Assessment of health risk associated with persistent organic pollutants in water

This paper presents the results of analyses of water samples taken from water intakes supplying one of the districts located near the city of Wroc?aw. Surprisingly high concentrations of polychlorinated biphenyls and chloroorganic pesticides, classified as persistent organic pollutants (POPs), were detected in the monitored sites. Basing on the analytical and toxicological data, the individual health risks related to carcinogenic effects (excess cancer risk over a lifetime) in humans were assessed, resulting from direct ingestion of community water. Also noncarcinogenic effects resulting from exposure to the examined POPs were determined. The conservative approach to risk assessment, taking into account a safety margin for data incompleteness, was adopted. The carcinogenic risk was found to slightly exceed the unconditionally acceptable risk of 10^?6 in the case of polychlorinated biphenyls and hexachlorocyclohexane, for all the inhabitant populations. The determined values of noncarcinogenic effects expressed by hazard quotient and hazard index indicate that the water pollutants and their concentrations do not cause an increase in noncarcinogenic incidences in the inhabitants using the monitored water sources.     

Ecotoxicity and biodegradability of antielectrostatic dicephalic cationic surfactants

Four series of dicephalic cationic surfactants, considered as new antielectrostatic agents have been investigated in order to establish their toxicity and biodegradability. Among them N,N-bis[3,3′-(dimethylamine)propyl]alkylamides, N,N-bis[3,3′-(dimethylamine)propyl]alkylamide dihydrochlorides, N,N-bis[3,3′-(trimethylammonio)propyl]alkylamide dibromides and N,N-bis[3,3′-(trimethylammonio)propyl]alkylamide dimethylsulphates with different hydrophobic chain length (n-C₉H₁₉ to n-C₁₅H₃₁) and type of counterion (chloride, bromide and methylsulfate) have been studied. The inhibitory effect against microorganisms has been examined using model gram-positive and gram-negative bacteria, and yeasts. None of the tested surfactants have shown antimicrobial activity against gram-negative bacteria (Escherichia coli, Pseudomonas putida) and yeasts (Saccharomyces cerevisiae, Rhodotorula glutinis) at a concentration below 1000 μg mL⁻¹, however some of them were moderately active against gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis). The Microtox® test was successfully applied to measure EC₅₀ values of the studied dicephalic cationic surfactants. Their toxicity to Vibrio fischeri depended upon the alkanoyl chain length with the EC₅₀ values in a range of 2.6-980 mg L⁻¹. N,N-bis[3,3′-(dimethylamine)propyl]alkylamide dihydrochlorides 2a-b and N,N-bis[3,3′-(trimethylammonio)propyl]alkylamide dibromides 3a-b comprising n-decanoyl and n-dodecanoyl hydrophobic tails appeared to be the least toxic. Furthermore, the biodegradability under aerobic conditions of 2a-b, 3a-b was evaluated using OECD Method 301F. According to the obtained results 2a, 3a-3b can be considered as almost readily biodegradable and they are not expected to be persistent in the environment. Additionally, partial biodegradation was observed for 2b, indicating its possible biodegradation in wastewater treatment systems.     

Inorganic and methyl-mercury speciation in sediments of the Swarzędzkie Lake

Sediment samples were analysed for mercury and methylmercury content in different parts of the bottom sediment of Swarz ?dzkie Lake, which were influenced by different external pollution sources. The results of determination with two methods of mineralization using two separate media (HNO₃/H₂O₂ and HF) were compared. The accuracy of the studied methods was analysed using certified reference material IAEA 405 of river sediment. The recovery of mercury was satisfactory and ranged from 97.5 to 98.8%. Methylmercury compounds in the studied sediments were found in limited concentrations. Their concentrations ranged from 0.26 to 58.1 μg kg^?1, i.e. 1.0–7.4% of the total mercury content. The depth profile displayed high values of both total and methylmercury content at a depth of 10–20 cm, related to the heavy pollution of the lake in the 1980s. Canonical analysis displayed the relationship of both total mercury and methylmercury concentrations with organic matter and phosphorus content in bottom sediments.     

Spatial distribution and reduction of PCDD/PCDF Toxic Equivalents along three shallow lowland reservoirs

Reservoirs situated along a river continuum are ecosystems where rates of transfer of suspended matter and associated micropollutants are reduced due to sedimentation, accumulation, and biological and physical transformation processes. Among the micropollutants, PCDDs and PCDFs are substances that are highly toxic and carcinogenic for humans and animals. They are emitted and dispersed in the environment throughout the whole catchment area and may accumulate in aquatic and terrestrial food chains, creating a risk for human health. A wealth of data exists indicating the increase in the concentrations of pollutants along a river continuum. A comparative analysis of total, individual, and TEQ PCDD/PCDF concentrations in large lowland, shallow reservoirs located in different catchments (“I”—industrial/urban/agricultural, “U”—urban/agricultural, and “A”—agricultural/rural) showed decreases of the TEQ concentrations in bottom sediments along a gradient from the middle sections to the dam walls. Moreover, penta-, hexa-, and heptachlorinated CDD/CDF congeners were reduced from 28.8 up to 93.6 % in all three types of reservoirs. A further analysis of water samples from the inlets and outlets of the “A” reservoir confirmed this tendency.     

Adaptive alterations in the fatty acids composition under induced oxidative stress in heavy metal-tolerant filamentous fungus Paecilomyces marquandii cultured in ascorbic acid presence

The ability of the heavy metal-tolerant fungus Paecilomyces marquandii to modulate whole cells fatty acid composition and saturation in response to IC₅₀ of Cd, Pb, Zn, Ni, and Cu was studied. Cadmium and nickel caused the most significant growth reduction. In the mycelia cultured with all tested metals, with the exception of nickel, a rise in the fatty acid unsaturation was noted. The fungus exposure to Pb, Cu, and Ni led to significantly higher lipid peroxidation. P. marquandii incubated in the presence of the tested metals responded with an increase in the level of linoleic acid and escalation of electrolyte leakage. The highest efflux of electrolytes was caused by lead. In these conditions, the fungus was able to bind up to 100 mg?g^?1 of lead, whereas the content of the other metals in the mycelium was significantly lower and reached from 3.18 mg?g^?1 (Cu) to 15.21 mg?g^?1 (Zn). Additionally, it was shown that ascorbic acid at the concentration of 1 mM protected fungal growth and prevented the changes in the fatty acid composition and saturation but did not alleviate lipid peroxidation or affect the increased permeability of membranes after lead exposure. Pro-oxidant properties of ascorbic acid in the copper-stressed cells manifested strong growth inhibition and enhanced metal accumulation as a result of membrane damage. Toxic metals action caused cellular modulations, which might contributed to P. marquandii tolerance to the studied metals. Moreover, these changes can enhance metal removal from contaminated environment.     

Transformation of a lowland river from a meandering and multi-channel pattern into an artificial canal: retracing a path of river channel changes (the Middle Obra River, W Poland)

At the beginning of the nineteenth century, a significant change in sedimentation took place along the middle course of the Obra River (W Poland): a “natural” channel bed was replaced by three artificial canals. Before that time the Obra River bed had been characterized by various river patterns (braided, meandering and disappearing in wetlands). GPR (ground-penetrating radar) surveys and the analysis of satellite and aerial images were carried out to retrace the natural river course near the village of Kopanica. The GPR, ground-truthed with core data, revealed that at least two types of the river pattern had been functioning here before the period of the hydrotechnical works: a large-scale meandering pattern (width-to-depth (w/d) ratio ranging from 15 to 40) and a relatively smaller-scale multi-channel pattern (w/d = 11–22). Possibly, the transformation was caused by forming a series of large floods followed by in-channel aggradation and avulsions. Next, the multi-channel pattern was artificially transformed into the North Obra Canal. This paper discusses possibilities of a creation of network of channels that were active after the construction of the North Obra Canal in the beginning of the nineteenth century. Such intervention would increase natural values of the presented section of the Obra valley. The presented study also shows that a detailed analysis of history and evolution of a given river course is needed before undertaking any restoration works.     

An appraisal of changes in seasonal water quality during passage through a shallow reservoir in Western Poland

Following restoration changes in Antoninek Reservoir physico-chemical and biological processes in the water column and bottom sediments were measured to outline mechanisms of changes in nitrogen, phosphorus and organic matter concentrations during water flow through this reservoir. Intensive mineralisation of organic matter in the shallow sediments stimulated primary production and influenced increasing ammonia and nitrite nitrogen concentrations. Two main factors affected concentrations of phosphorus: (1) its presence in the external loads of river waters entering the reservoir, more important in the colder seasons as the water discharge was higher and (2) from the internal loads coming from bottom sediments. The quality of the river water during its flow through this reservoir improved for most parameters and seasons. However, concentrations of nutrients were still high in waters flowing out from the reservoir and in some months they were higher in the outflow than in waters entering the reservoir.     

Metal contamination of farming soils affected by industry

The contents of nine elements (As, Cd, Cr, Cu, Hg, Ni, Pb, Sb and Zn) have been assayed in the farming soils of Suszec commune (southern Poland). This area is affected by the main industrial centre of Poland (the Upper Silesian Industrial Region), the Czech Republic (Trzyniec smelter) and local contamination sources (coal mine). The contamination of the soils was assessed on the basis of geoaccumulation index, enrichment factor, contamination factor and degree of contamination. The tests revealed elevated contents of cadmium, lead, arsenic, antimony and mercury. The contents of the other elements were similar to the levels in the Earth's crust or pointed to metal depletion in the soil (EF<1).     

Radon concentration in hospital buildings erected during the last 40 years in Białystok, Poland

The aim of the study was to compare radon concentrations in neighbouring hospital buildings which were constructed in different years during the period 1963-2000 and are located in areas with similar radon potential. The value of arithmetic mean (AM) radon concentration in soil gas amounted to 14,464 Bq m(-3). In a hospital built 40 years ago, the AM radon concentration in the cellar was 38.4+/-36.7 Bq m(-3) and on higher levels it was 17.1+/-10.3 Bq m(-3). In a hospital built 16 years ago, these values equaled 45.5+/-47.2 Bq m(-3) and 20.4+/-12.5 Bq m(-3), respectively. In the newest hospital, built three years ago, radon concentration (AM) in a cellar was 32.3+/-27.4 Bq m(-3) and the respective value on higher levels amounted to 20.4+/-12.6 Bq m(-3). When comparing radon concentrations in the cellars, no statistically significant differences were found. Similarly, no statistically significant differences were observed between radon concentrations measured on higher levels in investigated hospital buildings.     

Radon concentrations in groundwaters of the Polish part of the Sudety Mountains (SW Poland)

In the course of researches into radon occurrence in the groundwaters of the Polish part of the Sudety Mountains, conducted in various research centres in Poland, almost 1000 radon concentration determinations have been collected. These results have given the basis for an attempt to characterise the groundwaters of this region with respect to radon content. Radon concentrations oscillated within the range of 0.2-1645 Bq/dm3, with the arithmetic mean at 240.0 Bq/dm3 and the geometric mean at 106.7 Bq/dm3. The largest number of radon concentrations found in the Sudetic groundwaters ranged between ca. 3-6 and 1000 Bq/dm3. The values over 1000 Bq/dm3 can be considered anomalously high. They constitute 3.9% of all the results and occur around six localities within different geological units of the Sudety Mountains. These are shallow circulation, low mineralised groundwaters, which outflow from gneisses and granites. In the face of the fact that from 12.8% to 72.7% (depending on the adopted norm of maximum radon concentration for drinking waters) of the examined waters cannot be drunk directly without removing at least part of the radon, and in the face of the possibility of recognizing as many as 63.5% of the waters as potentially medicinal, extensive research of radon geochemistry in the Sudety Mountains area should be urgently undertaken.