Changes in blood lead and water lead in Edinburgh. An eight year follow-up to the Edinburgh lead study

This study aimed to measure changes in household water lead and blood lead in young people living in Edinburgh over a period of 8 years. Two hundred and twenty-three families were eligible and 207 (93%) agreed to participate. A half-hour stagnation sample of kitchen cold water was taken from each household, and 171 young people (aged 14–17 years) provided a blood sample for lead analysis. Information on plumbing changes, exposure to other sources of lead and factors which might influence blood lead was collected by questionnaire. Edinburgh is supplied with water treated in one of two treatment plants. There was a different programme of water treatment in each plant. In one (A) lime and orthophosphate was introduced in the interval between the original and follow-up studies. In the other (F) lime treatment began before the original study and orthophosphate was introduced subsequently. In water from treatment plant A, mean water lead levels fell from 34 to 4.3 gL-1 (87%). In water supplied from treatment plant F the corresponding values were 9.3 to 3.6 gL-1 (61%). These reductions were due to both water treatment and removal of lead plumbing. Houses with no lead plumbing have water lead levels 89% lower than houses with lead tanks, and 47% lower than houses with lead pipes. About one-third of households with lead tanks are predicted to have water lead levels above the current EC limit of 50 gL- 1, though only 3% or less of the remaining households would exceed this limit. If the proposed 10 gL-1 limit were introduced, 34% of households supplied from plant A and 25% from plant F would breach the limit. Blood lead levels fell from an average of 11.0 gdL-1 to 4.0 gdL-1. Males had higher values than females and the main factors influencing levels were water lead and age of house. Our results show substantial reductions in household water lead and blood lead in our sample over a period of 8 years and represent an important achievement in public health. However, more progress will be required if the proposed new limit of 10 gL-1 for water lead is to be met. There is a need for the continuing surveillance of household water lead and blood lead levels in representative samples of the population.     

Levels of cadmium and zinc in soil and plants following the toxic spill from a pyrite mine,Aznalcollar, Spain

On 25 April 1998, a breach of the tailings dam of the Los Frailes pyrite mine in southwestern Spain resulted in the release of 6 million m3 of acidic water and toxic sludge high in heavy metals. Contaminated material extended 40 km downstream, affecting agricultural land and parts of the wildlife-rich Do?ana Natural and National Parks, including the Entremuros, a very important area for birds. We report on the concentrations, distributions and bioavailability of zinc and cadmium in soil and vegetation from the Entremuros in November 1998 and October 1999, following 2 'cleanup' operations. Levels of Zn and Cd in soil increased significantly over this period, although this was not reflected consistently in metal concentrations in emergent macrophytes. We recommend monitoring of further cleanup attempts in order to develop means of minimizing potential impacts to wildlife in the area.     

Distribution of antimony in contaminated grassland: 2--Small mammals and invertebrates

Concentrations of antimony in invertebrates and small mammals from grasslands in the vicinity of an antimony smelter were significantly elevated compared to a control site. Higher concentrations of antimony were recorded in liver, lung and kidney tissue of herbivorous and insectivorous mammals from the contaminated sites. However, there is little evidence of bioaccumulation of antimony in food chains represented by the soil-vegetation-invertebrate-insectivore pathway of the grasslands, and little indication of significant accumulation by herbivorous mammals despite marked contamination of their diet.     

On the Use of Surrogate Species in Conservation Biology

Abstract: Conservation biologists have used surrogate species as a shortcut to monitor or solve conservation problems. Indicator species have been used to assess the magnitude of anthropogenic disturbance, to monitor population trends in other species, and to locate areas of high regional biodiversity. Umbrella species have been used to delineate the type of habitat or size of area for protection, and flagship species have been employed to attract public attention. Unfortunately, there has been considerable confusion over these terms, and several have been applied loosely and interchangeably. We attempt to provide some clarification and guidelines for the application of these different terms. For each type of surrogate, we briefly describe the way it has been used in conservation biology and then examine the criteria that managers and researchers use in selecting appropriate surrogate species. By juxtaposing these concepts, it becomes clear that both the goals and selection criteria of different surrogate classes differ substantially, indicating that they should not be conflated. This can be facilitated by first outlining the goals of a conservation study, explicitly stating the criteria involved in selecting a surrogate species, identifying a species according to these criteria, and then performing a pilot study to check whether the choice of species was appropriate before addressing the conservation problem itself. Surrogate species need to be used with greater care if they are to remain useful in conservation biology.     

Influence of cosolvents on quinoline sorption by subsurface materials and clays

Quinoline sorption was measured on Na-saturated subsurface materials, a natural clay isolate, and montmorillonite, and was dominated by exchange of the quinolinium ion. In water/methanol and water/acetone mixtures, quinoline sorption on the subsoils and clays was lower than from water. In cosolvent, sorption followed the ionization fraction indicating the continued predominance of ion exchange. The reduction in quinoline sorption by cosolvent was similar for all the subsoils and clays indicating commonality in the surface-solute-solvent interaction. Conditional equilibrium constants (_cK_ex) for quinoline exchange on the subsoils in water/methanol mixtures decreased log-linearly with mole percent cosolvent up to 20% methanol. This decrease closely followed the increase in quinoline solubility in the cosolvent mixtures. Acetone caused greater reduction in sorption than methanol, at comparable mole percent, in accordance with its lower dielectric constant and enhanced solvating power. A generalized thermodynamic approach based on the concept of transfer activity coefficients was developed to account for the cosolvent effect on _cK_ex, and was successfully applied to the quinoline sorption data. The thermodynamic analysis suggested that enhanced solvation of the organic cation in the bulk solvent and desolvation of Na⁺ at the charged surface predominate the cosolvent effect.     

Quantifying fluctuations in winter productive cropped area in the Central Indian Highlands

The Central Indian Highland landscape (CIHL) represents a complex, diverse, and highly human-modified system. Nearly half the landscape is cropland, yet it hosts 21 protected areas surrounded and connected by forests. Changing farming practices with increasing access to irrigation might alter this intensifying landscape in the near future particularly in light of weather variability. We analyzed a decade of remote sensing data for cropping patterns and climatic factors combined with census data for irrigation and demographic factors to understand winter cropping trajectories in the CIHL. We quantified ‘productive cropped area’ (PCA), defined as the area with planted crop that is green at the peak of the winter growing season. We find three primary trajectories in PCA—increasing, fluctuating, and decreasing. The most dominant trend is fluctuating PCA in two-thirds of the districts, ranging from ~2.11 million to ~3.73 million ha between 2001 and 2013, which is associated with village-level access to irrigation and local labor dynamics. In 58 % of all districts, clay soils were associated with winter cropping (p < 0.05). Increasing irrigation is associated with increased winter PCA in most (94 %) districts (p < 0.00001). We find strong negative association between PCA and land surface temperature (LST) in most (66 %) districts (p < 0.01). LST closely corresponds to daytime mean air temperature (p < 0.001) for available meteorological stations. Fine-scale meteorological and socioeconomic data, however, are needed to further disentangle impacts of these factors on PCA in this landscape.     

Effects of human demand on conservation planning for biodiversity and ecosystem services

Safeguarding ecosystem services and biodiversity is critical to achieving sustainable development. To date, ecosystem services quantification has focused on the biophysical supply of services with less emphasis on human beneficiaries (i.e., demand). Only when both occur do ecosystems benefit people, but demand may shift ecosystem service priorities toward human-dominated landscapes that support less biodiversity. We quantified how accounting for demand affects the efficiency of conservation in capturing both human benefits and biodiversity by comparing conservation priorities identified with and without accounting for demand. We mapped supply and benefit for 3 ecosystem services (flood mitigation, crop pollination, and nature-based recreation) by adapting existing ecosystem service models to include and exclude factors representing human demand. We then identified conservation priorities for each with the conservation planning program Marxan. Particularly for flood mitigation and crop pollination, supply served as a poor proxy for benefit because demand changed the spatial distribution of ecosystem service provision. Including demand when jointly targeting biodiversity and ecosystem service increased the efficiency of conservation efforts targeting ecosystem services without reducing biodiversity outcomes. Our results highlight the importance of incorporating demand when quantifying ecosystem services for conservation planning.     

Impacts of boat paint chips on the distribution and availability of copper in an English ria

Discarded paint chips collected from a leisure boat maintenance facility on the Kingsbridge estuary, SW England, have been fractionated to <63 microm and chemically characterised. At about 16% by weight, Cu was the most abundant metallic component, reflecting its biocidal application in antifouling paint. Bioavailability of Cu in the chips, determined by protein digestion, was about 4%, and sea water leachability was about 8%. Copper concentrations in fractionated intertidal sediment from the estuary were highly variable (<10-460 microg g(-1)). Specifically, greatest concentrations and greatest variability among replicates were found in samples collected near boat maintenance facilities. Bioavailability of Cu in sediment averaged 7% but was also variable. We attribute Cu "hot spots" to heterogeneous contamination of local sediment by small quantities of paint chips. Contamination may arise directly, from relatively inert particulates, or indirectly, via release of Cu from chips to interstitial waters and its subsequent adsorption to local sediment.     

Geographical and pedological drivers of distribution and risks to soil fauna of seven metals (Cd, Cu, Cr, Ni, Pb, V and Zn) in British soils

Concentrations of seven metals were measured in over 1000 samples as part of an integrated survey. Sixteen metal pairs were significantly positively correlated. Cluster analysis identified two clusters. Metals from the largest (Cr, Cu, Ni, V, Zn), but not the smallest (Cd, Pb) cluster were significantly negatively correlated with spatial location and soil pH and organic matter content. Cd and Pb were not correlated with these parameters, due possibly to the masking effect of recent extensive release. Analysis of trends with soil properties in different habitats indicated that general trends may not necessarily be applicable to all areas. A risk assessment indicated that Zn poses the most widespread direct risk to soil fauna and Cd the least. Any risks associated with high metal concentrations are, however, likely to be greatest in habitats such as arable and horticultural, improved grassland and built up areas where soil metal concentrations are more frequently elevated.     

Connectedness, social support and internalising emotional and behavioural problems in adolescents displaced by the Chechen conflict

The study investigated factors associated with internalising emotional and behavioural problems among adolescents displaced during the most recent Chechen conflict. A cross-sectional survey (N=183) examined relationships between social support and connectedness with family, peers and community in relation to internalising problems. Levels of internalising were higher in displaced Chechen youth compared to published norms among non-referred youth in the United States and among Russian children not affected by conflict. Girls demonstrated higher problem scores compared to boys. Significant inverse correlations were observed between family, peer and community connectedness and internalising problems. In multivariate analyses, family connectedness was indicated as a significant predictor of internalising problems, independent of age, gender, housing status and other forms of support evaluated. Sub-analyses by gender indicated stronger protective relationships between family connectedness and internalising problems in boys. Results indicate that family connectedness is an important protective factor requiring further exploration by gender in war-affected adolescents.