Bio-indicators in the monitoring of environmental pollution

Summary Surveying the chemical pollution status of a given area is increasingly becoming the task of biological indicators, ie animal and plant organisms capable of providing us with the necessary data. For example, in the wake of certain contaminations, they may increase or decrease in number, vary population proportions in relation to given traits, become vectors of certain toxic molecules or heavy metals, or accumulate them in their bodies or in their «products». The advantage of bioindicators over chemical or physical detectors is their ability to supply extensive — both spatially and temporally —rather than limited and instantaneous data, thus making such information more representative. In many instances the bioindicator takes samples for us-a service that is undoubtedly valuable even though it must be linked to a sound knowledge of the organism's ethogram and biology so as to arrive at a scientifically legitimate interpretation of the data provided.     

Exploiting antibody-based technologies to manage environmental pollution.

Many commodities used in the food, cosmetic, chemical and environmental industrial sectors function by binding to other molecules. Antibodies can bind virtually any molecule, from large proteins to small organic ligands, and could replace substances with undesirable medical, social or environmental side effects, if they could be provided in stable configurations and in quantities and at costs acceptable to industry. Antibody fragments also offer the possibility of sensitive detection and efficient removal of organic pollutants from the environment.     

Landscape-geochemical approach to solving problems of environmental pollution

This paper shows under which loads of pollutants their accumulation in soils occurs with the course of time. A map of soil contamination with fluorine, reflecting the patterns of its secondary differentiation in steppe geosystems is presented. The features of the fluorine distribution in soils depending on environmental conditions, as well as the factors that ensure the self-cleaning of soils under conditions of contamination, are revealed. The necessity of reducing dust and gas emissions from the production of aluminum is identified.     

Polycyclic aromatic hydrocarbons: environmental pollution and bioremediation

Polycyclic aromatic hydrocarbons (PAHs) are widely distributed and relocated in the environment as a result of the incomplete combustion of organic matter. Many PAHs and their epoxides are highly toxic, mutagenic and/or carcinogenic to microorganisms as well as to higher systems including humans. Although various physicochemical methods have been used to remove these compounds from our environment, they have many limitations. Xenobiotic-degrading microorganisms have tremendous potential for bioremediation but new modifications are required to make such microorganisms effective and efficient in removing these compounds, which were once thought to be recalcitrant. Metabolic engineering might help to improve the efficiency of degradation of toxic compounds by microorganisms. However, efficiency of naturally occurring microorganisms for field bioremediation could be significantly improved by optimizing certain factors such as bioavailability, adsorption and mass transfer. Chemotaxis could also have an important role in enhancing biodegradation of pollutants. Here, we discuss the problems of PAH pollution and PAH degradation, and relevant bioremediation efforts.     

Impact of environmental pollution on cyanobacterial proline content

This study describes the toxic effects of different prominent aquatic pollutants—heavy metals (Cd & Pb), pesticides (alphamethrin and deltamethrin) and salt (NaCl)—on the intracellular proline content in the cyanobacterium, Westiellopsis prolifica–Janet strain–NCCU331. Despite a reduction in growth (measured as chlorophyll a content), the intracellular proline content increased in the presence of heavy metals, pesticides and high salt concentration. The intracellular cyanobacterial proline accumulation was more pronounced under salt stress than in the presence of pesticides and heavy metals. We have also compared whether or not anionic components influence heavy metal toxicity. It was found that the chlorides of Cd and Pb were more toxic than the NO₃ and the order of toxicity was CdCl₂ > PbCl₂ > Cd (NO₃)₂ > Pb (NO₃)₂. Among pyrethroids, deltamethrin was more toxic than alphamethrin. Presented at the 6th Meeting of the Asian Pacific Society of Applied Phycology, Manila, Philippines.     

海洋生态环境污染研究概况

阐述了海洋生态环境污染的来源和危害,探讨其解决方法。     

The use of grasses as indicators of environmental pollution

Summary An exploratory examination of the use of rye grass as an indicator of environmental accumulation of minor elements confirmed that natural grass is contaminated by soil or airborne dust, and that this contamination cannot be washed off sampled grass with water without also removing elements from within the leaves, to an extent that varies with the age and/or environment of the grass. This reduces the suitability of natural grasses as indicators of pollution, and alternative procedures are required and proposed.     

On-line and in situ biosensors for monitoring environmental pollution

Efficient tools for on-line and in situ monitoring of environmental pollutants are required to provide early warning systems. In addition, such tools can contribute important information on the progress of various remediation treatments. One of the recently developed monitoring technologies involves the use of whole-cell biosensors. Such biosensors could be constructed to detect general toxicity or specific toxicity caused by one or more pollutants. Currently, a large spectrum of microbial biosensors have been developed that enable the monitoring of pollutants by measuring light, fluorescence, color or electric current. Electrochemical monitoring is of special interest for in situ measurements as it can be performed using simple, compact and mobile equipment and is easily adaptable for on-line measurements. Here we survey the potential application of electrochemical biosensors in monitoring of general toxicity as well as hydrocarbons and heavy metals.     

The environmental risks of pollution in the Scheldt estuary

The ecotoxicological effects of pollution in the Scheldt estuary is evaluated for several routes of exposure by comparing observed concentrations of micro-contaminants in water and tissues of biota with toxicity data in literature. Ecological risks are estimated for dissolved trace metals according to the method of VAN STRAALEN (1990) using published data on NOECs from aquatic toxicity tests concerning reproduction, mortality and growth for cold blooded marine and estuarine organisms. Of eight investigated trace metals, zinc and nickel cause the highest risks, both affecting up to 4% of the aquatic species. The occurrence of bioaccumulation of PCBs and cadmium is investigated in several trophic levels. High concentrations of PCBs are observed in tissues of biota and may indicate adverse effects on top predators (seals, terns), especially in the brackish zone. Environmental risks of other organic micro-contaminants have not been indicated due to the limited number of data on toxicity or environmental concentrations. The effects of a mixture of pollutants in sediments from the Scheldt estuary were investigated with an oyster larvae bioassay showing an increased toxicity in upstream direction. Moreover, in the upper part of the estuary, preconditions regarding the oxygen concentration are not met and overshadow the toxic effects of pollution with micro-contaminants. Especially in the less contaminated part of the estuary more ecotoxicolgical research is required to perform an integral risk evaluation. At present, still little is known about effects that may occur in the field.     

Plasmonic Perfect Absorbers for Biosensing Applications

We present a theoretical modal investigation of plasmonic perfect absorbers (PPAs) based on the localized surface plasmon resonance (LSPR) for biosensing applications. We design the PPA geometry with a layer of periodic metallic nanoparticles on one side of a dielectric substrate and a single metallic layer on the opposite side. The electromagnetic (EM) fields confine partly in the surrounding medium above the substrate and within the substrate itself. We examine the modes of the PPA geometry for a wavelength range of 600–1500 nm. The fundamental mode of the system provides perfect absorption for a wide angle of incidence 0–70°. The second-order mode shows a strong angular dependence with a sharp resonance and exhibits perfect optical absorption when the critical coupling condition for LSPR is achieved. The coupling condition depends on the size, periodicity, dielectric spacer, and the surrounding material of the system. The strong dependence on the surrounding material makes it a promising candidate for biosensing applications. We introduce a novel approach to investigate the angular dependence of the refractive index change for the PPA system. This novel technique contributes the significant attributes of the LSPR sensors, can be used for any required resonance wavelength depending on geometric design, and it also provides sensitivity analogous to the standard surface plasmon resonance (SPR) biosensors.     

Microorganisms as indices of environmental pollution by smelting industry.

The aim of the study was to prove suitability of some microbiological tests for determination of the degree of soil pollution by copper industry. The microbiological tests reveal sensitivity to metal compounds present in dusts emitted by smelters. The sensitivity of the selected strains to the dust present in the agar medium and soil has been determined and 30 strains, of which 50% reacted to the presence of 1--2 g of the dust in medium, were recommended for the tests. The tests showed accumulation of heavy metals contained in the dust mainly in the upper soil horizons and the highest pollution with the dust approximately 800 m away from the emitor in northeastern direction, which is the direction of prevailing winds of that area. The results obtained are in accordance with theoretical assumption as well as with the literature based on chemical analyses of polluted soil.     

Kinetic parameters of survival in daphnia under toxic environmental pollution

The combined effects of oil, copper, and chromium on the survival of the cladoceran crustacean Daphnia magna Straus was studied. The theoretically expected rates of mortality in crustaceans at various concentrations of toxicants at their combined action were calculated using the inhibition model commonly used in biochemistry for describing enzymatic kinetics. It was shown that the experimental and theoretically expected mortality rates of crustaceans conform well (the relative value of standard deviation is 17.58%). The results of the experiments show that the principles of enzymatic kinetics are applicable for studies on toxic effects on zooplankton. This makes it possible to use these principles for a quantitative assessment of the relations between the concentrations of chemical pollutants and the extents at which these chemicals suppress aquatic fauna.     

Disturbance of human immunohomeostasis by environmental pollution and alcohol consumption

Environmental pollution and consumption of alcohol evoke various immunomodulations promoting the progress of different pathologies. The purpose of this study was to evaluate the influence of alcohol consumption intensity on the immune system functions of humans living in ecologically different regions, i.e. in a district polluted with industrial siftings (Trakai, n = 270) and in a relatively clean district (Sirvintos, n = 250). In the Trakai cohort 96% and in Sirvintos group 89% of persons consumed alcohol. With regard to alcohol consumption habits the immunohaematological indices were investigated in the following four groups: abstinents, light alcohol users, moderate alcohol users and alcohol abusers. We determined the compensatory mechanisms of immune system functions of moderate alcohol users and alcohol abusers in comparison with abstinents in the relatively clean Sirvintos district. In the Trakai district polluted with industrial siftings such compensatory reactions where not found. Thus, damage to the immune system functions is not only an endogenous risk factor for many diseases, but also an indicator of organism injury. This investigation stated, that immunity disturbance in humans depends on alcohol consumption intensity and place of residence.