Perfluorooctane sulfonate increases β-oxidation of palmitic acid in chicken liver

Purpose

Perfluorooctane sulfonate (PFOS) belongs to a group of chemicals called perfluoroalkyl acids that have been extensively used in various applications such as stain and oil resistant treatments for fabrics, fire-fighting foams, and insecticides. These chemicals present an environmental and health risk being present in many samples both in wildlife and humans. In this study, we investigate the effect of PFOS on fatty acid ??-oxidation in developing chicken embryos.

Methods

Fertilized chicken eggs were exposed in ovo to PFOS at day?4 of incubation. On day?10, the eggs were dissected and livers were incubated in vitro with ³H-palmitic acid for 2?h. The media were collected, and after clean up, the amount of tritiated water was measured with liquid scintillation counting to determine the rate of palmitic acid ??-oxidation.

Results

PFOS was found to induce fatty acid ??-oxidation at doses starting from a lowest observed effect level (LOEL) of 0.1???g/g egg weight. Maximum induction of 77?% compared to control was seen at 0.3???g/g.

Conclusions

The administered doses in which effects are seen are around and even lower than the levels that can be found in wild populations of birds. General population human levels are a factor of two to three times lower than the LOEL value of this study. The environmental contamination of PFOS therefore presents a possibility of effects in wild populations of birds.     

Groundwater in the Limpopo Basin: occurrence,use and impact

The Limpopo River Basin is underlain by an alluvial aquifer along the main river stem and fractured water-bearing units in tributary catchments. Notwithstanding that development priorities in parts of the basin in South Africa have historically preferred surface water sources for irrigation and domestic supply, water resources auditing suggests that groundwater presents the only viable alternative source of cost-effective supply to meet future requirements. However, while aquifer yields are favourable in places, averaging 16.7 l/s for main-stem alluvium, groundwater is already extensively used. Between 1995 and 2002, total groundwater use in the area rose by almost 40%, increasing from 98 to 136 million m³ per year. In all catchments, groundwater use grew by varying proportions, reaching a rather high 200% in the Mogalakwena catchment. In the particular case of commercial irrigation, over-exploitation of groundwater has been recorded in a number of places, especially in the northwest where drawdowns of more than 50 m have resulted from decades of intense agricultural water use. Although groundwater use for mining is still low at 4% of total usage in the study area, the region is currently witnessing a surge in mining operations, and a significant growth in water requirements is envisaged for mining development. Further, domestic water supply to the predominantly rural dwellers in the area is relatively low, even in terms of meeting the basic need of 25 l/day per person, underscoring the fact that groundwater will remain a critical source of community drinking water in the foreseeable future. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Sources and pathways of Sr in the North Atlantic–Arctic region: present day and global warming

The spatial and temporal distributions of the anthropogenic radionuclides ¹³⁷Cs and ⁹⁰Sr, originating from nuclear bomb testing, the Sellafield reprocessing plant in the Irish Sea (UK), and from the Ob and Yenisey river discharges to the Arctic Ocean, have been simulated using the global version of the Miami Isopycnic Coordinate Ocean Model (MICOM). The physical model is forced with daily atmospheric re-analysis fields for the period of 1948–1999. Comparison of the temporal evolution of the observed and the simulated concentrations of ⁹⁰Sr has been performed in the Kara Sea. The relative contributions of the different sources on the temporal and spatial distributions of the surface ⁹⁰Sr are quantified over the simulated period. It follows that the Ob river discharge dominated the surface ⁹⁰Sr over most of the Arctic Ocean and along the eastern and western coasts of Greenland before 1960. During the period of 1980–1990, the atmospheric fallout and the Ob river discharge were equally important for the ⁹⁰Sr distribution in the Arctic Ocean. Furthermore, an attempt has been made to explore the possible dispersion of accidental released ⁹⁰Sr from the Ob and Yenisey rivers under a global warming scenario (2 × CO₂). The difference between the present-day and the global warming scenario runs indicates that more of the released ⁹⁰Sr from the Ob and Yenisey rivers is confined to the Arctic Ocean in the global warming run, particularly in the near coastal, non-European part of the Arctic Ocean.     

Assessment of Bilateral Thoracic Loading on the Near-Side Occupant Due to Occupant-to-Occupant Interaction in Vehicle Crash Tests

Objective: This study aims, by means of the WorldSID 50th percentile male, to evaluate thoracic loading and injury risk to the near-side occupant due to occupant-to-occupant interaction in combination with loading from an intruding structure.

Method: Nine vehicle crash tests were performed with a 50th percentile WorldSID male dummy in the near-side (adjacent to the intruding structure) seat and a THOR or ES2 dummy in the far-side (opposite the intruding structure) seat. The near-side seated WorldSID was equipped with 6 + 6 IR-Traccs (LH and RH) in the thorax/abdomen enabling measurement of bilateral deflection. To differentiate deflection caused by the intrusion, and the deflection caused by the neighboring occupant, time history curves were analyzed. The crash tests were performed with different modern vehicles, equipped with thorax side airbags and inflatable curtains, ranging from a compact car to a large sedan, and in different loading conditions such as car-to-car, barrier, and pole tests. Lateral delta V based on vehicle tunnel acceleration and maximum residual intrusion at occupant position were used as a measurement of crash severity to compare injury measurements.

Result: In the 9 vehicle crash tests, thoracic loading, induced by the intruding structure as well as from the far-side occupant, varied due to the size and structural performance of the car as well as the severity of the crash. Peak deflection on the thoracic outboard side occurred during the first 50 ms of the event. Between 70 to 150 ms loading induced by the neighboring occupant occurred and resulted in an inboard-side peak deflection and viscous criterion. In the tests where the target vehicle lateral delta V was below 30 km/h and intrusion less than 200 mm, deflections were low on both the outboard (20–40 mm) and inboard side (10–15 mm). At higher crash severities, delta V 35 km/h and above as well as intrusions larger than 350 mm, the inboard deflections (caused by interaction to the far-side occupant) were of the same magnitude or even higher (30–70 mm) than the outboard deflections (30–50 mm).

Conclusion: A WorldSID 50th percentile male equipped with bilateral IR-Traccs can detect loading to the thorax from a neighboring occupant making injury risk assessment feasible for this type of loading. At crash severities resulting in a delta V above 35 km/h and intrusions larger than 350 mm, both the inboard deflection and VC resulted in high risks of Abbreviated Injury Scale (AIS) 3+ injury, especially for a senior occupant.     

Bioremoval of PVP-coated silver nanoparticles using Aspergillus niger: the role of exopolysaccharides

Environmental Science and Pollution Research - Extensive use of engineered nanoparticles has led to their eventual release in the environment. The present work aims to study the removal of...     

Air contaminants in a submarine equipped with air independent propulsion

The Swedish Navy has operated submarines equipped with air independent propulsion for two decades. This type of submarine can stay submerged for periods far longer than other non-nuclear submarines are capable of. The air quality during longer periods of submersion has so far not been thoroughly investigated. This study presents results for a number of air quality parameters obtained during more than one week of continuous submerged operation. The measured parameters are pressure, temperature, relative humidity, oxygen, carbon dioxide, hydrogen, formaldehyde and other volatile organic compounds, ozone, nitrogen dioxide, particulate matter and microbiological contaminants. The measurements of airborne particles demonstrate that air pollutants typically occur at a low baseline level due to high air exchange rates and efficient air-cleaning devices. However, short-lived peaks with comparatively high concentrations occur, several of the sources for these have been identified. The concentrations of the pollutants measured in this study do not indicate a build-up of hazardous compounds during eight days of submersion. It is reasonable to assume that a substantial build-up of the investigated contaminants is not likely if the submersion period is prolonged several times, which is the case for modern submarines equipped with air independent propulsion.     

The effect of dynamic scheduling and routing in a solid waste management system

Solid waste collection and hauling account for the greater part of the total cost in modern solid waste management systems. In a recent initiative, 3300 Swedish recycling containers have been fitted with level sensors and wireless communication equipment, thereby giving waste collection operators access to real-time information on the status of each container. In this study, analytical modeling and discrete-event simulation have been used to evaluate different scheduling and routing policies utilizing the real-time data. In addition to the general models developed, an empirical simulation study has been performed on the downtown recycling station system in Malmoe, Sweden. From the study, it can be concluded that dynamic scheduling and routing policies exist that have lower operating costs, shorter collection and hauling distances, and reduced labor hours compared to the static policy with fixed routes and pre-determined pick-up frequencies employed by many waste collection operators today. The results of the analytical model and the simulation models are coherent, and consistent with experiences of the waste collection operators.