Multivariate analysis of the bioaccumulation of polychlorinated biphenyls (PCBs) in the marine pelagic food web from the southern part of the Baltic Sea,Poland

The concentration, pattern, bioaccumulation and biomagnification features of many chlorobiphenyl congeners including non- and mono-ortho chlorine substituted members have been determined in a pelagic food chain including mixed phyto- and zooplankton, herring (Clupea harengus), harbour porpoise (Phocoena phocoena) and black cormorants (Phalacrocorax carbo sinensis) collected from the southern part of the Baltic Proper. TCDD (tetrachlorodibenzo-p-dioxin) toxic equivalents (TEQs) in plankton, herring, harbour porpoise and cormorants were 0.42, 5.3, 79 and 2,700 pg g(-1) lipid weight, respectively. Concentrations of total polychlorinated biphenyls (PCBs) in plankton, herring, harbour porpoise and cormorants were 1.9, 120, 8700 and 2,100 ng g(-1) wet weight (210, 1,300, 10,000 and 42,000 ng g(-1) lipid weight) respectively. Herring, harbour porpoise and black cormorant apparently bioaccumulate many PCBs found in their food, and the values of the bioaccumulation factors (BAFs) for PCBs were approximately 10 in herring, 35 in harbour porpoise and up to 300 in breast muscle of cormorants. Harbour porpoise clearly is able to metabolize the most toxic non-ortho PCBs (no. 77, 126 and 169) and a few mono-ortho PCBs (no. 114, 123 and 156), while all non- and mono-ortho PCBs are bioaccumulated by herring. Penta-, hexa- and hepta-CBs were the dominatant homologue classes both in the muscle tissue and liver. PCB congeners nos. 201, 209, 172/192, 194 and 195 were characterized by the largest BAFs (between 100 and 300). Principal component analysis has been used to analyse the interdependences and differences in the CB congener accumulation patterns between the components of the investigated pelagic food web.     

A review of vulnerability indicators for deltaic social–ecological systems

The sustainability of deltas worldwide is under threat due to the consequences of global environmental change (including climate change) and human interventions in deltaic landscapes. Understanding these systems is becoming increasingly important to assess threats to and opportunities for long-term sustainable development. Here, we propose a simplified, yet inclusive social–ecological system (SES)-centered risk and vulnerability framework and a list of indicators proven to be useful in past delta assessments. In total, 236 indicators were identified through a structured review of peer-reviewed literature performed for three globally relevant deltas—the Mekong, the Ganges–Brahmaputra–Meghna and the Amazon. These are meant to serve as a preliminary “library” of potential indicators to be used for future vulnerability assessments. Based on the reviewed studies, we identified disparities in the availability of indicators to populate some of the vulnerability domains of the proposed framework, as comprehensive social–ecological assessments were seldom implemented in the past. Even in assessments explicitly aiming to capture both the social and the ecological system, there were many more indicators for social susceptibility and coping/adaptive capacities as compared to those relevant for characterizing ecosystem susceptibility or robustness. Moreover, there is a lack of multi-hazard approaches accounting for the specific vulnerability profile of sub-delta areas. We advocate for more comprehensive, truly social–ecological assessments which respond to multi-hazard settings and recognize within-delta differences in vulnerability and risk. Such assessments could make use of the proposed framework and list of indicators as a starting point and amend it with new indicators that would allow capturing the complexity as well as the multi-hazard exposure in a typical delta SES.     

Unravelling the association between the impact of natural hazards and household poverty: evidence from the Indian Sundarban delta

Coastal regions have long been settled by humans due to their abundant resources for livelihoods, including agriculture, transportation, and rich biodiversity. However, natural and anthropogenic factors, such as climate change and sea-level rise, and land subsidence, population pressure, developmental activities, pose threats to coastal sustainability. Natural hazards, such as fluvial or coastal floods, impact poorer and more vulnerable communities greater than more affluent communities. Quantitative assessments of how natural hazards affect vulnerable communities in deltaic regions are still limited, hampering the design of effective management strategies to increase household and community resilience. Drawing from Driving Forces–Pressure–State–Impact–Response (DPSIR), we quantify the associations between household poverty and the likelihood of material and human loss following a natural hazard using new survey data from 783 households within Indian Sundarban Delta community. The results suggest that the poorest households are significantly more likely to endure material and human losses following a natural hazard and repeated losses of livelihood make them more vulnerable to future risk. The results further suggest that salinization, tidal surge, erosion, and household location are also significant predictors of economic and human losses. Given the current and projected impact of climate change and importance of delta regions as the world’s food baskets, poverty reduction and increase societal resilience should be a primary pathway to strengthen the resilience of the poorest populations inhabiting deltas.     

A direct observation study of nighttime safety belt use in Indiana

INTRODUCTION: Nearly all direct observation studies of safety belt use are conducted exclusively during daylight hours. Recent work has suggested that safety belt use at night may differ from daytime belt use. METHODS: An observational study of nighttime safety belt use, utilizing specialized night vision equipment, was conducted in Indiana surrounding the Click It or Ticket 2006 safety belt mobilization activities. A pre- and a post-mobilization statewide direct observation survey was conducted at night coinciding with daytime safety belt use data collection conducted by the state of Indiana. Daytime and nighttime belt use rates were compared. RESULTS: The comparisons across the mobilization period revealed a significant increase during the day, but a significant decrease at night. Comparisons between daytime and nighttime belt use revealed no overall difference during the pre wave, but a significant difference during the post wave. Finally, many common daytime trends in belt use were also found at night, with the exception of the typical age and seating position effects. DISCUSSION: The mobilization activities had a positive effect on daytime belt use, but no effect on nighttime belt use, likely resulting in the differences between daytime and nighttime belt use observed during the post wave. IMPACT ON INDUSTRY: The findings of this study suggest that safety belt mobilizations implemented only during the day do not influence nighttime safety belt use. Changes to how these programs are implemented or additional programs specifically targeting belt use at night should be considered, along with continued monitoring of nighttime belt use.     

Air ion concentrations in various urban outdoor environments

Atmospheric ions are produced by many natural and anthropogenic sources and their concentrations vary widely between different environments. There is very little information on their concentrations in different types of urban environments, how they compare across these environments and their dominant sources. In this study, we measured airborne concentrations of small ions, particles and net particle charge at 32 different outdoor sites in and around a major city in Australia and identified the main ion sources. Sites were classified into seven groups as follows: park, woodland, city centre, residential, freeway, power lines and power substation. Generally, parks were situated away from ion sources and represented the urban background value of about 270 ions cm^?3. Median concentrations at all other groups were significantly higher than in the parks. We show that motor vehicles and power transmission systems are two major ion sources in urban areas. Power lines and substations constituted strong unipolar sources, while motor vehicle exhaust constituted strong bipolar sources. The small ion concentration in urban residential areas was about 960 cm^?3. At sites where ion sources were co-located with particle sources, ion concentrations were inhibited due to the ion-particle attachment process. These results improved our understanding on air ion distribution and its interaction with particles in the urban outdoor environment.     

Development of a composite line source emission model for traffic interrupted microenvironments and its application in particle number emissions at a bus station

A composite line source emission (CLSE) model was developed to specifically quantify exposure levels and describe the spatial variability of vehicle emissions in traffic interrupted microenvironments. This model took into account the complexity of vehicle movements in the queue, as well as different emission rates relevant to various driving conditions (cruise, decelerate, idle and accelerate), and it utilised multi-representative segments to capture the accurate emission distribution for real vehicle flow. Hence, this model was able to quickly quantify the time spent in each segment within the considered zone, as well as the composition and position of the requisite segments based on the vehicle fleet information, which not only helped to quantify the enhanced emissions at critical locations, but it also helped to define the emission source distribution of the disrupted steady flow for further dispersion modelling. The model then was applied to estimate particle number emissions at a bi-directional bus station used by diesel and compressed natural gas fuelled buses. It was found that the acceleration distance was of critical importance when estimating particle number emission, since the highest emissions occurred in sections where most of the buses were accelerating and no significant increases were observed at locations where they idled. It was also shown that emissions at the front end of the platform were 43 times greater than at the rear of the platform. Although the CLSE model is intended to be applied in traffic management and transport analysis systems for the evaluation of exposure, as well as the simulation of vehicle emissions in traffic interrupted microenvironments, the bus station model can also be used for the input of initial source definitions in future dispersion models.     

Influence of seat foam and geometrical properties on BioRID P3 kinematic response to rear impacts

As the primary interface with the human body during rear impact, the automotive seat holds great promise for mitigation of Whiplash Associated Disorders (WAD). Recent research has chronicled the potential influence of both seat geometrical and constitutive properties on occupant dynamics and injury potential. Geometrical elements such as reduced head to head restraint, rearward offset, and increased head restraint height have shown strong correlation with reductions in occupant kinematics. The stiffness and energy absorption of both the seating foam and the seat infrastructure are also influential on occupant motion; however, the trends in injury mitigation are not as clear as for the geometrical properties. It is of interest to determine whether, for a given seat frame and infrastructure, the properties of the seating foam alone can be tailored to mitigate WAD potential. Rear impact testing was conducted using three model year 2000 automotive seats (Chevrolet Camaro, Chevrolet S-10 pickup, and Pontiac Grand Prix), using the BioRID P3 anthropometric rear impact dummy. Each seat was distinct in construction and geometry. Each seat back was tested with various foams (i.e., standard, viscoelastic, low or high density). Seat geometries and infrastructures were constant so that the influence of the seating foams on occupant dynamics could be isolated. Three tests were conducted on each foam combination for a given seat (total of 102 tests), with a nominal impact severity of Delta V = 11 km/h (nominal duration of 100 msec). The seats were compared across a host of occupant kinematic variables most likely to be associated with WAD causation. No significant differences (p < 0.05) were found between seat back foams for tests within any given seat. However, seat comparisons yielded several significant differences (p < 0.05). The Camaro seat was found to result in several significantly different occupant kinematic variables when compared to the other seats. No significant differences were found between the Grand Prix and S-10 seats. Seat geometrical characteristics obtained from the Head Restraint Measuring Device (HRMD) showed good correlation with several occupant variables. It appears that for these seats and foams the head-to-head restraint horizontal and vertical distances are overwhelmingly more influential on occupant kinematics and WAD potential than the local foam properties within a given seat.     

Nitrate and chloride loading to groundwater from an irrigated north-central U.S. sand-plain vegatable field

Groundwater pollution and associated effects on drinking water have increased with the expansion of irrigated agriculture in north-central U.S. sand plains. Controlling this pollution requires an ability to measure and predict pollutant loading by specific agricultural systems. We measured NO3 and Cl loading to groundwater beneath a Wisconsin central sand plain irrigated vegetable field using both a budget method and a new monitoring-based method. By relying on frequent monitoring of shallow groundwater, the new method overcomes some limitations of other methods. Monitoring-based and budget methods agreed well, and indicated that loading to groundwater was 165 kg ha(-1) NO3-N and 111 kg ha(-1) Cl for sweet corn (Zea mays L.) in 1992, and 228 kg ha(-1) NO3-N and 366 kg ha(-1) Cl for potato (Solanum tuberosum L.) in 1993. Nitrate N loading was 56 to 60% of available N, or 66 to 70% of fertilizer N. Sweet corn NO3 loading was about typical for this region, but potato NO3 loading was probably 50% greater than typical because heavy rains provoked extra fertilizer application. Our results imply that typical NO3-N loading would be 119 kg ha(-1) for sweet corn and 203 kg ha(-1) for potato, even with strict adherence to University Extension fertilizer recommendations. To keep average groundwater NO3-N within the 10 mg L(-1) U.S. drinking water standard, each irrigated vegetable field would need to be offset by five to eight times as much land supplying NO3-free groundwater recharge.     

Collateral geochemical impacts of agricultural nitrogen enrichment from 1963 to 1985: a southern Wisconsin ground water depth profile

In this study, we used chlorofluorocarbon (CFC) age-dating to investigate the geochemistry of N enrichment within a bedrock aquifer depth profile beneath a south central Wisconsin agricultural landscape. Measurement of N(2)O and excess N(2) allowed us to reconstruct the total NO(3)(-) and total nitrogen (TN) leached to ground water and was essential for tracing the separate influences of soil nitrification and ground water denitrification in the collateral geochemical chronology. We identify four geochemical impacts due to a steady ground water N enrichment trajectory (39 +/- 2.2 micromol L(-1) yr(-1), r(2) = 0.96) over two decades (1963-1985) of rapidly escalating N use. First, as a by-product of soil nitrification, N(2)O entered ground water at a stable (r(2) = 0.99) mole ratio of 0.24 +/- 0.007 mole% (N(2)O-N/NO(3)-N). The gathering of excess N(2)O in ground water is a potential concern relative to greenhouse gas emissions and stratospheric ozone depletion after it discharges to surface water. Second, excess N(2) measurements revealed that NO(3)(-) was a prominent, mobile, labile electron acceptor comparable in importance to O(2.) Denitrification transformed 36 +/- 15 mole% (mol mol(-1) x 100) of the total N within the profile to N(2) gas, delaying exceedance of the NO(3)(-) drinking water standard by approximately 6 yr. Third, soil acids produced from nitrification substantially increased the concentrations of major, dolomitic ions (Ca, Mg, HCO(3)(-)) in ground water relative to pre-enrichment conditions. By 1985, concentrations approximately doubled; by 2006, CFC age-date projections suggest concentrations may have tripled. Finally, the nitrification induced mobilization of Ca may have caused a co-release of P from Ca-rich soil surfaces. Dissolved P increased from an approximate background value of 0.02 mg L(-1) in 1963 to 0.07 mg L(-1) in 1985. The CFC age-date projections suggest the concentration could have reached 0.11 mg L(-1) in ground water recharge by 2006. These results highlight an intersection of the N and P cycles potentially important for managing the quality of ground water discharged to surface water.