The [15N]methacetin liver function test characterizes multicomponent exposure of children in industrially polluted regions.

The [15N]methacetin urine test for assessing disturbances of the cytochrome P450-aided oxygenation of xenobiotics in the human liver has been approved in several environmental health studies. A recent longitudinal study of kindergarten children near chemical and mining companies undergoing fundamental restructuring showed high, seasonally fluctuating SO2 burden which was well correlated with alterations in the mean liver states of the children. At one point the correlation disappeared, together with indications of large amounts of chlorinated compounds overflowing locally at nighttime. This was finally proven by analyzing urine samples from the children for trichloroacetic acid (TCA). Chlorinated ethanes and ethenes-the precursors of TCA-seemed to dominate the air pollution and to affect the hepatic detoxification capacity. We concluded that the methacetin liver function test reflects multicomponent exposure, including acute monopolization by a dominant pollutant for a time.