Lagrangian Sampling for Emerging Contaminants Through an Urban Stream Corridor in Colorado1

Abstract: Recent national concerns regarding the environmental occurrence of emerging contaminants (ECs) have catalyzed a series of recent studies. Many ECs are released into the environment through discharges from wastewater treatment plants (WWTPs) and other sources. In 2005, the U.S. Geological Survey and the City of Longmont initiated an investigation of selected ECs in a 13.8‐km reach of St. Vrain Creek, Colorado. Seven sites were sampled for ECs following a Lagrangian design; sites were located upstream, downstream, and in the outfall of the Longmont WWTP, and at the mouths of two tributaries, Left Hand Creek and Boulder Creek (which is influenced by multiple WWTP outfalls). Samples for 61 ECs in 16 chemical use categories were analyzed and 36 were detected in one or more samples. Of these, 16 have known or suspected endocrine‐disrupting potential. At and downstream from the WWTP outfall, detergent metabolites, fire retardants, and steroids were detected at the highest concentrations, which commonly exceeded 1 μg/l in 2005 and 2 μg/l in 2006. Most individual ECs were measured at concentrations less than 2 μg/l. The results indicate that outfalls from WWTPs are the largest but may not be the sole source of ECs in St. Vrain Creek. In 2005, high discharge was associated with fewer EC detections, lower total EC concentrations, and smaller EC loads in St. Vrain Creek and its tributaries as compared with 2006. EC behavior differed by individual compound, and some differences between sites could be attributed to analytical variability or to other factors such as physical or chemical characteristics or distance from contributing sources. Loads of some ECs, such as diethoxynonylphenol, accumulated or attenuated depending on location, discharge, and distance downstream from the WWTP, whereas others, such as bisphenol A, were largely conservative. The extent to which ECs in St. Vrain Creek affect native fish species and macroinvertebrate communities is unknown, but recent studies have shown that fish respond to very low concentrations of ECs, and further study on the fate and transport of these contaminants in the aquatic environment is warranted.     

Polybrominated diphenyl ethers and polychlorinated biphenyls in human breast adipose samples from Brazil

Twenty five human breast adipose tissue samples were collected in Porto Alegre, Brazil during 2004-2005 and analyzed for polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs). SigmaPBDE concentrations (sum of tri- to hepta-BDEs) ranged from 0.19 to 132 ng/g lipid with a median of 1.51 ng/g lipid. These concentrations are 3- to 100-times lower than those reported from other countries, with the exception of Japan, probably reflecting lower usage of PBDE-containing products or lower exposures to these chemicals. The predominant congener was BDE-47, followed by BDEs 99, 183, 153 and 100. One individual in the dataset had about 70-times higher PBDE concentrations than the rest of the participants. SigmaPCB (sum of PCBs 118, 138, 153, 180) ranged from 30 to 339 ng/g lipid, with a median of 51 ng/g lipid. No age dependency was found for PBDEs (r=-0.800-0.374, p>0.05) or PCB 180 (r=0.278, p>0.05). On the other hand, PCBs 118, 138 and 153 did show age dependency (r=0.410-0.458, p<0.05). This is the first study to report levels of PBDEs in human breast adipose from Brazil.     

A commentary on decision-making and organisational legitimacy in the Risk Society

Key concepts of Risk Society as elaborated by Ulrich Beck and others (Beck, U., 1992 (trans. Mark Ritter). The Risk Society. Sage Publications, London. Beck, U., 1995, Ecological Politics in the Age of Risk. Polity Press, Cambridge. Beck, U., 1999, World Risk Society. Polity Press, Cambridge. Giddens, A., 1994, Beyond Left and Right. Polity Press, Oxford. Beck, U., Giddens, A. and Lash, S., 1994, Reflexive Modernisation: Politics, Tradition and Aesthetics in the Modern Social Order. Stanford University Press, Stanford. Beck, U., Bonss, W. and Lau, C., 2003, Theory, Culture & Society 2003, Sage, London, 20(2), pp. 1-33.) are illuminated though a case study of managed environmental risk, namely the hexachlorobenzene (HCB) controversy at Botany, a southeast suburb of Sydney. We observe the way multiple stakeholder decision-making plays out a number of Risk Society themes, including the emergence of 'unbounded risk' and of highly 'individualised' and 'reflexive' risk communities. Across several decades, the events of the HCB story support Risk Society predictions of legitimacy problems faced by corporations as they harness technoscientific support for innovation in their products and industrial processes without due recognition of social and environmental risk. Tensions involving identity, trust and access to expert knowledge advance our understanding of democratic 'sub-political' decision-making and ways of distributing environmental risk.     

Participatory scenario planning for developing innovation in community adaptation responses: three contrasting examples from Latin America

Environmental change requires adaptive responses that are innovative, forward-looking and anticipatory, in order to meet goals for sustainability in socio-ecological systems. This implies transformative shifts in understanding as conceptualised by the idea of ‘double’- or ‘triple-loop learning’. Achieving this can be difficult as communities often rely on shorter-term coping mechanisms that purport to maintain the status quo. The use of participatory scenario planning to stimulate forward-looking social learning for adaptation was investigated through three contrasting community case studies on natural resource management in Latin America (in Mexico, Argentina and Colombia). Exploratory scenario narratives that synthesised local knowledge and future perceptions were used iteratively to define response options considered robust across multiple futures. Despite its intensive format, participants in each case agreed that scenario planning enabled a more systematic appraisal of the future. Scenarios facilitated innovation by providing scope to propose new types of responses and associated actions. Differences in local context meant that learning about future change developed in diverse ways, showing a need for a reflexive process. Reframing of key issues characteristic of double-loop learning did occur, albeit through different forms of interaction in each location. However, a shift towards transformative actions characteristic of triple-loop learning was less evident. Achieving this would appear to require ongoing use of scenarios to challenge social norms in light of changing drivers. Use of learning loops as a diagnostic to evaluate adaptive responses provided a useful reference framework although in practice both innovation and consolidative approaches can develop concurrently for responses to different issues.     

Environmental accounting of natural capital and ecosystem services for the US National Forest System

The National Forests of the United States encompass 192.7?million acres (78?million hectares) of land, which is nearly five percent of the total land area of the nation. These lands are managed by the US Forest Service (USFS) for multiple uses, including extraction of timber, production of fossil fuels and minerals, public recreation, and the preservation of biodiversity, clean air, water, and soils. The USFS is interested in valuing the natural capital within, and the ecosystem services provided by, their lands. This is in part to justify expenditures in a time of limited resources. We used emergy and an environmental accounting approach, to quantify the ecosystem services, the exported environmental goods and information provided by National Forest System (NFS) lands, and the natural capital residing on those lands. Environmental accounting using emergy provides a method to value these flows of services and storages of capital using a common biophysical unit, the solar emjoule and its monetary equivalent the emdollar. We compare emdollar values to economic values gleaned from the literature. In 2005, the ecosystem services provided by USFS lands were equivalent to 197?billion emdollars, and the value of NFS natural capital was 24.3?trillion emdollars. Our evaluation suggests that the Federal Government budget allocation for the NFS ($5.55E+09 in 2005) was well spent, protecting 24.3?trillion emdollars in natural capital and insuring annual ecosystem services totaling 197?billion emdollars. Monetary values for some natural capital and ecosystem services are similar to emergy-derived values (resources like fish, wildlife, water, and firewood extracted from forests), and others are widely different (biodiversity, fossil, and mineral resources). There is large uncertainty associated with computing the environment’s contributions to society whether using emergy or accepted economic techniques; yet, the magnitude of these emergy-derived estimates suggests that even with the uncertainty, the values are significant and monetary expenditures for the Forest Service are justified.     

Use of Integrated Landscape Indicators to Evaluate the Health of Linked Watersheds and Coral Reef Environments in the Hawaiian Islands

A linkage between the condition of watersheds and adjacent nearshore coral reef communities is an assumed paradigm in the concept of integrated coastal management. However, quantitative evidence for this "catchment to sea" or "ridge to reef" relationship on oceanic islands is lacking and would benefit from the use of appropriate marine and terrestrial landscape indicators to quantify and evaluate ecological status on a large spatial scale. To address this need, our study compared the Hawai'i Watershed Health Index (HI-WHI) and Reef Health Index (HI-RHI) derived independently of each other over the past decade. Comparisons were made across 170 coral reef stations at 52 reef sites adjacent to 42 watersheds throughout the main Hawaiian Islands. A significant positive relationship was shown between the health of watersheds and that of adjacent reef environments when all sites and depths were considered. This relationship was strongest for sites facing in a southerly direction, but diminished for north facing coasts exposed to persistent high surf. High surf conditions along the north shore increase local wave driven currents and flush watershed-derived materials away from nearshore waters. Consequently, reefs in these locales are less vulnerable to the deposition of land derived sediments, nutrients and pollutants transported from watersheds to ocean. Use of integrated landscape health indices can be applied to improve regional-scale conservation and resource management.     

A case study of potential human health impacts from petroleum coke transfer facilities

Petroleum coke or “petcoke” is a solid material created during petroleum refinement and is distributed via transfer facilities that may be located in densely populated areas. The health impacts from petcoke exposure to residents living in proximity to such facilities were evaluated for a petcoke transfer facilities located in Chicago, Illinois. Site-specific, margin of safety (MOS) and margin of exposure (MOE) analyses were conducted using estimated airborne and dermal exposures. The exposure assessment was based on a combined measurement and modeling program that included multiyear on-site air monitoring, air dispersion modeling, and analyses of soil and surfaces in residential areas adjacent to two petcoke transfer facilities located in industrial areas. Airborne particulate matter less than 10 microns (PM₁₀) were used as a marker for petcoke. Based on daily fence line monitoring, the average daily PM₁₀ concentration at the KCBX Terminals measured on-site was 32 μg/m³, with 89% of 24-hr average PM₁₀ concentrations below 50 μg/m³ and 99% below 100 μg/m³. A dispersion model estimated that the emission sources at the KCBX Terminals produced peak PM₁₀ levels attributed to the petcoke facility at the most highly impacted residence of 11 μg/m³ on an annual average basis and 54 μg/m³ on 24-hr average basis. Chemical indicators of petcoke in soil and surface samples collected from residential neighborhoods adjacent to the facilities were equivalent to levels in corresponding samples collected at reference locations elsewhere in Chicago, a finding that is consistent with limited potential for off-site exposure indicated by the fence line monitoring and air dispersion modeling. The MOE based upon dispersion model estimates ranged from 800 to 900 for potential inhalation, the primary route of concern for particulate matter. This indicates a low likelihood of adverse health effects in the surrounding community.?Implications: Handling of petroleum coke at bulk material transfer facilities has been identified as a concern for the public health of surrounding populations. The current assessment, based on measurements and modeling of two facilities located in a densely populated urban area, indicates that petcoke transport and accumulation in off-site locations is minimal. In addition, estimated human exposures, if any, are well below levels that could be anticipated to produce adverse health effects in the general population.     

Degradation of disulfoton,oxydemeton‐methyl,methamidophos and demeton in asparagus plant

Abstract

Disulfoton and methamidophos (both at 1.12 kg a.i./ha), oxydemeton‐methyl and demeton, (both at 0.56 kg a.i./ha) were applied as post‐harvest foliar sprays to control the European asparagus aphid, Brachycolus asparagi. Oxidation of disulfoton, oxydemeton‐methyl and demeton to their corresponding sulfoxides and sulfones occurred in asparagus foliage 2 to 5 days after application. The total residues of these three compounds, including their toxic oxidative metabolites declined to less than 0.5 ppm about 47 days after the spray application whereas methamidophos persisted longer; 0.84 ppm of its residue was found even after 85 days. No residue was found above the limit of detection of 0.002 ppm in any asparagus spears which were produced in the following spring; the four compounds were sprayed on the asparagus plants during the previous season at realistic rates for aphid control.     

Mercury Measurement and Its Control: What We Know,Have Learned,and Need to Further Investigate

ABSTRACT

Based on the available evidence of health effects, the U.S. Environmental Protection Agency (EPA) has been evaluating the need to regulate mercury releases to the environment. In response to the congressional mandates in The 1990 Clean Air Act Amendments (CAAA), the EPA has issued the Mercury Study Report and the Study of Hazardous Air Pollutant Emissions from Electric Utility Steam Generating Units Report. In spite of the enormous effort represented by these reports, as well as the efforts of both the U.S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI), in conducting the field measurement programs that form the basis for these reports, a definitive answer on the need for mercury regulation has not been found. However, the EPA, as well as other regulatory agencies and health researchers, have suggested a "plausible link" between anthropogenic sources emitting mercury and the methylation, bioaccumulation in the food chain, and adverse health effects in humans and wildlife.     

Processes Influencing Secondary Aerosol Formation in the San Joaquin Valley during Winter

Abstract

Air quality data collected in the California Regional PM₁₀/PM_2.5 Air Quality Study (CRPAQS) are analyzed to qualitatively assess the processes affecting secondary aerosol formation in the San Joaquin Valley (SJV). This region experiences some of the highest fine particulate matter (PM_2.5) mass concentrations in California (≤188 μg/m³ 24-hr average), and secondary aerosol components (as a group) frequently constitute over half of the fine aerosol mass in winter. The analyses are based on 15 days of high-frequency filter and canister measurements and several months of wintertime continuous gas and aerosol measurements. The phase-partitioning of nitrogen oxide (NO_x)-related nitrogen species and carbonaceous species shows that concentrations of gaseous precursor species are far more abundant than measured secondary aerosol nitrate or estimated secondary organic aerosols. Comparisons of ammonia and nitric acid concentrations indicate that ammonium nitrate formation is limited by the availability of nitric acid rather than ammonia. Time-resolved aerosol nitrate data collected at the surface and on a 90-m tower suggest that both the daytime and nighttime nitric acid formation pathways are active, and entrainment of aerosol nitrate formed aloft at night may explain the spatial homogeneity of nitrate in the SJV. NO_x and volatile organic compound (VOC) emissions plus background O₃ levels are expected to determine NO_x oxidation and nitric acid production rates, which currently control the ammonium nitrate levels in the SJV. Secondary organic aerosol formation is significant in winter, especially in the Fresno urban area. Formation of secondary organic aerosol is more likely limited by the rate of VOC oxidation than the availability of VOC precursors in winter.