Aquivalence revisited--new model formulation and application to assess environmental fate of ionic pharmaceuticals in Hamilton Harbour, Lake Ontario

A model formulation based on "aquivalence", as defined in terms of activity is presented to estimate the multimedia fate of ionizing chemicals. The aquivalence approach is analogous to fugacity but aquivalence is applicable to neutral and ionizing compounds, and has been applied previously to speciating chemicals, notably metals. The new aquivalence-based mass-balance model treats ionizing organic compounds that exist as interconverting neutral and ionic species which are subject to fate processes at differing rates. The model is illustrated by application to four ionizing pharmaceuticals in Hamilton Harbour, Lake Ontario. At the system pH of 7.9-8.5, ibuprofen, gemfibrozil, and naproxen are expected to be almost entirely ionic and triclosan split between ionic and neutral forms. Measured seasonal surface water concentrations, which were 2-10 times lower in the late summer and fall than during spring, were used to solve for unknown values of chemical half-life in the water column due to degradation (photo- and bio-) of the ionizing and neutral forms and secondarily, ionic sorption coefficients of the ionizing forms. Model estimates of half-lives in the habour's water ranged from 11 to 77, 11 to 147 and 10 to 37 for ionic ibuprofen, gemfibrozil, and naproxen, respectively; and 4-22 days and 2-9 days for ionic and neutral triclosan, respectively, with the shortest half-lives in spring and the longest in summer.     

Place attachment,identification and environment perception: An empirical study

The relationship between people and places is characterized by affective and cognitive dimensions, defined, respectively, as place attachment and identification. This paper aims at clarifying differences between place attachment and identification by (1) identifying their predictors in a structural equation model and (2) exploring their association with the environmental perception. To this purpose, we conducted a research on a sample of 328 residents of a city in the north of Italy. Results show that the affective and the cognitive dimensions (1) are directly predicted by different demographical and psychosocial variables and (2) are strictly associated to the perception of the place and its inhabitants. Place attachment and identification are two distinct but correlated components. Semantic contents related to the environmental perception are described in respect to different levels of attachment and identification.     

Evolution rates and PCB content of surface films that develop on impervious urban surfaces

Surface films on impervious surfaces mediate the fate of organic contaminants in urban areas. Using sheltered 3-mm diameter glass beads as a surrogate impervious urban surface, studies in downtown Toronto showed that surface films developed at a consistent rate of 1.6–2.6 nm day⁻¹. Linear film growth was observed up to and including the last day of three studies of 89-, 273-, and 84-day duration. Total PCB content (sum of 15 PCB congeners) also increased linearly, at a similar rate as the surface film. A complementary study using unsheltered beads showed that up to 80% of film mass and PCB content were removed by film wash-off during rain events. The film growth rate on beads exposed at a rural site, 200 km northeast of Toronto, was 12–20 times lower with PCB burdens that were 7–22 times lower compared to Toronto. Based on these findings, it is estimated that approximately 56–226 g of PCBs are captured by a 70 nm thick film covering just the horizontal surface area of Toronto. This is a substantial quantity of PCB that is available for rapid surface–air exchange and wash-off.     

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) in the serum of US Air Force veterans in 2002

We measured levels of PCDDs, PCDFs, non-ortho, and mono-ortho substituted PCBs in 106 US Air Force Vietnam veterans, participants of the Air Force Health Study (AFHS) who attended the final medical examination in 2002. Twelve veterans were Ranch Hands involved in aerial spraying of herbicides in Vietnam (1962-1971), and 94 were Comparisons who flew transport missions in Southeast Asia (SEA) during the same time period. These veterans had no previous 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) measurement because they had not attended any of the previous AFHS examinations, or their previous measurements were missing or not valid. The mean TCDD levels in 2002 were 1.7 pg/g lipid in Comparisons and 5.5 pg/g lipid in Ranch Hands. The mean PCDD toxic equivalent - TEQ (1997) in Comparisons was 12.6 pg/g lipid, 5.4 pg/g lipid for PCDFs, 5.2 pg/g lipid for non-ortho PCBs, and 9.4 pg/g lipid for mono-ortho PCBs, with a total mean TEQ (1997) of 32.6 pg/g lipid. Corresponding mean TEQs in Ranch Hands were 15.5 pg/g lipid for PCDDs, 4.6 pg/g lipid for PCDFs, 2.2 pg/g lipid for non-ortho PCBs, and 9.3 pg/g lipid for mono-ortho PCBs, yielding the total mean TEQ (1997) of 31.6pg/g lipid. Using the re-evaluated 2005 WHO TEFs, the total mean TEQs (2005) decreased by about 28% in both Comparisons and Ranch Hands, to 23.6 pg/g lipid and 22.8 pg/g lipid, respectively. This was mainly due to changes of TEFs for the group of mono-ortho PCBs, which decreased the mono-ortho PCBs TEQs by almost 90% in both Ranch Hands and Comparisons.     

Species' traits predict phenological responses to climate change in butterflies

How do species' traits help identify which species will respond most strongly to future climate change? We examine the relationship between species' traits and phenology in a well-established model system for climate change, the U.K. Butterfly Monitoring Scheme (UKBMS). Most resident U.K. butterfly species have significantly advanced their dates of first appearance during the past 30 years. We show that species with narrower larval diet breadth and more advanced overwintering stages have experienced relatively greater advances in their date of first appearance. In addition, species with smaller range sizes have experienced greater phenological advancement. Our results demonstrate that species' traits can be important predictors of responses to climate change, and they suggest that further investigation of the mechanisms by which these traits influence phenology may aid in understanding species' responses to current and future climate change.     

Effects and success factors of sustainable consumption policy instruments: a comparative assessment across Europe

Important knowledge gaps exist regarding the effects of policy instruments for sustainable consumption (SC) and success factors of such instruments. This article compares and summarizes the results of six case studies on the effects and success factors of SC instruments in the need areas of housing and food. While analysing different instrument types from four different European countries, all case studies were guided by the same analytical framework and mixed-methods approach. This synthesis article particularly emphasizes factors fostering the generation of instrument effects (outcomes and impacts) or hampering the creation of such effects, respectively. These factors include instrument goals and design, the accommodation of consumer needs, and the simultaneous addressing of framework conditions, as well as market context, policy interaction, and stakeholder involvement. The findings and conclusions can contribute to a better understanding of the conditions under which policy instruments can steer consumer behaviour towards sustainability.     

Use of Constructed Wetlands for Urban Stream Restoration: A Critical Analysis

/ Investigation of a delta marsh restoration project proposed forthe Don River in Toronto, Ontario, underlines several concerns aboutconstructed wetland projects designed for water quality improvement andaquatic habitat enhancement. The Don is a highly urbanized river that hasundergone significant physiographic modifications and continually receives acomplex mixture of conventional, metallic, and organic contaminants frommultiple point and nonpoint sources. Rather than providing permanent removalof urban contaminants, wetland processes offer a limited capacity fortemporary storage of contaminant inputs, and potential reactions may actuallyproduce more toxic and/or bioavailable forms of some chemicals. Theseprocesses tend to result in the concentration of watershed contaminants inwetland vegetation and sediments. As the restored marsh would be availablefor spawning and feeding by aquatic fauna, the potential exists for chemicalbioconcentration and biomagnification through the aquatic community.Accordingly, wetland systems are not suited to the dual purposes of waterquality improvement and aquatic habitat enhancement. Upstream controls,including source reduction of contaminant inputs, are recommended asessential components of all constructed wetland projects.KEY WORDS: Constructed wetlands; Water quality; Ecological restoration;Don River     

Accumulation of metals,trace elements and semi-volatile organic compounds on exterior window surfaces in Baltimore

Organic films have been found to develop on window surfaces [Diamond et al., Environmental Science and Technology 34 (2000a) 2900]. The film contains organic compounds that are in dynamic equilibrium with the gas-phase in air, and organic and inorganic compounds and elements associated with deposited air particles. In this study, the exterior surfaces of windows were sampled in downtown and suburban Baltimore, Maryland. Higher concentrations of PCBs, PAH, metals and trace elements were found at downtown than a suburban site. PCBs in the films at downtown sites were dominated by penta and hexa homologue groups and PAH signatures resembled that of vehicle emissions. Twenty-six metals and trace elements were separated into two groups according to their enrichment factors (EF). Ag, Hg, Se, Sb and Zn had EF > 100, suggesting anthropogenic sources of these metals in the films; whereas Fe, Ca, Co, Cr and others had EF <10, suggesting a crustal origin. An unusual profile dominated by deca- and nona- PCBs and relatively higher concentrations of Ag, Hg and Zn may be attributable to emissions from a medical waste incinerator. Dry deposition fluxes of selected metals on windows were 1.4-94 times higher on windows with than without films, indicating that the film increases the dry deposition of particles and their associated chemicals. This implies that film development, which is associated with elevated VOC and SOC emissions to urban air, will increase film development that will, in turn, increase the accumulation of other atmospherically deposited constituents such as metals.