Butyltins in shellfish, finfish, water and sediment from the Coos Bay estuary (Oregon, USA)

Butyltin was measured in tissue, water and sediment samples collected throughout Coos Bay estuary between 1986 and 1997. Butyltin-induced shell deformation in commercial oysters prompted this assessment. Butyltins are released from tributyltin oxide (TBTO)-containing boat paint. Clams from three sites contained tributyltin (TBT) levels ranging from 168 to 457 microg/kg in 1992-1994. Consequently, Oregon Health Division (OHD) issued a shellfish consumption advisory in 1995; it was rescinded in 1997 after US Environmental Protection Agency (EPA) revised the TBTO oral reference dose (RfD). The revised RfD changed the tissue screening level from 112 to 1120 microg TBT/kg. Fifty percent of sediment samples collected during 1991-1997 and analyzed for total butyltins (TotBT) exceeded the Puget Sound Dredge Disposal Analysis Screening Level (PSDDA SL) of 73 microg TBT/kg dw. TotBT at three shipyards selected for site assessment by EPA ranged from 24 to 68,613 microg/kg dw. Sediment and tissue butyltins have been decreasing in all but one area of the estuary.     

珠三角地区大气中HCFC-22的浓度观测和变化趋势初步研究

通过罐采样和预浓缩-色谱/质谱方法,对珠三角地区广州城区和鼎湖山大气中HCFC-22进行了初步的观测和分析.结果表明,2005年广州城区HCFC-22年平均体积分数达到(479.5±241.4)×10-12,鼎湖山仅为(244.4±51.3)×10-12.广州城区大气HCFC-22日变化幅度夏秋季节相对较大,而鼎湖山日变化不明显;广州城区大气HCFC-22的体积分数夏秋季节高于冬春季节,鼎湖山则相反.与城区HCFC-22排放的季节性有关,夏秋季节广州城区与鼎湖山HCFC-22体积分数差别很大,冬春季节则比较接近.初步研究结果表明,广州城区和鼎湖山大气HCFC-22的体积分数呈现快速增长趋势,年增长率分别达到6.57%和7.28%,约为一些全球基准观测站(NOAA/CMDL)的1.9～2.8倍.     

Atmospheric composition change – global and regional air quality

Air quality transcends all scales with in the atmosphere from the local to the global with handovers and feedbacks at each scale interaction. Air quality has manifold effects on health, ecosystems, heritage and climate. In this review the state of scientific understanding in relation to global and regional air quality is outlined. The review discusses air quality, in terms of emissions, processing and transport of trace gases and aerosols. New insights into the characterization of both natural and anthropogenic emissions are reviewed looking at both natural (e.g. dust and lightning) as well as plant emissions. Trends in anthropogenic emissions both by region and globally are discussed as well as biomass burning emissions. In terms of chemical processing the major air quality elements of ozone, non-methane hydrocarbons, nitrogen oxides and aerosols are covered. A number of topics are presented as a way of integrating the process view into the atmospheric context; these include the atmospheric oxidation efficiency, halogen and HO_x chemistry, nighttime chemistry, tropical chemistry, heat waves, megacities, biomass burning and the regional hot spot of the Mediterranean. New findings with respect to the transport of pollutants across the scales are discussed, in particular the move to quantify the impact of long-range transport on regional air quality. Gaps and research questions that remain intractable are identified. The review concludes with a focus of research and policy questions for the coming decade. In particular, the policy challenges for concerted air quality and climate change policy (co-benefit) are discussed.     

Functional gene expression of oil-degrading bacteria resistant to hexadecane toxicity

Contamination with oil poses a threat to the environment and to human health worldwide. Biological methodologies have proved to be economical, versatile and efficient for the remediation of pollutants. In this paper, a highly efficient oil-degrading bacterial strain USTB-2 was isolated from an oil production well of Dagang oil field in Tianjin, China. The 16S rRNA sequence of USTB-2 showed 100% similarity with that of Bacillus subtilis BSn5. Hexadecane is one of the most important components in petroleum. The half inhibitory ratio (IC₅₀) of hexadecane inhibited organisms, determined by microcalorimetry, was lower in USTB-2 than in B. BSn5. The results indicate that the strain USTB-2 degrades hexadecane to make it less toxic compared with the normal strain. RT-PCR was used to evaluate the expression of oil-degrading enzymes, specifically 4-hydroxyphenylacetate 3-monooxygenase genes (HPMO). A sharp increase in the expression of HPMO genes was observed for USTB-2, while the expression of HPMO genes in reference strain B. BSn5 remained relatively stable. These methods can be used to study the metabolic potential of microorganisms for in situ oil decontamination.     

Effects of HMX exposure upon metabolic rate of northern bobwhite quail (Colinus virginianus) in ovo

We evaluated the use of the gas exchange rate as an ecologically relevant indicator of chemical stress in avian embryos/eggs. Northern bobwhite quail (Colinus virginianus) were exposed to octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) via feed containing nominal concentrations of 0, 12.5, 50.0, and 125.0 mg kg(-1). Metabolic rates (oxygen consumption) of developing quail eggs were then measured via respirometry to examine potential effects of HMX exposure. Metabolic rates were examined on 5, 9, and 21 d of incubation. Next, concentrations of HMX in embryos/eggs were determined by liquid chromatography-mass spectrometry. Mean (+/-SE) concentrations of HMX in eggs were 21.0+/-5.9, 1113+/-79.0, 3864+/-154.0, and 7426+/-301.1 ng g(-1) in control, low, medium and high dose groups, respectively. There were significant differences in oxygen consumption among the three embryo ages, however differences among the ages were not consistent among dose groups (age x dose group interaction p<0.0001). Oxygen consumption rates did not vary as a function of HMX in embryos (p=0.18). No evidence was observed for alterations of in ovo metabolic rates associated with HMX exposure.     

Fatal crash between a car operating with automated control systems and a tractor-semitrailer truck

Abstract

Objective: The objective of this investigation was to evaluate the interaction between an SAE level 2 automated vehicle and the driver, including the limitations imposed by the vehicle on the driver.

Methods: A case study of the first fatal crash involving a vehicle operating with an automated control system was performed using scene evidence, vehicle damage, and recorded data available from the vehicle, and information from both drivers, including experience, phone records, computer systems, and medical information, was reviewed.

Results: System performance data downloaded from the car indicated that the driver was operating it using the Traffic-Aware Cruise Control and Autosteer lane-keeping systems, which are automated vehicle control systems within Tesla’s Autopilot suite. As the car crested the hill, a tractor trailer began its left turn onto a crossing roadway. Although reconstruction of the crash determined that there was sufficient sight distance for both drivers to see each other and take action, neither responded to the circumstances leading to the collision. Further, based on the speeds of the vehicles and simulations of the truck’s path, the car driver had at least 10.4?s to detect the truck and take evasive action. Neither the car driver nor the Autopilot system changed the vehicle’s velocity.

?At the time of the crash, the system performance data indicated that the last driver interaction with the system was 1?min 51?s prior when the cruise control speed was set to 74?mph. The driver was operating the vehicle using the Autopilot system for 37 of the 41?min in the last trip. During this period, the vehicle detected the driver’s hands on the steering wheel for a total of 25?s; each time his hands were detected on the wheel was preceded by a visual alert or auditory warning.

Conclusions: The National Transportation Safety Board (NTSB) determined that the probable cause of the Williston, Florida, crash was the truck driver’s failure to yield the right of way to the car, combined with the car driver’s inattention due to overreliance on vehicle automation, which resulted in the car driver’s lack of reaction to the presence of the truck. Contributing to the car driver’s overreliance on the vehicle automation was the car’s operational design, which permitted the driver’s prolonged disengagement from the driving task and his use of the automation in ways inconsistent with guidance and warnings from the manufacturer.     

Genomic instability in human osteoblast cells after exposure to depleted uranium: delayed lethality and micronuclei formation

It is known that radiation can induce a transmissible persistent destabilization of the genome. We have established an in vitro cellular model using HOS cells to investigate whether genomic instability plays a role in depleted uranium (DU)-induced effects. Transmissible genomic instability, manifested in the progeny of cells exposed to ionizing radiation, has been characterized by de novo chromosomal aberrations, gene mutations, and an enhanced death rate. Cell lethality and micronuclei formation were measured at various times after exposure to DU, Ni, or gamma radiation. Following a prompt, concentration-dependent acute response for both endpoints, there was de novo genomic instability in progeny cells. Delayed reproductive death was observed for many generations (36 days, 30 population doublings) following exposure to DU, Ni, or gamma radiation. While DU stimulated delayed production of micronuclei up to 36 days after exposure, levels in cells exposed to gamma-radiation or Ni returned to normal after 12 days. There was also a persistent increase in micronuclei in all clones isolated from cells that had been exposed to nontoxic concentrations of DU. While clones isolated from gamma-irradiated cells (at doses equitoxic to metal exposure) generally demonstrated an increase in micronuclei, most clonal progeny of Ni-exposed cells did not. These studies demonstrate that DU exposure in vitro results in genomic instability manifested as delayed reproductive death and micronuclei formation.     

Impact caps: why population,affluence and technology strategies should be abandoned

This paper classifies strategies to reduce environmental impact according to the terms of the I = PAT formula. Policies limiting resource depletion and pollution (Impact) – by heavily taxing resources or rationing them on a country basis – are thus called ‘direct’ or ‘left-side’ strategies. Other policies to achieve the environmental goal of lowering Impact strive to limit Population and Affluence, or to use Technology to lower the ratio of resource inputs to goods-and-services outputs. Next it is shown that lowering any of these ‘right-side’ factors causes or at least enables the other two to rise or ‘rebound’. This has two consequences: 1) Since I = PAT does not express these interdependencies on the right side, it is more accurately written I = f(P,A,T); and 2) Success in lowering any of the right-side factors does not necessarily lower Impact. Rationing or Pigouvian taxation of resources or pollution, on the other hand, necessarily lower impact and are therefore preferable to population, consumption and technological environmental strategies. Finally, lifestyle and technology changes towards more sufficiency and efficiency would follow the caps as consumers and producers work to retain the greatest amount of welfare within the limits given.