Abstract-The multimedia equilibrium criterion model, which can be used to evaluate the environmental fate of a variety of chemicals, is described. The model treats chemicals that fall into three categories. In the first the chemicals may partition into all environmental media, in the second they are involatile, and in the third they are insoluble in water. The structure of the model, the process equations, and the required input data for each chemical type are described. By undertaking a sequence of level I, II, and III calculations, increasing information is obtained about the chemical's partitioning, its susceptibility to transformation and transport, and the environmental process and the chemical characteristics that most influence chemical fate. Output data, consisting of tables and charts, give a complete picture of the chemical's fate in an evaluative or generic environment. The model is illustrated by applying it to two chemicals, pyrene, which is a chemical of the first type, and lead, which is of a second type. The role of this model as a tool for assessing the fate of new and existing chemicals is discussed.

The multimedia equilibrium criterion model, which can be used to evaluate the environmental fate of a variety of chemicals, is described. The model treats chemicals that fall into three categories. In the first the chemicals may partition into all environmental media, in the second they are involatile, and in the third they are insoluble in water. The structure of the model, the process equations, and the required input data for each chemical type are described. By undertaking a sequence of level I, II, and III calculations, increasing information is obtained about the chemical's partitioning, its susceptibility to transformation and transport, and the environmental process and the chemical characteristics that most influence chemical fate. Output data, consisting of tables and charts, give a complete picture of the chemical's fate in an evaluative or generic environment. The model is illustrated by applying it to two chemicals, pyrene, which is a chemical of the first type, and lead, which is of a second type. The role of this model as a tool for assessing the fate of new and existing chemicals is discussed.

Abstract-A five-stage process is described for obtaining an understanding of the fate of a substance after discharge to the environment and for predicting the concentrations to which organisms in various environmental media will be exposed. These five stages are: classifying the substance as to its chemical type and collecting the appropriate physical, chemical, and reactivity data based on this classification; obtaining information on the substance's past, present, and/or proposed production, use, and discharges and, if appropriate, background concentrations; conducting an evaluative fate assessment with the objective of determining the general features of the substance's behavior; conducting a regional or far-field fate evaluation using regional climatic and geographic conditions, to determine the role of environmental conditions on the substance's behavior and estimate average regional concentrations; and conducting one or more local or near-field evaluations on points of entry and other potentially impacted sites to predict the exposure concentration. With this information on fate, risk can be assessed by comparing predicted environmental concentrations with no-effect concentrations. This paper contains a detailed discussion of stage 1 (classification into one of five categories) and a discussion of how multimedia models can be used to conduct the evaluative (stage 3), regional (stage 4), and near-field (stage 5) assessments.

Abstract-Evaluation of chemical fate in the environment has been suggested to be best accomplished using a five-stage process in which a sequence of increasing site-specific multimedia mass balance models is applied. This approach is illustrated for chlorobenzene and linear alkylbenzene sulfonates (LAS). The first two stages involve classifying the chemical and quantifying the emissions into each environmental compartment. In the third stage, the characteristics of the chemical are determined using the evaluative equilibrium criterion model, which is capable of treating a variety of chemicals including those that are involatile and insoluble in water. This evaluation is conducted in three steps using levels I, II, and III versions of the model, which introduce increasing complexity and more realistic representations of the environment. In the fourth stage, ChemCAN, which is a level III model for specific regions of Canada, is used to predict the chemical's fate in southern Ontario. The final stage is to apply local environmental models to predict environmental exposure concentrations. For chlorobenzene, the local model was the SoilFug model, which predicts the fate of agrochemicals, and for LAS the WW-TREAT, GRiDS, and ROUT models were used to predict the fate of LAS in a sewage treatment plant and in riverine receiving waters. It is concluded that this systematic approach provides a comprehensive assessment of chemical fate, revealing the broad characteristics of chemical behavior and quantifying the likely local and regional exposure levels.

Solving mobile manipulation tasks in inaccessible and dangerous environments is an important application of robots to support humans. Example domains are construction and maintenance of manned and unmanned stations on the moon and other planets. Suitable platforms require flexible and robust hardware, a locomotion approach that allows for navigating a wide variety of terrains, dexterous manipulation capabilities, and respective user interfaces. We present the CENTAURO system which has been designed for these requirements and consists of the Centauro robot and a set of advanced operator interfaces with complementary strength enabling the system to solve a wide range of realistic mobile manipulation tasks. The robot possesses a centaur-like body plan and is driven by torquecontrolled compliant actuators. Four articulated legs ending in steerable wheels allow for omnidirectional driving as well as for making steps. An anthropomorphic upper body with two arms ending in five-finger hands enables human-like manipulation. The robot perceives its environment through a suite of multimodal sensors. The resulting platform complexity goes beyond the complexity of most known systems which puts the focus on a suitable operator interface. An operator can control the robot through a telepresence suit, which allows for flexibly solving a large variety of mobile manipulation tasks. Locomotion and manipulation functionalities on different levels of autonomy support the operation. The proposed user interfaces enable solving a wide variety of tasks without previous task-specific training. The integrated system is evaluated in numerous teleoperated experiments that are described along with lessons learned. 3D laser scanner Cameras RGB-D sensor 7 DoF arm 9 DoF dexterous hand 1 DoF soft hand 5 DoF leg 360°steerable wheel Base with CPUs, router and battery Figure 1: The Centauro robot. IntroductionCapable mobile manipulation robots are desperately needed in environments which are inaccessible or dangerous for humans. Missions include construction and maintenance of manned and unmanned stations, as well as exploration of unknown environments on the moon and other planets. Furthermore, such systems can be employed in search and rescue missions on earth. It applies to all these missions that human deployment is impossible or dangerous, and depends on extensive logistical and financial effort.To address the wide range of possible tasks, a suitable platform needs to provide a wide range of capabilities. Regarding locomotion, exemplary tasks are to overcome a variety of obstacles which can occur on planetary surfaces and in man-made environments, e.g., in space stations. Regarding manipulation, tasks may be to use power tools, to physically connect and disconnect objects such as electrical plugs, or to scan surfaces, e.g., for radiation. Since maintenance is not possible during missions, a high hardware and software reliability is necessary. Furthermore, suitable operator interfaces are key to enable the control of a system that must solve suc...