Continuous determination of fine particulate matter mass in the Salt Lake City Environmental Monitoring project: a comparison of real-time and conventional TEOM monitor results

Fine particulate matter (PM2.5) mass was determined on a continuous basis at the Salt Lake City Environmental Protection Agency Environmental Monitoring for Public Awareness and Community Tracking monitoring site in Salt Lake City, UT, using three different monitoring techniques. Hourly averaged PM2.5 mass data were collected during two sampling periods (summer 2000 and winter 2002) using a real-time total ambient mass sampler (RAMS), sample equilibration system (SES)-tapered element oscillating microbalance (TEOM), and conventional TEOM monitor. This paper compares the results obtained from the various monitoring systems, which differ in their treatment of semivolatile material (SVM; particle-bound water, semivolatile ammonium nitrate, and semivolatile organic compounds). PM2.5 mass results obtained by the RAMS were consistently higher than those obtained by the SES-TEOM and conventional TEOM monitors because of the RAMS ability to measure semivolatile ammonium nitrate and semivolatile organic material but not particle-bound water. The SES-TEOM monitoring system was able to account for an average of 28% of the SVM, whereas the conventional TEOM monitor loses essentially all of the SVM from the single filter during sampling. Occasional mass readings by the various TEOM monitors that are higher than RAMS results may reflect particle-bound water, which, under some conditions, is measured by the TEOM but not the RAMS.     

The behaviour of residual contaminants at a former station site,Antarctica

In 1994, New Zealand's only mainland Antarctic base, Vanda Station, was removed from the shores of Lake Vanda, in the McMurdo Dry Valleys region of southern Victoria Land, Antarctica. Residual chemical contamination of the station site has been identified, in the form of discrete fuel spills, locally elevated Pb, Zn, Ag and Cd concentrations in soil and elevated Cu, Ni, Co and phosphate concentrations in suprapermafrost fluids in a gully formerly used for domestic washing water disposal. Pathways for contaminant transfer to Lake Vanda, potential environmental impacts and specific remediation/monitoring options are considered. While some contaminants (particularly Zn) could be selectively leached from flooded soil, during a period of rising lake level, the small area of contaminated soils exposed and low level of contamination suggests that this would not adversely affect either shallow lake water quality or the growth of cyanobacteria. Phosphate-enhanced growth of the latte may, however, be a visible consequence of the minor contamination occurring at this site.     

Simulation of the evolution of particle size distributions in a vehicle exhaust plume with unconfined dilution by ambient air

Over the past several years, numerous studies have linked ambient concentrations of particulate matter (PM) to adverse health effects, and more recent studies have identified PM size and surface area as important factors in determining the health effects of PM. This study contributes to a better understanding of the evolution of particle size distributions in exhaust plumes with unconfined dilution by ambient air. It combines computational fluid dynamics (CFD) with an aerosol dynamics model to examine the effects of different streamlines in an exhaust plume, ambient particle size distributions, and vehicle and wind speed on the particle size distribution in an exhaust plume. CFD was used to calculate the flow field and gas mixing for unconfined dilution of a vehicle exhaust plume, and the calculated dilution ratios were then used as input to the aerosol dynamics simulation. The results of the study show that vehicle speed affected the particle size distribution of an exhaust plume because increasing vehicle speed caused more rapid dilution and inhibited coagulation. Ambient particle size distributions had an effect on the smaller sized particles (approximately 10 nm range under some conditions) and larger sized particles (>2 microm) of the particle size distribution. The ambient air particle size distribution affects the larger sizes of the exhaust plume because vehicle exhaust typically contains few particles larger than 2 microm. Finally, the location of a streamline in the exhaust plume had little effect on the particle size distribution; the particle size distribution along any streamline at a distance x differed by less than 5% from the particle size distributions along any other streamline at distance x.     

Environmental and phylogenetic correlates of Eulemur behavior and ecology (Primates: Lemuridae)

The extent of diversity within closely related taxa may be a function of their shared evolutionary history or of selective forces causing adaptive changes. Examining variation among taxa within a single genus may help to identify flexibility in trait variation because recently diverged populations are more likely living in the environment of adaptation. This study examines correlates of diversity in Eulemur, a genus that has a wide distribution in a variety of habitat types throughout Madagascar. Previously published data were gathered from 11 long-term studies of Eulemur populations. Variables were categorized into multiple datasets: (1) environmental characteristics, (2) social organization, and (3) ecology, which included subsets for ranging behavior, diet, and activity budget. Molecular phylogenies from the literature were used to create the fourth and final dataset, a dissimilarity matrix of evolutionary distance among the 12 species and subspecies. Principal components and cluster analyses were implemented to examine the overall ecological similarity among Eulemur populations and to determine which variables contribute most to the variation among taxa. Partial Mantel tests were conducted to test for correlations among the dataset matrices. The results suggest ecological flexibility for the genus, in particular, populations in similar environments displayed similar activity patterns. In contrast, social organization showed no relationship with environment but was correlated with phylogenetic distance among populations. While Eulemur seems to demonstrate some flexibility for ecological adaptations, characteristics related to group size and sex ratio more closely track phylogeny and thus may be less flexible.Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible to authorized users.     

Giving respondents time to think in contingent valuation studies: A developing country application

This paper evaluates whether the time given people to think about their responses to CVM valuation questions influences their answers. Our study was conducted in Nigeria as part of an evaluation of rural households' willingness to pay for public taps and private connections to improved drinking water systems. Respondents who were allowed time to evaluate the proposed water system bid significantly less than those who did not have that time. Moreover, this conclusion was upheld regardless of whether the water system was a public tap or a private connection.     

The geological setting of lode-gold deposits in the central southern Urals: a review

The late-Paleozoic Uralides represent one of the largest lode-gold metallogenic provinces in the world. In the southern Urals, gold distribution is heterogeneous and is confined mainly to two tectonostratigraphic zones, namely the Main Uralian fault and the East Uralian zone. The important lode-gold districts within and in the immediate hangingwall of the first-order crustal suture of the Main Uralian fault are characterized by a complex tectonic history of earlier compressional tectonics involving thrusting, folding and reverse faulting and later transcurrent shearing. Gold mineralization is hosted by second- and third-order brittle to brittle–ductile strike-slip faults that developed late during the kinematic history of the Main Uralian fault. Strike-slip reactivation of earlier compressional structures was related to the late-stage docking of the passive margin of the East European platform with island-arc complexes of the southern Urals, an event that is tentatively related to changes in plate motion during the final stages of terrane accretion during the upper Permian and lower Triassic. Gold mineralization was controlled by the permeability characteristics of the hydrothermal conduits, as well as by competence contrasts and geochemistry of the mainly volcanic host rocks. Mineralization occurred at relatively shallow crustal levels (2–6 km) and largely post dates peak-metamorphism of the host rocks. The large and very large (up to 300 to Au) gold deposits of the East Uralian zone are hosted by upper-Paleozoic granitoid massifs. Gold mineralization is temporally associated with the main phase of regional-scale compressional tectonics and granite plutonism during the upper Carboniferous and lower Permian. Controlling structures have a dominantly east–west strike and occur as hybrid shear-tensional vein systems in competent granitoids subjected to east/west-directed regional shortening. Deformation textures and alteration mineral assemblages indicate lower-amphibolite-facies conditions of mineralization close to peak metamorphic conditions that are associated with the mid-Permian regional metamorphism and tectonism. Gold deposits in the southern Urals are, therefore, polygenetic and are temporally and genetically distinct in each of the two major mineralized tectonostratigraphic zones of this well-preserved collisional orogenic belt. The different timing of ore fluid generation and fluid discharge is interpreted to be the result of the different tectonic, metamorphic and magmatic evolution of terranes in the southern Urals.