Camelia Draghici

HEAVY METALS DETERMINATION IN ENVIRONMENTAL AND BIOLOGICAL SAMPLES

Heavy metals are present as elementary compounds or mineral deposits in nature, from which they are extracted and processed for different purposes. During these processes, heavy metals are released in the environment and reach the atmosphere, waters, soils, and biota (plants and animals). Heavy metals release into the environment is of great concern, due to their ability to concentrate and accumulate, in different stable forms and in different media. Quantitative determination methods and techniques are developed in order to provide valid results about the heavy metals content in different matrixes. This study presents the main analytical techniques available for heavy metals determination in environmental and biological samples, as well as an example of method validation and uncertainty estimation for Cu2+ determination in waste water samples.

POLLUTANTS EFFECTS ON HUMAN BODY – TOXICOLOGICAL APPROACH

It is a fact that any compound coming into contact with biological systems will cause some perturbations in that system. These biological responses may not be always toxicologically relevant, and from that point of view it is important to correlate information on the sources, interactions, dose and their toxicity. The interest in toxicology increased continuously in the last years with the synthesis and use of different chemicals. In the environment, humans and other leaving organisms are exposed to support the increasing number of xenobiotics: industrial chemicals, pesticides, drugs, and additives from food or beverage. The effects of some most frequently present and relevant pollutants on human body, presented as typical diseases registered at organisms’ level are presented in this paper work.

Analytical Approaches for Sampling and Sample Preparation for Heavy Metals Analysis in Biological Materials

Heavy metals concentrations in biological materials are necessary to be known when investigations in environmental or health risk assessment are done. The paper aims to review the modern aspects of the first step of the analytical process, sampling and sample preparation which involve some of the following operations: sample collection (sampling), washing, storage, preservation, followed by sample transformation to the most appropriate form for measurement. New separation techniques, applied for specific analytes extraction or preconcentration from biological matrices and metal speciation are also briefly described.

NATO Advanced Research Workshop on Environmental Heavy Metal Pollution and Effects on Child Mental Development: Discussion, Conclusions and Recommendations

Heavy metals can be emitted into environment by both natural and anthropogenic sources, mainly mining and industrial activity. Human exposure occurs through all environmental media. Infants are more susceptible to the adverse effects of exposure. Recently more attention is paid to the mental development of children exposed to heavy metals. The purpose of the Advanced Research Workshop was to evaluate the existing knowledge in this field, to recommend a strategy for countries and regions in risk to protect today’s children and future generations from exposure to heavy metals, and to propose the necessary coordinated studies. This paper is a draft of the findings, conclusions and recommendations, formulated as a result of the presentations of the key-speakers; of the work of two round-table discussions: one on the need for studies of the health effects of environmental pollution on children’s mental development and the second on prevention strategies; and of the finalizing working groups to summarize the output scientific value of the ARW meeting.

Accumulation and Transformation Processes of Pollutants in Soil

The starting point of this paper is the need of knowledge on the influence of different (wastes) deposits on the soil quality. A general pre- sentation of the accumulation and (bio)transformation of pollutants in soils, with emphasis on heavy metals behaviour will be given. A case study on heavy metals presence in a wastewater sludge deposit and their migration in the surrounding soil will be presented.

Contamination of Soils by Waste Deposits

The purpose of this paper is to present original results concerning concentrations of eight metals in soils adjacent to municipal waste deposits from Constanta County, Romania, during April-October 2006. The surface and depth soil solutions were obtained using aqua regia and the applied analytical technique for metal determination was flame atomic absorption spectrometry (FAAS). The mean measured values ranged as follows: Cd: 0.09-0.15 mg/kg d.w.; Co: 7.92-9.27 mg/kg d.w.; Cr: 11.37-13.86 mg/kg d.w.; Cu: 16.91-20.92 mg/kg d.w.; Mn: 379-441 mg/kg d.w.; Ni: 20.58-28.95 mg/kg d.w.; Pb: 7.24- 9.08 mg/kg d.w. and Zn: 44.28-49.93 mg/kg d.w. Except nickel all other metals concentrations have been founded below the normal limits accepted by the Romanian regulations. As a general observation, in depth soil concentrations are higher (Cr, Cu, Ni, Pb) or similar (Mn, Zn) than in surface samples (except cadmium and cobalt).

COMPLEX CHARACTERIZATION OF POLLUTED SAMPLES

Environmental risk assessment (ERA) is a complex process that requires specific data to be processed, in order to give relevant and certain information about the possible risks that could affect the status of human and ecological health. As part of the ERA activity, exposure assessment results are relaying on monitoring data as well as on models that are developed based on quite sophisticated equations, requiring a lot of information. Environmental monitoring is, therefore, a complex surveillance process of which purpose is to deliver the most relevant information on the accumulation, persistence or dispersion in space and time of the pollutants in the environmental compartments (air, water, soil and biota), considering all their specific sub-systems: aerosols, suspensions, groundwater, surface water, soils, sediments, microorganisms, plants, animals, humans. The actual paper is aiming to give a basic and simple description of the environmental monitoring process, with emphasis on the analytical stages of the pollutants determination: principles of sampling and chemical analytical methods and techniques that are used for the complex characterization of polluted samples.

Risk Assessment of Mixtures of Chemical Pollutants in the Environment

Environmental contamination problems are complex issues with worldwide implications. Risks to human and ecological health as a result of toxic compounds and their introduction into the environment is a matter of great interest to modern society. Ecological risk assessment and the human health risk assessment are the two related activities of which the environmental risk assessment is comprised. Mixtures of pollutants can contain all type of chemicals: organic, inorganic, organometallic in gaseous, liquid or solid state. This paper presents the steps to be carried out in order to perform the risk assessment for environment and human health. Exposure assessment is detailed by the presentation of original results obtained in studies concerning the determination of bioconcentration factors (BCF) of six metals (cadmium, chromium, copper, lead, nickel and silver) in the Romanian Black Sea coast, sediments and marine biota, during 2003–2006. The reported BCF allow concluding that at the moment there is no pollution concern in the studied area.

Compost Based on Biomass Wastes Used as Biofertilizers or as Sorbents

Recycling the biodegradable waste by composting represents a sustainable solution for developing new ecological compost-type substrates, useful both as biofertilizers and as sorbents for the removal of heavy metals from wastewaters. By this paper we aim to present an overview of our studies related to using composted biomass from biodegradable wastes, as viable solution for biofertilizers or sorbents for heavy metals removal from the environmental. The novelty of our studies consists of the new materials that were prepared by composting together different biomass wastes. Aerobic fermentation was used to obtain sixteen different composts from vegetables waste, sewage sludge, beech sawdust and beech ash, in different mixing ratio, and the composting process was monitored. Based on their composition, three of these mature and stable composts were selected, while their capacity as nutrients and suitability as bio-fertilizers were analyzed in terms of C/N ratio, germination tests. Furthermore, one of these composts was also demonstrated to be suitable as low-costs sorbent, specifically to remove heavy metals from polluted waters. For this application the topography and morphology of compost substrates were determined, before and after sorption of metal cations. The sorption parameters (contact time, ratio of wastewater volume: sorbent compost mass) were optimized. Both, kinetic and thermodynamic sorption mechanisms were discussed and the results were further correlated with the structural properties of the compost substrate. The advantaged of biodegradation wastes by composting different raw biomaterials for preparation of ecological soil fertilizers and sorbents to remove heavy metals from contaminated waters, as low cost and environmental friendly solutions were also discussed.

HEAVY METALS ACTIVITY MECHANISMS AT CELLULAR LEVEL AND POSSIBLE ACTION ON CHILDRENS BODIES

Different natural and artificial sources of pollution (manufacturing, metallurgy, mining, constructions, and incinerators) can contaminate the environ ment with heavy metals. If natural sources contribute to environmental pollution only to a little extent, artificial ones, which result from different human activities, contribute decisively to the pollution of the environment. Recently, interest in heavy metals (Pb, Hg, Cu, Zn, Cd, Sn, Ni, Cr, Mn, Se, As) has increased as they contaminate the environment and severely affect human and animal health. This paper presents some theoretical toxicity aspects of three elements (cadmium, lead, arsenic) and possible additive or synergistic action in human bodies, especially in children. Evaluating these actions is essential for risk assessment and management of heavy metals as single or mixture environment pollutants.