Changes in the heavy metal and nutrient contents of dried feather mosses during long-term storage

This study measured heavy metal and nutrient concentrations of two feather mosses during the periods of dry storage. Samples (Hylocomium splendens, Pleurozium schreberi) were collected in the nationwide moss surveys carried out on the permanent sample plots of the 8th Finnish National Forest Inventory in 1985–86, 1990, 1995 and 2000. A small amount of each moss sample was analyzed soon after collection, and the remainder was dried and stored at the Paljakka environmental specimen bank (ESB). The 108 stored samples from 27 plots were reanalyzed in 2008. Concentrations of heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, Zn) and nutrients (Ca, K, Mg, P) were determined and compared for each survey year. Overall, Fe, Pb and Cr concentrations decreased, and Cu concentrations increased significantly during storage. The greatest decrease was observed in samples from plots where their initial concentrations were the highest. Changes in the concentrations of Cd, Ni and Zn were less pronounced. The loss of heavy metals is likely due to drying when cell membranes rupture and some of the surface material is lost. K, P and, to some extent, Mg concentrations increased during storage, whereas Ca did not change significantly. Nutrient increase is probably due to their movement from older to younger growths during the initial phase of drying. Ca is mostly bound to cell walls and is not easily released. Results emphasize the importance of establishing the intended use of a stored moss prior to sampling, in order to select and optimize an appropriate storage technique.     

Phosphorus in runoff assessed by anion exchange resin extraction and an algal assay

Eutrophication of surface waters can be accelerated by agricultural inputs of phosphorus (P), provided that P is in a form that can be utilized by aquatic algae. We studied anion exchange resin (AER) extraction and a dual culture algal assay (DCAA) for the determination of potentially algal-available P in water samples without sediment preconcentration. Our material consisted of agricultural and forest runoff and wastewaters. The results obtained by the two methods were essentially equal when the samples contained only small amounts of particulate phosphorus (PP) in relation to dissolved molybdate-reactive phosphorus (DRP). However, in turbid agricultural runoff, P extracted with AER averaged 72% (n = 17) of the P yield of the 3-wk DCAA (R2 = 0.94). When the runoff samples were diluted for the AER extraction in the same manner as for the DCAA, the AER-P yield increased to 85% (n = 5) of DCAA-P. The minimum detectable value was greater for the AER test (41 microg L(-1) AER-extractable P) than for the DCAA (7 microg L(-1) DCAA-P). At concentrations greater than about 50 microg L(-1) AER-P or DCAA-P, the accuracy of the methods was satisfactory, with the coefficient of variation in replicated analyses being less than 10% for the AER test and less than 20% for the DCAA. Other anions competing for the exchange sites of the AER decreased P recovery by 15 to 20% when their equivalent concentration exceeded about 4 mmol, L(-1), and this effect was relatively constant over a large concentration range. We consider that AER extraction is a suitable low-cost method to estimate the algal availability of P in runoff samples.     

Using Multicriteria Methods in Environmental Planning and Management

In environmental planning and decision processes several alternatives are analyzed in terms of multiple noncommensurate criteria, and many different stakeholders with conflicting preferences are involved. Based on our experience in real-life applications, we discuss how multicriteria decision aid (MCDA) methods can be used successfully in such processes. MCDA methods support these processes by providing a framework for collecting, storing, and processing all relevant information, thus making the decision process traceable and transparent. It is therefore possible to understand and explain why, under several conflicting preferences, a particular decision was made. The MCDA framework also makes the requirements for new information explicit, thus supporting the allocation of resources for the process.     

Variable emissions of microbial volatile organic compounds (MVOCs) from root-associated fungi isolated from Scots pine

Soils emit a large variety of volatile organic compounds. In natural ecosystems, measurements of microbial volatile organic compound (MVOC) exchange rates between soil and atmosphere are difficult due to e.g. the spatial heterogeneity of the belowground organisms, and due to the many potential sources for the same compounds. We measured in laboratory conditions the MVOC emission rates and spectra of eight typical fungi occurring in boreal forest soils. The studied species are decomposers (Gymnopilus penetrans, Ophiostoma abietinum), ectomycorrhizal (Cenococcum geophilum, Piloderma olivaceum, Suillus variegatus, Tomentellopsis submollis) and endophytic fungi (Meliniomyces variabilis, Phialocephala fortinii). The MVOC emissions contained altogether 21 known and 6 unidentified compounds whose emission rates were >0.1 μg g(DW)^?1 h^?1. The most abundant compounds were the short-chain carbonyl compounds (acetone and acetaldehyde). The greatest carbonyl emissions were measured from P. olivaceum (1.9 mg acetone g(DW)^?1 h^?1) and P. fortinii (0.114 mg acetaldehyde g(DW)^?1 h^?1). Terpenoid emissions (isoprene, mono- and sesquiterpenes) were detected from some fungal cultures, but in relatively small amounts. We conclude that soil micro-organisms can potentially be responsible for significant emissions of volatiles, especially short-chain oxygenated compounds, to the below-canopy atmosphere.     

Geochemical interpretation of cancer maps of Finland

In order to reveal possible cause-and-effect relationships and correlations between geochemical variables and the incidences of various forms of cancer, geochemical maps (soil and groundwater) and cancer maps of Finland are compared using standard methods of correlation analysis. The cancer incidence maps published by the Finnish Cancer Registry and soil and groundwater geochemical maps published by the Geological Survey of Finland, both in colour, were decoded to numerical incidence or concentration values by placing a rectangular grid of 684 evenly spaced observation points over each map representing the entire area of the mainland of Finland,i.e. the points were located at intervals of about 25 kilometres on the ground. Bivariate correlation coefficients were calculated between the variables for cancer incidence and the geochemical data matrices. As a general rule, the results show a low degree of correlation between the variables (r = 0.00 – 0.40), which suggests that the types studied of cancer are not related to the geochemical variables. There are a few possible exceptions, however, such as cancer of the colon in males and females in relation to arsenic and uranium in the soil and hardness of the groundwater, where the Spearman product-moment correlation coefficients are 0.59, 0.55 and 0.51 respectively, so that the cancer case may have a geochemical factor implicated in their aetiology, albeit very vaguely. The relatively high correlation coefficients (0.61, 0.62 and 0.63 respectively) recorded for the dependence of total cancer in females on groundwater hardness and uranium and arsenic in till must be regarded as meaningless in view of the multicausative aetiology of total cancer (all forms combined).     

Water hardness and cardiovascular mortality in Finland

In Finland, where mortality rates of cardiovascular diseases are as a rule among the highest in the world, significant areal differences in these figures are encountered especially between the eastern and western parts of the country. To test the hypothesis that these differences,( the reason of which has long been a subject for a lively debate in Finland), may result from geochemical factors such as variations in the hardness or calcium or magnesium content of well water a correlation analysis was carried out in which the geochemical properties in each of the country's individual administrative districts, or communes (444 in all, excluding Åland) were compared with the percentage of heart diseases among the causes of death from diseases in 1991. The results show a poor or extremely low correlation nation-wide (r ranging from –0.039 to +0.045), indicating a virtual absence of any causal relationship. On the other hand, taken pairwise, the extreme western and eastern provinces, Vaasa andNorthern Karelia, show marked differences both in their geochemical and mortality data, the percentage of deaths caused by cardiovascular diseases being markedly lower in the province of Vaasa, where the hardness and the magnesium content of well water (but not the calcium content) are significantly higher (p < 0.001 and 0.002 respectively). This inverse relationship is in line with the supposition that in addition to other factors, geochemical differences may have an effect on mortality.     

Comparison of health patterns in two geochemically contrasted areas of northern Finland

In order to prepare the ground for a discussion of possible causal relationships between health patterns and the geochemistry of an area, health patterns in the form of age-adjusted cancer incidence values and rates of mortality due to (1) cancer of the stomach, colon or rectum, (2) lung cancer and (3) ischaemic heart diseases are compared between the populations of two geochemically contrasted communes of northern Finland (Kemijärvi and Kuusamo). Statistically significant differences (p < 0.001) are encountered in the mortality rates due to ischaemic heart diseases and marked differences in the incidence values of lung cancer, the former being higher in Kuusamo and the latter in Kemijärvi. The higher incidence of lung cancer observed in Kemijärvi is in accordance with previous results reported from the USA, where higher incidences have been observed in areas of granitic bedrock. Regarding the higher mortality rate due to ischaemic heart diseases In Kuusamo, which is geochemically characterised by higher potassium (p < 0.002) and calcium (p < 0.004) and lower Zn, V, Ti, and Fe (p > 0.002) in the soil (actually, in the fine till fraction), no easily demonstrable cause- and-effect relationship can be established.     

The use of a sequential leaching procedure for assessing the heavy metal leachability in lime waste from the lime kiln at a caustizicing process of a pulp mill

A five-stage sequential leaching procedure was used to fractionate 13 heavy metals (Cd, Cu, Pb, Cr, Zn, Fe, Mn, Al, Ni, Co, As, V, Ba) and sulphur (S) in lime waste from the lime kiln at the causticizing plant of Stora Enso Oyj Veitsiluoto Pulp Mills at Kemi, Northern Finland, into the following fractions: (1) water-soluble fraction (H₂O), (2) exchangeable fraction (CH₃COOH), (3) easily reduced fraction (HONH₃Cl), (4) oxidizable fraction (H₂O₂ + CH₃COONH₄), and (5) residual fraction (HF + HNO₃ + HCl). Although metals were leachable in all fractions, the highest concentrations for most of the metals were observed in the residual fraction (stage 5). It was also notable that the total heavy metal concentrations in lime waste did not exceed the maximal allowable heavy metal concentrations for soil conditioner agents set by the ministry of the Agricultural and Forestry in Finland. The heavy metals concentrations in lime waste were also lower than the maximal allowable heavy metals concentrations of the European Union Directive 86/278/EEC on the protection of environment, and in particular of the soil, when sewage sludge is used in agriculture. The Ca concentration (420 g kg⁻¹; d.w.) was about 262 times higher than the typical value of 1.6 g kg⁻¹ (d.w.) in arable land in Central Finland. However, the concentration Mg (0.2 g kg⁻¹; d.w.) in lime waste was equal to the Mg concentration in arable land in the Central Finland. The lime waste has strongly alkaline pH (12.8) and a neutralizing value (i.e. liming effect) of 47.9% expressed as Ca equivalents (d.w.). This indicates lime waste to be a potential soil conditioner and improvement as well as a pH buffer.     

Radiation hormesis — fact or fiction?

Deriving from the Greek verbhormein, which means to stimulate and excite, hormesis literally refers to any kind of stimulation and excitation. As a medical and geomedical term (though of unsettled status) it has a more restricted meaning however, indicating merely the putative or real stimulatory and beneficial effects observed when a biological system is exposed to a low dose of an agent known to be toxic or hazardous at a significantly larger dose. Depending on the type of stimulatory agent, one can speak of chemical or physical hormesis, radiation hormesis being a member of the latter group. The present paper reviews and evaluates the history and origins of the concept of radiation hormesis and its present status — fact or fiction. It is concluded that despite the numerous, sometimes undeniably strong, individual pieces of evidence that have been presented in favour of this phenomenon, the bulk of the evidence is so far not strong enough to establish it as a scientifically proven fact. It is also evident that, instead of speaking of radiation hormesis as an entity, one should pay attention separately to the effects of alpha, beta and gamma radiation, the deleterious and possible beneficial hormetic effects being different in each case.