Toxic metals speciation in river Tisa D. Vujanovic 1, Z. Plamenac 1, S. Razic 2 & P. Simonovic 3 Farmaceutski Fakultet, Institut za Toksikologiju 1 & Analiticku hemiju 2, Biloski Fakultet 3 Univerzitet u Beogradu

Introduction (Short dates about pollution from the mine “Aurul” in Baira-Mare in Romania) 19 mines (hot spots) in Tisa river basin… -during the night January 30/31, 2000 the dam of flotation dump site in the gold mine “Aural” was broken; m 3 of muddy water containing cyanide, heavy metals and other pollutants spilled to the stream Lapus, reached rivers Somes, Tisza and finally Danube (official Romanian data); First traces of cyanide at “Martonos” detected in february 10 th, at 6 a.m.; max. CN - conc. was observed (2.5 mg/l) in February 11 th ; increased conc. of Cu (13 times higher than MPL), Mn and Fe (12 times higher); Consequence: havoc in the rivers Lapus, Somes and Tisa serious destruction of aquatic life in Danube River-largest fresh water environmental catastrophe in Central and Eastern Europe so far… Baia Borsa–Romania- 10 th March 2000-accident caused new pollution with heavy metals tons of mineral waste with big concentration of Pb and Zn)…

Environmental consequences of cyanide and heavy metals spill on Tisa (and Danube) Severe decrease of number of plankton-important component in the nutrition of fish (80-90% phytoplankton has been destroyed); further disintegration on river bottom- secondary pollution; further pollution in the life chain… Fish –bioaccumulation of toxic substances (final stage of nutrition chain); about 15 tons of died fish was collected in Yu; Long term consequences of this ecological catastrophe are difficult to estimate!

Our results… Metals differ from other toxic substances in that they are neither created nor destroyed by humans. Nevertheless, their utilization by humans influences the potential for health effects in at least two major ways: first, by environmental transport, that is, by human anthropogenic contribution to air, water, soil, and food, and second, by altering the speciation or biochemical form of the element. Mechanism of toxicity and toxic effects of cyanides and metals are quiet different: site of effects, t 1/2 of elimination, biotransformation processes…; Pollution of rivers by toxic metals is permanent problem! (metals are not degradabile, their effects are cumulative with long t 1/2 of elimination);

Contents of toxic metals in fish of river Tisa (March, 2000) We found that fishes from river Tisa have more toxic metals (we analyzed all important organs in a means of metal toxocinetic and toxodinamic) then controls (the same species of fishes from fish pond). Values for muscles were not over MAC (Maximum Avaluilable Concentration) and if we have law and roles in our mind we can say: "Analyzed fish are good for use". Values applies only for muscle, which is not representative organ for evaluation the state of intoxication fish by toxic metals…

The most important results and comments 1. Enhanced content of Cu were in liver (the place of accumulation), in muscle and skin, contrary to controls (fishes from ponds); 2. Differences in Fe contents (gills, brain, skin, bones); 3. Mn was significantly higher in analyzed skills, brain (the largest t 1/2 ), liver and skin; 4. Zn was enhanced in skills, brain, liver and muscle; 5. Hg was enhanced in all analyzed tissues, especially in skills, skin and bones; 6. As was enhanced, too, and the differences between Tisa fish and controls were the biggest;

The most important results and comments -results from single measurements may reflect recent exposure or long term exposure or past exposure,depending of the retention time in particular tissue; -a critical determinant of the metabolism and toxic behavior of metal is dose (or estimate of exposure to a metal -it may be function of time as well as the concentration of metal) and it’s biological half time (t ½) – the time it takes the body to excrete half an accumulated amount (different for different metals and organs); *the most precise definition of dose is the amount of metal within cells of organs manifesting of toxicological effects: of our interest – in analyzed species (fish) and in men (which is only a small segment of aquatic contamination by toxic metals)

Results and comments Fishes & other aquatic life:-the evolution of the ecological risk assessment process is so new that currently there are relatively few examples…; it is imperative in the problem formulation phase that an appropriate overview be considered for the ecological issue of concern, to answer the question of what toxic substance and/or other stressors might have an impact on important species and/or their population; Men:-The element of risk evaluation: the dose (chemical form of metals), % of absorption of examined metal; the other nutrition factors (proteins, bioelements, vitamins) at the absorption level; T 1/2 ; interactions with bioelements and other metals at the biologand level (enterocit-absorption, proteins- hormone, enzymes, molecular or other membranes e.t.c.)

Contents of Cu (mg/kg) in some analyzed tissues of fish Cu-essential element; absorption- about 50% from GIT; t 1/2 - 4 weeks; liver and muscle (the biggest content); Mo can influence on the Cu metabolism; (dates for men); -aquatic life is very sensitive on enhanced Cu level; significant inhibition of mycrosomal enzymes in liver and some other enzymes in fish…The similar effect show Zn…

Contents of Fe (mg/kg) in some analyzed tissues of fish 5% of all elements present in the ground of the Earth; Essential element (a lot of enzymes-oxide-reduced processes and active proteins- hem); Absorption from GIT 5-15%; t ½ years; FeO –co carcinogen (animal study) Co, Cu and Zn reduce absorption of Fe;

Content of Mn (mg/kg) in some analyzed tissues Mn presents in Fe ores; Essential element in men, but without observe deficiency; 1-3% GIT absorption;(liver, kidney and brain –highest conc.); brain-the highest t ½… rice and wheat can accumulate Mn from soil… Mn presents only in the tissue of fish from river Tisa…

Content of Zn (mg/kg) in some analyzed tissues Essential metal (in 200 enzymes); Git absorption 10-90%; t ½ -1 year (highest level in liver bones, muscle); Observed antagonism between Zn and Cd, Zn and Cu…(resorption level) Carcinogen effects on experimental animals…(human dates); More toxic effects for aquatic life than for people…

Content of Hg (mg/kg) in some analyzed tissues Organic Hg is more toxic for water plants ( times more); Hg accumulate in the algae and stop mitosis process; Organic Hg- better resorption (case of biomagnification in shells and crayfish); Young organisms are more sensitive; (inhibition of mitochondrial and lisosomal functions-connection with SH groups of enzymes);

Content of As (mikrog/kg) in some analyzed tissues Inorganic As-in the sediment of the river; organic As-influence of anaerobic microorganisms; Organic As easy enter in the chain of the food (very toxic); case of biomagnification in shells and crayfish; Inhibition of enzymes by connection with SH groups; inhibition ATP syntheses (similarity with P)

Assessment toxicity of metals Metals have different toxic effects on water plants and animals; combination of presence metals have synergistic or antagonistic effects on living world in the rivers: additive effects - Cr and Zn; Cu and Ni; Cd and Pb enhance toxic effect of Zn… The influence of toxic metals from fish to men dependents of many factors: % of fish meat in nutrition; properties of ingested metals-chemical form and presence of different nutrition factors; individual health conditions and age, life style factors…