Human reproductive endocrine effects of controlled toluene exposure.
Faustman-EM; Luderer-U; Kalman-D; Morgan-MS; Brodkin-CA
NIOSH 2000 Jan; :1-6
Despite previous observations of adverse reproductive effects of toluene, including alterations of serum gonadotropins (luteinizing hormone, LH, and folliclestimulating honnone, FSH) in men, little is known regarding the mechanism of toxicity. We tested the hypothesis that toluene acutely suppresses pulsatile gonadotropin secretion by measuring LH and FSH at frequent intervals during controlled exposure to toluene. Women in the follicular and luteal phases of the menstrual cycle and men were randomized to inhale filtered air with or without 50 ppm toluene by mouthpiece for 3 hours (19% of the OSHA Pennissable Exposure Limit). Blood sampling by intravenous catheter was done at 20 min intervals for 3 h before, 3 h during and 3 h after exposure. Plasma LH, FSH, and testosterone were measured. LH and FSH pulse amplitude, pulse frequency, and mean concentrations for each of the 3 h periods before, during and after toluene versus sham exposure were calculated using the ULTRA pulse detection program and compared by analysis of variance with repeated measures. In men a significant interaction (p<0.05) between exposure and sampling period on LH mean levels was observed, with a greater LH decline during toluene than sham exposure. However, there was no concomitant effect on testosterone levels. In luteal phase women a trend towards a statistically significant interaction between exposure and sampling period (p=0.06) on LH pulse frequency occurred, with a greater decline in pulse frequency during toluene than sham exposure. There were no other significant effects of toluene exposure. Three hour exposure to 50 ppm toluene did not result in abnonnal episodic LH or FSH secretion profiles, however, subtle effects on LH secretion in men and luteal phase women were observed. The clinical significance of the observed effects is unclear, underscoring the need for further study of reproductive function in exposed workers.
Endocrine-system-disorders; Reproductive-effects; Reproductive-system-disorders; Hormone-activity; Hormones; Toluenes; Humans; Exposure-levels; Exposure-methods; Blood-sampling; Toxicology
University of Washington, Department of Environmental Health, Seattle, W A 98105
Final Grant Report
Disease and Injury: Fertility and Pregnancy Abnormalities
National Institute for Occupational Safety and Health
University of Washington, Department of Environmental Health, Seattle, Washington