The Interstate Air Pollution Surveillance Program Effects Network

A program has been designed to meet a nationwide intelligence-gathering responsibility to obtain general and relative information on current and potential air pollution in areas where interstate transport of pollution may reasonably be expected to exist. This paper describes the field devices utilized in the program. By means of these static “effects packages,” data will be accumulated on: dustfall, particulate impingement, sulfation, corrosion, and tarnishing of metals, and deterioration of textiles, dyes, and rubber. Data accumulated during the “pilot phase” of the program will be discussed.     

Sequential extraction combined with isotope analysis as a tool for the investigation of lead mobilisation in soils: application to organic-rich soils in an upland catchment in Scotland

Sequential extraction (modified BCR procedure) combined with isotope analysis has been investigated as a tool for assessing mobilisation of lead into streams at an upland catchment in NE Scotland. The maximum lead concentrations (up to 110 mg kg(-1) in air-dried soil) occurred not at the surface but at about 10 cm depth. The lowest (206)Pb/(207)Pb ratios in any profile occurred, with one exception, at 2.5-5 cm depth. In the one exception, closest to the only road in the area, significantly lower (206)Pb/(207)Pb ratios in the surface soil together with much increased chloride concentrations (in comparison to other surface waters) indicated the possible mobilisation of roadside lead and transfer to the stream. The (206)Pb/(207)Pb ratios in extractable fractions tended at depth towards the ratio measured in the residual phase but the ratios in the oxidizable fraction increased to a value higher than that of the residual phase.     

Relationships among Isolated Wetland Size, Hydroperiod, and Amphibian Species Richness: Implications for Wetland Regulations

Abstract: Wetland development within the United States is regulated primarily by size. Decisions concerning wetland destruction or conservation are therefore based in part on three inherent assumptions: (1) small wetlands contain water for short portions of the year; (2) small wetlands support few species; and (3) species found in small wetlands are also found in larger wetlands. We tested these assumptions using data on wetland size, relative hydroperiod (drying scores), and relative species richness of amphibians in depression wetlands of the southeastern United States. We found a significant (p = 0.03) but weak (r² = 0.05) relationship between hydroperiod and wetland size and no relationship (p = 0.48) between amphibian species richness and wetland size. Furthermore, synthetic models of lentic communities predict that short-hydroperiod wetlands support a unique group of species. Empirical investigations support this prediction. Our results indicate that hydroperiod length should be included as a primary criterion in wetland regulations. We advocate a landscape approach to wetlands regulation, focused in part on conserving a diversity of wetlands that represent the entire hydroperiod gradient.     

Use of Experimental Translocations of Allegheny Woodrat to Decipher Causal Agents of Decline

Translocations are an important tool for wildlife conservation, although progress in the field of reintroduction biology has been hindered by the ad hoc and opportunistic nature of many translocations. We used an experimental translocation to elucidate the role of raccoon roundworm (Baylisascaris procyonis) and inbreeding depression in the decline of the Allegheny woodrat (Neotoma magister), an endangered species. We translocated woodrats from genetically diverse populations in the core of the species range to 4 previously occupied sites (reintroductions) and 2 sites supporting genetically depauperate populations (reinforcements) in Indiana (U.S.A.). In 2 reintroduction sites and 1 reinforcement site, we distributed anthelmintic baits to passively deworm raccoons and reduce the risk of woodrat exposure to roundworms. The remaining sites served as controls. We used raccoon latrine surveys and fecal flotation to monitor temporal variability in roundworm prevalence and effect of treatment. We used live trapping and microsatellite genotyping to monitor the demographic and genetic response of translocated populations over the following 54 months. At the conclusion of the study, 4 of 6 translocations were successfully maintaining abundance through local recruitment. The distribution of anthelmintic baits reduced levels of roundworm contamination, but levels of contamination were also low in 2 of 3 control sites. Reintroductions failed at control sites, one of which was due to high roundworm exposure. The other failed control reintroduction was likely attributable to demographic stochasticity and limited reproductive potential following initial mortality within the first 4 months. In both control and treatment reinforcements, increases in both allelic richness and heterozygosity were accompanied by increases in abundance, which is suggestive of genetic rescue. Our results demonstrate that mitigation of roundworm exposure through the distribution of anthelmintic baits can facilitate woodrat recovery and that diversity within genetically depauperate populations can be restored through the introduction of a limited number of individuals. El Uso de Reubicaciones Experimentales de Neotoma magister para Descifrar Agentes Causales de Disminución     

Belief network models of land manager decisions and land use change

A two-stage model of land use change is described, which is driven by the types of decisions that land managers make when changing their broad styles of use. The first stage uses decision modelling techniques to assess if a manager is currently satisfied with the present situation, when compared to various potential alternatives. If this evaluation indicates satisfaction, it is assumed that the present land use will continue. However, if it indicates dissatisfaction, Belief Network techniques are used to estimate, in more detail, both how dissatisfied the manager is and whether the costs of changing, from the present use to a potentially better one, will be out-weighed by the anticipated benefits. The proposed models can use a variety of cost and benefit criteria (e.g. financial, social and ecological). The approach is illustrated with a case-study of the factors that might influence changes from farming to forestry in marginal upland areas of the UK.     

ASSESSING POTENTIAL SOURCES OF ASBESTOS FIBERS IN WATER SUPPLIES OF S. E. QUEBEC1

ABSTRACT: A comparative study of the concentration of asbestos fibers in drinking water supplies of southeastern Quebec was undertaken to assess the relative contributions of fibers by asbestos-bearing railway ballast and naturally occurring asbestos deposits. Water samples were taken from areas where one or the other potential sources or neither potential source was present. In addition, rainwater samples were taken to assess the importance of atmospheric contributions. The sampling design accounted for potential variations in fiber counts due to the season, location and analytical procedures. Fiber concentrations were estimated from counts made on a JEOL 100CX scanning transmission electron microscope and statistically compared among areas. These levels were then compared with levels found in other areas of Canada and the United States. The results indicate that the rail ballast could be contributing statistically (albeit marginally) significant quantities of fibers to water supplies during the summer but not in the spring. Estimated concentrations in water supplies ranged between 1.7 × 10⁶fibers/liter and 147.8 × 10⁶fibers/liter. Fiber levels in samples taken during the spring were significantly higher and more variable than those taken during the summer. The presence of fibers in rainwater samples at concentrations of 1.9 × 10⁶fibers/liter, 18.3 × 10⁶fibers/liter and 23.7 × 10⁶fibers/liter suggests that atmospheric transport may play an important role in contributing fibers to regional systems. Fiber levels found in these systems are not unique when compared to levels observed elsewhere in North America.     

Origin of lead associated with different reactive phases in Scottish upland soils: an assessment made using sequential extraction and isotope analysis

Soil samples (0-25 cm) have been taken annually since 1991 from three protected plots set up at an upland location at Glensaugh in Aberdeenshire, Scotland. The soils were analysed using the original BCR sequential extraction procedure and the lead isotopic composition was determined in each of the fractions, as well as the unfractionated soil using thermal ionisation mass spectrometry (TIMS). The lead concentrations in all the soils, including those well away from the road, were much higher than typical background values indicating that the whole area has been subject to deposition of anthropogenic lead. The distribution of lead between the different fractions was similar for the two non-roadside soils with most lead present in the oxidizable fraction. Although most lead in the roadside soil was also present in the oxidizable fraction, a substantial proportion (about 10%) was in the easily soluble fraction suggesting that roadside lead could be more mobile than lead in the other soils. Good reproducibility was obtained for the isotope analyses in all the fractions. The ratios calculated for the bulk soil from the ratios in the individual fractions agreed very closely with those measured directly in the unfractionated soil thereby demonstrating both reproducibilty and accuracy. The lowest (206)Pb/(207)Pb ratios were found in the roadside soil consistent with the recent deposition of petrol lead. The (206)Pb/(207)Pb ratios in all fractions of the other soils fell into a narrow band and it was necessary to use (204)Pb ratios to differentiate between lead in the extractable fractions and lead in the residual component. It is probable that lead in the non-roadside soils was deposited a considerable time ago and is characterised by a relatively high (206)Pb/(207)Pb ratio. Use of the (204)Pb ratios showed that the residual components in each of the three soils were isotopically distinct.