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Biogeochemical couplings between land and coastal waters are increasingly altered by land cover changes forced by accumulation of human uses of watersheds. In particular, human activities increase nitrogen loads to receiving waters. Definitions of forcings require estimation of external nitrogen sources and evaluation of the effects on the roles of different land covers, retention within watersheds, and net exports to the sea. One powerful example of change in N loads is the effect of urban development on the watershed and concentrations of inorganic nitrogen in the water of Great South Bay (GSB), New York. We defined land uses, delimited subwatersheds emptying into GSB, and estimated nitrogen loads to subwatersheds and from these to receiving waters. Wastewater-derived nitrogen was the dominant source to watershed surfaces (55%), with lesser amounts added by atmospheric deposition to land (31%) and fertilizer use (15%). About 77% of nitrogen entering the watershed was retained within the watershed, so that despite land use changes, the watershedfurnished a substantial water quality subsidy, preventing enrichment of GSB. This high within-watershed retention is similar to rates observed elsewhere and was to a significant degree linked to areas of natural vegetation.About 50% of total nitrogen that entered GSB was of wastewater origin; only 16% was contributed by atmospheric deposition on land, 26% by direct atmospheric deposition on GSB, and 7% by use of fertilizer on land. In addition, the direct atmospheric deposition onto GSB amounted to 44% of the land-derived load, within ranges affecting other estuaries.GSB is low on the range of eutrophication of estuaries. Within-watershed retention is still high, but land cover changes manage to force enough throughput of land-derived nitrogen—particularly wastewater nitrogen—to enrich coastal receiving waters. As land cover further shifts away from natural vegetation, eutrophication of GSB, and coastal receivingwaters in general, will increase. [ABSTRACT FROM AUTHOR]

Introduction: Literature is lacking on the safety of storing contaminated PPE in paper bags for reuse, potentially increasing exposure to frontline healthcare workers (HCW) and patients. The aim of this study is to evaluate the effectiveness of paper bags as a barrier for fomite transmission of SARS-CoV-2 by storing face masks, respirators, and face shields. Methods: This quasi-experimental study evaluated the presence of SARS-CoV-2 on the interior and exterior surfaces of paper bags containing PPE that had aerosolized exposures in clinical and simulated settings. Between May and October 2020, 30 unique PPE items were collected from COVID-19 units at two urban hospitals. Exposed PPE, worn by either an infected patient or HCW during a SARS-CoV-2 aerosolizing event, were placed into an unused paper bag. Samples were tested at 30-minute and 12-hour intervals. Results: A total of 177 swabs were processed from 30 PPE samples. We found a 6.8% positivity rate among all samples across both collection sites. Highest positivity rates were associated with ventilator disconnection and exposure to respiratory droplets from coughing. Positivity rates differed between hospital units. Total positivity rates were similar between 30-minute (6.7%) and 12-hour (6.9%) sample testing time intervals. Control samples exposed to inactivated SARS-CoV-2 droplets had higher total viral counts than samples exposed to nebulized aerosols. Conclusions: Data suggests paper bags are not a significant fomite risk for SARS-CoV-2 transmission. However, controls demonstrated a risk with droplet exposure. Data can inform guidelines for storing and re-using PPE in situations of limited supplies during future pandemics. [ABSTRACT FROM AUTHOR]

Abstract: Couplings between land use and marine food webs in tropical systems are poorly understood. We compared land–sea coupling in seven sites around Puerto Rico, differing in the degree of precipitation and urbanization, by measuring δ 13C and δ 15N in producers and consumers. δ 15N values were influenced by human activity: the food web from sites near urbanized centers was on average 1‰ heavier in δ 15N compared to undeveloped sites. This is most likely due to wastewater inputs from septic systems relatively near the shoreline. Changes in δ 13C were best explained by differences in the degree of marine influence. Where terrestrial inputs from a major river dominated, δ 13C values were lighter, whereas sites further from land and in locations exposed to oceanic currents had heavier δ 13C values, characteristic of a marine source of dissolved organic carbon. We found no significant effect of precipitation on connectivity in spite of a twofold difference in annual average rainfall between the north and south coast. The results suggest there is some connectivity between land and sea in Puerto Rico, despite high rates of evaporation relative to precipitation. [Copyright &y& Elsevier]