OBJECTIVE To investigate the possible impact of long-term occupational exposure to hydrocarbons on respiratory health. METHODS Respiratory health was assessed by questionnaires, spirometry, and exhaled nitric oxide in 250 male workers from a company handling and distributing refined petroleum products (exposed) and 250 electricians (controls). Exposure to hydrocarbons was assessed by personal...

Air pollution in the Los Angeles area is Characterized by a decrease in visibility, crop damage, eye irritation, objectionable odor, and rubber deterioration. These effects are attributed to the release of large quantities of hydrocarbons and nitrogen oxides to the atmosphere. The photochemical action of nitrogen oxides oxidizes the hydrocarbons and thereby forms ozone, responsible for rubber c...

While briefly reviewing how the concepts of strictly pericondensed, strain-free, Clar's aromatic sextet, and symmetry are interconnected in the topological correspondence between strictly pericondensed and total resonant sextet (TRS) benzenoid hydrocarbons, new structural correlations in isomer numbers, symmetry distributions, and empty rings between various strain-free TRS benzenoids made up o...

Seven crude oil samples recovered from wells of El Hamd and Bakr oil Fields locates in Egyptian central Gulf of Suez were subjected for Description, bulk composition of Maltene Fraction and hydrocarbons distribution. The Comparison of collected crude oils was achieved using Bulk parameters and Specific parameters, the first ones refer to properties of the whole sample such as API gravity, sulfu...

Altan derivatives of polycyclic conjugated hydrocarbons were recently introduced and studied in theoretical organic chemistry. We now provide a generalization of the altan concept, applicable to any graph. Several earlier noticed topological properties of altan derivatives of polycyclic conjugated hydrocarbons are shown to be the properties of all altan derivatives of all graphs. Among these ar...

The present paper provides results of a study on heterotrophic bacteria occurrence and quantity in the biofilm and subsurface water of lake Jeziorak Maty. Degradation of several polycyclic aromatic hydrocarbons (PAH's) (anthracene, naphthalene) by neustonic and planktonic bacteria have been examined. It has been discovered that some aromatic hydrocarbons were better decomposed by neustonic bact...

Exhaust gases from an internal combustion engine, alternatively powered by gasoline or by liquefied petroleum gas, were analysed for polynuclear aromatic hydrocarbons. The engine operated a lift truck for the handling of warehouse goods. A combined condensation-filtration apparatus was constructed for sampling of the exhausts. The basic steps of the analytical procedure are summarized here. Sev...