Common environmental contaminants

Di- and mono-esters of phthalic acid, an ortho-dicarboxylic acid derivative of benzene. These compounds are widely used as industrial plasticizers to coat polyvinylchloride surfaces of plastics used in food packaging and medical devices (iv drip bags, blood storage bags, etc.) and are common environmental contaminants. Several phthalate mono-esters are peroxisome proliferator chemicals and can activate the peroxisome proliferator-activated receptor PPAR. 

This PAH is a common environmental contaminant. However, it is inactive as a carcinogen in animal tests (50. The trans-1,2-di-hydrodiol of triphenylene has been synthesized from phenanthrene by a route analogous to that employed for the preparation of BeP 9,10-dihydrodiol (48). Like the latter compound, epoxidation with per-acid affords a mixture of the anti and syn diol epoxides (Figure 9) (48,50). 

Benzo(b)-, benzo(k)-, and benzo(j)fluoranthene are common environmental contaminants (38). The tumor-initiating activity of benzo-(b)fluoranthene on mouse skin is about equal to that of DBA (38). All three isomers are mutagenic in the Ames assay (110). Syntheses of the 1,2-, 9,10-, and 11,12-dihydrodiols of benzo(b)fluoranthene by Method I have been reported (111,112). 

Interaction effects of arsenic with other carcinogens, cocarcinogens, promoting agents, inhibitors, and common environmental contaminants... 

We begin with a discussion of the most common minerals present in Earth s crust, soils, and troposphere, as well as some less common minerals that contain common environmental contaminants. Following this is (1) a discussion of the nature of environmentally important solid surfaces before and after reaction with aqueous solutions, including their charging behavior as a function of solution pH (2) the nature of the electrical double layer and how it is altered by changes in the type of solid present and the ionic strength and pH of the solution in contact with the solid and (3) dissolution, precipitation, and sorption processes relevant to environmental interfacial chemistry. We finish with a discussion of some of the factors affecting chemical reactivity at mineral/aqueous solution interfaces. 

Examples of less common minerals that contain common environmental contaminants and their relative solubilities or ease of removal of adsorbed species. 

To better understand the structure and the inner workings of an environmental laboratory, we need to familiarize ourselves with laboratory functional groups and their responsibilities. Figure 4.2 shows an example of a typical full service environmental laboratory organization chart. A full service laboratory has the capabilities to perform analysis for common environmental contaminants, such as VOCs and SVOCs (including petroleum fuels and their constituents, pesticides, herbicides, and PCBs), trace elements (metals), and general chemistry parameters. Analysis of dioxins/furans, explosives, radiochemistry parameters, and analysis of contaminants in air are not considered routine, and are performed at specialized laboratories. 

Jansson et al. [52] developed a low resolution method for PCA analyses, based on GC/ECNI-MS in the selected ion mode (SIM). In this method, PCAs were selectively removed from other common environmental contaminants by GPC, and quantification was performed by integrating the response of the Clj (m/z 70) ion, an ion that predominates in the mass spectra of individual PCA congeners at high ion source temperatures [54]. 

TPH has been identified in 34 of the 1,519 current or former EPA National Priorities List (NPL) hazardous waste sites (ATSDR 1998a). Components of TPH are common environmental contaminants in all media and are likely contaminants at many NPL sites. However, the number of sites evaluated for TPH and TPH components is not known. The frequency of the TPH reported sites within the United States can be seen in Ligure 5-1. 

Phthalates are common environmental contaminants that frequently contaminate laboratory glassware, sampling equipment, and solvents used to extract di- -butyl phthalate from various media for analysis (Staples et al. 1997). As a result, it is difficult to make accurate measurements at low levels (<10 ppb). Care must be taken to preclude environmental and other samples from contamination with di-n-butyl phthalate. 

The versatility of the P450 oxygenases is summarized in Figure 9.3. Epoxides can be introduced into aromatic rings or across double bonds. The former reaction leads to a hydroxy or dihydodiol. It is most unlikely to observe aldrin in environmental samples since it is rapidly converted to dieldrin, a common environmental contaminant that is very stable. Aliphatic chains can be hydroxylated and ethers, thioethers, and substituted amines dealkylated. The conversion of parathion to the more reactive paraoxon is a factor in the mechanism of toxic action, as well as its environmental stability (see Hydrolysis, Chapter 8). The situation can be complicated by the fact that a substrate can often undergo more than one reaction. 

Challenge Microorganisms. The antimicrobial spectrum of activity of the test products must be broad, versus 25 ATCC strains of 20 species of bacteria and 2 species of yeasts listed in 333.470(a)(l)(ii) of the TFM, plus 25 fresh clinical isolates of these same species of bacteria and yeasts. The challenge microorganisms include members of normal flora in humans, common environmental contaminants, or systemic pathogens. 

This section contains a summary of the application of IRMS for the analysis of a range of petroleum products, which are common environmental contaminants and also encountered in forensic fire debris examination... 

A further complication is that the specific toxicity of a trace element may vary widely for different species of organisms. Thus it is virtually impossible to compare, in any meaningful way, the global effect of large-scale dispersal of an element like zinc, which is a relatively non-toxic and common environmental contaminant, with the effect of dispersal of beryllium, a highly toxic element in limited use. 

Bowen [2] (pp. 19-20) has summarised published data for the concentrations of most trace elements in sea water (Goldberg, 1963 [382], Goldberg, 1965 [383], Turekian, 1965 [38A]), the levels mined annually (Day, 1963, [385]) and the amounts added to the ocean each year calculated on the basis of analysis of river water. These data are given in Table 39, for trace elements which are common environmental contaminants. 

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