Do concentrations in eggs and liver tissue tell the same story of temporal trends of mercury in high Arctic seabirds?

Mercury(Hg) remains a key contaminant of concern in Arctic biota, and monitoring of Hg concentrations in seabird tissues will be an effective approach to track the effects of implementing the Minamata Convention. We examined trends in total Hg(THg) in liver and egg tissues of two Arctic seabirds, thick-billed murres(Uria lomvia) and northern fulmars(Fulmarus glacialis), between 1976 and 2013 to assess whether both tissues showed similar patterns of Hg change. Hepatic THg was consistently higher than egg THg, and both species had similar egg THg concentrations, but fulmars had higher hepatic THg than murres.Murre THg concentrations showed more relative variation through time than fulmars.We suggest that egg THg better reflects exposure of birds to THg in local, Arctic prey,whereas liver THg may incorporate longer term, year-round THg exposure. Additional analysis of THg distribution in Arctic seabirds post-laying would help inform interpretation of long-term trends.     

Restraint use in the Eastern Province of the Kingdom of Saudi Arabia

Objectives: This study set out to examine seat belt and child restraint use in the Dammam Municipality of the Kingdom of Saudi Arabia, based on the premise that an increase in seat belt use would significantly reduce personal injury in traffic crashes. It was expected that local data would help identify intervention strategies necessary to improve seat belt use in the region.

Methods: The research involved 2 methodologies. First, 1,389 face-to-face interviews were conducted with male and female adults in regional shopping plazas regarding their own and their children's restraint use in their vehicles and reasons for these attitudes and beliefs. Second, 2 on-road observation studies of adult and child restraint use were conducted by trained observers. Occupants of approximately 5,000 passenger vehicles were observed while stopped at representative signalized traffic intersections.

Results: The findings showed front seat belt use rates of between 43 and 47% for drivers and 26 to 30% for front seat passengers; rear seat belt use rates were lower. While there seemed to be some knowledge about the purpose and reasons for restraining both adults and children in suitable restraints, this failed to be confirmed in the on-road observations.

Conclusions: Reasons for these rates and findings are discussed fully, and recommendations for improving seat belt use in the Dammam Municipality are included.     

Seat belt use among car drivers in Iranian safe communities: An observational study

Objective: The number of road traffic injuries and fatalities in Iran is high. The aim of the present study was to investigate the rate of drivers' seat belt use and a number of related factors in Kashmar, Bardaskan, and Khalilabad (Iranian Safe Communities).Methods: In 2014, driver observations were made at 48 road sites on intercity roads, main streets, side streets, and rural roads in these 3 cities.Results: A total of 10,255 vehicles were observed, with the overall rate of seat belt use being 51.8%. The rates in Kashmar, Bardaskan, and Khalilabad were 51.4, 56.3, and 47.7%, respectively. In Kashmar, the odds of seat belt use were higher among drivers who were female, older, and taxi drivers. Higher use was also found during the afternoon, and lower use was observed on rural roads. In Khalilabad the odds of seat belt use were higher among females, older drivers, taxis, and private car drivers. Seat belt use was also higher on weekends and during the morning but was significantly lower on rural roads. Similarly, in Bardaskan the odds of using a seat belt were higher among females, older drivers, taxis, and private car drivers. Seat belt use was also higher during the afternoon but was significantly lower on rural roads, in comparison to main streets and intercity roads.Conclusions: The rate of seat belt use in these 3 cities was found to be low, despite these cities being designated as International Safe Communities. Therefore, seat belt promotion programs, tougher regulations, stronger enforcement, public awareness campaigns, and more research are needed to promote seat belt use in these Iranian cities.     

A comparison of employment growth and stability before and after the Fort Worth tornado

This study examined the time series pattern of employment growth and stability in Fort Worth, Texas taking into account the March 28, 2000 tornado. The tornado is treated econometrically as an intervention and both the mean and conditional variance of employment growth were estimated. Overall, this regional labor market experienced a decline in the employment growth rate following the tornado. Among the sectors that exhibited differences in employment dynamics between the pre- and post-tornado periods, the mining sector experienced a significant increase in employment growth following the tornado while the service andwholesale, retail trade sectors experienced significant declines in employment growth in the post-tornado period. The manufacturing, service, and wholesale, retail trade sectors were characterized by greater stability (i.e., a lower level of employment growth volatility) in the post-tornado period than in the pre-tornado period. Interestingly, in several sectors, no differences in the time series dynamics of employment growth were detected between the pre- and post-tornado periods. These sectors included construction, finance, insurance, real estate, government, and transportation and public utilities.     

Measuring in-cabin school bus tailpipe and crankcase PM2.5: a new dual tracer method

Exposures of occupants in school buses to on-road vehicle emissions, including emissions from the bus itself, can be substantially greater than those in outdoor settings. A dual tracer method was developed and applied to two school buses in Seattle in 2005 to quantify in-cabin fine particulate matter (PM2.5) concentrations attributable to the buses' diesel engine tailpipe (DPMtp) and crankcase vent (PMck) emissions. The new method avoids the problem of differentiating bus emissions from chemically identical emissions of other vehicles by using a fuel-based organometallic iridium tracer for engine exhaust and by adding deuterated hexatriacontane to engine oil. Source testing results showed consistent PM:tracer ratios for the primary tracer for each type of emissions. Comparisons of the PM:tracer ratios indicated that there was a small amount of unburned lubricating oil emitted from the tailpipe; however, virtually no diesel fuel combustion products were found in the crankcase emissions. For the limited testing conducted here, although PMck emission rates (averages of 0.028 and 0.099 g/km for the two buses) were lower than those from the tailpipe (0.18 and 0.14 g/km), in-cabin PMck concentrations averaging 6.8 microg/m3 were higher than DPMtp (0.91 microg/m3 average). In-cabin DPMtp and PMck concentrations were significantly higher with bus windows closed (1.4 and 12 microg/m3, respectively) as compared with open (0.44 and 1.3 microg/m3, respectively). For comparison, average closed- and open-window in-cabin total PM2.5 concentrations were 26 and 12 microg/m3, respectively. Despite the relatively short in-cabin sampling times, very high sensitivities were achieved, with detection limits of 0.002 microg/m3 for DPMtp and 0.05 microg/m3 for PMck.     

Influences of redox transformation, metal complexation and aggregation of fulvic acid and humic acid on Cr(VI) and As(V) removal by zero-valent iron

This study investigated the removal kinetics and mechanisms of Cr(VI) and As(V) by Fe(0) in the presence of fulvic acid (FA) and humic acid (HA) by means of batch experiments. The focus was on the involvements of FA and HA in redox reactions, metal complexation, and iron corrosion product aggregation in the removal of Cr(VI) and As(V) removal by Fe(0). Synthetic groundwater was used as the background electrolyte to simulate typical groundwater. The results showed faster Cr(VI) removal in the presence of HA compared to FA. Fluorescence spectroscopy revealed that no redox reaction occurred in the FA and HA. The results of the speciation modeling indicate that the free Fe(II) concentration was higher in the presence of HA, resulting in a higher removal rate of Cr(VI). However, the removal of As(V) was inhibited in the HA solution. Speciation modeling showed that the concentration of dissolved metal-natural organic matter (metal-NOM) complexes significantly affected the aggregation of the iron corrosion products which in turn affected the removal of As(V). The aggregation was found to be induced by gel-bridging of metal-NOM with the iron corrosion products. The effects of metal-NOM on the aggregation of the iron corrosion products were further confirmed by TEM studies. Larger sizes of iron corrosion products were formed in the FA solution compared to HA solution. This study can shed light on understanding the relationships between the properties of NOM (especially the content of metal-binding sites) and the removal of Cr(VI) and As(V) by Fe(0).     

Forest and agroecosystem fire management in Ghana

The threat of wildfires to the economic potential of forestry and agriculture is one of the persistent national and international concerns. Improving and applying indigenous wildfire management (IWM) approaches is seen as one of the main hopes for mitigating and adapting to this threat to rural forest communities. Identifying the contextual causes and adaptation measures practiced by local people is essential for planning an appropriate mechanism for IWM. Yet only limited studies are available on IWM practices and most of those studies were conducted outside of this study region. To fill this gap, this study examined the wildfire mitigation and adaptation methods of forest communities in Ghana using interviews with 266 farming households. Their perceptions of the causes, cost and risk factors were also examined. The result suggests that wildfires are annual events. More than half of the wildfires reported were caused by slash-and-burn land preparation, with hunting-related fires in second place. Forest households loose about 208 Ghana cedi (US$ 231 in 2006) in value due to damaged crops and tree seedlings annually (i.e. about 50% of annual income of a Ghanaian farmer). The respondents had the operational skill and coping abilities to deal with small-scale wildfires and were supported by well-established local arrangements, community rules and silvicutural techniques. In addition, they were well informed about the basic risk factors (e.g. fuel load, climate, and presence of ignition triggers) and how these can interact to cause devastating wildfire. Therefore it is critical that policies and institutions that promote IWM initiatives build on the strong underlying community knowledge and local networks to enhance their effectiveness.     

Reducing Air Pollution from Urban Passenger Transport: A Framework for Policy Analysis

Air quality is declining in urban areas, in part because of the rapid motorization of societies world-wide. To combat the problem, various pollution control strategies have been used or proposed for urban passenger transport. This paper develops a simple framework to analyse the impact of these strategies. The paper examines the point of impact of different policy levers and categorizes different instruments in a way that should help policy makers choose between them. The framework explicitly recognizes behavioural incentives, especially the fact that offsetting changes in consumer behaviour can often undermine the original intent of particular policies. The paper concludes that policies aimed at improving transport efficiency often improve air quality at the same time. However, supply side policies to relieve traffic congestion can conflict with the objective of controlling air pollution. It is hence vital that policy makers are aware of the incentives created by different interventions and weigh the impact of these incentives on subsidiary objectives before adoption of particular policies.