**5. Methods for detection of DNA damage**

DNA damage associated with PAH exposure is mainly assessed by measuring the number of adducts formed. Several methods, such as 32P-postlabelling or immunochemical analysis with specific antibodies, have been applied extensively. However, the arrival of new molecular techniques and innovations in previously well-established biochemical methods, have increased the possibility of the early detection of DNA damage. Polymorphisms and gene expression analysis are helping to determine susceptibility of individuals and populations. Use of mass spectrometry and high performance liquid chromatography (HPLC) with increased sensitivity is another common tool to evaluate and quantify adduct formation. A brief description of the available methods to detect DNA damage is listed in Table 2.

On the other hand, some studies have proposed using molecules included in natural compounds to reduce DNA damage induced by PAHs (Chan, et al., 2003). Green tea consumption may reduce the risk of lung cancer by several hypothesized mechanisms including scavenging oxidative radicals (Bonner, et al., 2005). In previous studies, the role of green tea polyphenols has been associated with protective effects against tumor induction in mice to which PAHs were topically applied (Wang, et al., 1989). Resveratrol (Leung, et al., 2009) and Genistain (Leung, et al., 2009) reduced DNA oxidative damage and adduct formation induced by 7,12-dimethylbenz[*a*]anthracene in MCF-10A cells.


Table 2. Methods to detect DNA damage caused by PAH exposure.

These studies offer novel alternatives for the prevention of further DNA damage caused by PAH exposure. Additionally, mechanisms of damage and repair are revealed through understanding the interactions and pathways involved when these molecules come into contact.

Both methods of detection and prevention of DNA damage are candidates for becoming new molecular alternatives for therapy and diagnosis of PAH-exposed individuals, and new tools in environmental biomonitoring.
