Reference values of urinary trans,trans-muconic acid: Italian Multicentric Study

Area of Science:

• Environmental Health
• Biomonitoring
• Toxicology

Background:

• Benzene exposure assessment is crucial for public health.
• Urinary trans,trans-muconic acid (t,t-MA) is a biomarker of benzene exposure.
• Establishing reference values for t,t-MA is essential for interpreting exposure levels in the general population.

Purpose of the Study:

• To define reference values for urinary t,t-MA in a general Italian population not occupationally exposed to benzene.
• To investigate the influence of smoking, gender, and geographic location on t,t-MA levels.
• To assess the relationship between personal benzene inhalation exposure and urinary t,t-MA concentrations.

Main Methods:

• A cross-sectional study involving 376 subjects from three Italian regions.
• Urinary t,t-MA concentrations were measured by three laboratories with interlaboratory controls.
• Personal air sampling for benzene inhalation exposure was conducted concurrently with urine sample collection.

Main Results:

• The 5th-95th percentile for urinary t,t-MA was 14.4-225.0 microg/L, with a geometric mean of 52.5 microg/L.
• Smokers exhibited significantly higher geometric mean t,t-MA concentrations (76.1 microg/L) than non-smokers (44.8 microg/L).
• In non-smokers, females showed higher t,t-MA levels (44.7 microg/g creatinine) than males (36.7 microg/g creatinine) after creatinine correction.

Conclusions:

• Reference values for urinary t,t-MA in the Italian general population were established.
• Tobacco smoking is a major determinant of t,t-MA levels, overshadowing low-level benzene exposure.
• Gender influences t,t-MA excretion in non-smokers, highlighting the complexity of biomonitoring benzene exposure.