Increased deposition of polychlorinated biphenyls (PCBs) under an AC high-voltage power line

There is considerable public concern regarding the potential risks to health of electromagnetic fields in general and high-voltage power lines in particular. As epidemiological findings are not supported by a clearly defined mechanism of direct magnetic field interactions with the human body, potential indirect effects are of interest. It has been suggested that an increased exposure to chemical pollutants could occur near high-voltage power lines due to formation and deposition of charged aerosols. The current study reports empirical evidence that seems to support this hypothesis. The deposition of 18 congeners of polychlorinated biphenyls (PCBs) was studied by collecting samples of pine needles under a 400 kV AC power line and at reference sites in the vicinity. Compared to the reference sites, the average deposition of PCB congeners under the power line was almost double. This difference between the two groups of samples was statistically significant. While it is premature to draw any conclusions regarding the human exposure near high-voltage power lines, the issue deserves attention and further investigations.     

Managing Boreal Forest Landscapes for Flying Squirrels

Abstract: Flying squirrel (Pteromys volans) populations have declined severely during the past few decades, and the species has become a focal species in forest management and the conservation debate in Finland. We compared landscape structure around known flying squirrel home ranges with randomly chosen forest sites to determine which landscape patterns characterize the areas occupied by the species in northern Finland. We sought to identify the key characteristics of the landscape that support the remaining flying squirrel populations. We analyzed landscape structure within circular areas with 1- and 3-km radii around 63 forest sites occupied by flying squirrels, and around 96 random sites. We applied stepwise analysis of the landscape structure where landscapes were built up step-by-step by adding patch types in order of their suitability for the flying squirrel. The land-use and forest-resource data for the analysis were derived from multisource national forest inventory and imported to a geographical information system. Landscape patch types were divided into three suitability categories: breeding habitat (mixed spruce-deciduous forests); dispersal habitat ( pine and young forests); and unsuitable habitat ( young sapling stands, open habitats, water). Flying squirrel landscapes contained more suitable breeding habitat patches and were better connected by dispersal habitats than random landscapes. Our results suggest that for the persistence of the flying squirrel, forest managers should 1) maintain a deciduous mixture, particularly in spruce-dominated forests; 2) maintain physical connectivity between optimal breeding habitats; and 3) impose coarse-grained structures on northeastern Finnish landscapes at current levels of habitat availability.     

A test of male mating and hunting success in the kestrel: the advantages of smallness?

We tested female choice for male wing and tarsus length and body mass in the kestrel (Falco tinnunculus), a species in which males average about 10% smaller than females. We also studied how male characters are related to their hunting success. In the laboratory, females preferred lighter males with shorter tarsi as mates, if the difference in those characters between competing males was larger than average. Lighter and shorter-winged males seemed to be better hunters than heavier and longer-winged males. Field observations in a year in which voles were scarce suggested that shorter-winged males were also better food providers in courtship feeding than longer-winged males,although in good vole years such a relationship was not found. We argue that females may prefer to pair with smaller males, because they have higher flight performance and better hunting success than heavier males. By doing so, females may gain direct breeding advantages. We conclude that both female choosiness and the hunting efficiency of males well contribute to reversed sexual size dimorphism (RSD, females larger than males) in the kestrel. Received: 18 July 1995/Accepted after revision: 17 August 1996     

Roadside aerosol study using hygroscopic,organic and volatility TDMAs: Characterization and mixing state

Traffic-related aerosol particles are ubiquitous in the urban atmosphere. As they are produced at ground level, they can also cause adverse health effects to urban dwellers. However, knowledge of the formation, transformation and chemically resolved size distribution of urban ultrafine particles is incomplete. Thus, more of these measurements are needed for better assessment of ambient air quality and its potential health effects. The particle number concentration, aerosol black carbon (BC) concentration and size distribution of traffic-related aerosols were measured near two major roads in Kuopio, Finland, from 16 June to 5 July, 2004. Furthermore, the properties of roadside aerosol particles were examined with the Tandem Differential Mobility Analyzer technique (TDMA). A suite of TDMA instruments relying on water (hygroscopic TDMA) and ethanol (organic TDMA) condensation as well as heating (volatility TDMA) were deployed to study the composition of the nucleation and Aitken mode particles (D_p = 10–50 nm) formed from vehicle exhaust. The results show that a simple three-component model was able to reproduce characteristic insoluble, organic and water-soluble volume fractions. Insoluble constituents were dominant in the Aitken mode particles, whereas organic compounds dominated the nucleation mode sizes. On average, only a small volume fraction was water-soluble, but a clear external mixing was observed particularly when enough time was allowed after the tail pipe emissions. The contribution of the insoluble material was seen to increase as a function of particle size, being typically less than 10% at 10 nm and between 20 and 50% at 50 nm, in contrast to the organic fraction, which decreased from about 80% at nucleation mode size range to 50–60% at 50 nm.     

Perceived Mental Stress and Reactions in Heart Rate Variability—A Pilot Study Among Employees of an Electronics Company

In this study perceived mental stress during occupational work was compared to heart rate variability (HRV) using a traditional questionnaire and a novel wristop heart rate monitor with related software. The aim was to find HRV parameters useful for mental stress detection. We found the highest correlation between perceived mental stress with the differences between the values of triangular interpolation of rythm-to-rythm (RR) interval histogram (TINN) and the root mean square of differences of successive RR intervals (RMSSD) obtained in the morning and during the workday(r = -.73 andr = -.60, respectively). The analysis shows that as the RMSSD and TINN value differences increase from night to morning, the stress decreases.     

Total vs. internal element concentrations in Scots pine needles along a sulphur and metal pollution gradient

Analysis of foliar elements is a commonly used method for studying tree nutrition and for monitoring the impacts of air pollutants on forest ecosystems. Interpretations based on the results of foliar element analysis may, however, be different in nutrition vs. monitoring studies. We studied the impacts of severe sulphur and metal (mainly Cu and Ni) pollution on the element concentrations (Al, Ca, Cu, Fe, K, Mg, Mn, Ni, P, Pb, S and Zn) in Scots pine (Pinus sylvestris L.) foliage along an airborne sulphur and metal pollution gradient. Emphasis was put on determining the contribution of air-borne particles that have accumulated on needle surfaces to the total foliage concentrations. A comparison of two soil extraction methods was carried out in order to obtain a reliable estimate of plant-available element concentrations in the soil. Element concentrations in the soil showed only a weak relationship with internal foliar concentrations. There were no clear differences between the total and internal needle S concentrations along the gradient, whereas at the plot closest to the metal smelter complex the total Cu concentrations in the youngest needles were 1.3-fold and Ni concentrations over 1.6-fold higher than the internal needle concentrations. Chloroform-extracted surface wax was found to have Ni and Cu concentrations of as high as 3000 and 600 microg/g of wax, respectively. Our results suggest that bioindicator studies (e.g. monitoring studies) may require different foliar analysis techniques from those used in studies on the nutritional status of trees.     

Comparison of particle emissions from small heavy fuel oil and wood-fired boilers

Flue gas emissions of wood and heavy fuel oil (HFO) fired district heating units of size range 4–15 MW were studied. The emission measurements included analyses of particle mass, number and size distributions, particle chemical compositions and gaseous emissions. Thermodynamic equilibrium calculations were carried out to interpret the experimental findings.In wood combustion, PM1 (fine particle emission) was mainly formed of K, S and Cl, released from the fuel. In addition PM1 contained small amounts of organic material, CO₃, Na and different metals of which Zn was the most abundant. The fine particles from HFO combustion contained varying transient metals and Na that originate from the fuel, sulphuric acid, elemental carbon (soot) and organic material. The majority of particles were formed at high temperature (>800 °C) from V, Ni, Fe and Na. At the flue gas dew point (125 °C in undiluted flue gas) sulphuric acid condensed forming a liquid layer on the particles. This increases the PM1 substantially and may lead to partial dissolution of the metallic cores.Wood-fired grate boilers had 6–21-fold PM1 and 2–23-fold total suspended particle (TSP) concentrations upstream of the particle filters when compared to those of HFO-fired boilers. However, the use of single field electrostatic precipitators (ESP) in wood-fired grate boilers decreased particle emissions to same level or even lower as in HFO combustion. On the other hand, particles released from the HFO boilers were clearly smaller and higher in number concentration than those of wood boilers with ESPs. In addition, in contrast to wood combustion, HFO boilers produce notable SO₂ emissions that contribute to secondary particle formation in the atmosphere. Due to vast differences in concentrations of gaseous and particle emissions and in the physical and chemical properties of the particles, HFO and wood fuel based energy production units are likely to have very different effects on health and climate.     

Concentrations and Diversity of Microbes from Four Local Bioaerosol Emission Sources in Finland

ABSTRACT

Microbial particles can readily be released into the air from different types of man-made sources such as waste operations. Microbiological emissions from different biological sources and their dispersion may be an issue of concern for area planning and for nearby residents. This study was designed to determine the concentrations and diversity of microbiological emissions from four different man-made source environments: waste center with composting windrows, sewage treatment plant, farming environment, and cattle manure spreading. Samples of airborne particles were collected onto polyvinyl chloride filters at three distances along the prevailing downwind direction, from each source environment during a period of approximately 1 week. These samples were analyzed for 13 species or assay groups of fungi, bacterial genus Streptomyces, and Gram-positive and -negative bacteria using quantitative polymerase chain reaction (PCR). Samples for determining the concentrations of viable fungi and bacteria were collected from all environments using a six-stage impactor. The results show that there were variations in the microbial diversity between the source environments. Specifically, composting was a major source for the fungal genera Aspergillus and Penicillium, particularly for Aspergillus fumigatus, and for the bacterial genus Streptomyces. Although the microbial concentrations in the sewage treatment plant area were significantly higher than those at 50 or 200 m distance from the plant area, in the farming environment or cattle manure spreading area, no significant difference was observed between different distances from the source. In summary, elevated concentrations of microbes that differ from background can only be detected within a few hundred meters from the source. This finding, reported earlier for culturable bacteria and fungi, could thus be confirmed using molecular methods that cover both culturable and nonculturable microbial material.

IMPLICATIONS Concentrations and diversity of airborne microbes increase due to particle emissions from different biological waste treatment applications. However, these emissions cannot be separated from the background concentrations after more than a few hundred meters from the source. As part of a risk assessment, it may be necessary to confirm the behavior of microbial emissions from a specific source. Quantitative PCR is a useful tool for estimating total concentrations of different microbial species or groups as it detects both culturable and nonculturable microbial material.     

Aerosol Particle Number Concentration Measurements in Five European Cities Using TSI-3022 Condensation Particle Counter over a Three-Year Period during Health Effects of Air Pollution on Susceptible Subpopulations

Abstract

In this study, long-term aerosol particle total number concentration measurements in five metropolitan areas across Europe are presented. The measurements have been carried out in Augsburg, Barcelona, Helsinki, Rome, and Stockholm using the same instrument, a condensation particle counter (TSI model 3022). The results show that in all of the studied cities, the winter concentrations are higher than the summer concentrations. In Helsinki and in Stockholm, winter concentrations are higher by a factor of two and in Augsburg almost by a factor of three compared with summer months. The winter maximum of the monthly average concentrations in these cities is between 10,000 cm^-3 and 20,000 cm^-3, whereas the summer min is ?;5000–6000 cm^-3. In Rome and in Barcelona, the winters are more polluted compared with summers by as much as a factor of 4–10. The winter maximum in both Rome and Barcelona is close to 100,000 cm^-3, whereas the summer minimum is >10,000 cm^-3. During the weekdays the maximum of the hourly average concentrations in all of the cities is detected during the morning hours between 7 and 10 a.m. The evening maxima were present in Barcelona, Rome, and Augsburg, but these were not as pronounced as the morning ones. The daily maxima in Helsinki and Stockholm are close or even lower than the daily minima in the more polluted cities. The concentrations between these two groups of cities are different with a factor of about five during the whole day. The study pointed out the influence of the selection of the measurement site and the configuration of the sampling line on the observed concentrations.