α-Ketophenylacetic Acid, also known as phenylglyoxylic acid (PGA), is a urinary metabolite of styrene, toluene, xylenes, and ethylbenzene.
It acts as a urinary marker of recent exposure via inhalation, contact, oral, and others.
The biologic half-life of styrene in humans is fairly short and corresponds with the disappearance of PGA from the urine. Styrene is widely used for synthesis of polymers such as plastics, rubbers, and surface coating. It is also used in the pharmaceutical industry. Styrene is commonly applied in the manufacturing of paints, pigments, and glues. Coexposure to other solvents, like toluene and ethyl acetate is common in workplaces where styrene is a concern. Since toluene and xylene are components of unleaded gasoline, workers at gas stations are at potential risk of exposure, as well as the general population.
Styrene exposure may interfere with peripheral metabolism of thyroid hormones by inhibiting conversion of T4 to T3.
It may also affect DNA repair capacity and damage. There are also clinical associations with insulin resistance, oxidative stress, and inflammation.
References:
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- Ikeda M, Imamura T, Hayashi M, Tabuchi T, Hara I. Evaluation of hippuric, phenylglyoxylic and mandelic acids in urine as indices of styrene exposure. Int Archiv Arbeitsmedizin. 1974;32(1-2):93-101.
- Wigaeus E, Lof A, Nordqvist MB. Uptake, distribution, metabolism, and elimination of styrene in man. A comparison between single exposure and co-exposure with acetone. Br J Indust Med. 1984;41(4):539-546.
- Eitaki Y, Kawai T, Kishi R, Sakurai H, Ikeda M. Stability in urine of authentic phenylglyoxylic and mandelic acids as urinary markers of occupational exposure to styrene. J Occupat Health. 2008:0804030004-0804030004.
- Szucs S, Toth L, Legoza J, Sarvary A, Adany R. Simultaneous determination of styrene, toluene, and xylene metabolites in urine by gas chromatography/mass spectrometry. Archives of toxicology. 2002;76(10):560-569.
- Santini F, Mantovani A, Cristaudo A, et al. Thyroid function and exposure to styrene. Thyroid. 2008;18(10):1065-1069.
- Wongvijitsuk S, Navasumrit P, Vattanasit U, Parnlob V, Ruchirawat M. Low level occupational exposure to styrene: Its effects on DNA damage and DNA repair. Int J Hyg Environ Health. 2011;214(2):127-137.
- Won YL, Ko Y, Heo K-H, Ko KS, Lee M-Y, Kim K-W. The effects of long-term, low-level exposure to monocyclic aromatic hydrocarbons on worker’s insulin resistance. Safety and health at work. 2011;2(4):365-374.
a-Ketophenylacetic Acid (from Styrene)
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