The effect of wastewater treatment on antibiotic resistance in Escherichia coli and Enterococcus sp.

The effects of wastewater treatment on the proportion of Escherichia coli and Enterococcus sp. resistant to specific antibiotics were investigated at two facilities in Davis County, Utah, one of which received hospital waste. Samples were taken from the influent, effluent before disinfection, and secondary anaerobic sludge digester effluent. There was very little difference in antibiotic resistance among E. coli in the inflow waters of the plants but the plant receiving hospital waste had a significantly higher proportion of antibiotic resistant Enterococcus. The effect of wastewater treatment on antibiotic resistance was more pronounced on enterococci than E. coli. Although some increases in antibiotic resistance were observed, the general trend seemed to be a decrease in resistance, especially in the proportion of multidrug resistant Enterococcus sp.     

Fate, effects and potential environmental risks of ethylene glycol: a review

The fate, effects, and potential environmental risks of ethylene glycol (EG) in the environment were examined. EG undergoes rapid biodegradation in aerobic and anaerobic environments (approximately 100% removal of EG within 24 h to 28 days). In air, EG reacts with photo-chemically produced hydroxyl radicals with a resulting atmospheric half-life of 2 days. Acute toxicity values (LC(50)s and EC(50)s) were generally >10,000 mg/l for fish and aquatic invertebrates. The data collectively show that EG is not persistent in air, surface water, soil, or groundwater, is practically non-toxic to aquatic organisms, and does not bioaccumulate in aquatic organisms. Potential long-term, quasi-steady state regional concentrations of EG estimated with a multi-media model for air, water, soil, and sediment were all less than predicted no effect concentrations (PNECs).     

Linking Ecological Science to Decision-Making: Delivering Environmental Monitoring Information as Societal Feedback

The paper describes the Ecological Monitoring and Assessment Network's (EMAN) operational and program response to certain challenges of environmental monitoring in Canada, in particular, efforts to improve the ability of the network to deliver relevant information to decision makers. In addition to its familiar roles, environmental monitoring should deliver feedback to society on environmental changes associated with development patterns, trends, processes and interventions. In order for such feedback to be effective, it must be relevant, timely, useful and accessible: all characteristics that are defined by the user, not the provider. Demand driven environmental monitoring is explored through EMAN's experiences with Canada's Biosphere Reserves, the NatureWatch Program and the Canadian Community Monitoring Network.     

Effect of contaminated groundwater on tree growth: A tree-ring analysis

A study was conducted of the effect of contaminated groundwater seepage on tree growth downslope from the F- and H-Area seepage basins of the Department of Energy's Savannah River Site in South Carolina. Trees in wetlands along Four Mile Creek began to show localized stress and mortality in the late 1970s. Extreme winter temperatures and high rainfall were ruled out as potential causal factors of tree stress. Drought was shown to affect trees in both contaminated and uncontaminated zones, but trees in uncontaminated areas exhibited better recovery after drought than trees in contaminated areas. Pollution-mediated alteration of soil acidity and aluminum, sodium, and heavy metal concentrations likely acted to predispose trees to decline, with severe drought acting as the trigger for decline initiation and tree death. Thus, a moderate pollution loading, not sufficient to cause visible damage of itself, may create conditions in which sudden, severe decline could result from natural stresses. This mechanism of forest decline may be common, and should be considered in evaluations of the impact of pollution on wetland forest systems.     

Thermal and oxidative disproportionation in amine degradation—O2 stoichiometry and mechanistic implications

Three modes of amine degradation have been previously identified—direct oxidation by metal ions, thermal disproportionation and autoxidation. Results are presented in which products of disproportionation reactions of quaternary compounds are compared to those seen in the thermal degradation of methyldiethanolamine, MDEA. This strongly suggests a role of a quaternary or a protonated amine intermediate in this reaction. Products of MDEA autoxidation at 140 °C also show characteristics of disproportionation reactions. Potential mechanisms are presented to account for the products seen.     

Non-market valuation of off-highway vehicle recreation in Larimer County, Colorado: Implications of trail closures

Few economic studies are available to measure off-highway vehicle recreation benefits foregone when trails must be closed to protect the environment. This paper estimates the non-market benefits associated with off-highway vehicle (OHV) recreation on National Forest lands in Larimer County, Colorado. We use a contingent valuation model (CVM) to estimate benefits to OHV users, which includes dirt bike riders, all terrain vehicle (ATV) riders, and 4-wheel drive (4 × 4) users. Using CVM we find the mean consumer surplus estimates to be $78 per person per day. These results are consistent with the few previous estimates of OHV recreation benefits. This equates to a per trail per summer consumer surplus of at least between $219,467 and $296,876, and a county level surplus per summer to be at least between $796,447 and $1,077,367. These benefits can be compared to environmental costs to obtain a more complete picture of the effects of trail closure, as well as the negative spillovers to non-motorized users.     

Stockpiles of obsolete pesticides and cleanup priorities: A methodology and application for Tunisia

Obsolete pesticides have accumulated in almost every developing country or economy in transition over the past several decades. Concerned about the risks these chemicals pose to nearby residents, public health and environmental authorities are eager to reduce health threats by removing and decontaminating stockpile sites. However, there are many sites, cleanup can be costly, and public resources are scarce, so decision makers need to set priorities. Under these conditions, it seems sensible to develop a methodology for prioritizing sites and treating them sequentially, as budgetary resources permit.This paper presents a new methodology that develops a cleanup priority index for 1915 metric tons of obsolete pesticide formulations at 197 stockpile sites in Tunisia. The approach integrates information on populations at risk, their proximity to stockpiles, and the relative toxic hazards of the stockpiles. What emerges from the Tunisia results is a strategy for sequentially addressing all 197 sites to rapidly reduce potential health damage in a cost-effective way.     

Identifying management opportunities to combat climate,land, and marine threats across less climate exposed coral reefs

Conserving coral reefs is critical for maintaining marine biodiversity, protecting coastlines, and supporting livelihoods in many coastal communities. Climate change threatens coral reefs globally, but researchers have identified a portfolio of coral reefs (bioclimatic units [BCUs]) that are relatively less exposed to climate impacts and strongly connected to other coral reef systems. These reefs provide a proactive opportunity to secure a long-term future for coral reefs under climate change. To help guide local management efforts, we quantified marine cumulative human impact (CHI) from climate, marine, and land pressures (2013 and from 2008 to 2013) in BCUs and across countries tasked with BCU management. Additionally, we created a management index based on common management measures and policies for each pressure source (climate, marine, and land) to identify a country's intent and commitment to effectively manage these pressures. Twenty-two countries (79%) had increases in CHI from 2008 to 2013. Climate change pressures had the highest proportional contribution to CHI across all reefs and in all but one country (Singapore), but 18 BCUs (35%) and nine countries containing BCUs (32%) had relatively high land and marine impacts. There was a significant positive relationship between climate impact and the climate management index across countries (R² = 0.43, p = 0.02), potentially signifying that countries with greater climate impacts are more committed to managing them. However, this trend was driven by climate management intent in Fiji and Bangladesh. Our results can be used to guide future fine-scale analyses, national policies, and local management decisions, and our management indices reveal areas where management components can be improved. Cost-effectively managing local pressures (e.g., fishing and nutrients) in BCUs is essential for building a climate-ready future that benefits coral reefs and people.