Analysis of Water Quality and Flow Data for the Addington Catchment (2015-2016)

Addington Brook is a stormwater-influenced Christchurch waterway. Substantial instream surface water quality monitoring has shown elevated solids, metal and nutrient concentrations along the brook, which is thought to be a major contributor of these pollutants to the Avon River/Ōtākaro system and downstream estuary. Longitudinal and spatial patterns of water quality within the catchment were investigated from four wet weather events sampled in the spring-summer of 2015-2016. Analysis included assessment of treatment performance of the KiwiRail Stormwater Ponds (Matipo Street ponds) at the top of the catchment. Sites throughout the catchment responded in similar magnitudes to rainfall, with higher water levels measured from stormwater runoff shortly after rainfall was recorded. Similar inflow and outflow water levels in the Matipo ponds indicate that the detention system is mitigating peak inflows to some extent. Large amounts of TSS enter Addington Brook downstream just before it converges with the Avon River/Ōtākaro so targeting pollutant mitigation at this point could substantially reduce the amount of solids entering the Avon River/Ōtākaro. Dissolved zinc is consistently and highly elevated above the relevant Land and Water Regional Plan (LWRP) in-stream guideline, despite the pond’s ability to retain large portions of it and should be targeted at the Deans Ave location where its concentration is consistently highest. Dissolved copper was effectively removed within the pond system and is not an apparent cause for concern further down-stream in this catchment. More metals were removed in the ponds, in all sampling years, when concentrations were greatest indicating that the capacity of the system does not appear to be exhausted. Given the ubiquitous nature of dissolved zinc in Christchurch urban waterways, it would be wise to implement source-control of this highly bioavailable metal, especially given dissolved fractions are much more difficult to remove than particulate fractions. Concentrations of TN (predominantly TKN) and of TP (predominantly particulate) between sampling locations are generally similar. Some nutrients are retained within the Matipo pond system although inorganic nitrate/nitrate concentrations in the outflow were higher during larger rainfall durations and depths, suggesting that nitrogen in the pond was converted from organic to inorganic fractions. TN and nitrate removal efficiencies seem to have decreased compared to estimates in 2008. Despite the ability of the ponds to significantly reduce net phosphorus overall, DRP concentrations consistently exceeded the LWRP guideline. Although solids concentrations were often very high in the stormwater, the ponds were quite effective at reducing these concentrations, which is most likely attributed to adequate settling potential within the ponds. Dissolved metal loads for the downstream site at Riccarton Ave measured during the four sampled events, were very similar to modelled loads. Overall, 2.3-2.8 kg dissolved Zn/event originate from impermeable surfaces (which comprise 79% roofs, 12% carparks, 9% roads) within the catchment while 45-84 g dissolved Cu/event originate from impermeable surfaces (39% carparks, 30% roads, 31% roofs)

Stormwater Contaminant Load Monitoring (2016) and Modelling of the Heathcote Catchment and Six Representative Subcatchments

Adverse effects from sediment and heavy metals have been observed in the Heathcote catchment, which is diverse in its land use activities. Stormwater management improvements are planned for the catchment through the Heathcote Stormwater Management Plan. Contaminant load monitoring and modelling for subcatchments in the Heathcote were undertaken to help inform the stormwater management policies and planning. The UC’s event-based contaminant load model, MEDUSA (Modelled Estimates of Discharges for Urban Stormwater Assessments), that predicts the amount of total suspended solids (TSS), and total and dissolved copper and zinc generated by individual roof, road and carpark surfaces, was employed for the modelling. Stormwater monitoring of key impermeable surfaces was used to calibrate the model and also quantify the chemical speciation of the contaminants (i.e. particulate or dissolved form), important for assessing appropriate future treatment or mitigation strategies. Stormwater runoff monitoring and predictive modelling (using MEDUSA) was previously conducted in the Okeover and Addington subcatchments of the Avon Catchment. In those studies, four roof types, three road types and three carpark classifications were monitored and modelled. In this study, stormwater runoff quality was monitored from eight different impermeable surfaces in the Heathcote catchment over 9 rainfall events from July to November 2016. These sites represented typical surfaces in the catchment: a new Coloursteel® roof, an older Coloursteel® roof, a concrete roof, a galvanized painted roof, three roads (local, collector, minor arterial) and a commercial/light industrial carpark. First flush (first 1 L of runoff) and steady state samples were analysed for TSS and total and dissolved zinc and copper. Data from the monitoring campaign was analyzed and then used to refine MEDUSA to Heathcote conditions. The model was applied to estimate zinc loads from roofs for the Heathcote catchment as a whole, as well as from six individual subcatchments representing industrial areas (Curries and Jardens Drains; Awatea), mixed use areas (Curletts Drain; Waltham) and mostly residential areas (Jacksons Creek; Wilderness Drain). Predictions of contaminant loads were obtained for each rainfall event sampled in 2016. Additionally, predictive simulations were conducted for all events for years between 2011-2016 to ascertain differences as a function of variable weather conditions. The galvanized roof surfaces produced significantly more zinc than other surfaces. Coloursteel® Old and Galvanised Painted first flush runoff contributed some of the highest zinc concentrations measured in recent Christchurch untreated stormwater sampling. First flush concentrations from the new Coloursteel® roof were consistently lower than the steady state concentrations from the old Coloursteel® roof. Similarly, zinc concentrations from the galvanised painted roof were higher than the new Coloursteel® roof, but lower than the old Coloursteel® roof. The data also clearly show that the majority of zinc from the four roof types is in the dissolved form, substantiating previous monitored data in Christchurch. These data confirm that the key mechanism for zinc generation from roofs is direct dissolution of the roof material, enhanced and sustained by the exposure and breakdown of the galvanizing layer through weathering. Zinc measured in concrete roof runoff is believed to originate from galvanised components in the guttering and downpipes rather than from atmospheric deposition alone. Therefore, while concrete and other non-metallic roofs may not contribute large zinc loads to stormwater runoff, some zinc is dissolved from their galvanised drainage components, which may be something to consider in management decisions about roof replacements along with roof condition. Because zinc was defined as the focus of the study, total zinc loads were predicted using MEDUSA. Modelling results revealed that there is a clear difference in the rate at which total zinc is derived from each roof type, with concrete and Coloursteel® roofs yielding the least amount of zinc (per area) in roof runoff. Zincalume® and painted Galvanised roofs released more than double the amount (per area) of concrete and Coloursteel® roofs, but not as much as unpainted galvanised roofs. The data highlight the availability of zinc from roofs (with metallic surfaces) to stormwater runoff and the positive effect of painting these surfaces to immobilize some of the zinc. The yearly scenario results reveal the influence of variable wet weather conditions (including rainfall pH, antecedent dry days, rainfall intensity and duration) on zinc runoff from roofs. Despite the relatively low proportion (7 %) of roofs within the Heathcote Catchment that are defined as poorly painted or unpainted, they consistently contribute more than 30 % of the total zinc load from roofs in each year. Waltham (mixed landuse) roofs, which make up 29 % of the catchment and comprise the highest proportion (16 ha) of unpainted galvanized roofs, contribute between 2.2 and 7.6 net kg TZn/event to stormwater runoff. Similarly, Wilderness Drain (residential landuse) roofs, which make up 26 % of the catchment and comprise 12 ha of unpainted galvanized roofs, 34 ha of painted galvanized roofs and 27 ha of Coloursteel® roofs, produces nearly the same net zinc loads (2.0 -7.9 TZn kg) per rain event as Waltham. These disaggregated data are important because they highlight that the proportional area of specific roof types (e.g. unpainted galvanized) is a clear determinant of how much total zinc can be expected in roof runoff rather than assuming greater contributions from a more industrial/commercial area alone. Furthermore, depending on the condition of that roof material, a range of lower or higher zinc loads can be expected from roof runoff during rain events. Changes (as modelled scenarios) in proportional roof areas from the current status would result in significant reductions of total zinc runoff from roofs in the Heathcote subcatchments across all the modelled years, with some variability between years due to the influence of rainfall parameters. This reduction is more pronounced at the higher ranges for each scenario. A change in proportional zinc loads in different subcatchments results from the change in their proportional areas (and condition), highlighting the value in examining specific subcatchment responses to variable modelling scenarios

Identifying the provenance of Leach's storm petrels in the North Atlantic using polychlorinated biphenyl signatures derived from comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry.

PCB signatures can be used for source identification, exposure studies, age dating and bio-monitoring. This study uses comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GCxGC-ToFMS) to produce a PCB signature comprised of over 80 PCBs for individual Leach's storm petrels (Oceanodroma leucorhoa). The Leach's storm petrel is a relatively small, elusive, understudied pelagic bird, which only returns to remote islands under darkness during the breeding season. Samples were obtained from 25 Leach's storm petrels found dead in Canada and the UK following storm events in 2006 and 2009. Tissue samples were extracted and analysed by GCxGC-ToFMS and results showed that 83 PCB congeners were present in >60% of samples. An assessment of the PCB signature in four different tissue types showed that it did not vary greatly in samples obtained from the gut, heart, liver and stomach. Multivariate statistical analysis identified a distinctive PCB signature in birds from Canada and Europe which was used to identify the regional provenance and transatlantic movement of individual birds. The findings showcase the ability of GCxGC-ToFMS to provide the high quality congener specific analysis that is necessary for PCB fingerprinting, as well as highlighting the potential of PCB signatures for use in ecological studies of movement, foraging and behaviour

Latent physiological factors of complex human diseases revealed by independent component analysis of clinarrays

<p>Abstract</p> <p>Background</p> <p>Diagnosis and treatment of patients in the clinical setting is often driven by known symptomatic factors that distinguish one particular condition from another. Treatment based on noticeable symptoms, however, is limited to the types of clinical biomarkers collected, and is prone to overlooking dysfunctions in physiological factors not easily evident to medical practitioners. We used a vector-based representation of patient clinical biomarkers, or clinarrays, to search for latent physiological factors that underlie human diseases directly from clinical laboratory data. Knowledge of these factors could be used to improve assessment of disease severity and help to refine strategies for diagnosis and monitoring disease progression.</p> <p>Results</p> <p>Applying Independent Component Analysis on clinarrays built from patient laboratory measurements revealed both known and novel concomitant physiological factors for asthma, types 1 and 2 diabetes, cystic fibrosis, and Duchenne muscular dystrophy. Serum sodium was found to be the most significant factor for both type 1 and type 2 diabetes, and was also significant in asthma. TSH3, a measure of thyroid function, and blood urea nitrogen, indicative of kidney function, were factors unique to type 1 diabetes respective to type 2 diabetes. Platelet count was significant across all the diseases analyzed.</p> <p>Conclusions</p> <p>The results demonstrate that large-scale analyses of clinical biomarkers using unsupervised methods can offer novel insights into the pathophysiological basis of human disease, and suggest novel clinical utility of established laboratory measurements.</p

Combination of psychotherapy and benzodiazepines versus either therapy alone for panic disorder: a systematic review

<p>Abstract</p> <p>Background:</p> <p>The efficacy of combined psychotherapy and benzodiazepine treatment for panic disorder is still unclear despite its widespread use. The present systematic review aims to examine its efficacy compared with either monotherapy alone.</p> <p>Methods:</p> <p>All randomised trials comparing combined psychotherapy and benzodiazepine for panic disorder with either therapy alone were identified by comprehensive electronic search on the Cochrane Registers, by checking references of relevant studies and of other reviews, and by contacting experts in the field. Two reviewers independently checked eligibility of trials, assessed quality of trials and extracted data from eligible trials using a standardized data extraction form. Our primary outcome was "response" defined by global judgement. Authors of the original trials were contacted for further unpublished data. Meta-analyses were undertaken synthesizing data from all relevant trials.</p> <p>Results:</p> <p>Only two studies, which compared the combination with behaviour (exposure) therapy, met our eligibility criteria. Both studies had a 16-week intervention. Unpublished data were retrieved for one study. The relative risk for response for the combination was 1.25 (95%CI: 0.78 to 2.03) during acute phase treatment, 0.78 (0.45 to 1.35) at the end of treatment, and 0.62 (0.36 to 1.07) at 6–12 months follow-up. Some secondary outcomes hinted at superiority of the combination during acute phase treatment.</p> <p>One study was identified comparing the combination to benzodiazepine. The relative risk for response was 1.57 (0.83 to 2.98), 3.39 (1.03 to 11.21, statistically significant) and 2.31 (0.79 to 6.74) respectively. The superiority of the combination was observed on secondary outcomes at all the time points. No sub-group analyses were conducted due to the limited number of included trials.</p> <p>Conclusion:</p> <p>Unlike some narrative reviews in the literature, our systematic search established the paucity of high quality evidence for or against the combined psychotherapy plus benzodiazepine therapy for panic disorder. Based on limited available published and unpublished data, however, the combined therapy is probably to be recommended over benzodiazepine alone for panic disorder with agoraphobia. The combination might be superior to behaviour therapy alone during the acute phase, but afterwards this trend may be reversed. We know little from these trials about their adverse effects.</p