Partnerships and governance at the environment–health nexus in Ontario: lessons from five case examples

The move towards partnerships and collaborative governance models has been advocated in global health discussions for many years now. A case example methodology was applied to this study. It was composed of a document review and semi-structured interviews with key informants from five environment and public health partnerships in the province of Ontario, Canada. These case examples highlight the merits and the challenges of diverse partnerships, and the importance of governance and leadership models, scaling up (and out) impact, and cross-cultural communications to these arrangements. Further work is required to articulate situations in which public health partnerships can be strengthened.     

Downstream Dissipation of Storm Flow Heat Pulses: A Case Study and its Landscape‐Level Implications

Storms in urban areas route heat and other pollutants from impervious surfaces, via drainage networks, into streams with well‐described negative consequences on physical structure and biological integrity. We used heat pulses associated with urban storms as a tracer for pavement‐derived stormwater inputs, providing a conservative estimate of the frequency with which these pollutants are transported into and through protected stream reaches. Our study was conducted within a 1.5‐km reach in Durham, North Carolina, whose headwaters begin in suburban stormwater pipes before flowing through 1 km of protected, 100‐year‐old forest. We recorded heat‐pulse magnitudes and distances travelled downstream, analyzing how they varied with storm and antecedent flow conditions. We found heat pulses >1°C traveled more than 1 km downstream of urban inputs in 11 storms over one year. This best‐case management scenario of a reach within a protected forest shows that urban impacts can travel far downstream of inputs. Air temperature and flow intensity controlled heat‐pulse magnitude, while heat‐pulse size, mean flow, and total precipitation controlled dissipation distance. As temperatures and sudden storms intensify with climate change, heat‐pulse magnitude and dissipation distance will likely increase. Streams in urbanized landscapes, such as Durham municipality, where 98.9% of streams are within 1 downstream km of stormwater outfalls, will be increasingly impacted by urban stormwaters.     

Estimation of daily intake of potentially toxic elements from urban street dust and the role of oral bioaccessibility testing

The pseudo-total and oral bioaccessible concentration of six potentially toxic elements (PTEs) in urban street dust was investigated. Typical pseudo-total concentrations across the sampling sites ranged from 4.4 to 8.6 mg kg⁻¹ for As, 0.2-3.6 mg kg⁻¹ for Cd, 25-217 mg kg⁻¹ for Cu, 14-46 mg kg⁻¹ for Ni, 70-4261 mg kg⁻¹ for Pb, and, 111-652 mg kg⁻¹ for Zn. This data compared favourably with other urban street dust samples collected and analysed in a variety of cities globally; the exception was the high level of Pb determined in a specific sample in this study. The oral bioaccessibility of PTEs in street dust is also assessed using in vitro gastrointestinal extraction (Unified Bioaccessibility Method, UBM). Based on a worst case scenario the oral bioaccessibility data estimated that Cd and Zn had the highest % bioaccessible fractions (median >45%) while the other PTEs i.e. As, Cu, Ni and Pb had lower % bioaccessible fractions (median <35%). The pseudo-total and bioaccessible concentrations of PTEs in the samples has been compared to estimated tolerable daily intake values based on unintentional soil/dust consumption. Cadmium, Cu and Ni are well within the oral tolerable daily intake rates. With respect to As and Pb, only the latter exceeds the TDI_oral if we model ingestion rate based on atmospheric ‘dustiness’ rather than the US EPA (2008) unintentional soil/dust consumption rate of 100 mg d⁻¹. We consider it unlikely that even a child with pica tendencies would ingest as much as 100 mg soil/dust during a daily visit to the city centre, and in particular to the sites with elevated Pb concentrations observed in this study.     

Long-Term Effects of Changing Land Use Practices on Surface Water Quality in a Coastal River and Lagoonal Estuary

The watershed of the Neuse River, a major tributary of the largest lagoonal estuary on the U.S. mainland, has sustained rapid growth of human and swine populations. This study integrated a decade of available land cover and water quality data to examine relationships between land use changes and surface water quality. Geographic Information Systems (GIS) analysis was used to characterize 26 subbasins throughout the watershed for changes in land use during 1992–2001, considering urban, agricultural (cropland, animal as pasture, and densities of confined animal feed operations [CAFOs]), forested, grassland, and wetland categories and numbers of wastewater treatment plants (WWTPs). GIS was also used together with longitudinal regression analysis to identify specific land use characteristics that influenced surface water quality. Total phosphorus concentrations were significantly higher during summer in subbasins with high densities of WWTPs and CAFOs. Nitrate was significantly higher during winter in subbasins with high numbers of WWTPs, and organic nitrogen was higher in subbasins with higher agricultural coverage, especially with high coverage of pastures fertilized with animal manure. Ammonium concentrations were elevated after high precipitation. Overall, wastewater discharges in the upper, increasingly urbanized Neuse basin and intensive swine agriculture in the lower basin have been the highest contributors of nitrogen and phosphorus to receiving surface waters. Although nonpoint sources have been emphasized in the eutrophication of rivers and estuaries such as the Neuse, point sources continue to be major nutrient contributors in watersheds sustaining increasing human population growth. The described correlation and regression analyses represent a rapid, reliable method to relate land use patterns to water quality, and they can be adapted to watersheds in any region.     

Circular RNA circ_0005835 promotes promoted neural stem cells proliferation and differentiate to neuron and inhibits inflammatory cytokines levels through miR-576-3p in Alzheimer’s disease

Environmental Science and Pollution Research - Alzheimer’s disease (AD) is the most frequent neurodegenerative disease and it is difficult to have an effective and simple method for AD early...