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Các hợp chất hữu cơ dễ bay hơi (VOC) là những hợp chất hữu cơ với một loạt boilingpoint từ 50-100 240-260 ° C (WHO) .1 Chúng bao gồm một số lượng lớn các chất ô nhiễm không khí lớn phát ra từ các cơ sở công nghiệp và nonindustrial. Hóa học, chất VOC bao gồm cả béo và hydrocarbon thơm, các dẫn xuất halogen hydrocarbon, một số rượu, este, và aldehyde. Bảng 11.1 cho thấy một số ví dụ của nhóm các hợp chất này. Tầm quan trọng của hợp chất VOC như là một lớp không khí ô. | CHAPTER 11 Volatile Organic Compounds 11.1 INTRODUCTION Volatile organic compounds VOCs are those organic compounds with a boilingpoint range from 50-100 to 240-260 C WHO .1 They are composed of a large number of major air pollutants emitted from both industrial and nonindustrial facilities. Chemically VOCs include both aliphatic and aromatic hydrocarbons halogenated hydrocarbons some alcohols esters and aldehydes. Table 11.1 shows several examples of this group of compounds. The importance of VOCs as a class of air pollutants is clear. The U.S. Environmental Protection Agency has designated them as one of the six Criteria Air Pollutants. In this chapter we will discuss the sources characteristics and health effects of some VOCs. 11.2 SOURCES Both natural and anthropogenic sources contribute to VOC emissions. Natural sources of VOCs include petroleum forest fires and the transformation of biogenic precursors. Main anthropogenic sources include high-temperature combustion of fuels emissions from crude and refined oil municipal incineration burning of crops before or after harvesting as an agricultural practice emissions from power boats and others. A recent survey by the EPA showed indoor pollution as an important source of VOCs. More than 500 VOCs were detected most only once in a survey involving 10 buildings. The study showed that a variety of VOCs originated from common items such as building materials cleaning solvents furnishings and pesticides. Since indoor concentrations for all compounds except benzene exceeded outdoor levels it was concluded that indoor sources contributed to the observed results. The importance of indoor VOC pollution in health has been recognized in World Health Organization publications.1 139 2001 by CRC Press LLC 140 ENVIRONMENTAL TOXICOLOGY Table 11.1 Examples of Volatile Organic Compounds Group Examples Aliphatics Pentane hexane heptane cyclohexane octane nonane eicosane dodecane 2 4-dimethylhexane Aromatic hydrocarbons Benzene .
