none of the population groups would be likely to experience potential health risk due to exposure to PBDEs from indoor dust in the study area. Considering only ingestion + dermal contact, the carcinogenic risk levels of both B2 PAHs and BDE-209 for adults were 6.2 × 10^?5 in the US EPA safe limit range while those for children were 5.6 × 10^?4 and slightly higher than the US EPA safe limit range (1 × 10^?6 and 1 × 10^?4). Certain precautions should be considered for children.