Modelling micro-pollutant fate in wastewater collection and treatment systems: status and challenges.

This paper provides a comprehensive summary on modelling of micro-pollutants' (MPs) fate and transport in wastewater. It indicates the motivations of MP modelling and summarises and illustrates the current status. Finally, some recommendations are provided to improve and diffuse the use of such models. In brief, we conclude that, in order to predict the contaminant removal in centralised treatment works, considering the dramatic improvement in monitoring and detecting MPs in wastewater, more mechanistic approaches should be used to complement conventional, heuristic and other fate models. This is crucial, as regional risk assessments and model-based evaluations of pollution discharge from urban areas can potentially be used by decision makers to evaluate effluent quality regulation, and assess upgrading requirements, in the future.

Inputs of chemicals from recreational activities into the Norwegian coastal zone.

Wastewater treatment works effluent is often considered to be one of the most important point sources of a wide range of anthropogenic contaminants to aquatic systems, however, this paper discusses other potential sources. With the aim of establishing the important sources of UV filters, insect repellent and biocides to the aquatic environment, samples were collected from sites with direct (bathing areas and marinas) and indirect (sites receiving wastewater effluent) human influences. Sunscreens containing UV filters are used in large volumes during the summer months and often applied shortly before a person enters the water for swimming activities. The results presented here demonstrate that washing directly from the skin is an important point source of 4 UV filters to the Oslofjord. The insect repellent, diethyl toluamide, was also measured and it was concluded that washing from the skin was not such an important point source into the fjord. Concentrations of the biocide Irgarol 1051 were also measured and were elevated in the small boat marina and surrounding enclosed area. This work demonstrates that man recreational water-based activities are a diffuse source of some contaminants into coastal and fjord environments and this study provides an initial assessment of the levels being released.

Analytical methods for the determination of alkylphenolic surfactants and polybrominated diphenyl ethers in wastewaters and sewage sludges. II method development.

Analytical methods for the determination of two groups of compounds, the non-polar alkyl phenols along with their more polar ethoxylates, and the hydrophobic polybrominated flame retardants in wastewater samples have been developed. The methods allow for determination of the analytes in both the aqueous and solid phases, which were separated by centrifugation and filtration. Extraction from the aqueous phase involved the use of SPE for the surfactants, however, liquid-liquid extraction was found to be more efficient for the PBDE. Alkyl phenols and their ethoxylates were extracted from the solid phase by shaking with solvent and Soxhlet was used for extraction of PBDE. Sample cleanup was based on alumina columns for the PBDE and surfactants when extracted form solids. Quantification of surfactants utilised LC-MS with ESI in both positive and negative ionisation mode, and GC-MS (NCI) was used to determine the PBDE, with the exception of the deca congener, where a 10 m column installed on GC-ECD resulted in short run times and reduced thermal decomposition. Method recoveries for the surfactants were above 80%, and for PBDE 92.5% from the solid phase and 95+/-5% from the liquid phase.

Analytical methods for the determination of alkylphenolic surfactants and polybrominated diphenyl ethers in wastewaters and sewage sludges. I a review of methodologies.

Alkylphenolic surfactants (alkylphenol polyethoxylates) and the polybrominated diphenyl ether flame retardants are important environmental contaminants and have been implicated as endocrine disrupters. Both groups of compounds have come under increasing scrutiny from legislators and there are proposals to curb their use. However, these compounds continue to enter the environment and there is a need to determine their occurrence, fate and behaviour throughout the hydrosphere and in wastewater treatment processes to determine mass fluxes and sources. This paper reviews analytical methods for their determination in the aqueous and solid (sediment / sludge) phase. Extraction, cleanup and quantification by gas and liquid chromatographic (GC and LC) techniques linked to mass spectrometric (MS) detectors are considered. The literature indicates that for the alkylphenols research papers favour the use of LC/MS which is more amenable to determination of more highly ethoxylated oligomers, however, standard methods focus on GC/MS and the less ethoxylated oligomers and parent alkylphenols. The use of GC with negative chemical ionisation MS techniques predominates for the analysis of polybrominated diphenyl ethers.

Polycyclic aromatic hydrocarbons in sediments, mussels and crustacea around a former gasworks site in Shoreham-by-Sea, UK.

Concentrations of polycyclic aromatic hydrocarbons have been determined in sediments, mussels and crustacea in the vicinity of a former gasworks site by Shoreham Harbour, UK. Very high concentrations of PAH were found in the substrate, an ash-like material deposited on the former gasworks site, which exhibited a profile consistent with the major source of contamination being coal or coke tar produced during the period of gas production at the site. Elevated PAH concentrations were also found in mussels both from the beach below the former gasworks site, and from sites further to the east in Portslade and Hove. The significance of these concentrations were assessed using an approach which involved the calculation of benzo[a]pyrene equivalent conoentrations (BaPEs), summing concentrations of individual PAH on the basis of their comparative potency as carcinogens. BaPE ranged from values of, or close to, zero for crustacea, to 336 microg kg(-1) wet weight in mussels from Southwick Beach. The contaminated mussels are not exploited commercially but may be taken by casual gatherers, and notices have been posted to warn potential consumers.

Polybrominated diphenyl ether (PBDE) flame retardants.

Polybrominated diphenyl ether, PBDE, flame retardants are now a world-wide pollution problem reaching even remote areas. They have been found to bioaccumulate and there are concerns over the health effects of exposure to PBDEs, they also have potential endocrine disrupting properties. They are lipophilic compounds so are easily removed from the aqueous environment and are predicted to sorb onto sediments and particulate matter or to fatty tissue, aiding their distribution throughout the environment. PBDEs are structurally similar to PCBs and DDT and, therefore, their chemical properties, persistence and distribution in the environment follow similar patterns. Concentrations of PBDEs found in environmental samples are now higher than those of PCBs. Evidence to date demonstrates that PBDEs are a growing problem in the environment and concern over their fate and effects is warranted. The manufacture of reactive and additive flame retardants is briefly discussed and their fate and behaviour in the environment is assessed. PBDE toxicology is reviewed and methods of analysis are evaluated.

Spinal cord stimulation for the failed back syndrome.

Thirty-two patients with failed back syndrome received a trial of spinal cord stimulation. Stimulators were internalized in 26; long-term follow-up was available for 23 of these patients. Seventy-six percent of the 22 patients with stimulators still present at 1 year and 74% of the 19 patients with stimulators still present at 2 years were receiving 50% or better pain relief. Patients routinely underwent pain team evaluation and therapy, psychological testing and a transcutaneous electrical nerve stimulator trial prior to consideration of spinal cord stimulation. The most common complication was electrode migration. Spinal cord stimulation should be considered as an important therapeutic modality in carefully selected patients with failed back syndrome.

Hydroxylapatite: an adjunct to cranial bone grafting.

Hydroxylapatite is a dense pure ceramic material which has been used extensively in the reconstruction of atrophic maxillary and mandibular ridges. The authors describe a technique for the use of hydroxylapatite in combination with grafting of bone, either autogenous or from the bone bank, to restore contour to cranial defects. The use of hydroxylapatite in combination with bone grafting for contour restoration is recommended, as attempts to place the material directly on dura were not successful.

Computed tomography and magnetic resonance imaging in traumatic locked-in syndrome.

The first reported case of traumatic locked-in syndrome with computed tomographic and magnetic resonance scan confirmation of the brain stem lesion is presented. The lesion responsible for the patient's condition consisted of a hemorrhage in the ventral pontomedullary junction. The pathophysiology of the production of such lesions is discussed.

Symptomatic spinal epidural lipomatosis as a complication of steroid immunosuppression in cardiac transplant patients. Report of two cases.

Patients with Cushing's syndrome may develop spinal epidural lipomatosis, an abnormal accumulation of fat in the spinal epidural space. This accumulation of fat may cause compression of the spinal cord or cauda equina with resulting neurological deficit. Two cases of symptomatic spinal lipomatosis are reported in cardiac transplant patients receiving chronic corticosteroid treatment. The literature is reviewed, and diagnostic and therapeutic considerations are discussed.

Migration of detachable mini-balloon from the ICA causing occlusion of the MCA. Case report.

This patient had an aneurysm on the internal carotid artery that was responsible for episodes of severe hemorrhage through the nose. During occlusion of the aneurysm by a detachable balloon, the balloon became dislodged and migrated, obstructing the middle cerebral artery territory and causing a life-threatening situation. This was treated promptly and successfully by removal of the balloon and repair of the artery. Attention is drawn to the risk of such migration occurring, and the possible causes.

Pulmonary toxicity associated with bischloroethylnitrosourea (BCNU).

Ten patients developed pulmonary fibrosis after bischloroethylnitrosourea (BCNU) therapy for malignancy. This was lethal in seven patients, four of whom had no evidence of tumor at autopsy. Presenting symptoms were either the insidious onset of cough and dyspnea or the sudden onset of respiratory failure. Physical findings were unremarkable. Chest roentgenogram usually showed interstitial infiltrates. Pulmonary function studies showed resting hypoxia with diffusion and restrictive defects. This complication of therapy does not appear to be dose related and may be made more likely by the concomitant administration of cyclophosphamide. Prednisone therapy did not benefit most patients. The literature and the implications of the use of BCNU alone or in combination are reviewed.

Abnormal brain scan with subacute extradural haematomas.

Four patients are described with proven subacute extradural haematomas, each with an abnormal cerebral scan of diagnostic assistance. A possible mechanism of production of the subacute extradural haematoma is discussed, and appears to be similar to the mechanism involved in the subacute subdural haematoma. The means by which the abnormal scan results in such cases is also examined, from which it appears that non-specific meningeal membrane inflammatory reaction surrounding the haematoma is significant.