Esa Tulisalo

Exchange of mercury between atmosphere and vegetation under contaminated conditions

Adsorption and desorption of mercury was studied under laboratory conditions using moss (Sphagnum girgensohnii) and Rye grass (Lolium perenne) at different temperatures. Desorption was also studied in a transplantation experiment. The adsorption was rapid and strong for both plant species at different temperatures (+10 to +60 degrees C) and exposure times (1 h, 1 month) while the evaporation was negligible. Also the leaching of adsorbed mercury was of minor importance. The results emphasise the importance of vegetation in removal of mercury from the atmosphere. They also confirm the suitability of moss and grass for biomonitoring purposes. The high retention of mercury in moss even at +60 degrees C indicates the possibility of using higher temperatures in pretreatment of samples for mercury analyses.

Environmental mercury contamination around a chlor-alkali plant.

The chlor-alkali industry is one of the most important emitters of mercury. This metal is effectively spread from chlor-alkali plants into the atmosphere and it has been reported that only a few percent of the mercury emissions are deposited locally the major part spreading over very large areas. The purpose of this investigation was to study the spreading of mercury up to 100 km from a chlor-alkali plant using three different biological indicators.

Time-related effects of intoxication with cadmium and mercury in the red wood ant

Biochemical and physiological effects of prolonged feeding of the ant Formica aquilonia, in natural conditions with excess of cadmium or mercury, were studied. In all developmental stages metals caused the time-dependent increase of AMP, parallel with a decrease of ATP and the pool size of adenylates. This was reflected by a low adenylate energy charge (AEC) index and accompanied by an inhibition of ATPases. Despite the fall in the adenylate pool of workers, the levels of adenylate energy charge confirmed their ability to maintain energetic balance. Prolonged access to food highly contaminated with Cd, or Cd with Hg, diminished these adaptive abilities, but pre-adaptive reactions (not correlated with the metal load) were induced. Activity patterns of enzymes involved in energy metabolism showed metal dependent inhibitory effects, but repeated contamination evoked some compensatory mechanisms, both in workers and in the pupal stage from the next generations. Cadmium (indirectly) stimulated the esterases and free radical scavengers. Compensatory mechanisms were insufficient in insects contaminated with both Hg and Cd, even causing family disappearance, through increased mortality and migration to other colonies. Compensatory mechanisms expressed by the adult workers appeared to be of a phenotypic origin

The Effect of Metals on the Mortality of Parnassius Apollo Larvae (Lepidoptera: Papilionidae)

The population sizes and range of Parnassius apollo started to decline in Finland in the 1930s and resulted in complete extinction in many parts of its former range 30 years later. It has been suggested that metal pollution is one potentially very important reason for the decline. Recently, a recovery of P. apollo and widening of its range has started in the southwestern Finland, simultaneously with a decline in metal fallout from air. Metal analyses were performed with larval and host plant samples collected from an area where P. apollo is recolonising its former range (the archipelago between the island of Kemiö and the Hankoniemi peninsula). In the host plants (Sedum telephium), the level of Fe was significantly lower and the levels of Cd and Zn suggestively lower in the current range (n = 35) of P. apollo than in the former range (n = 12). Analyses on larvae of P. apollo (n = 29) showed lower levels of Cd, Fe and Mn than in the host plant leaves. The excretion of these metals, as well as Zn, via the faeces was effective. The level of the Cd-antagonist Cu was considerably higher in caterpillars than in the food. When caterpillars were fed with metal-polluted food from Helsinki city (4.35 ppm Cd/dwt; n = 5) they died, whereas control individuals fed with food from the archipelago (2.49 ppm Cd/dwt; n = 5) survived. These results indicate that metals may play an important role in the large-scale decline and partial recovery of P. apollo in the western Europe.

Open digestion of some plant and fungus materials for mercury analysis using different temperatures and sample sizes

Dry samples of lichen, moss and mushroom were treated by open wet digestion at different temperatures and different sample sizes and analyzed for mercury. No temperature (+80°C, +90°C, +105°C) dependent differences were observed for the moss and mushroom analyses. For lichen the variations were larger. In this material the digestion was more efficient at +120°C and +140°C than at lower temperatures. For this matrix the best results were obtained when using smaller samples at higher temperatures. The sample weight seemed to be even more important for the digestion efficiency.

Effect of Heavy Metals on Soil Enzyme Activity at Different Field Conditions in Middle Spis Mining Area (Slovakia)

Heavy metals concentrations were measured in the former mining area located in Hornad river valley (Slovakia). Soil samples were taken in 2012 from 20 sites at two field types (grasslands, heaps of waste material) and two different areas. Total content of heavy metals (Cu, Pb, Zn, Hg), urease (URE), acid phosphatase (ACP), alkaline phosphatase (ALP), soil reaction (pH) were changing depending on the field/area type. The tailing pond and processing plants have been found as the biggest sources of pollution. URE, ACP and ALP activities significantly decreased while the heavy metal contents increased. Significant differences were found among area types in the heavy metal contents and activity of URE. No statistical differences in the content of heavy metals but significant statistical differences for soil pH were found for field types (grassland and heaps). Significant negative correlation was found for URE–Pb, URE–Zn and also between soil reaction and ACP and ALP.

Cadmium in insects after ash fertilization.

Ash fertilization of forests returns nutrients to forest ecosystems and has a positive effect on soil pH, but it also may elevate Cd concentrations of forest biota. Cadmium concentrations of some forest insects (Formica ants, carabids and Coleopteran larvae from decaying wood) were investigated in southern Finland, where two plots were fertilized with wood ash, while two other plots represented unfertilized control plots. In ants, mean Cd concentration was 3.6 ± 1.4 mg/kg, with nest workers having significantly higher concentrations than workers trapped in pitfall traps. Concentrations at fertilized and unfertilized plots were similar. In carabid beetles, the average Cd concentration of Carabus glabratus was 0.44 ± 0.36 mg/kg, with no significant difference between control plots and fertilized plots. In another carabid beetle, Pterostichus niger, mean Cd concentration was higher at fertilized plots compared to control plots. We conclude that the variation of Cd concentrations in the insects studied is more efficiently controlled by species‐specific differences than fertilization history of the forest floor.

Mercury in various tissues of three mustelid species and other trace metals in liver of European otter from Eastern Finland

Mercury concentrations were monitored in European otter (Lutra lutra), European polecat (Mustela putorius) and European pine marten (Martes martes) collected in Eastern Finland during the period 1972–2008. Otters mainly eat fish, which is an important reason to monitor the bioaccumulation of mercury in this predator. In this species, the highest concentrations were found in fur followed by liver and kidney, and the mercury concentrations increased with increasing age and body weight. Males showed in general higher concentrations than females of otters. The food of European polecat consists of small mammals, frogs, birds and insects from both aquatic and terrestrial food chains. The mercury concentrations were lower than in otters without significant differences related to body weight or sex. In European pine martens, the concentrations were rather evenly distributed except for two specimens with high concentrations. Also, concentrations of some other metals (Al, Cd, Cu, Fe, Mn, Ni, Pb and Zn) were analysed from liver samples of otter. Possible adverse effects of mercury on the Finnish populations of these mustelids are discussed.