Assessment across borders: Stumbling blocks and options in the practical implementation of the Espoo Convention

In the 1990s, the obligation to assess transboundary environmental impacts has become part of international law. The UN/ECE Convention on environmental impact assessment (EIA) in a transboundary context, which entered into force in 1997, is one of the key documents. In this study, we show that difficulties with the practical implementation of the Convention arise partly from an incomplete sharing of the concept of EIA, and partly from different material interests on the part of the Parties to the Convention. Attempts to improve the practical implementation should recognize both aspects. Several approaches are thus needed for improving the implementation. Some will help in developing a mutual understanding of impact assessments, whereas others may help in overcoming differences in material interests.     

Post‐Ike economic resilience along the Texas coast

The economic devastation resulting from recent natural disasters has spawned intense interest in programmes that promote regional resilience. The economic impacts of Hurricane Ike (September 2008) endured long beyond the storm's landfall, compounded by a national recession. This study analyses the pattern of post‐Ike industrial growth in eight coastal counties of Texas, United States, and identifies sources of resilience and potential drivers of recovery. The results indicate that post‐disaster growth patterns differ from established growth patterns. Levels of resilience vary across industrial sectors, and service sectors tend to lead a recovery. The resilience of the hotel and restaurant sector, for instance, suggests that the presence of relief workers might immunise certain sectors against a post‐disaster economic downturn. Besides the sectors that are generally resilient, each county has its own distinct sectors that, depending on the extent of the damage suffered, tend to perform strongly after a disaster, owing to the characteristics of the respective county's economy.     

Indoor and outdoor air concentrations of BTEX and NO2: correlation of repeated measurements

Studies on health effects of air pollutants ideally define exposure through the collection of air samples in the participants' homes. Concentrations derived from these samples are then considered as an estimate for the average concentration of air pollutants in the homes. Conclusions drawn from such studies therefore depend very much on the validity of the measured air pollution concentrations. In this paper we analysed repeated BTEX and NO(2) measurements with a time period of several months lying between the two conducted home visits. We investigated the variability of their concentrations over time by determining correlation coefficients and calculating within- and between-home variances. Our population consisted of 631 homes of participants from two cohort studies within the framework of the German study on Indoor Factors and Genetics in Asthma. Air pollutants were measured using passive samplers both indoors and outdoors. The measured BTEX concentrations were poorly correlated, with Pearson's correlation coefficient r ranging from -0.19 to 0.27. Additionally, a considerable seasonal effect could be observed. A higher correlation was found for the NO(2) concentrations with r ranging between 0.24 and 0.55. For the BTEX, the between-home variance was bigger than the within-home variance, for NO(2) both variances were of about the same order. Our results indicate that in a setting of moderate climate like in Germany, the variability of BTEX and NO(2) concentrations over time is high and a single measurement is a poor surrogate for the long-term concentrations of these air pollutants.     

Comparison of methods used to calculate typical threshold values for potentially toxic elements in soil

The environmental quality of land can be assessed by calculating relevant threshold values, which differentiate between concentrations of elements resulting from geogenic and diffuse anthropogenic sources and concentrations generated by point sources of elements. A simple process allowing the calculation of these typical threshold values (TTVs) was applied across a region of highly complex geology (Northern Ireland) to six elements of interest; arsenic, chromium, copper, lead, nickel and vanadium. Three methods for identifying domains (areas where a readily identifiable factor can be shown to control the concentration of an element) were used: k-means cluster analysis, boxplots and empirical cumulative distribution functions (ECDF). The ECDF method was most efficient at determining areas of both elevated and reduced concentrations and was used to identify domains in this investigation. Two statistical methods for calculating normal background concentrations (NBCs) and upper limits of geochemical baseline variation (ULBLs), currently used in conjunction with legislative regimes in the UK and Finland respectively, were applied within each domain. The NBC methodology was constructed to run within a specific legislative framework, and its use on this soil geochemical data set was influenced by the presence of skewed distributions and outliers. In contrast, the ULBL methodology was found to calculate more appropriate TTVs that were generally more conservative than the NBCs. TTVs indicate what a “typical” concentration of an element would be within a defined geographical area and should be considered alongside the risk that each of the elements pose in these areas to determine potential risk to receptors.     

A tiered procedure for assessing the formation of biotransformation products of pharmaceuticals and biocides during activated sludge treatment

Upon partial degradation of polar organic micropollutants during activated sludge treatment, transformation products (TPs) may be formed that enter the aquatic environment in the treated effluent. However, TPs are rarely considered in prospective environmental risk assessments of wastewater-relevant compound classes such as pharmaceuticals and biocides. Here, we suggest and evaluate a tiered procedure, which includes a fast initial screening step based on high resolution tandem mass spectrometry (HR-MS/MS) and a subsequent confirmatory quantitative analysis, that should facilitate consideration of TPs formed during activated sludge treatment in the exposure assessment of micropollutants. At the first tier, potential biotransformation product structures of seven pharmaceuticals (atenolol, bezafibrate, ketoprofen, metoprolol, ranitidine, valsartan, and venlafaxine) and one biocide (carbendazim) were assembled using computer-based biotransformation pathway prediction and known human metabolites. These target structures were screened for in sludge-seeded batch reactors using HR-MS/MS. The 12 TPs found to form in the batch experiments were then searched for in the effluents of two full-scale, municipal wastewater treatment plants (WWTPs) to confirm the environmental representativeness of this first tier. At the second tier, experiments with the same sludge-seeded batch reactors were carried out to acquire kinetic data for major TPs that were then used as input parameters into a cascaded steady-state completely-stirred tank reactor (CSTR) model for predicting TP effluent concentrations. Predicted effluent concentrations of four parent compounds and their three major TPs were corroborated by comparison to 3-day average influent and secondary effluent mass flows from one municipal WWTP. CSTR model-predicted secondary effluent mass flows agreed within a factor of two with measured mass flows and confidence intervals of predicted and measured mass flows overlapped in all cases. The observed agreement suggests that the combination of batch-determined transformation kinetics with a simple WWTP model may be suitable for estimating aquatic exposure to TPs formed during activated sludge treatment. Overall, we recommend the tiered procedure as a realistic and cost-effective approach to include consideration of TPs of wastewater-relevant compounds into exposure assessment in the context of prospective chemical risk assessment.     

The potential for anaerobic mineralisation of hydrocarbon constituents of oily drill cuttings from the North Sea seabed

The potential for natural attenuation of hydrocarbons in oily drill cuttings from the seabed beneath a North Sea oil platform was investigated. The study focused on the anaerobic degradation of n-hexadecane, n-octacosane and naphthalene using additions of 14C-labelled analogues to drill cuttings samples and was conducted under realistic seabed conditions (except pressure) over an 11-month period. No mineralisation of naphthalene was detected over this time period and mineralisation of octacosane represented only 0.5-1.5% of the added label. In contrast, mineralisation of hexadecane was 10-49% after 11 months of incubation. Selective inhibition of key functional bacterial groups revealed the key role of both sulfate reduction and methanogenesis in the degradation process. This study demonstrates the potential for natural attenuation of at least some hydrocarbon constituents of oily drill cuttings under realistic environmental conditions and highlights the involvement of a wide functional consortium in the natural attenuation process.