We here report the first sign of amphibian recovery after a strong decline due to acidic precipitation over many decades and peaking around 1980-90. In 2010, the pH level of ponds and small lakes in two heavily acidified areas in southwestern Scandinavia (Aust-Agder and Østfold in Norway) had risen significantly at an (arithmetic) average of 0.14 since 1988-89. Parallel with the general rise in pH, amphibians (Rana temporaria, R. arvalis, Bufo bufo, Lissotriton vulgaris, and Triturus cristatus) had become significantly more common: the frequency of amphibian localities rose from 33% to 49% (n = 115), and the average number of amphibian species per locality had risen from 0.51 to 0.88. In two other (reference) areas, one with better buffering capacity (Telemark, n = 21) and the other with much less input of acidic precipitation (Nord-Trøndelag, n = 106), there were no significant changes in pH or amphibians.
Cites: BMC Evol Biol. 2011 Dec 19;11:366 PMID 22182445
Police records are the most common source of data used to estimate motor-vehicle collision risks, understand causal or contributing factors, and evaluate the efficacy of interventions. The literature notes concerns about this information citing discrepancies between police reports and other sources of injury occurrence and severity data. The primary objective of the analysis was to assess the adequacy of police reports for an examination of weather-related injury collision risk.
Analyses of relative risk were carried out using both police records and comprehensive insurance claim data for Winnipeg, Canada over the period 1999-2001.
Both data sets yielded very similar results-precipitation substantially increases the risk of injury collision (police records: RR 1.76, CI 1.55-2.00; insurance: RR 1.80, CI 1.62-1.99) and risk of injury (police records, RR 1.74, CI 1.55-1.96; insurance, RR 1.69, CI 1.55-1.85) relative to corresponding dry weather control periods. Both rainfall and snowfall were associated with large increases in collisions and injuries.
While relative risks are almost identical, over 64% more injury collisions and 74% more injuries were identified using the insurance data, which is an important difference for evaluating absolute risk and exposure.
The occurrence of deoxynivalenol (DON) in Danish wheat flour was studied during the period 1998-2003 by either capillary gas chromatography with electron capture detection and liquid chromatography coupled to an ion trap mass spectrophotometer. A total of 151 samples were collected from mills and the retail market in Denmark. Contamination levels varied considerably from year-to-year with the highest concentrations occurring in samples from the 2002 harvest with mean and median concentrations of 255 and 300 microg kg(-1), respectively. Compared to other harvest years, 2002 had the highest amount of precipitation around flowering time, i.e. from the end of June to the beginning of July covering weeks 25-27. The lowest average levels were found in samples from the 2001 harvest, where weeks 25-27 were dry compared with other harvest years. The highest value (705 microg kg(-1)) was obtained in a flour sample from the 2002 harvest, but none of the tested samples exceeded the maximum limit of 750 microg kg(-1), which has been recently introduced by the European Commission for DON in flour used as raw materials in food products. Calculation of chronic or usual intake by a deterministic approach showed that intake did not exceed the TDI of 1 microg kg(-1) bw day(-1) either for the whole population or for children. A probabilistic approach also showed that intake in general was below the TDI, but intake for children in the 99% percentile amounted to more than 75% of the TDI. The highest intake is calculated to be 2.5 microg kg(-1) bw day(-1).
The Palaeocene/Eocene thermal maximum represents a period of rapid, extreme global warming 55 million years ago, superimposed on an already warm world. This warming is associated with a severe shoaling of the ocean calcite compensation depth and a >2.5 per mil negative carbon isotope excursion in marine and soil carbonates. Together these observations indicate a massive release of 13C-depleted carbon and greenhouse-gas-induced warming. Recently, sediments were recovered from the central Arctic Ocean, providing the first opportunity to evaluate the environmental response at the North Pole at this time. Here we present stable hydrogen and carbon isotope measurements of terrestrial-plant- and aquatic-derived n-alkanes that record changes in hydrology, including surface water salinity and precipitation, and the global carbon cycle. Hydrogen isotope records are interpreted as documenting decreased rainout during moisture transport from lower latitudes and increased moisture delivery to the Arctic at the onset of the Palaeocene/Eocene thermal maximum, consistent with predictions of poleward storm track migrations during global warming. The terrestrial-plant carbon isotope excursion (about -4.5 to -6 per mil) is substantially larger than those of marine carbonates. Previously, this offset was explained by the physiological response of plants to increases in surface humidity. But this mechanism is not an effective explanation in this wet Arctic setting, leading us to hypothesize that the true magnitude of the excursion--and associated carbon input--was greater than originally surmised. Greater carbon release and strong hydrological cycle feedbacks may help explain the maintenance of this unprecedented warmth.
People in the Arctic face uncertainty in their daily lives as they contend with environmental changes at a range of scales from local to global. Freshwater is a critical resource to people, and although water resource indicators have been developed that operate from regional to global scales and for midlatitude to equatorial environments, no appropriate index exists for assessing the vulnerability of Arctic communities to changing water resources at the local scale. The Arctic Water Resource Vulnerability Index (AWRVI) is proposed as a tool that Arctic communities can use to assess their relative vulnerability-resilience to changes in their water resources from a variety of biophysical and socioeconomic processes. The AWRVI is based on a social-ecological systems perspective that includes physical and social indicators of change and is demonstrated in three case study communities/watersheds in Alaska. These results highlight the value of communities engaging in the process of using the AWRVI and the diagnostic capability of examining the suite of constituent physical and social scores rather than the total AWRVI score alone.
Individual and organisational receptivity for change towards the use of sustainable stormwater management systems has been previously examined, but the significance of the different contexts for achieving this has been largely unexplored. This paper examines the significance of contexts associated to the actions to bring this about by proposing and evaluating an emerging framework based on two related receptivity theories: the individual or organisational approach and the contextual approach. Results from a Swedish national questionnaire with professionals in stormwater management have been used, together with a limited number of interviews to develop and understand the validity of the framework. The analysis has indicated that the respondents were professionally prepared for change (action) but not practically prepared due to inadequate supportive contexts. In response, a number of potential contexts associated to the necessary actions were identified. The framework was found to provide new insights into the influence of receptive contexts for a change in water management practice. These insights can be used by policy makers and others to better support the realization of professional openness for change and thus accelerate the process of change to sustainable stormwater practice.
Climate change is expected to lead to higher precipitation amounts and intensities causing an increase of the risk for flooding and combined sewer overflows in urban areas. To cope with these changes, water managers are requesting practical tools that can facilitate adaptive planning. This study was carried out to investigate how recent developments in downscaling techniques can be used to assess the effects of adaptive measures. A combined spatial-temporal downscaling methodology using the Statistical DownScaling Model-Decision Centric (SDSM-DC) and the Generalized Extreme Value distribution was applied to project future precipitation in the city of Bergen, Norway. A raingarden was considered a potential adaptive measure, and its performance was assessed using the RECARGA simulation tool. The benefits and limitations of using the proposed method have been demonstrated and compared to current design practices in Norway. Large differences in the raingarden's performance with respect to percentage overflow and lag-time reduction were found for varying projections. This highlights the need for working with a range of possible futures. Further, it was found that Ksat was the determining factor for peak-flow reduction and that different values of Ksat had different benefits. Engineering flexible solutions by combining measures holding different characteristics will induce robust adaptation.
This study quantifies the effects of common stormwater management techniques on urban runoff generation. Simulated flow rates for different low impact development (LID) scenarios were compared with observed flow rates during different urban construction phases in a catchment (12.3 ha) that was developed from natural forest to a residential area over a monitoring period of 5 years. The Storm Water Management Model (SWMM) was calibrated and validated against the observed flow rates in the fully developed catchment conditions, and it was then applied to parameterize the LID measures and produce scenarios of their hydrological impacts. The results from the LID scenarios were compared with the observed flow rates in the pre-development and the partially developed catchment conditions. The results show that LID controls reduce urban runoff towards the flow conditions in the partially developed catchment, but the reduction effect diminishes during large rainfall events. The hydrographs with LID are still clearly different from the observed pre-development levels. Although the full restoration of pre-development flow conditions was not feasible, a combination of several measures controlling both volumes and retention times of storm runoff appeared to be effective for managing the stormwater runoff and mitigating the negative impacts of urban development.
Increasing livestock density and animal manure spreading, along with climate factors such as heavy rainfall, may increase the risk of acute gastrointestinal illness (AGI). In this study we evaluated the association between farming activities, precipitation and AGI.
A cross-sectional telephone survey of randomly selected residents (n = 7006) of 54 rural municipalities in Quebec, Canada, was conducted between April 2007 and April 2008. AGI symptoms and several risk factors were investigated using a phone questionnaire. We calculated the monthly prevalence of AGI, and used multivariate logistic regression, adjusting for several demographic and risk factors, to evaluate the associations between AGI and both intensive farming activities and cumulative weekly precipitation. Cumulative precipitation over each week, from the first to sixth week prior to the onset of AGI, was analyzed to account for both the delayed effect of precipitation on AGI, and the incubation period of causal pathogens. Cumulative precipitation was treated as a four-category variable: high (> or = 90th percentile), moderate (50th to