The efficacy of hydrogen sulfide (H2S) tests for detecting microbial contamination in rooftop-harvested rainwater.

As climate change strains the world's freshwater resources, access to safe and clean water becomes limited. The use of alternative water sources, such as rooftop-harvested rainwater, has become one mechanism to address freshwater scarcity in the American Southwest, particularly when it comes to home gardening. The University of Arizona's Project Harvest, in partnership with the Sonora Environmental Research Institute, Inc., is a multi-year, co-created citizen science project aimed at increasing current understanding of harvested rainwater quality. Citizens in four Arizona, USA, communities (Hayden/Winkelman, Globe/Miami, Dewey-Humboldt, and Tucson) submitted harvested rainwater samples over 3 years. The harvested rainwater samples were then analyzed using IDEXX Colilert® for total coliforms and E. coli and using Hach PathoScreen™ test for sulfate-reducing bacteria (SRB). This study design allows for the validation of a low-cost, at-home alternative methodology for testing rainwater for bacteria that may indicate fecal contamination. In total, 226 samples were tested using both methodologies, revealing a positive correlation (r=0.245; p<0.002) between total coliform MPN and SRB MPN, but no discernable correlation between E. coli MPN and SRB MPN. This work indicates a potential value of SRB testing for harvested rainwater if cost, laboratory access, and fecal contamination are of concern.

Foliar surfaces as dust and aerosol pollution monitors: An assessment by a mining site.

Recent studies in the southwestern United States have shown that smelting processes and mine tailings emit heavy metal(loid)s that are distributed via wind dispersion to nearby communities. With increased attention regarding the effect of air pollution on environmental health, communities have begun to use citizen/community-based monitoring techniques to measure the concentration of metal(loid)s and evaluate their air quality. This study was conducted in a mining community to assess the efficacy of foliar surfaces as compared to an inverted disc (frisbee) to sample aerosol pollutants in ambient air. The assessment was conducted by evaluating As, Pb, Cd, Cu, Al, Ni, and Zn concentrations versus distance from a former smelter, statistical and regression analyses, and enrichment factor calculations compared to similar sites worldwide. Both the foliar and frisbee collection methods had a decrease in metal(loid)s concentration as a function of distance from the retired smelter. Statistical calculations show that the collection methods had similar mean concentrations for all of the metal(loid)s of interest; however, the tests also indicate that the frisbee collection method generally collected more dust than the foliar method. The enrichment factors from both collection methods were comparable to similar studies by other mining areas referenced, except for aluminum. Since there is evidence of enrichment, correlation between methods, and citizen/community science potential, these efforts show promise for the field. Further studies should consider alternating the types of plant used for foliar collection as well as collecting samples on a more frequent basis in order to sufficiently categorize results based on meteorological conditions.

Public Participation, Trust and Data Sharing: Gardens as Hubs for Citizen Science and Environmental Health Literacy Efforts.

Gardenroots: A Citizen Science Project (2015) is the product of a needs assessment, revealing environmental quality concerns of gardeners living near hazardous waste or resource extraction activities. Participants were trained, collected garden samples for analysis, and later received their data visualized (individual and aggregated) via community events or mail. This article describes participant motivations, changes in knowledge and efficacy, and whether these depend on the mode of data sharing and visualization. Motivations were internal, and self-efficacy increased, while knowledge and satisfaction were higher in event attendees due to increased researcher contact. This reveals importance of data-sharing events, data visualizations, and participatory research processes.

Understanding the Intrinsic and Extrinsic Motivations Associated with Community Gardening to Improve Environmental Public Health Prevention and Intervention.

Considering that community members continue to garden in and near environments impacted by pollutants known to negatively impact human health, this paper seeks to characterize the intrinsic and extrinsic motivations of a gardener and elucidate their perception of soil quality and environmental responsibility, awareness of past land use, and gardening behavior. Via semi-structured interviews with community gardeners in the Boston area (N = 17), multifactorial motivations associated with gardening as well as ongoing environmental health challenges were reported. Gardeners are knowledgeable about their garden's historical past and are concerned with soil quality, theft, trash maintenance, animal waste, and loss of produce from foraging animals. Study findings directly inform the field of environmental health exposure assessments by reporting gardening duration, activities that can lead to incidental soil ingestion, and consumption patterns of locally grown produce. This information combined with an understanding of a gardener's intrinsic and extrinsic motivations can be used to develop urban agricultural infrastructure and management strategies, educational programming, and place-based environmental public health interventions.

Ecosystem-bedrock interaction changes nutrient compartmentalization during early oxidative weathering.

Ecosystem-bedrock interactions power the biogeochemical cycles of Earth's shallow crust, supporting life, stimulating substrate transformation, and spurring evolutionary innovation. While oxidative processes have dominated half of terrestrial history, the relative contribution of the biosphere and its chemical fingerprints on Earth's developing regolith are still poorly constrained. Here, we report results from a two-year incipient weathering experiment. We found that the mass release and compartmentalization of major elements during weathering of granite, rhyolite, schist and basalt was rock-specific and regulated by ecosystem components. A tight interplay between physiological needs of different biota, mineral dissolution rates, and substrate nutrient availability resulted in intricate elemental distribution patterns. Biota accelerated CO2 mineralization over abiotic controls as ecosystem complexity increased, and significantly modified the stoichiometry of mobilized elements. Microbial and fungal components inhibited element leaching (23.4% and 7%), while plants increased leaching and biomass retention by 63.4%. All biota left comparable biosignatures in the dissolved weathering products. Nevertheless, the magnitude and allocation of weathered fractions under abiotic and biotic treatments provide quantitative evidence for the role of major biosphere components in the evolution of upper continental crust, presenting critical information for large-scale biogeochemical models and for the search for stable in situ biosignatures beyond Earth.

Combating Climate Injustices: An Informal Science and Popular Education Approach to Addressing Environmental Health Disparities.

As global warming worsens, addressing environmental health disparities and justice is increasingly important. This necessity is evident in southern metropolitan Tucson, Arizona, an area underserved and disproportionately experiencing the effects of climate change. Including underserved groups in problem solving can spur knowledge generation and the building of community capacity to address and mitigate environmental health challenges posed by climate justice. This article describes a community-based project that utilized a peer education framework coupled with citizen science design. Community health workers (promotoras) were trained in environmental health, climate change, and environmental monitoring protocols to then educate and train families about these same subjects. The study goal was to evaluate science and environmental health learning, awareness, and self-efficacy at the promotora and residential levels resulting from intensive 40-hour trainings, peer education via home visits, and environmental monitoring. Pre- and postsurveys were completed by the promotoras and the families they visited. Motivations for participation as well as changes in self-efficacy and knowledge were analyzed. Results revealed that the promotora's motivations were primarily internal and they were concerned with health. Using the Wilcoxon signed-rank test (p =.05), it was observed that for both study groups, knowledge of water and energy conservation statistically increased, as well as self-efficacy for environmental action and scientific learning. This article demonstrates that promotoras are critical in environmental health and climate science peer education. These findings can be used to further develop peer education citizen science projects in underserved communities, ensuring that efforts increase participants' learning, self-efficacy, and enhance social-ecological outcomes.