Toxicity polynuclear aromatic hydrocarbons

Outside of carbon monoxide for which the toxicity is already well-known, five types of organic chemical compounds capable of being emitted by vehicles will be the focus of our particular attention these are benzene, 1-3 butadiene, formaldehyde, acetaldehyde and polynuclear aromatic hydrocarbons, PNA, taken as a whole. Among the latter, two, like benzo [a] pyrene, are viewed as carcinogens. Benzene is considered here not as a motor fuel component emitted by evaporation, but because of its presence in exhaust gas (see Figure 5.25). 

Methanol use would also reduce pubHc exposure to toxic hydrocarbons associated with gasoline and diesel fuel, including ben2ene, 1,3-butadiene, diesel particulates, and polynuclear aromatic hydrocarbons. Although pubHc formaldehyde exposures might increase from methanol use in garages and tunnels, methanol use is expected to reduce overall pubHc exposure to toxic air contaminants. 

Hallett, D.J., Brecher, R.W. (1984) Cycling of polynuclear aromatic hydrocarbons in the Great Lakes ecosystem. In Toxic Contaminants in the Great Lakes. Advances in Environment Sciences and Technology. Nriagu, J.O., Simmons, M.S., Editors, John Wiley Sons, New York, New York. pp. 213-237. 

Warshawsky, D., T. Cody, M. Radike, B.A. Smiddy, and B. Nagel. 1983. Toxicity and metabolism of benzo[a]pyrene in the green alga Selenastrum capricomutum. Pages 1235-1245 in M. Cooke and A.J. Dennis.(eds.). Polynuclear Aromatic Hydrocarbons Formation, Metabolism and Measurement. Battelle Press, Columbus, OH. 

Among the polynuclear aromatic hydrocarbons, the toxicity of petroleum is a function of its di- and triaromatic hydrocarbon content. Like the single aromatic... 

There are indications that pure naphthalene (a constituent of mothballs, which are, by definition, toxic to moths) and alkylnaphthalenes are from three to 10 times more toxic to test animals than are benzene and alkylbenzenes. In addition, and because of the low water solubility of tricyclic and polycyclic (polynuclear) aromatic hydrocarbons (i.e., those aromatic hydrocarbons heavier than naphthalene), these compounds are generally present at very low concentrations in the water-soluble fraction of oil. Therefore, the results of this smdy and others conclude that the soluble aromatics of crude oil (such as benzene, toluene, ethylbenzene, xylenes, and naphthalenes) produce the majority of its toxic effects in the enviromnent. 

Rossi. S.S. and Neff. J.M. Toxicity of polynuclear aromatic hydrocarbons to the polychaete Neanthes arenaceodentata. Mar. Pollut. Bull, 9 220-223. 1978. 

Beltran, FJ., Gonzales, M., and Rivas, F.J., Advanced oxidation of polynuclear aromatic hydrocarbons in natural waters, ]. Environ. Sci. Health A Environ. Sci. Eng. Toxic. Hazardous Substance Contr., A31, 2193-2210, 1996. 

Similarly, many xenobiotics, such as pesticides, polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), plasticizers, phenols, and some other dmg residues, are also toxic even at trace levels present in the earth s ecosystem [5-7], Without analytical techniques capable of detecting them at nanolevels, we assume the absence of these pollutants in the environment, while these notorious pollutants accumulate in our body tissues resulting in various diseases and side effects such as carcinogenesis and failure of many vital body organs including the kidney, liver, and heart [8-11]. Under such situations, it is essential to have analytical techniques that can detect dmgs, pharmaceuticals, and xenobiotics in biological and environmental samples at very low concentrations. 

Organics, especially polynuclear aromatic hydrocarbons, were measured at a number of facilities. Dioxin and furan formation are also of concern because of their toxic nature. 

Schwarz RC, Schults DW, Ozretich RW, Lamberson JO, Cole FA, DeWitt TH, Redmond MS, Ferraro SP. 1995. Sigma PAH a model to predict the toxicity of polynuclear aromatic hydrocarbon mixtures in field-collected sediments. Environ Toxicol Chem 14 1977-1978. 

Capillary electrophoresis has been used for the analysis of chiral pollutants, e.g., pesticides, polynuclear-aromatic hydrocarbons, amines, carbonyl compounds, surfactants, dyes, and other toxic compounds. Moreover, CE has also been utilized to separate the structural isomers of various... 

During the last decade, CE has been increasingly used for the determination of environmental pollutants. Some of the methods of pre-treatment of waste environmental samples have been carried out prior to the injection into the CE system, as discussed above. CE has been applied for the determination of inorganic and organic pollutants. The major inorganic pollutants include metal ions and anions. On the other hand, the most common toxic organic environmental pollutants analysed by CE are phenols, pesticides, polynuclear aromatic hydrocarbons,... 

Crude oil contains many chemicals considered toxic and the effects of these individual chemicals should be evaluated if exposure is possible. These chemicals are aromatic solvents including benzene, aliphatic chemicals including hexane, and naphthenic chemicals including the polynuclear aromatic hydrocarbons. 

As discussed in previous sections, there are numerous factors that can modify the toxicity of materials. The prediction of the toxicity of mixtures is also difficult. One of the best attempts at toxicity prediction has been formulated by Swartz et al. (1995) and predicts the sediment toxicity of polynuclear aromatic hydrocarbons. The model is based on the concentration of 13 PAHs in collected sediments, the predicted concentration in the sediment pore water, and the toxicity of these concentrations as determined by a large toxicity data set. 

Most of the research on xenobiotic receptors has been conducted in mammalian systems. These studies have identified three families of proteins as having important roles in regulating the response to xenobiotic chemicals (Table 1). The aryl hydrocarbon receptor (AHR), a member of the basic helix-loop-helix Per-ARNT-Sim (bHLH-PAS) family of transcription factors, is well known for its role in the altered gene expression and toxicity elicited by chlorinated dioxins and related planar halogenated aromatic hydrocarbons (PHAHs) as well as certain polynuclear aromatic hydrocarbons (PAHs)114 188 244. Several members of the nuclear/steroid... 

The polynuclear aromatic hydrocarbons (PAH) are an important family of aromatic hydrocarbons that generally have toxic effects. They have also been shown to be carcinogenic, that is, they cause cancer. PAH are formed from the joining of the rings so that they share a common bond (edge). Three common examples are shown ... 

Belkin, S., Stieber, M., Tiehm, A., Frimmel, F.R, Abeliovich, A., Warner, P., and Ulitzur, S., Toxicity and Genotoxicity Enhancement During Polynuclear Aromatic Hydrocarbon Biodegradation , Toxicity Assessment Symposium, 1993, Berlin, Germany. 

Polycyclic organic matter, derived from the total exhaust emission, is an extremely complex mixture. It includes a large number of compounds such as polynuclear aromatic hydrocarbons (PAH), derivations of PAH such as nitro-PAH and amino-PAH, oxygenated PAH such as phenols and quinones, and heterocyclic aromatic compounds containing sulfur and oxygen. In order to assist in the identification of classes of toxic compounds it is possible to fractionate the exhaust emissions into vapor and... 

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