Linking empirical estimates of body burden of environmental chemicals and wellness using NHANES data

Biomonitoring of industrial chemicals in human tissues and fluids has shown that all people carry a “body burden” of synthetic chemicals. Although measurement of an environmental chemical in a person's tissues/fluids is an indication of exposure, it does not necessarily mean the exposure concentration is sufficient to cause an adverse effect. Since humans are exposed to multiple chemicals, there may be a combination effect (e.g., additive, synergistic) associated with low-level exposures to multiple classes of contaminants, which may impact a variety of organ systems. The objective of this research is to link measures of body burden of environmental chemicals and a “holistic” measure of wellness. The approach is demonstrated using biomonitoring data from the National Health and Nutrition Examination Surveys (NHANES). Forty-two chemicals were selected for analysis based on their detection levels. Six biological pathway-specific indices were evaluated using groups of chemicals associated with each pathway. Five of the six pathways were negatively associated with wellness. Three non-zero interaction terms were detected which may provide empirical evidence of crosstalk across pathways. The approach identified five of the 42 chemicals from a variety of classes (metals, pesticides, furans, polycyclic aromatic hydrocarbons) as accounting for 71% of the weight linking body burden to wellness. Significant interactions were detected indicating the effect of smoking is exacerbated by body burden of environmental chemicals. Use of a holistic index on both sides of the exposure-health equation is a novel and promising empirical “systems biology” approach to risk evaluation of complex environmental exposures.     

Below-ground carbon allocation in mature beech and spruce trees following long-term, experimentally enhanced O3 exposure in Southern Germany

Canopies of adult European beech (Fagus sylvatica) and Norway spruce (Picea abies) were labeled with CO₂ depleted in ¹³C to evaluate carbon allocation belowground. One-half the trees were exposed to elevated O₃ for 6 yrs prior to and during the experiment. Soil-gas sampling wells were placed at 8 and 15 cm and soil CO₂ was sampled during labeling in mid-late August, 2006. In beech, δ¹³CO₂ at both depths decreased approximately 50 h after labeling, reflecting rapid translocation of fixed C to roots and release through respiration. In spruce, label was detected in fine-root tissue, but there was no evidence of label in δ¹³CO₂. The results show that C fixed in the canopy rapidly reaches respiratory pools in beech roots, and suggest that spruce may allocate very little of recently-fixed carbon into root respiration during late summer. A change in carbon allocation belowground due to long-term O₃ exposure was not observed.     

Comparison and Verification of Bacterial Water Quality Indicator Measurement Methods Using Ambient Coastal Water Samples

During the summers of 2002 and 2004, in-stream integrated flow and concentration measurements for the total dissolved solids in the Cheyenne River, South Dakota, USA was conducted in order to compare the obtained actual field measurements with the predictions values made by the Bureau of Reclamation in the Environmental Impact Statement. In comparison to the actual field measurements conducted in this study, The Bureau of Reclamation extension of a small database used in the analysis for the impact of operations at the Angostura Unit over the past 50 years and into the future to predict the annual total dissolved solid loadings doesn't represent the actual loading values and various conditions in the study area. Additional integrated flow and concentration sampling is required to characterize the impact of the current Angostura Dam operations and Angostura Irrigation District return flows on the Cheyenne River in different seasons of the year.     

Human–forest relationships: ancient values in modern perspectives

The relationship between human beings and forests has been important for the development of society. It is based on various productive, ecological, social and cultural functions of forests. The cultural functions, including the spiritual and symbolic role of forests, are often not addressed with the same attention as the other functions. The aim of this paper is to put a stronger emphasis on the fact that the acknowledgement of cultural bonds is needed in the discussion of sustainable development. Forest should not only be considered as a technical means to solve environmental and economic problems. To achieve a deeper understanding of the dependency of society on forests, it is necessary to recognise the role of forests in our consciousness of being human. Giving a historical overview about the cultural bonds between people and forests, the first part of the paper puts focus on non-productive aspects in human–forest relationships. Through history, forest values have changed and new functions have emerged. Industrialisation and urbanisation have contributed to an alienation from nature and weakened the connection of humans to forests. The consequences of these changes for the development of society and its environment are discussed in the second part of the paper. Finally, it is elaborated how the awareness of the cultural bonds can be strengthened in the population and especially in forest management; a management which should relate to cultural, emotional and aesthetical aspects, in addition to economic, ecological and social functions, and lead towards a sustainable relationship between forests and society.     

Octanol/water partition coefficients for environmentally important organic compounds

Partition coefficients P_O,w ⁽ⁱ⁾ describing the distribution of a solute i onto coexisting phases of 1-octanol and water are needed in a large variety of applications. They can be measured directly by HPLC as long as log P_O,w ⁽ⁱ⁾≧ 3.5. For more hydrophobic substances, several experimental procedures have been proposed in the literature. The reliability of those methods is questionable. Therefore, in the present work, P_O,w ⁽ⁱ⁾ is determined experimentally by three HPLC methods using reversed-phase HPLC [1]. Results from different procedures are compared critically. The method of Braumann [2] proved to be superior over the OECD-guidelines [3]. It was therefore applied to determine octanol/water partition coefficients for 23 substances at 25 °C. For eight of those substances (4-methylindole; 9-(hydroxymethyl)anthracene; N-ethylcarbazol; ethylcyclohexane; trans-2-octene; l,l-dimethyl-(ethy])cyclohexane; heptylbenzene; 4-dodecyl-l,3-benzenediol) no experimentally determined number for P_O,w ⁽ⁱ⁾ has been published before.