Creating an integrated historical record of extreme particulate air pollution events in Australian cities from 1994 to 2007

Epidemiological studies of exposure to vegetation fire smoke are often limited by the availability of accurate exposure data. This paper describes a systematic framework for retrospectively identifying the cause of air pollution events to facilitate a long, multicenter analysis of the public health effects of vegetation fire smoke pollution in Australia. Pollution events were statistically defined as any day at or above the 95th percentile of the 24-hr average concentration of particulate matter (PM). These were identified for six cities from three distinct ecoclimatic regions of Australia. The dates of each event were then crosschecked against a range of information sources, including online newspaper archives, government and research agency records, satellite imagery, and aerosol optical thickness measures to identify the cause for the excess particulate pollution. Pollution events occurred most frequently during summer for cities in subtropical and arid regions and during winter for cities in temperate regions. A cause for high PM on 67% of days examined in the city of Sydney was found, and 94% of these could be attributed to landscape fire smoke. Results were similar for cities in other subtropical and arid locations. Identification of the cause of pollution events was much lower in colder temperate regions where fire activity is less frequent. Bushfires were the most frequent cause of extreme pollution events in cities located in subtropical and arid regions of Australia. Although identification of pollution episodes was greatly improved by the use of multiple sources of information, satellite imagery was the most useful tool for identifying bushfire smoke pollution events.     

Improving mental health status and coping abilities for long‐term unemployed youth using cognitive‐behaviour therapy based training interventions

This paper reports on immediate and long‐term well‐being outcomes for a group of long‐term unemployed youth who attended specially devised training courses based on the cognitive‐behaviour therapy (CBT) model. The courses were aimed specifically at improving the mental health of participants, and providing them with coping skills to deal better with the negative consequences of prolonged unemployment. Results for participants were compared with a waiting‐list, control group. Outcomes investigated were well‐being (psychological distress, self‐esteem, positive and negative affect), and coping behaviours (social support, self care, recreation, and cognitive coping strategies). Behavioural plasticity effects were also examined by comparing outcomes for participants who had higher distress scores prior to the course with participants who reported lower scores at that time. Immediate benefits were identified for both mental health and coping behaviours, and many of these benefits persisted into the long term. Participants with higher levels of pre‐course psychological distress improved more than their low distressed counterparts, supporting the behavioural plasticity hypothesis. Copyright © 1999 John Wiley & Sons, Ltd.     

The effects of plant traits and phylogeny on soil-to-plant transfer of Tc

Assessments of the behaviour of ⁹⁹Tc in terrestrial environments necessitate predicting soil-to-plant transfer. An experiment with 116 plant taxa showed that ⁹⁹Tc transfer to plants was positively related to plant dry weight but negatively related to % dry matter and age at exposure. Activities of ⁹⁹Tc analysed by hierarchical ANOVA coded with an angiosperm phylogeny revealed significant effects, with 55% of the variance between species explained at the Ordinal level and above. Monocots had significantly lower transfer of ⁹⁹Tc than Eudicots, within which Caryophyllales > Solanales > Malvales > Brassicales > Asterales > Fabales. There was a significant phylogenetic signal in soil-to-plant transfer of ⁹⁹Tc. This phylogenetic signal is used to suggest that, for example, a nominal Tc Transfer Factor of 5 could be adjusted to 2.3 for Monocots and 5.3 for Eudicots.     

The scope and severity of white-nose syndrome on hibernating bats in North America

Assessing the scope and severity of threats is necessary for evaluating impacts on populations to inform conservation planning. Quantitative threat assessment often requires monitoring programs that provide reliable data over relevant spatial and temporal scales, yet such programs can be difficult to justify until there is an apparent stressor. Leveraging efforts of wildlife management agencies to record winter counts of hibernating bats, we collated data for 5 species from over 200 sites across 27 U.S. states and 2 Canadian provinces from 1995 to 2018 to determine the impact of white-nose syndrome (WNS), a deadly disease of hibernating bats. We estimated declines of winter counts of bat colonies at sites where the invasive fungus that causes WNS (Pseudogymnoascus destructans) had been detected to assess the threat impact of WNS. Three species undergoing species status assessment by the U.S. Fish and Wildlife Service (Myotis septentrionalis, Myotis lucifugus, and Perimyotis subflavus) declined by more than 90%, which warrants classifying the severity of the WNS threat as extreme based on criteria used by NatureServe. The scope of the WNS threat as defined by NatureServe criteria was large (36% of Myotis lucifugus range) to pervasive (79% of Myotis septentrionalis range) for these species. Declines for 2 other species (Myotis sodalis and Eptesicus fuscus) were less severe but still qualified as moderate to serious based on NatureServe criteria. Data-sharing across jurisdictions provided a comprehensive evaluation of scope and severity of the threat of WNS and indicated regional differences that can inform response efforts at international, national, and state or provincial jurisdictions. We assessed the threat impact of an emerging infectious disease by uniting monitoring efforts across jurisdictional boundaries and demonstrated the importance of coordinated monitoring programs, such as the North American Bat Monitoring Program (NABat), for data-driven conservation assessments and planning.     

Dry deposition of O3, SO2, and HNO3 to different vegetation in the same exposure environment

Agricultural meteorological modeling techniques are used to investigate the relative and absolute dry deposition fluxes of SO2 (as sulfur), HNO3 (as nitrogen) and O3 to large fields of maize, soybeans, and alfalfa exposed in conditions as measured in northern Illinois, central Pennsylvania, and eastern Tennessee. For HNO3, the differences in seasonal deposition rates among the three types of plant species are small. Within the same environment, the soybean canopy has the potential to receive substantially more gaseous dry deposition of SO2 and O3 than the maize and alfalfa (which are about the same), as a result of lower stomatal resistance and consequently higher deposition velocities. Deposition differences among the sites are small except for the case of SO2, for which deposition rates estimated for northern Illinois are nearly double those at the other locations. The high SO2 deposition at the northern Illinois location is a consequence of the higher air concentrations observed there.