The Value of Footpath Provision in the Countryside: A Case-study of Public Access to Urban-fringe Woodland

This paper presents a case-study of valuation of public access to a woodland site owned by The Crown Estate in Windsor Forest. It supports the view that contingent valuation is an appropriate technique to use for assessing recreational benefits in the countryside and that consistent and useful results can be obtained. The study found that the recreational benefits far outweighed the costs of access provision, thus giving reassurance to the providers that their efforts are worthwhile.     

Leaching of copper,chromium and arsenic in a soil of south west Victoria,Australia

The movement of copper, chromium and arsenic originating from samples of the wood preservative Tanalith® through mildly acidic, sandy loam soil was investigated. Small, undisturbed soil cores (of dimensions 15 × 15 × 15 cm) were removed from the topsoil of a paddock adjacent to the Glenelg River in the Western District of Victoria, Australia. The paddock soils were thin (<30cm) greyish brown, mildly acidic, sandy loams with a moderate organic carbon content (2–5%) overlying a limestone cap. Tanalith® was applied to the surface of the cores which were then irrigated with deionised water at approximately 30 mm day^‐1. Copper concentrations in all leachate remained at background levels throughout the experiment, and this element was found to be immobilised in the top 4 cm of the soil. Up to 29% of the applied dose of chromium was detected in the leachate, with breakthrough occurring within 20 days of Tanalith® application. Up to 13% ofthe applied dose ofarsenic was detected in the leachate, although in this case breakthrough was not observed until 25 days after Tanalith® application and leachate concentrations were still rising when the experiment came to a close. Significant concentrations of arsenic and chromium were found in the top 6 cm of the soil profile.     

Lessons for sustainability from the world’s most sustainable culture

Environmentally sustainable development is one of the key challenges faced by societies today. Yet it is not a new challenge; throughout history, societies have faced the need to live within environmental constraints. Some have done so well, and some poorly. One society which did well for tens of thousands of years is that of Aboriginal Australia. This paper explores some lessons from Aboriginal Australia which have resonance in the modern world and shows that countries which have learned those lessons are in fact more sustainable than those which have not. It thus suggests that there is much that the pantheon of human experience can teach the modern world as it endeavours to create a sustainable future.     

Carbon bed mercury emissions control for mixed waste treatment

Mercury has various uses in nuclear fuel reprocessing and other nuclear processes, and so it is often present in radioactive and mixed (radioactive and hazardous) wastes. Compliance with air emission regulations such as the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards can require off-gas mercury removal efficiencies up to 99.999% for thermally treating some mixed waste streams. Test programs have demonstrated this level of off-gas mercury control using fixed beds of granular sulfur-impregnated activated carbon. Other results of these tests include (1) the depth of the mercury control mass transfer zone was less than 15-30 cm for the operating conditions of these tests; (2) MERSORB carbon can sorb mercury up to 19 wt % of the carbon mass; and (3) the spent carbon retained almost all (98.3-99.99%) of the mercury during Toxicity Characteristic Leachability Procedure (TCLP) tests, but when even a small fraction of the total mercury dissolves, the spent carbon can fail the TCLP test when the spent carbon contains high mercury concentrations.     

Subregional differences in Australian climate risk perceptions: coastal versus agricultural areas of the Hunter Valley,NSW

‘Environmental cognitive stress’ a hybrid model combining environmental stress and cognitive determinants of pro-environmental behavior is explored among Australians living in contrasting ‘micro’ climates in the same river catchment system. Peoples’ climate risk perceptions are mediated by their connections to local environment, observations of environmental change and personal weather experiences. A longitudinal study randomly sampled 1,162 Hunter Valley coastal and rural residents in New South Wales. Telephone interviewers (2008) recruited lakeside homeowners ‘at risk’ of sea level rise, nearby ‘control’ residents and a comparable farming area group. Follow-up interviews (2011) located 81.5 % of the original sample. Fifty-six items based on the model asked about climate change observations, concerns, impacts and actions. Statistically significant rural–suburban and time differences were found. The rural sample was attuned to conditions affecting agricultural productivity: They worried about drought and heat, saw trees dying and changes to seasons and natural rhythms. They anticipate the impact of water scarcity, conserve water and value protecting plants and animals. Compared to higher elevation residents, lake dwellers observed marine life loss, worry about sea level rise and predict the decline of property values. Across time, all groups’ perceptions of warming indicators declined. Concerns and impacts were high and generally stayed high, as did actions related to energy use. No differences emerged in beliefs about climate warming. Climate change observations, along with concerns and actions, have important implications for the environmental cognitive stress model. Overall, dynamic changes in residents’ understandings are related to a changing policy environment, the vicissitudes of climate debates and weather experiences, including extreme swings from inundation to drought.     

轻型柴油车排放特性与机动车比功率分布的实例研究

引入机动车比功率概念研究了驾驶条件(DrivingCondition)对机动车排放的影响及二者间的关系.利用美国Sensors公司生产的SEMTECH-D车载排放测试仪在上海选取2辆轻型柴油客货两用车开展了实际道路排放测试.测试道路包括城市快速道、主干道和次干道,2辆轻型车测试的道路全长分别为31·8和39·7km.通过计算逐秒的比功率值,研究了实际行驶中机动车比功率(VSP)与机动车油耗、空燃比和污染物排放的关系.回归分析结果表明,比功率比加速度能够更好地反映与NOx排放之间的关系,不同道路上机动车的CO、TC、NOx排放速率和油耗的比功率区间(VSPbin)分布具有较好的一致性.实测研究中VSPbin分布于-20~20kW·t-1的范围内,其中超过50%的数据分布在-3~1kW·t-1之间.高排放集中在分布频率较低的高VSP区间.应用污染物排放与VSP分布的关系式和VSPbins的频率分布可以估算机动车污染物排放总量.排放速率计算式具有一定的不确定性,还有待将来进一步修正.     

Interference from HONO in the measurement of ambient air NO2 via photolytic conversion and quantification of NO

The reference method to quantify mixing ratios of the criteria air pollutant nitrogen dioxide (NO₂) is NO-O₃ chemiluminescence (CL), in which mixing ratios of nitric oxide (NO) are measured by sampling ambient air directly, and mixing ratios of NO_x (= sum of NO and NO₂) are measured by converting NO₂ to NO using, for example, heated molybdenum catalyst or, more selectively, photolytic conversion (P-CL). In this work, the nitrous acid (HONO) interference in the measurement of NO₂ by P-CL was investigated. Results with two photolytic NO₂ converters are presented. The first used radiation centered at 395 nm, a wavelength region commonly utilized in P-CL. The second used light at 415 nm, where the overlap with the HONO absorption spectrum and hence its photolysis rate are less. Mixing ratios of NO₂, NO_x and HONO entering and exiting the converters were quantified by Thermal Dissociation Cavity Ring-down Spectroscopy (TD-CRDS). Both converters exhibited high NO₂ conversion efficiency (CF_NO2; > 90%) and partial conversion of HONO. Plots of CF against flow rate were consistent with photolysis frequencies of 4.2 s^-1 and 2.9 s^-1 for NO₂ and 0.25 s^-1 and 0.10 s^?1 for HONO at 395 nm and 415 nm, respectively. CF_HONO was larger than predicted from the overlap of the emission and HONO absorption spectra. The results imply that measurements of NO₂ by P-CL marginally but systematically overestimate true NO₂ concentrations, and that this interference should be considered in environments with high HONO:NO₂ ratios such as the marine boundary layer or in biomass burning plumes.     

Organochlorine pesticides in elementary school yards along the Texas-Mexico border

A reconnaissance study was undertaken to determine potential contaminant exposures to children through soil from elementary school playgrounds. Soil samples were collected from areas along the Texas-Mexico border, inland areas (soils from elementary school yards in cities/towns within the state of Texas), and three National Parks (one on the border, one in Tennessee, and one in Washington). The present study focused on organochlorine (OC) pesticides as the potential contaminants of concern because of their historical (and possibly current) use, and their importance as persistent organic pollutants (POPs). DDE and heptachlor were the most frequently detected OCs (69 and 63%, respectively), although heptachlor concentrations in soil never exceeded 5 ppb. Relatively higher concentrations of DDE were observed in agricultural areas along the border (50-60 ppb in soils from McAllen, Palmview, and San Benito) than in other soils. However, a school yard in Lubbock, TX had the highest OC concentration observed (70 ppb dieldrin). These results may be due to historical agriculture activity prior to the banning of OC pesticides such as DDT in the early 1970s, as well as the more recent use of DDT in Central and South America for malaria control.     

Prioritizing islands for the eradication of invasive vertebrates in the United Kingdom overseas territories

Invasive alien species are one of the primary threats to native biodiversity on islands worldwide. Consequently, eradicating invasive species from islands has become a mainstream conservation practice. Deciding which islands have the highest priority for eradication is of strategic importance to allocate limited resources to achieve maximum conservation benefit. Previous island prioritizations focused either on a narrow set of native species or on a small geographic area. We devised a prioritization approach that incorporates all threatened native terrestrial vertebrates and all invasive terrestrial vertebrates occurring on 11 U.K. overseas territories, which comprise over 2000 islands ranging from the sub‐Antarctic to the tropics. Our approach includes eradication feasibility and distinguishes between the potential and realistic conservation value of an eradication, which reflects the benefit that would accrue following eradication of either all invasive species or only those species for which eradication techniques currently exist. We identified the top 25 priority islands for invasive species eradication that together would benefit extant populations of 155 native species including 45 globally threatened species. The 5 most valuable islands included the 2 World Heritage islands Gough (South Atlantic) and Henderson (South Pacific) that feature unique seabird colonies, and Anegada, Little Cayman, and Guana Island in the Caribbean that feature a unique reptile fauna. This prioritization can be rapidly repeated if new information or techniques become available, and the approach could be replicated elsewhere in the world. Priorización de Islas para la Erradicación de Vertebrados Invasores en los Territorios Exteriores del Reino Unido