Contaminated media

Multimedia Analysis In order to properly design and then implement a pohution prevention program, sources of all wastes must be fuhy understood and evaluated. A multimedia analysis involves a multifaceted approach. It must not only consider one waste stream but all potentially contaminant media (e.g., air, water, land). Past... 

Chemical treatment is a class of processes in which specific chemicals are added to wastes or to contaminated media in order to achieve detoxification. Depending on the nature of the contaminants, the chemical processes required will include pH adjustment, lysis, oxidation, reduction or a combination of these. Thus, chemical treatment is used to effect a chemical transformation of the waste to an innocuous or less toxic form. In addition, chemical treatment is often used to prepare for or facilitate the treatment of wastes by other technologies. Figure 12 identifies specific treatment processes which perform these functions. 

All feed streams are sterilised before being metered into the fermentation vessel. Contaminants resistant to the antibiotic rarely find their way into the fermenter. When they find a way to contaminate media, their effects are so catastrophic that prevention is of paramount importance. A resistant, (3-lactamase producing, fast-growing bacterial contaminant can destroy the penicillin.5 The contaminants not only consume nutrients intended for the fungus, but also cause loss of pH control and interference with the subsequent extraction process. 

The sizes of these populations and the concentrations of methyl parathion in all of the contaminated media to which these people would potentially be exposed have not been adequately characterized. 

Overview. Humans living in areas surrounding hazardous waste sites may be exposed to endosulfan primarily via dermal contact with or ingestion of contaminated soils since this compound is found bound to soil particles. Although endosulfan can be found in water as colloidal suspensions adsorbed to particles, ingestion of contaminated finished drinking water is not expected to be a major route of exposure since endosulfan is not very water soluble. Likewise, inhalation exposure to endosulfan via volatilization from contaminated media is not a major route of exposure since endosulfan is not very... 

Reliable monitoring data for the levels of endosulfan in contaminated media at hazardous waste sites are needed. This information could be used in combinahon with the known body burdens of endosulfan to assess the potential risk of adverse health effects in populations living in the vicinity of hazardous waste sites. 

U.S. EPA proposed to significantly impact the RCRA hazardous waste identification process through a rulemaking effort called the Hazardous Waste Identification Rules (H WIR). The first rule, HWIR-media, was finalized on November 30,1998, and addressed contaminated media.16 The second rule, HWIR-waste, was finalized on May 16, 2001, and modified the mixture and derived-from rules, as well as the contained-in policy for listed wastes.5 Both the HWIR-media rule and the HWIR-waste rule attempt to increase flexibility in the hazardous waste identification system by providing a regulatory mechanism for certain hazardous wastes with low concentrations of hazardous constituents to exit the RCRA Subtitle C universe. 

The sources of contamination are usually those hazardous materials that are contained in drums, tanks, surface impoundments, waste piles, and landfills, as well as heavily contaminated media (such as soil) affected by the original leaking or spilling source. The purpose of defining sources of contamination is to help to identify the source location, potential releases, and engineering characteristics that are important in the evaluation of remedial actions, as well as waste characteristics, such as the type and quantity of contaminants that may be contained in or released to the environment, and the physical or chemical characteristics of the hazardous wastes present in the source. 

Further definition of each alternative, if necessary, with respect to the volumes or areas of contaminated media to be addressed, the technologies to be used, and any performance requirements associated with those technologies... 

Exposure Levels in Environmental Media. Reliable monitoring data for the levels of di- -octylphthalate in contaminated media at hazardous waste sites are needed so that the information obtained on levels of di-ra-octylphthalate in the environment can be used in combination with the known body burden of di-w-octylphthalate to assess the potential risk of adverse health effects in populations living in the vicinity of hazardous waste sites. Di-u-octylphthalate has been detected in ambient air, rain, surface water, groundwater, and sediment. However, as a result of the confusion about the nomenclature for octylphthalate esters, much of the historical monitoring data available actually pertain to the branched isomer, di(2-ethylhexyl)phthalate (Vista Chemical 1992). Therefore, little current information specific to the /1-octyl isomer is available regarding concentrations of the compound in foods, drinking water, and environmental media, particularly with respect to media at hazardous waste sites. The lack of monitoring data precludes the estimation of human exposure via intake of or contact with contaminated media. 

Members of the general population with potentially high exposure to 1,2- dibromoethane include individuals living near the nine NPL sites currently known to be contaminated with the compound. The size of the population and the concentrations of 1,2-dibromoethane in all of the contaminated media to which these people are potentially exposed have not been completely characterized. Other populations with potentially high exposures to 1,2-dibromoethane include individuals in the six states with confirmed groundwater contamination, and workers involved in the manufacture and continued use of 1,2-dibromoethane. 

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