17 β-estradiol mineralization in human waste products and soil in the presence and the absence of antimicrobials

Natural steroidal estrogens, such as 17 β-estradiol (E2), as well as antimicrobials such as doxycycline and norfloxacin, are excreted by humans and hence detected in sewage sludge and biosolid. The disposal of human waste products on agricultural land results in estrogens and antibiotics being detected as mixtures in soils. The objective of this study was to examine microbial respiration and E2 mineralization in sewage sludge, biosolid, and soil in the presence and the absence of doxycycline and norfloxacin. The antimicrobials were applied to the media either alone or in combination at total rates of 4 and 40 mg kg^?1, with the 4 mg kg^?1 rate being an environmentally relevant concentration. The calculated time that half of the applied E2 was mineralized ranged from 294 to 418 days in sewage sludge, from 721 to 869 days in soil, and from 2,258 to 14,146 days in biosolid. E2 mineralization followed first-order and the presence of antimicrobials had no significant effect on mineralization half-lives, except for some antimicrobial applications to the human waste products. At 189 day, total E2 mineralization was significantly greater in sewage sludge (38 ±0.7%) > soil (23 ±0.7%) > biosolid (3 ±0.7%), while total respiration was significantly greater in biosolid (1,258 mg CO₂) > sewage sludge (253 mg CO₂) ≥ soil (131 mg CO₂). Strong sorption of E2 to the organic fraction in biosolid may have resulted in reduced E2 mineralization despite the high microbial activity in this media. Total E2 mineralization at 189 day was not significantly influenced by the presence of doxycycline and/or norfloxacin in the media. Antimicrobial additions also did not significantly influence total respiration in media, except that total CO₂ respiration at 189 day was significantly greater for biosolid with 40 mg kg^?1 doxycycline added, relative to biosolid without antimicrobials. We conclude that it is unlikely for doxycycline and norfloxacin, or their mixtures, to have a significant effect on E2 mineralization in human waste products and soil. However, the potential for E2 to be persistent in biosolids, with and without the presence of antimicrobials, is posing a challenge for biosolid disposal to agricultural lands.     

LEHR superfund stormwater runoff and putah creek mercury issues

Stormwater runoff from the University of California, Davis/U.S. Department of Energy Laboratory for Energy‐Related Health Research (UCD/US DOE LEHR) Superfund site located on the University of California campus in Davis, California, has been found to contain over 500 ng/L of total recoverable mercury, which is about ten times the California Toxics Rule criterion. This stormwater runoff is discharged to Putah Creek, which is Clean Water Act Section 303(d) listed as impaired for excessive mercury bioaccumulation in edible fish. A discussion is presented on the potential impact of the mercury in stormwater runoff from LEHR leading to excessive bioaccumulation of mercury in Putah Creek fish. The mercury in the stormwater runoff is derived from former flooding of the soils near the creek, which contains mercury derived from abandoned upstream mercury mines located in the Coast Range Vaca Hills to the west of LEHR. The implications of this situation for implementing a Total Maximum Daily Load (TMDL) to control mercury in stormwater runoff to Putah Creek are presented. © 2009 Wiley Periodicals, Inc.     

Pesticide concentrations in agricultural storm drainage inlets of a small Swiss catchment

Agricultural pesticides transported to surface waters pose a major risk for aquatic ecosystems. Modelling studies indicate that the inlets of agricultural storm drainage systems can considerably increase the connectivity of surface runoff and pesticides to surface waters. These model results have however not yet been validated with field measurements. In this study, we measured discharge and concentrations of 51 pesticides in four out of 158 storm drainage inlets of a small Swiss agricultural catchment (2.8 km²) and in the receiving stream. For this, we performed an event-triggered sampling during 19 rain events and collected plot-specific pesticide application data. Our results show that agricultural storm drainage inlets strongly influence surface runoff and pesticide transport in the study catchment. The concentrations of single pesticides in inlets amounted up to 62 µg/L. During some rain events, transport through single inlets caused more than 10% of the stream load of certain pesticides. An extrapolation to the entire catchment suggests that during selected events on average 30 to 70% of the load in the stream was transported through inlets. Pesticide applications on fields with surface runoff or spray drift potential to inlets led to increased concentrations in the corresponding inlets. Overall, this study corroborates the relevance of such inlets for pesticide transport by establishing a connectivity between fields and surface waters, and by their potential to deliver substantial pesticide loads to surface waters.

     

Thermal strain in fire fighters while wearing task-fitted versus en 469:2005 protective clothing during a prolonged rescue drill.

Fire fighters are normally overprotected during their working hours because of the tendency to keep the personal protection level sufficiently high in case of the worst possible scenarios. This study investigated the effects of task-fitted protective clothing on thermal strain in fire fighters as compared to EN 469:2005 protective clothing during a prolonged (2 1/2 hrs) job-related rescue drill under neutral and hot climates. The subjects were 23 healthy, physically fit professional male fire fighters aged 26-44 years. Measurements included cardiovascular and thermal responses and subjective assessments. Wearing task-fitted clothing during rescue tasks in a neutral climate considerably reduced total thermal and cardiovascular strain in prolonged rescue work. The fire fighters also perceived physical work as significantly harder on average, and reported more intense subjective discomfort while wearing EN 469:2005 as compared to task-fitted clothing.     

Framing the flood: a media analysis of themes of resilience in the 2011 Brisbane flood

In the wake of the flood that affected Brisbane, Australia, in January 2011, public attention turned to the causes of the event and lessons for minimizing the impacts of future floods. The news media was an important vehicle for understanding and internalizing the 2011 Brisbane flood. Examining how the flood was framed in the media is, therefore, useful to understand broad public perception of floods. We undertook a systematic newspaper analysis during a one-year period to explore media framings of the flood, focused on learning as an aspect of resilience in relation to two themes: (1) perceived links between the flood and climate change and (2) perceived roles of government in managing the flood. We show that media coverage of the flood reinforces aspects of resilience by acknowledging community spirit, self-reliance and the importance of sharing experiences for learning; articulating the risk of extreme events in a changing climate; and highlighting regional management trade-offs. Much of the discourse is likely to inhibit resilience, however, by casting the flood in terms of blame and political opportunity and paying inadequate attention to longer-term aspects of regional resilience. The limited learning observed to date may highlight a need for other mechanisms and actors to lead learning processes. As policy related to the 2011 Brisbane flood, and extreme events more generally, is influenced by the public discourse, it is important to understand the nuances of communication around these events and the media’s role in reinforcing or changing perceptions.     

Remediation of chloroform in fine-textured soil using zero-valent iron

Chloroform, a probable human carcinogen, is mainly produced anthropogenically for industrial use and may be released to the environment from a large number of sources related to its manufacture and use, including pulp and paper mills, hazardous waste sites, and sanitary landfills. Remediation of chloroform through conventional technologies has been met with limited success due to the conditions required and the formation of hazardous substances such as dichloromethane. The objective of this study was to investigate chloroform reduction in multicontaminated fine-textured soil using zero-valent iron (Fe⁰) in anaerobic microcosms. Four amended matrices were tested: simple matrix control (glass beads), soil matrix control (glass beads + soil), Fe⁰ in a simple matrix (glass beads + Fe⁰), and Fe⁰ in a soil matrix (soil + Fe⁰). Headspace chloroform and its transformation products dichloromethane, chloromethane, and methane were measured over 230 days and during short intervals in the initial 3 days. Chloroform (~0.3 mM initial mass) persisted in both control microcosms but was completely transformed in microcosms containing soil + Fe⁰ by 12 h and glass beads + Fe⁰ by 48 h. Reductive dechlorination of chloroform occurred with simultaneous production of dichloromethane (~0.11 to 0.14 mM mass) and chloromethane (~0.02 to 0.13 mM mass). Little methane (~0.07 to 0.26 μM mass) production as an end product of chloroform reduction was observed in microcosms amended with Fe⁰. Produced dichloromethane and chloroform almost disappeared by 230 days. The results showed a complete chloroform transformation pathway that has good potential for the remediation of chlorinated compounds in fine-textured soil. The role of soil clay minerals in redox reactions can be further investigated to improve the reductive dechlorination of chlorinated compounds in contaminated environments.     

Comparison of EDTA-enhanced phytoextraction and phytostabilisation strategies with Lolium perenne on a heavy metal contaminated soil

Phytoremediation is a promising and cost-effective strategy to manage heavy metal polluted sites. In this experiment, we compared simultaneously phytoextraction and phytostabilisation techniques on a Cd and Zn contaminated soil, through monitoring of plant accumulation and leaching. Lolium perenne plants were cultivated for 2 months under controlled environmental conditions in a 27.6 dm³-pot experiment allowing the collect of leachates. The heavy metal phytoextraction was promoted by adding Na-EDTA (0.5 g kg⁻¹ of soil) in watering solution. Phytostabilisation was assessed by mixing soil with steel shots (1%) before L. perenne sowing. Presence of plants exacerbated heavy metal leaching, by improving soil hydraulic conductivity. Use of EDTA for phytoextraction led to higher concentration of heavy metal in shoots. However, this higher heavy metal extraction was insufficient to satisfactory reduce the heavy metal content in soil, and led to important heavy metal leaching induced by EDTA. On the other hand, addition of steel shots efficiently decreased both Cd and Zn mobility, according to 0.01 M CaCl₂ extraction, and leaching. However, improvement of growth conditions by steel shots led to higher heavy metal mass in shoot tissues. Therefore, soil heavy metal mobility and plant metal uptake are not systematically positively correlated.     

Influence of competing inorganic cations on the ion exchange equilibrium of the monovalent organic cation metoprolol on natural sediment

The aim of this study was to systematically investigate the influence of the mono- and divalent inorganic ions Na⁺ and Ca²⁺ on the sorption behavior of the monovalent organic cation metoprolol on a natural sandy sediment at pH = 7. Isotherms for the beta-blocker metoprolol were obtained by sediment–water batch tests over a wide concentration range (1–100 000 μg L^?1). Concentrations of the competing inorganic ions were varied within freshwater relevant ranges. Data fitted well with the Freundlich sorption model and resulted in very similar Freundlich exponents (n = 0.9), indicating slightly non-linear behavior. Results show that the influence of Ca²⁺ compared to Na⁺ is more pronounced. A logarithmic correlation between the Freundlich coefficient K_Fr and the concentration or activity of the competing inorganic ions was found allowing the prediction of metoprolol sorption on the investigated sediment at different electrolyte concentrations. Additionally, the organic carbon of the sediment was completely removed for investigating the influence of organic matter on the sorption of metoprolol. The comparison between the experiments with and without organic carbon removal revealed no significant contribution of the organic carbon fraction (0.1%) to the sorption of metoprolol on the in this study investigated sediment. Results of this study will contribute to the development of predictive models for the transport of organic cations in the subsurface.     

A reflection on four impactful Ambio papers: The biotic perspective: This article belongs to Ambio’s 50th Anniversary Collection. Theme: Climate change impacts

Climate change represents one of the most pressing societal and scientific challenges of our time. While much of the current research on climate change focuses on future prediction, some of the strongest signals of warming can already be seen in Arctic and alpine areas, where temperatures are rising faster than the global average, and in the oceans, where the combination of rising temperatures and acidification due to increased CO₂ concentrations has had catastrophic consequences for sensitive marine organisms inhabiting coral reefs. The scientific papers highlighted as part of this anniversary issue represent some of the most impactful advances in our understanding of the consequences of anthropogenic climate change. Here, we reflect on the legacy of these papers from the biotic perspective.