Aliphatic hydrocarbons accumulation

Peroxides. These are formed by aerial oxidation or by autoxidation of a wide range of organic compounds, including diethyl ether, allyl ethyl ether, allyl phenyl ether, dibenzyl ether, benzyl butyl ether, n-butyl ether, iso-butyl ether, r-butyl ether, dioxane, tetrahydrofuran, olefins, and aromatic and saturated aliphatic hydrocarbons. They accumulate during distillation and can detonate violently on evaporation or distillation when their concentration becomes high. If peroxides are likely to be present materials should be tested for peroxides before distillation (for tests see entry under "Ethers", in Chapter 2). Also, distillation should be discontinued when at least one quarter of the residue is left in the distilling flask. 

Oil accumulation in the lungs after long-term or high-level exposure to aerosols of polyalphaolefin may be a concern, based on observations of lipoid pneumonia in humans after prolonged intranasal application of mineral oil mists (Lushbaugh 1950) and the physical and chemical similarities between mineral oil and polyalphaolefins (i.e., both are composed predominately of aliphatic hydrocarbons). 

Second, some organisms are able to incorporate longer pendent chains yielding another class of PHA medium chain length PHA, poly(HAMCL). Poly (HAmcl) is specifically accumulated by fluorescent pseudomonads. When aliphatic hydrocarbons like n-alkane, n-alkanoate, or n-alkanol serve as feedstocks for Pseudomonas oleovorans the resulting PHA is a random copolymer... 

The solubility parameter or cohesive force of an individual solvent is believed to result from its inner molecular forces of attraction. Individual molecular forces characterize and dominate certain molecular regions of the structure. For instance dispersion (or London) forces result from the association between the electron systems of two adjacent molecules and the arrangement of the electrons. These forces are not affected by temperature, they operate within a short distance, they are accumulative, and they are general They reside in all molecules and represent the total attractive force known in saturated aliphatic hydrocarbons. 

Long-chain and branched hydrocarbons that are primary components of JP-8, include -nonanc, -dccanc, -dodccanc, -tridecane, isopropylbenzene, -propylbcnzcnc, trirnethylbenzene, -dimcthylbenzene, naphthalene, n-pentylbenzene, and -tricthylbcnzcnc. Inhaled long-chain aliphatic hydrocarbons generally show poor blood uptake because of lower blood solubility. They have relatively high lipid blood partition coefficients this can result in accumulation in lipid-rich tissues, such as brain and fat. In laboratory studies, brain concentrations of hydrocarbons and their metabolites greatly exceed their plasma concentrations. 

Discrimination between hydrocarbons occurs during uptake. Blumer et al. (1970) found that among various species of copepods, Rhincalanus was the only species to accumulate n-C2i 6. Boutry et al. (1977) showed that the uptake of hydrocarbons by the diatom Chaetoceros calcitrans simplex was irregular and depended upon the age of the cultures and the composition of the medium. Bioaccumulation has been invoqued by Murray et al. (1977) to explain the enrichment of long-chain aliphatic hydrocarbons in mixed plankton. 

Fuel oils may be absorbed through the respiratory tract, the gastrointestinal tract and percutaneously. The higher the molecular weight of the hydrocarbons in the oils, the less likely that absorption will occur. Metabolism via oxidation is also likely to occur since the components of fuel oils are hydrocarbons. The degree of metabolism would, of course, be dependent on the nature of the hydrocarbon (i.e., aliphatic, aromatic, etc.), the molecular weight and any other associated molecule (e.g., sulfur, nitrogen). Excretion from the body would also be dependent on the above and could occur via exhalation, in the urine or feces. These molecules are not likely to accumulate in the body. 

Bomhard E, Marsmann M, Ruhl-Fehlert C, et al. 1990. Relationships between structure and induction of hyaline droplet accumulation in the renal- cortex of male-rats by aliphatic and alicyclic hydrocarbons. Arch Toxicol 64 530-538. 

Reproductive disorders in humans are known to be caused by more than 100 different individual chemicals and are suspected to be caused by some 200 more. Table 23.1 lists some of these compounds and their Kqw values. W As can be seen from this table, many different types of chemicals containing far different functional groups cause reproductive disorders. These include aliphatic and aromatic hydrocarbons, glycol ethers, chlorinated hydrocarbons, pesticides, and heavy metals. Both lipophilic and hydrophilic compounds are contained in the list. Some of the chemicals are rapidly metabolized, whereas others accumulate in adipose tissue and are stored in the body for long periods of time. The mechanisms by which many of these chemicals act remain unknown. 

Petroleum-derived hydrocarbons and their metabolites (e.g., fatty acids), especially those in the aliphatic and aromatic EC>16-EC35 fractions, tend to accumulate in the liver, spleen, and adipose tissues. There are no known clinical methods to facilitate or accelerate removal of petroleum hydrocarbons or their metabolites from these tissues. 

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