Biomonitoring Summary

Polycyclic Aromatic Hydrocarbons Overview


CAS No. 86-73-7

Fluorene can be an intermediate in several chemical processes, and it is used to form polyradicals for resins and in manufacturing dyestuffs. Fluorene is frequently detected in the vapor phase of various PAH emission sources, including coal tar pitch, petroleum refineries, diesel exhaust fumes, and tobacco smoke, where it is the second most abundant PAH (Ding et al., 2005). Fluorene is present in air particulates resulting from vehicle emissions and combustion of coal and petroleum-based fuels (Fang et al., 2006). IARC determined that fluorene was not classifiable with respect to human carcinogenicity.

Biomonitoring Information

Urinary levels of 2-hydroxyfluorene, 3-hydroxyfluorene, and 9-hydroxyfluorene reflect recent exposure. Mean levels of 2-hydroxyfluorene were significantly higher in Japanese smokers than non-smokers in one small study (Toriba et al., 2003).By comparison, geometric mean and median urinary 2-hydroxyfluorene levels in adults in NHANES 2003-2004 and 2005-2006 were similar to the mean levels in the smokers and somewhat higher than those in the non-smokers.

Finding a measurable amount of one or more urinary fluorene metabolites does not imply that the level causes an adverse health effect. Biomonitoring studies of urinary fluorene metabolites can provide physicians and public health officials with reference values so that they can determine whether or not people have been exposed to higher levels of fluorene than levels found in the general population. Biomonitoring data can also help scientists plan and conduct research on exposure and health effects.


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Page last reviewed: April 7, 2017