Releases of xylene occur primarily from industrial sources, automobile exhaust, and from the use of xylene as a solvent. Hazardous waste disposal sites and spills of xylene into the environment also serve as possible sources of exposure. Xylene is sometimes released into water and soil as a result of the use, storage, and transport of petroleum products. Levels of xylene in public drinking water supplies range from 0 to 750 ppb. Because xylene evaporates rapidly, the presence of xylene in upper layers of soil is probably not large.
Little information exists about the amount of xylene in food.
Levels ranging between 0.05 ppm and 0.12 ppm xylene have been found in fish. You may also come in contact with xylene from a variety of consumer products, including cigarette smoke, gasoline, paint, varnish, shellac, and rust preventives. Breathing vapors from these types of products can expose you to xylene. Indoor levels of xylene can be higher than outdoor levels, especially in buildings with poor ventilation. Skin contact with products containing xylene, such as solvents, lacquers, paint thinners and removers, and pesticides may also expose you to xylene.