Risk perception, risk communication, and stakeholder involvement for biosolids management and research

An individual's perception of risk develops from his or her values, beliefs, and experiences. Social scientists have identified factors that affect perceptions of risk, such as whether the risk is knowable (uncertainty), voluntary (can the individual control exposure?), and equitable (how fairly is the risk distributed?). There are measurable differences in how technical experts and citizen stakeholders define and assess risk. Citizen knowledge and technical expertise are both relevant to assessing risk; thus, the 2002 National Research Council panel on biosolids recommended stakeholder involvement in biosolids risk assessments. A survey in 2002 identified some of the factors that influence an individual's perception of the risks involved in a neighbor's use of biosolids. Risk communication was developed to address the gap between experts and the public in knowledge of technical topics. Biosolids management and research may benefit from applications of current risk communication theory that emphasizes (i) two-way communications (dialogue); (ii) that the public has useful knowledge and concerns that need to be acknowledged; and (iii) that what may matter most is the credibility of the purveyor of information and the levels of trustworthiness, fairness, and respect that he or she (or the organization) demonstrates, which can require cultural change. Initial experiences in applying the dialogue and cultural change stages of risk communication theory--as well as consensus-building and joint fact-finding--to biosolids research suggest that future research outcomes can be made more useful to decision-makers and more credible to the broader public. Sharing control of the research process with diverse stakeholders can make research more focused, relevant, and widely understood.     

Age-related shifts in the diet composition of southern elephant seals expand overall foraging niche

Southern elephant seals are important apex predators in a highly variable and unpredictable marine environment. In the presence of resource limitation, foraging behaviours evolve to reduce intra-specific competition increasing a species’ overall probability of successful foraging. We examined the diet of 141 (aged 1–3 years) juvenile southern elephant seals to test the hypotheses that differences between ages, sexes and seasons in diet structure occur. We described prey species composition for common squid and fish species and the mean size of cephalopod prey items for these age groups. Three cephalopod species dominated the stomach samples, Alluroteuthis antarcticus, Histioteuthis eltaninae and Slosarczykovia circumantarcticus. We found age-related differences in both species composition and size of larger prey species that probably relate to ontogenetic changes in diving ability and haul-out behaviour and prey availability. These changes in foraging behaviour and diet are hypothesised to reduce intra-specific food competition concomitant with the increase in foraging niche of growing juveniles.     

An assessment of the potential adverse properties of fluorescent tracer dyes used for groundwater tracing

The potential ecotoxicity of fluorescent dyes used in tracing, and their possible effects on human health, were evaluated by reviewing available toxicological information for 12 dyes — fluorescein, Lissamine Flavine FF, Rhodamine WT, Rhodamine B, Sulpho Rhodamine G, Sulpho Rhodamine B, eosin, pyranine, Phorwite BBH Pure, Tinopal 5BM GX, Tinopal CBS-X, and Diphenyl Brilliant Flavine 7GFF — and a dye-intermediate, amino G acid. This evaluation used available toxicological information, test data on analogous substances, and mathematical expressions for biological activity. Based on set criteria for human health and acute ecotoxicity, the evaluation indicated that these tracers have low to moderate levels of concern. The use of these tracers for the study of groundwater flow is appropriate if consideration is given to the overall human health and environmental effects. Their use in the environment requires tracer concentrations not exceeding 1–2 mg 1^–1 persisting for a period in excess of 24 h in the groundwater at the point of groundwater withdrawal or discharge. A simple calculated potential dose was used in a comparison of the estimated acute toxicity of Rhodamine WT in rats to the known acute oral toxic dose in humans for several known acutely toxic chemicals. This comparison showed that none of the fluorescent dyes evaluated would present an acutely toxic threat at or substantially above the recommended 2 mg 1^–1 concentration.The U.S. Governments right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged. Disclaimer: The views of this paper are solely those of the authors and do not necessarily reflect the views or policies of the U.S. Environmental Protection Agency.     

Testing for a change in diet using fatty acid signatures

Determining whether the diet of predators has changed is an important ecological problem and appropriate methodology is needed in order to test for differences or changes in diet. It is known that the fatty acid (FA) signature in a predator’s adipose tissue predictably reflects the prey consumed and that, consequently, a change in the FA signatures can be largely attributed to changes in the predator’s diet composition. The use of FA signatures as a means of detecting change in diet presents some statistical challenges however, since the FA signatures are compositional and sample sizes relative to the dimension of a signature are often small due to biological constraints. Furthermore, the FA signatures often contain zeros precluding the direct use of traditional compositional data analysis methods. In this paper, we provide the methodology to carry out valid statistical tests for detecting changes in FA signatures and we illustrate both independent and paired cases using simulation studies and real life seabird and seal data. We conclude that the statistical challenges using FA data are overcome through the use of nonparametric tests applied to the multivariate setting with suitable test statistics capable of handling the zeros that are present in the data.     

Radon exposure and risk of cerebrovascular disease: a systematic review and meta-analysis in occupational and general population studies

Environmental Science and Pollution Research - Although it is biologically plausible, findings relating radon exposure to the risk of cerebrovascular disease (CeVD) are inconsistent and...     

Active and effective nest defence by males in a social apoid wasp

Altruism in the social Hymenoptera is generally considered to be a feature of females rather than males. A popular explanation for this is that in the solitary ancestors of today's social species, males provided little brood care. Males might therefore lack the preadaptations necessary to evolve altruism in social contexts. While anecdotal observations of male contributions to colony life have been reported, there are few reports of male participation in nest defence. In apoid wasps, there have been several reports of male nest-guarding behaviour in solitary species, potentially setting the evolutionary stage for similar behaviours in social lineages. Here, we present evidence of active and effective nest defence in males of the social apoid wasp Microstigmus nigrophthalmus. Males were observed chasing intruders away from the nest, and the presence of males had a significant effect on nest survival when females were removed. Males potentially obtained direct benefits through defence, so that defence may not represent male altruism. However, our results do show that males can perform acts that benefit their colony.     

Spatio-temporal patterns in the diversity of demersal fish communities off the south coast of South Africa

The diversity of ecological communities has been the focus of many studies. Because biodiversity provides several indicators used in an Ecosystem Approach to Fisheries (EAF) to track changes in fish communities, we investigated the spatial and temporal patterns in the diversity of some demersal fish communities subjected to varying fishing pressure. Depth and catch rate were the most important predictors in explaining changes in diversity followed by longitude and survey year. Diversity, as measured by the various indices except for taxonomic distinctness (∆*), initially declined with increasing depth to about a depth of 80 m, then increased to about 150 m after which it declined. Taxonomic distinctness index (∆*) showed an increase in the taxonomic heterogeneity of the demersal community below the 300-m isobath. Diversity remained relatively constant with increase in longitude to around 24°E (which has the lowest diversity) after which it increased. The assessment of the temporal trend in diversity indicates that survey year has a significant effect on all diversity indices except for ∆*. Diversity increased and dominance declined with time. This may be result of a decline in the abundance of dominant species or an increase in the abundance less dominant species, or a combination of both effects. Multivariate analysis of the set of diversity indices showed three groups of indices: those reflecting species richness (S, Margalef’s d), those measuring mainly taxonomic relatedness (∆*), and those balancing the richness and evenness components of diversity (J′, H′, λ, ∆, Hill’s N1, and Hill’s N2). The relationship between evenness, catch rate, and size was also investigated. Size classes with highest evenness were found to have lowest catch rate and vice versa. This highlights the need to consider the size and trophic level of species when linking diversity to the functioning of ecosystems.     

Institutional deficiencies and capacity building constraints: the dilemma for environmentally sustainable development in Africa

SUMMARY

The authors question Africa's ability to achieve sustainable development in view of the erosion of its institution building capacity, a problem compounded by the alarming rate of Africa's continuing marginalisation in the world economy. The situation has been provoked by inappropriate domestic policies which have not only compromised Africa's competitiveness, but also made it particularly vulnerable given the increasing globalisation of markets and factors of production. The benefits associated with effective global economic participation transcend direct financial gains and include technology transfers, technical and managerial skills transfers, and other skills transfers associated with the ‘learning and doing’ process. These benefits are instrumental in the development of the economic, administrative, legislative and social institutions that prescribe the organisational and managerial structure of an economy and define its capacity for sustainable growth. In Africa, the absence of such structures has undermined development efforts and created large impoverished populations. But poverty in living standards is not only prevalent, there is also the acute poverty in knowledge and skills which is so damaging to institution building capacity. The socio-economic impact is manifest in dilapidated infrastructure, decaying institutions, the exodus of the professional and managerial cadre, and the almost total disintegration of society. It is within this context that Africa's ability to evolve and effectively manage sustainable development policies is questioned. The study concludes that the continent's capacity to initiate sound environmental and sustainable development policies depends crucially on its ability to develop appropriate and functional institutions.     

Detecting and quantifying reductive dechlorination under monitored natural attenuation conditions

Field sampling and testing were used to investigate the relationship between baseline geochemical and microbial community data and in situ reductive dechlorination rates at a site contaminated with trichloroethene (TCE) and carbon tetrachloride (CTET). Ten monitoring wells were selected to represent conditions along groundwater flow paths from the contaminant source zone to a wetlands groundwater discharge zone. Groundwater samples were analyzed for a suite of geochemical and microbial parameters; then push‐pull tests with fluorinated reactive tracers were conducted in each well to measure in situ reductive dechlorination rates. No exogenous electron donors were added in these tests, as the goal was to assess in situ reductive dechlorination rates under natural attenuation conditions. Geochemical data provided preliminary evidence that reductive dechlorination of TCE and CTET was occurring at the site, and microbial data confirmed the presence of known dechlorinating organisms in groundwater. Push‐pull tests were conducted using trichlorofluoroethene (TCFE) as a reactive tracer for TCE and, in one well, trichlorofluoromethane (TCFM) as a reactive tracer for CTET. Injected TCFE was transformed to cis‐ and trans‐dichlorofluoroethene and chlorofluoroethene, and, in one test, injected TCFE was completely dechlorinated to fluoroethene (FE). In situ TCFE transformation rates ranged from less than 0.005 to 0.004/day. In the single well tested, injected TCFM was transformed in situ to dichlorofluoromethane and chlorofluoromethane; the TCFM transformation rate was estimated as 0.001/day. The results indicate that it is possible to use push‐pull tests with reactive tracers to directly detect and quantify reductive dechlorination of chlorinated ethenes and ethanes under monitored natural attenuation conditions, which has not previously been demonstrated. Transformation rate estimates obtained with these techniques should improve the accuracy of contaminant transport modeling. © 2012 Wiley Periodicals, Inc.     

COMBINED SEWER OVERFLOW CONTROL THROUGH IN-RECEWING WATER STORAGE: AN EFFICIENCY EVALUATION1

ABSTRACT: A demonstration and efficiency evaluation project was conducted for the flow balancing method (FBM) facility, a combined sewer overflow (CSO) storage facility at Fresh Creek in Brooklyn, New York City. The FBM is a curtained tank located directly in the receiving water that captures CSO. The CSO floats on top of and displaces Fresh Creek saltwater before it is pumped back to the publicly owned treatment works (POTW). The facility was a pilot scale subject to the full CSOs. The purpose of the project was to show how the FBM can withstand severe weather and tidal conditions and to develop a procedure for estimating CSO control efficiency (percentage of CSO pumped back to the POTW). The procedure proved successful and incorporated specific conductivity as a tracer in mass balance equations. These equations provided estimates of the net percent, capture-pumpback of the CSO using the FBM, including the amount of Fresh Creek water that was included in the pumpback to the P01W. The efficiency was directly related to the volume of the CSO and the pumpback rate and ranged from a low of 3.3 percent for the largest event to a high of 76.9 percent for the smallest event. Recent FBM enlargement should result in substantial increases in CSO control. The FBM facility has operated successfully for over five years, withstanding ice storms, near hurricane force winds and up to 7 ft tidal range.