Lead in grain size fractions of road-deposited sediment

Road-deposited sediment (RDS) is an important environmental medium for assessing contaminant levels in urban systems. Their atmospheric resuspension has significant implications for human health, and storm water transport can directly impact aquatic biota. Data from 20 RDS samples from Palolo Valley, Oahu, Hawaii, were fractionated into six grain-size classes and analyzed for Pb using a weak HCl (0.5 M) digestion. Data indicate significant Pb contamination in all samples. Median labile Pb concentration (n = 120) was 170 mg/kg, with a range from 4 to 1750 mg/kg. The five sediment fractions < 1000 microm had statistically similar Pb concentrations, but all were significantly greater than the coarsest fraction examined (1000-2000 microm). Silt plus clay ( < 63 microm) was the single most important mass component with 38% of the total sediment stored in this fraction. Mass of sediment < 63 microm combined with a median labile Pb concentration of 222 mg/kg accounted for 51% of the total Pb load stored in road sediments. These findings are significant from an environmental management perspective, and these issues are discussed in light of street sweeper sediment grain size removal efficiencies.     

Thresholds of species loss in Amazonian deforestation frontier landscapes

In the Brazilian Amazon, private land accounts for the majority of remaining native vegetation. Understanding how land‐use change affects the composition and distribution of biodiversity in farmlands is critical for improving conservation strategies in the face of rapid agricultural expansion. Working across an area exceeding 3 million ha in the southwestern state of Rondônia, we assessed how the extent and configuration of remnant forest in replicate 10,000‐ha landscapes has affected the occurrence of a suite of Amazonian mammals and birds. In each of 31 landscapes, we used field sampling and semistructured interviews with landowners to determine the presence of 28 large and medium sized mammals and birds, as well as a further 7 understory birds. We then combined results of field surveys and interviews with a probabilistic model of deforestation. We found strong evidence for a threshold response of sampled biodiversity to landscape level forest cover; landscapes with <30–40% forest cover hosted markedly fewer species. Results from field surveys and interviews yielded similar thresholds. These results imply that in partially deforested landscapes many species are susceptible to extirpation following relatively small additional reductions in forest area. In the model of deforestation by 2030 the number of 10,000‐ha landscapes under a conservative threshold of 43% forest cover almost doubled, such that only 22% of landscapes would likely to be able to sustain at least 75% of the 35 focal species we sampled. Brazilian law requires rural property owners in the Amazon to retain 80% forest cover, although this is rarely achieved. Prioritizing efforts to ensure that entire landscapes, rather than individual farms, retain at least 50% forest cover may help safeguard native biodiversity in private forest reserves in the Amazon. Umbrales de Pérdida de Especies en los Paisajes Fronterizos de Deforestación en el Amazonas Ochoa‐Quintero     

Societal implications of nanotechnology: occupational perspectives

Nanotechnology-infused products have begun to enter the market in spite of the fact that many sectors of society are still debating whether or not exposure to such products will result in detrimental side effects. Due to a lack of regulation of nanoproducts, it is difficult to track these products to assess how they interact with humans and the environment. Acknowledging this limitation, several studies are starting to investigate situations where individuals are exposed to nanoparticles in the workplace; it is to be noted that manufacturing of materials is the first stage in the product life cycle where exposure may occur. This paper reviews and discusses the potential societal implications associated with the manufacturing of nanoparticles: health concerns, workers’ perceptions, rights, ethics, and the role of policy and regulation. Scenarios are presented, possible implications are discussed, and recommendations are given for appropriate action. Finding the right solution to the identified implications represents a critical challenge. In summary, it is imperative that all stakeholders including industry, academia, government entities, and the public adopt a proactive attitude to ensure that nanotechnology matures in a sustainable manner.     

Grain size partitioning of platinum-group elements in road-deposited sediments: implications for anthropogenic flux estimates from autocatalysts

Twelve road-deposited sediment samples were analyzed for platinum-group elements (PGEs) and Pb in the <63 microm fraction of an urban watershed in Hawaii. Three samples were further fractionated into five size classes, from 63-125 microm to 1000-2000 microm, and these were analyzed for PGEs and Pb. Concentrations in the <63 microm fraction reached 174 microg/kg (Pt), 101 microg/kg (Pd), 16 microg/kg (Rh), and 1.3 microg/kg (Ir). Enrichment ratios followed the sequence Rh>Pt=Pd>Ir. Iridium was geogenic in origin, while the remaining PGEs indicated significant anthropogenic contamination. Palladium, Pt and Rh concentrations and enrichment signals were consistent with PGE bivariate ratios and PGE partitioning in three-way catalysts. Size partitioning indicated that the <63 microm fraction had the lowest PGE concentrations and mass loading percentages. These data suggest that autocatalyst PGE flux estimates into the environment will be significantly underestimated if only a fine grain size fraction is analyzed.     

Curtin industrial safety trial: Managerial behavior and program effectiveness

Behavior-based safety has been found universally efficacious when evaluated under controlled conditions. The Curtin Trial aimed to test the general acceptability of behavior-based safety in Australian industry. A 50% failure rate was observed. This paper presents the results of a qualitative analysis of observed managerial behavior in relation to program effectiveness. Field notes taken in the course of 325 hours of participant observation during implementation of behavior-based safety in 9 work areas were analyzed qualitatively and categorized. These data were compared with statistical results of the safety program's effectiveness on improving safe practices and good housekeeping. Nine dimensions to managerial behavior were identified which were associated with program effectiveness. A relatively small number of studies investigating organizational characteristics and safety have found generally similar social environmental features to those observed in this study. Behavior-based safety appears to be effective only in organizations with recognizable managerial styles.     

Chronic and episodic acidification of Adirondack streams from acid rain in 2003-2005

Limited information is available on streams in the Adirondack region of New York, although streams are more prone to acidification than the more studied Adirondack lakes. A stream assessment was therefore undertaken in the Oswegatchie and Black River drainages; an area of 4585 km(2) in the western part of the Adirondack region. Acidification was evaluated with the newly developed base-cation surplus (BCS) and the conventional acid-neutralizing capacity by Gran titration (ANC(G)). During the survey when stream water was most acidic (March 2004), 105 of 188 streams (56%) were acidified based on the criterion of BCS < 0 microeq L(-1), whereas 29% were acidified based on an ANC(G) value < 0 microeq L(-1). During the survey when stream water was least acidic (August 2003), 15 of 129 streams (12%) were acidified based on the criterion of BCS < 0 microeq L(-1), whereas 5% were acidified based on ANC(G) value < 0 microeq L(-1). The contribution of acidic deposition to stream acidification was greater than that of strongly acidic organic acids in each of the surveys by factors ranging from approximately 2 to 5, but was greatest during spring snowmelt and least during elevated base flow in August. During snowmelt, the percentage attributable to acidic deposition was 81%, whereas during the October 2003 survey, when dissolved organic carbon (DOC) concentrations were highest, this percentage was 66%. The total length of stream reaches estimated to be prone to acidification was 718 km out of a total of 1237 km of stream reaches that were assessed.     

Dynamics of the epibenthic community on roots of the mangrove Rhizophora mangle,at Bahía de Buche,Venezuela

The community of epibenthic organisms growing on the roots of the red mangrove Rizophora mangle was studied from March 1976 to September 1977, at a site 100 km east of Caracas, Venezuela. Recruitment was relatively constant and low in intensity for most species. Asbestos panels submerged in March–April 1976 and November 1976 were similar in species composition by September 1977; species composition of panels submerged in March–April 1976 did not change greatly between November 1976 and September 1977. There was little change in the mean species composition on ca. 120 roots during the 18 month study period. The major feature of the community was the large differences in species composition among roots. Even species which were rare in the community as a whole were common on some roots. I ascribe these differences to chance resulting from the low recruitment rate of most species and the low rate of supply of new roots (8% yr^-1). Once present on a given root, species seem to live for many years and resist the invasion of most other larvae. The initial differences in species composition among roots persists and the overall community does not change greatly with time. Predation had little effect on community development.     

2,4-D levels in the South Saskatchewan River in 1973 as determined by GLC method.

2,4-D levels in the South Saskatchewan River near Saskatoon in 1973 at the height of the spraying season, and at harvestime, were determined by a method involving direct glc analysis, ankaline hydrolysis, followed by n-butylation of the liberated free acid after acidification of the alkaline solution, and confirmed by subsequent n-octylation. GC/MS also confirmed the presence of 2,4-D. 2,4-D was detected during the spraying season but not at harvest time or in river mud samples. The average level was ca. 2mug of acid equivalent to 2,4-D per liter of river water at the height of the spraying season.     

Physical basis of coastal adaptation on tropical small islands

Small tropical islands are widely recognized as having high exposure and vulnerability to climate change and other natural hazards. Ocean warming and acidification, changing storm patterns and intensity, and accelerated sea-level rise pose challenges that compound the intrinsic vulnerability of small, remote, island communities. Sustainable development requires robust guidance on the risks associated with natural hazards and climate change, including the potential for island coasts and reefs to keep pace with rising sea levels. Here we review these issues with special attention to their implications for climate-change vulnerability, adaptation, and disaster risk reduction in various island settings. We present new projections for 2010–2100 local sea-level rise (SLR) at 18 island sites, incorporating crustal motion and gravitational fingerprinting, for a range of Intergovernmental Panel on Climate Change global projections and a semi-empirical model. Projected 90-year SLR for the upper limit A1FI scenario with enhanced glacier drawdown ranges from 0.56 to 1.01 m for islands with a measured range of vertical motion from ?0.29 to +0.10 m. We classify tropical small islands into four broad groups comprising continental fragments, volcanic islands, near-atolls and atolls, and high carbonate islands including raised atolls. Because exposure to coastal forcing and hazards varies with island form, this provides a framework for consideration of vulnerability and adaptation strategies. Nevertheless, appropriate measures to adjust for climate change and to mitigate disaster risk depend on a place-based understanding of island landscapes and of processes operating in the coastal biophysical system of individual islands.