A review of biochars' potential role in the remediation, revegetation and restoration of contaminated soils

Biochars are biological residues combusted under low oxygen conditions, resulting in a porous, low density carbon rich material. Their large surface areas and cation exchange capacities, determined to a large extent by source materials and pyrolysis temperatures, enables enhanced sorption of both organic and inorganic contaminants to their surfaces, reducing pollutant mobility when amending contaminated soils. Liming effects or release of carbon into soil solution may increase arsenic mobility, whilst low capital but enhanced retention of plant nutrients can restrict revegetation on degraded soils amended only with biochars; the combination of composts, manures and other amendments with biochars could be their most effective deployment to soils requiring stabilisation by revegetation. Specific mechanisms of contaminant-biochar retention and release over time and the environmental impact of biochar amendments on soil organisms remain somewhat unclear but must be investigated to ensure that the management of environmental pollution coincides with ecological sustainability.     

Nocturnal NO3 radical chemistry in Houston,TX

Radical chemistry in the nocturnal urban boundary layer is dominated by the nitrate radical, NO₃, which oxidizes hydrocarbons and, through the aerosol uptake of N₂O₅, indirectly influences the nitrogen budget. The impact of NO₃ chemistry on polluted atmospheres and urban air quality is, however, not well understood, due to a lack of observations and the strong impact of vertical stability of the boundary layer, which makes nocturnal chemistry highly altitude dependent.Here we present long-path DOAS observations of the vertical distribution of the key nocturnal species O₃, NO₂, and NO₃ during the TRAMP experiment in Summer 2006 in Houston, TX. Our observations confirm the altitude dependence of nocturnal chemistry, which is reflected in the concentration profiles of all trace gases at night. In contrast to other study locations, NO₃ chemistry in Houston is dominated by industrial emissions of alkenes, in particular of isoprene, isobutene, and sporadically 1,3-butadiene, which are responsible for more than 70% of the nocturnal NO₃ loss. The nocturnally averaged loss of NO_x in the lowest 300 m of the Houston atmosphere is ～0.9 ppb h^?1, with little day-to-day variability. A comparison with the daytime NO_x loss shows that NO₃ chemistry is responsible for 16–50% of the NO_x loss in a 24-h period in the lowest 300 m of the atmosphere. The importance of the NO₃ + isoprene/1,3-butadiene reactions implies the efficient formation of organic nitrates and secondary organic aerosol at night in Houston.     

Adverse perinatal outcome in patients screen-positive for neural tube defects and fetal down syndrome

An association between various abnormal mid-trimester maternal serum analyte values and adverse perinatal outcome has been reported. From an original sample of 14 857 women, we observed five women who were ‘screen-positive’ for both neural tube defects [maternal serum alpha-fetoprotein (MSAFP) ≥2·5 multiples of the median] and Down syndrome [risk ≥1/274 using MSAFP, maternal serum unconjugated oestriol (MSuE3), maternal serum human chorionic gonadotropin (MShCG), and maternal age]. The four patients who elected to undergo amniocentesis all demonstrated both normal karyotype and normal amniotic fluid AFP levels. All five cases were associated with intrauterine growth retardation (IUGR) and abnormal pregnancy outcomes. Two cases exhibiting severe IUGR on ultrasound examination were terminated at 19·1 and 21·2 weeks, respectively; the former also exhibited fetal calcifications and positive maternal serology for toxoplasmosis. In another case, fetal demise occurred at 36 weeks' gestation in a patient who had been treated for syphilis in the second trimester. Neither infection was confirmed in fetal tissue studies. Though resulting in live births, the remaining two cases required operative deliveries; emergency Caesarean sections for fetal distress were performed at 38 and 32 weeks, respectively, the latter case being associated with severe pre-eclampsia. We conclude that elevated mid-trimester MSAFP levels concurrent with maternal serum analyte values associated with increased risk for fetal Down syndrome may presage a poor perinatal outcome, particularly IUGR and possibly congenital infection.     

Incorporating connectivity into conservation planning for the optimal representation of multiple species and ecosystem services

Conservation planning tends to focus on protecting species’ ranges or landscape connectivity but seldom both—particularly in the case of diverse taxonomic assemblages and multiple planning goals. Therefore, information on potential trade-offs between maintaining landscape connectivity and achieving other conservation objectives is lacking. We developed an optimization approach to prioritize the maximal protection of species’ ranges, ecosystem types, and forest carbon stocks, while also including habitat connectivity for range-shifting species and dispersal corridors to link protected area. We applied our approach to Sabah, Malaysia, where the state government mandated an increase in protected-area coverage of approximately 305,000 ha but did not specify where new protected areas should be. Compared with a conservation planning approach that did not incorporate the 2 connectivity features, our approach increased the protection of dispersal corridors and elevational connectivity by 13% and 21%, respectively. Coverage of vertebrate and plant species’ ranges and forest types were the same whether connectivity was included or excluded. Our approach protected 2% less forest carbon and 3% less butterfly range than when connectivity features were not included. Hence, the inclusion of connectivity into conservation planning can generate large increases in the protection of landscape connectivity with minimal loss of representation of other conservation targets.     

The use of personalised social marketing to foster voluntary behavioural change for sustainable travel and lifestyles

Changing public attitudes and behaviour is key to achieving the UK target of a 60% reduction in carbon dioxide emissions by 2050. Top-down campaigns that have provided information to a passive public have not necessarily resulted in pro-environmental behavioural change. This paper examines the use of a personalised social marketing approach to engage the public in changing their personal travel. It provides the results of a project in the City of York to foster voluntary travel behavioural change. Using face-to-face discussions, personalised information and incentives, a statistically significant reduction in car use and an increase in cycling and the use of public transport were achieved over a six-month period. However, this change was not sustained 12 months later. The paper explores the contrasting perspectives on behavioural change and examines the possible lessons that can be learnt to foster voluntary behavioural change in other aspects of household consumption.     

A targeted social marketing approach for community pro-environmental behavioural change

Community-level initiatives will play a key role in meeting greenhouse gas reduction targets. This paper examines the experience gained in applying a targeted social marketing approach to foster local-scale community pro-environmental behavioural change in the City of York, UK. This involved determining the neighbourhood carbon footprint, identifying residents that had access to appropriate infrastructure and were receptive to green issues. Six community teams were recruited from the selected neighbourhoods and provided with information, advice and mentoring on how to reduce their carbon footprint over a six-month period. A statistically significant reduction in carbon emissions was achieved. Each participant achieved a mean reduction in their carbon footprint of 2.0 tonnes of CO₂e/year. The largest reductions were achieved in the areas of shopping and home energy. In addition, it helped to foster community spirit. Based on the experience gained from implementing this approach, a cost-effective model of community engagement is proposed.