Setting occupational health standards: toxicokinetic differences among and between men and women

Differences between and among men, nonpregnant women, and pregnant women can influence exposure and response to workplace toxicants. These differences should be delineated, compared, and used when setting regulatory standards to protect workers from potentially hazardous workplace environments. Anatomical and physiological parameters include: body composition; surface area; blood, organ, and tissue volume; metabolism; and cardiovascular, pulmonary, gastrointestinal, and renal structure and function. Although men differ among themselves, on average, they also differ from women by weighing more, being taller, and having a larger surface area. Total body water is 40% greater in men than nonpregnant women; however, during pregnancy, body water increases from 29 to 33 liters. Extracellular and intracellular water volumes are smallest in nonpregnant women, increase with pregnancy, but remain smaller than those in men. Pulmonary function differs; pregnant women have the largest minute volume and greatest volume of air exchanged in an 8-hour period. This article compares anatomical, physiological, and toxicokinetic characteristics of men and nonpregnant and pregnant women to explore how differences in these factors contribute to variations in exposures, target tissue doses, and responses to workplace or environmental chemicals.