Satellite-based estimation of total suspended solids and chlorophyll-a concentrations for the Gold Coast Broadwater, Australia.

Satellite retrieval of total suspended solids (TSS) and chlorophyll-a (chl-a) was performed for the Gold Coast Broadwater, a micro-tidal estuarine lagoon draining a highly developed urban catchment area with complex and competing land uses. Due to the different water quality properties of the rivers and creeks draining into the Broadwater, sampling sites were grouped in clusters, with cluster-specific empirical/semi-empirical prediction models developed and validated with a leave-one-out cross validation approach for robustness. For unsampled locations, a weighted-average approach, based on their proximity to sampled sites, was developed. Confidence intervals were also generated, with a bootstrapping approach and visualised through maps. Models yielded varying accuracies (R2 = 0.40-0.75). Results show that, for the most significant poor water quality event in the dataset, caused by summer rainfall events, elevated TSS concentrations originated in the northern rivers, slowly spreading southward. Conversely, high chl-a concentrations were first recorded in the southernmost regions of the Broadwater.

Baseline water quality of the Gold Coast Broadwater, southern Moreton Bay (Australia).

This study establishes baseline water quality characteristics for the Gold Coast Broadwater, southern Moreton Bay (Australia) utilising routinely monitored parameters between 2016 and 2021, across 18 sites. Combined site mean concentrations of NOx-N, NH3-N and total nitrogen were 11.4 ± 33.4 µg/L, 12.7 ± 27.2 µg/L, and 169 ± 109 µg/L, respectively, whilst PO4-P and total phosphorous were 7.30 ± 5.10 µg/L and 21.7 ± 14.1 µg/L. Additionally, total suspended solids and turbidity combined site means were 6.6 ± 6.0 mg/L and 3.4 ± 2.9 NTU, respectively. During high rainfall periods nutrient concentrations increased by up to >200-, >150-, 15-, 12- and >12-fold for NOx-N, NH3-N, TN, PO4-P and TP, respectively, compared to quiescent conditions. Furthermore, TSS and NTU values increased by up to 15- and 40-fold during periods of measured rainfall compared to quiescent conditions.

Healthcare Economics of a Coronavirus Disease 2019 Pop-Up Vaccination Center.

Introduction: Creation of pop-up vaccination sites at trusted community locations has been encouraged to address vaccine hesitancy and provide equitable access to COVID-19 vaccination in minority communities. This study sought to study the healthcare economics of a community-based COVID-19 pop-up vaccination center in terms of the following: costs associated with operating the vaccination center, analysis of billing data from patients who received the Moderna COVID-19 vaccine, and costs of hospitalization for COVID-19 which may be avoided with widespread vaccination. Methods: The pop-up vaccination center was located in Port Jefferson Station, NY, USA. Costs associated with operation of the COVID-19 pop-up vaccination center were quantified, itemized, and tabulated. Current Procedural Technology codes were used to identify patients who received the Moderna COVID-19 vaccine. Billing data were quantified for the cohort as well as per each patient to receive the vaccine. Costs associated with provision of urgent care, emergency, and hospital services to patients with COVID-19 were obtained. Results: The total cost to operate the vaccination center was $25,880. The vaccination center administered the initial dose of the Moderna COVID-19 vaccine to N=251 patients between March and May, 2021. The standard hospital costs for patients admitted to the medical ICU due to COVID-19 ranged from $8,913 to $190,714, per patient. Conclusion: Since the Moderna COVID-19 vaccine series is effective in preventing hospitalization for 93% of patients, this community-based vaccination center's administration of the vaccine series to 240 patients meant aversion of hospitalization due to COVID-19 related morbidity for 223 patients. Therefore, the true impact of this vaccination center, measured in averted hospital costs, ranges from $1,987,599 to $42,529,222.

Modelling the dispersion of treated wastewater in a shallow coastal wind-driven environment, Geographe Bay, Western Australia: implications for environmental management.

Numerical models are useful for predicting the transport and fate of contaminants in dynamic marine environments, and are increasingly a practical solution to environmental impact assessments. In this study, a three-dimensional hydrodynamic model and field data were used to validate a far-field dispersion model that, in turn, was used to determine the fate of treated wastewater (TWW) discharged to the ocean via a submarine ocean outfall under hypothetical TWW flows. The models were validated with respect to bottom and surface water current speed and direction, and in situ measurements of total nitrogen and faecal coliforms. Variations in surface and bottom currents were accurately predicted by the model as were nutrient and coliform concentrations. Results indicated that the ocean circulation was predominately wind driven, evidenced by relatively small oscillations in the current speeds along the time-scale of the tide, and that dilution mixing zones were orientated in a predominantly north-eastern direction from the outfall and parallel to the coastline. Outputs of the model were used to determine the 'footprint' of the TWW plume under a differing discharge scenario and, particularly, whether the resultant changes in TWW contaminants, total nitrogen and faecal coliforms would meet local environmental quality objectives (EQO) for ecosystem integrity, shellfish harvesting and primary recreation. Modelling provided a practical solution for predicting the dilution of contaminants under a hypothetical discharge scenario and a means for determining the aerial extent of exclusion zones, where the EQOs for shellfish harvesting and primary recreation may not always be met. Results of this study add to the understanding of regional discharge conditions and provide a practical case study for managing impacts to marine environments under a differing TWW discharge scenario, in comparison to an existing scenario.

Investigation of recreational boats as a source of copper at anchorage sites using time-integrated diffusive gradients in thin film and sediment measurements.

Antifouling paints on small to medium recreational vessels were first recognized as an important source of pollution in the 1970s. One of the principle biocides in these paints is Cu. Results from a field program in the Gold Coast Broadwater, Queensland, demonstrate a clear correlation between recreational boat numbers at anchorage sites and water column Cu concentrations, for both time-integrated 24 h DGT measurements (n=14, r=0.815, p<0.001) and measurements on composite 0.45 mum-filtered grab samples (n=14, r=0.698, p<0.01) collected every 4 h over 24 h. At boat numbers above 30 the 0.45 microm-filterable Cu concentrations were mostly above the relevant guideline value (1.3 microgl(-1)) but the DGT-reactive Cu concentrations were well below this value at all boat numbers studied. For three-day DGT deployments in Moreton Bay, Queensland, correlations between Cu levels and vessel numbers were not observed, possibly because of uncertain estimates of boat numbers. However, using a multi-factorial ANOVA, DGT-reactive Cu concentrations showed a significant effect for 'sites with vessels vs. sites without vessels' (alpha=0.10, p=0.077) and for 'sampling period' (non-holiday weekdays, weekends, holiday weekdays, holiday weekends) at alpha=0.10, p=0.02. Cu levels in sediments at the same sites were strongly influenced by fraction of clay (<63 microm) material but also by whether the samples were collected at an anchorage or control site. Results from this study further support the view that Cu emissions from antifouling paints may become an important source in waters with high boat numbers and should be taken into account when designing management instruments for coastal waterways.

Evaluation of the diffusive gradient in a thin film technique for monitoring trace metal concentrations in estuarine waters.

Monitoring trace metal concentrations in dynamic estuarine waters is not straightforward. This study demonstrated that important information could be obtained from intensive sampling of physicochemical parameters and trace metal concentrations, in the Gold Coast Broadwater, Australia. A regular pattern of variation in Cu and Ni concentrations was related to the movement of water passed point sources with tidal flows, rather than due to conventional estuarine mixing of end-member waters. However, this approach was logistically demanding and expensive. The diffusive gradients in a thin film (DGT) technique was used as an alternative method due to its continual time-integrated response to changes in trace metal concentrations. Significant correlations were found between 24 h DGT-labile measurements and 0.45-microm filterable measurements, on time-averaged composite samples (grab samples combined every 4 h for 24 h), for Cu (n = 24, r = 0.965, p < 0.001), Pb (n = 24, r = 0.799, p < 0.001), Zn (n = 17, r = 0.909, p < 0.001), and Ni (n = 23, r = 0.916, p < 0.001). DGT-labile measurements as a fraction of 0.45 microm-filterable concentrations were 21 +/- 2% for Cu, 29 +/- 11% for Pb, 28 +/- 5% for Zn, and 27 +/- 12% for Ni, demonstrating the speciation capabilities of DGT. Although DGT measurements were confirmed as being highly operationally defined, DGT was still found to be very promising as a monitoring approach, particularly for dynamic estuarine waters.