Benzene is the simplest aromatic hydrocarbon that is represented with the formula C6H6. It was discovered in 1825 by a British scientist, Michael Faraday, who extracted it from crude oil by applying pressure, and named it “Bicarburet of hydrogen”. However, its chemical synthesis did not start until in 1843, Charles Mansfield, discovered a method to extract benzene from coal tar.
Since its industrialization, benzene is produced and used in many industrial processes. Today, plastics, resins, dyes, implies the generation of benzene as intermediate. Also, chemical synthesis of phenol, cyclohexane, ethylbenzene and other aromatic hydrocarbons generates benzene as part of their production. In 1989, the Environmental Protection Agency of USA estimates …show more content…
Forest fires, volcanos, petroleum leakage, and emissions from vegetation constitute natural sources of emissions of benzene in the air (Lagorio et al. 1994). Human activities such as tobacco smoking, car garages and service stations, car exhaust, and industrial emissions represent the major sources. In the USA, daily air median concentration of 0.47 ppb have been reported in rural areas, while in urban/suburban areas 1.8 ppb (ATSDR 2007).
According to CAREX Canada, the primary source of exposure to benzene is the indoor air. Benzene is released by multiple indoor sources such as glues, paints, furniture wax, and household products. In Addition, indoor combustion emissions such as gas furnaces, car starting in attached garage, fireplaces, and cigarettes smoking contribute to elevated the level of benzene indoors (Héroux et al. 2010). Measurements of benzene air concentration in Regina, Canada, reported a range from 1.2 to 5.4 μg/m3, commented that higher values may be were due to the presence of attached garage or recent furniture renovation (Héroux et al. 2010). Cigarette smoking accounts as an important contributor to indoor benzene levels. Brunnemann et al, reported a concentration of benzene from 345 to 653 μg/cigarette in the sidestream smoke and ranged from 5.9 to 73 μg/cigarette in the mainstream smoke(Brunnemann et al. …show more content…
In their study, they exposed an NQO1-deficient (NQO1−/−) mice and a wild-type NQO1 (NQO1+/+; 129/Sv background strain) of both genders to an increased concentration (0, 10, 50, 100, 200 p.p.m) of inhaled benzene for 14 days. Genotoxicity was assessed by micronucleated peripheral blood cell quantification and DNA damage by p21 mRNA levels in bone marrow. P21 is a cyclin-dependent kinase inhibitor that can lead to cell cycle arrest, when DNA is damaged, p53 activation transcribes many genes, including p21. Bone marrow p21 RNA level is a determinant of DNA insult. At 100 p.p.m of inhaled benzene, a > 10-fold increase was noted in male mice of both genotypes compared with an unexposed mouse.
Since its industrialization, benzene is produced and used in many industrial processes. Today, plastics, resins, dyes, implies the generation of benzene as intermediate. Also, chemical synthesis of phenol, cyclohexane, ethylbenzene and other aromatic hydrocarbons generates benzene as part of their production. In 1989, the Environmental Protection Agency of USA estimates …show more content…
Forest fires, volcanos, petroleum leakage, and emissions from vegetation constitute natural sources of emissions of benzene in the air (Lagorio et al. 1994). Human activities such as tobacco smoking, car garages and service stations, car exhaust, and industrial emissions represent the major sources. In the USA, daily air median concentration of 0.47 ppb have been reported in rural areas, while in urban/suburban areas 1.8 ppb (ATSDR 2007).
According to CAREX Canada, the primary source of exposure to benzene is the indoor air. Benzene is released by multiple indoor sources such as glues, paints, furniture wax, and household products. In Addition, indoor combustion emissions such as gas furnaces, car starting in attached garage, fireplaces, and cigarettes smoking contribute to elevated the level of benzene indoors (Héroux et al. 2010). Measurements of benzene air concentration in Regina, Canada, reported a range from 1.2 to 5.4 μg/m3, commented that higher values may be were due to the presence of attached garage or recent furniture renovation (Héroux et al. 2010). Cigarette smoking accounts as an important contributor to indoor benzene levels. Brunnemann et al, reported a concentration of benzene from 345 to 653 μg/cigarette in the sidestream smoke and ranged from 5.9 to 73 μg/cigarette in the mainstream smoke(Brunnemann et al. …show more content…
In their study, they exposed an NQO1-deficient (NQO1−/−) mice and a wild-type NQO1 (NQO1+/+; 129/Sv background strain) of both genders to an increased concentration (0, 10, 50, 100, 200 p.p.m) of inhaled benzene for 14 days. Genotoxicity was assessed by micronucleated peripheral blood cell quantification and DNA damage by p21 mRNA levels in bone marrow. P21 is a cyclin-dependent kinase inhibitor that can lead to cell cycle arrest, when DNA is damaged, p53 activation transcribes many genes, including p21. Bone marrow p21 RNA level is a determinant of DNA insult. At 100 p.p.m of inhaled benzene, a > 10-fold increase was noted in male mice of both genotypes compared with an unexposed mouse.