Our project initiated from dealing with toxic chemicals found in second-hand smoke (or environmental tobacco smoke, ETS) and cooking fume. After carefully examining the composition of pollutes, we noticed that there was one group of highly toxic and carcinogenic compounds, polycyclic aromatic hydrocarbons (PAHs). The toxicity of PAHs is difficult to handle, and many scientists are doing intensive research on this issue.

PAHs are notorious for its harm to both environment and human health. PAHs commonly appear in people’s daily life, from second-hand smoke to cooking fume. Also, PAHs can be generated in a large amount by incomplete combustion of carbon-containing fuels. (Li et al. 2003, Zhang et al. 2013) PAHs may dissolve in air, diffuse in water, or precipitate in soil, causing large-scale, wide-spread pollution. (Samanta, Singh, and Jain 2002).Furthermore, most of the PAHs is recorded to be carcinogenic, mutagenic, or teratogenic. (Li et al. 2003, Gauggel-Lewandowski et al. 2013) For example, the first and foremost study of carcinogenicity of benzo[a]pyrene (BAP), a compound belongs to PAHs family, dates back to the observation that chimney sweepers developed scrotum cancer easier than others in 18th century. (Boffetta, Jourenkova, and Gustavsson 1997)

With the power of synthetic biology, we aimed to develop a method using E. coli to degrade PAHs into other non-toxic chemicals.