The oesophagus or food pipe is part of the digestive system. It is also sometimes called the gullet. It is the tube that carries food from your mouth to your stomach. It is about 26cm (10.5 inches) long in adults.
Benzo[a]pyrene is a polycyclic aromatic hydrocarbon found in coal tar with the formula C 20 H 12. Its metabolites are mutagenic and highly carcinogenic, and it is listed as a Group 1 carcinogen by the IARC.The compound is one of the benzopyrenes, formed by a benzene ring fused to pyrene, and is the result of incomplete combustion at temperatures between 300 Â°C (572 Â°F) and 600 Â°C (1,112 Â°F).roperly speaking, benzo[ a ]pyrene is a procarcinogen, meaning that the mechanism of carcinogenesis of benzo[ a ]pyrene depends on enzymatic metabolism of benzo[ a ]pyrene to the ultimate mutagen, benzo[ a ]pyrene diol epoxide, pictured above at right.
p-Xylene (para-xylene) is an aromatic hydrocarbon. It is one of the three isomers of dimethylbenzene known collectively as xylenes. The p-stands for para-, indicating that the two methyl groups in p-xylene occupy the diametrically opposite substituent positions 1 and 4.