Cadmium,zinc, copper and metallothionein levels in the kidney and liver of humans from central Poland

Cd, Zn, Cu, and metallothionein (MT) levels have been determined in the renal cortex and liver of 70 persons who died in Lodz and its surroundings in the years 1985–1989. The mean concentrations were: 44.9±28.6 µg Cd/g, 52.0±16.7 µg Zn/g, 2.4±1.0 µg Cu/g, 0.79±0.40 µmol Hg/g, and 3.5±1.8 µg Cd/g, 66.7±30.5 µg Zn/g, 4.9±2.1 µg Cu/g, 0.50±0.38 µmol Hg/g wet tissue in renal cortex and liver, respectively, with mean age 54.0±13.8. Smokers showed 2.4 times higher levels of Cd in the renal cortex than non-smokers. The mean body burden of Cd was 33.4±17.3 mg. Smoking increases it twofold from 22.0 mg in non-smokers to 41.8 mg in smokers.This work was supported by the grant CPBR 11.12(C-56/86) from the Institute of Rural Medicine, Lublin, Poland.Deceased.     

Ultrastructural study and calcium and cadmium localization in the marine coccolithophoridCricosphaera elongata

Cells of the coccolithophoridCricosphaera elongata (Droop) Braarud (Prymnesiophyceae) were concentrated by means of tangential ultrafiltration. Ultrastructural features of control cells were typical of the genusCricosphaera. The flagellar apparatus consists of two flagella, a bulbous haptonema, an axosome and a basal helical band, as recently reported in the literature for another coccolithophorid. We observed a very-well developed Golgi apparatus, displaying all the features of the peculiar Golgi of the Prymnesiophytes. Observations with the light microscope did not reveal any difference between control algae and algae contaminated with 1, 10 and 20 µmol Cd 1^–1 (i.e., 112 µg 1^–1, 1.12 and 2.24 mg Cd 1^–1) for 48 h. However, algae treated with the highest cadmium concentration exhibited loss of motility after 6 h contact, but without apparent ultrastructural damage. Qualitative X-ray microanalysis of the dense granules present in Golgi vacuoles of control cells demonstrated the presence of calcium and chlorine and, at a lower level, sulphur and aluminium. The same elements were also identified in the dense part of the lysosomes. In situ,C. elongata produces coccoliths; this did not occur in culture. However, the coccolith-generating apparatus (Golgi complex and Ca²⁺) was present in culture, and the cells were able to synthesize unmineralized scales.     

Mercury loss from soils following conversion from forest to pasture in Rondônia, Western Amazon, Brazil

This work reports on the effect of land use change on Hg distribution in Amazon soils. It provides a comparison among Hg concentrations and distribution along soil profiles under different land use categories; primary tropical forest, slashed forest prior to burning, a 1-year silviculture plot planted after 4 years of forest removal and a 5-year-old pasture plot. Mercury concentrations were highest in deeper (60-80 cm) layers in all four plots. Forest soils showed the highest Hg concentrations, ranging from 128 ngg(-1) at the soil surface to 150 ngg(-1) at 60-80 cm of depth. Lower concentrations were found in pasture soils, ranging from 69 ngg(-1) at the topsoil to 135 ngg(-1) at 60-80 cm of depth. Slashed and silviculture soils showed intermediate concentrations. Differences among plots of different soil-use categories decreased with soil depth, being non-significant below 60 cm of depth. Mercury burdens were only statistically significantly different between pasture and forest soils at the topsoil, due to the large variability of concentrations. Consequently, estimated Hg losses were only significant between these two land use categories, and only for the surface layers. Estimated Hg loss due to forest conversion to pasture ranged from 8.5 mgm(-2) to 18.5 mgm(-2), for the first 20 cm of the soil profile. Mercury loss was comparable to loss rates estimated for other Amazon sites and seems to be directly related to Hg concentrations present in soils.     

Simple and sequential extractions of heavy metals from different sewage sludges

The presence of heavy metals in the sludges produced in waste-water treatment plants restricts their use for agricultural purposes. This study looks at different types of sludges (aerobic, anaerobic, unstabilised and sludge from a waste stabilisation pond) and compares the distribution of the heavy metals they contain according to the treatment that they have undergone. Some agronomic parameters necessary for characterising a sludge as suitable for use as amendment were determined. The aim of this study is to compare the availability and the localisation of heavy metals in different sewage sludges using simple (water and DTPA) extraction and the BCR (Community Bureau of Reference) sequential extraction procedure. It was confirmed that the total concentration of heavy metals did not exceed the limits set out by European legislation and that the stabilisation treatment undergone by the sludges strongly influenced the heavy metal distribution and the phases to which they were associated and their bioavailability level. The DTPA extraction procedure is cheap and easy to perform and the obtained results are similar to those obtained with the sequential procedure.     

Survival of brown trout during spring flood in DOC-rich streams in northern Sweden: the effect of present acid deposition and modelled pre-industrial water quality

Mortality and physiological responses in brown trout (Salmo trutta) were studied during spring snow melt in six streams in northern Sweden that differed in concentrations of dissolved organic carbon (DOC) and pH declines. Data from these streams were used to create an empirical model for predicting fish responses (mortality and physiological disturbances) in DOC-rich streams using readily accessible water chemistry parameters. The results suggest that fish in these systems can tolerate higher acidity and inorganic aluminium levels than fish in low DOC streams. But even with the relatively low contemporary deposition load, anthropogenic deposition can cause fish mortality in the most acid-sensitive surface waters in northern Sweden during spring flood. However, the results suggests that it is only in streams with high levels of organically complexed aluminium in combination with a natural pH decline to below 5.0 during the spring where current sulphur deposition can cause irreversible damage to brown trout in the region. This study support earlier studies suggesting that DOC has an ameliorating effect on physiological disturbances in humic waters but the study also shows that surviving fish recover physiologically when the water quality returns to less toxic conditions following a toxic high flow period. The physiological response under natural, pre-industrial conditions was also estimated.     

Determination of aliphatic and polycyclic aromatic hydrocarbons in atmospheric particulate samples of a coruña city (Spain)

The hydrocarbon composition of atmospheric particulate matter from A Coruña city (Northwest Spain) has been studied. TSP (total suspended particulate) and PM₁₀ (particulate matter with aerodynamic diameter <10 µm) samples were taken over 7 and 4 months at two stations located in residential and industrial sectors of A Coruña city, respectively. The levels of hydrocarbons found in atmospheric particulate samples of A Coruña city are higher than the ones found in other cities over the world. Ratios between the analysed compounds and their sources were established. Both anthropogenic and biogenic origins were found.     

Assessing microbial communities for a metabolic profile similar to activated sludge.

To search for reliable testing inocula alternatives to activated sludge cultures, several model microbial consortia were compared with activated sludge populations for their functional diversity. The evaluation of the metabolic potential of these mixed inocula was performed using the Biolog EcoPlates and GN and GP MicroPlates (Biolog, Inc., Hayward, California). The community-level physiological profiles (CLPPs) obtained for model communities and activated sludge samples were analyzed by principal component analysis and hierarchic clustering methods, to evaluate the ability of Biolog plates to distinguish among the different microbial communities. The effect of different inocula preparation methodologies on the community structure was also studied. The CLPPs obtained with EcoPlates and GN MicroPlates showed that EcoPlates are suitable to screen communities with a metabolic profile similar to activated sludge. New, well-defined, standardized, and safe inocula presenting the same metabolic community profile as activated sludge were selected and can be tested as surrogate cultures in activated-sludge-based bioassays.     

How ants determine the number of potential recruits

In this paper we present a model that determines the number of potential recruits of Lasius niger, when feeding on a liquid sugar source. The core of the model are two rules: (i) there is a number of workers (facultative foragers) that become potential recruits if starved and (ii) facultative foragers are more likely to become starved than nonforagers because they are more likely to donate food in a trophallaxis (sugar-exchange) event. We develop and explore an analytical model based on these rules, deriving the number of potential recruits after an arbitrary period of starvation. We develop a simplified recruitment model and observe that the predictions of the model are in rough agreement with the empirical data.     

Investigation of organic nitrogen and carbon removal in the aerobic digestion of various sludges

Nitrification and carbon removal are investigated in aerobicbatch digestion of various sludges. The experiments arecarried out with activated sludge (Test 1) and with amixture of activated and primary settling sludge (Test2). The nitrification rate was monitored, measuring theNO₂ ^- concentration. At the 3rd day of thedigestion 40.7 mg_NO2-N/l and 3.89 mg_NO2-N/l werefound in Tests 1 and 2 respectively. In a digestion process,the degradation of biomass indicates the beginning of theendogenous phase. Our measure for biomass content of thesludge was protein analysis. In Test 1, the first day valuesof 50.93 mg_TOC/ g_{dry matter}/day and 138.53mg_protein-C/g_{dry matter}/day for specific TOC andprotein-C removal rates showed, that the digestion processbegan in the endogenous phase. For Test 2, since theendogenous phase began after removal of raw organic matter inprimary settling sludge, specific TOC and protein-C removalrates were observed to be 60.12 mg_TOC/g_{dry matter}/dayand 26.72 mg_protein-C/g_{dry matter}/day,respectively.     

Correction to: Ecological restoration as a strategy for mitigating and adapting to climate change: lessons and challenges from Brazil

Mitigation and Adaptation Strategies for Global Change - The original version of the article unfortunately contained an error.