Research on gender differences in susceptibility to environmental exposures in the workplace must answer a number of questions relating to physiological and hormonal differences, differences in susceptibility and deposition of toxicants, and to metabolic and genetic differences between men and women. These issues will be addressed by other speakers. However, research on environmental exposure and gender susceptibility also requires careful attention to issues of methodology and experimental design. For example, there are no standardized definitions of job titles or job content, making it difficult to compare the actual exposures or outcomes of different groups of workers, male and female. Failure to address these conceptual problems will lead to inaccurate data, misleading findings, and poor policy decisions.
Approximately 20 years ago, General Motors, among other employers, established a so-called ''fetal protection policy" that simply excluded all fertile women from jobs that involved exposure to lead, regardless of the women's intentions with regard to childbearing. Nearly two decades later, the Supreme Court, in a 9-0 decision (UAW v. Johnson Control), ruled that employers could not establish such fetal protection policies, because there was abundant evidence that pregnant women were not the only group of workers vulnerable to the effects of lead. One of the lessons learned from this experience is that research which seeks to explore issues of differential vulnerability to toxins in the workplace should not be narrowly focused on those groups perceived as most vulnerable but should encompass all groups that are "at risk."
When research is carried out on a particular biological process, such as pregnancy, care should be taken to avoid over-extrapolation of the results to broad categories of workers, as this can lead to the development of poor social policy. Conversely, research which is grounded on clear definitions of the limitations to generalizability and on hypotheses that take into account the social and physical realities of the workplace and of employment can provide a sound scientific basis for prevention and control of environmental hazards in the workplace.
A major methodological problem in carrying out such research is that men and women do not encounter the same environmental exposures at work. For the most part, American women remain in "ghettoes of employment." Today there are more women in the workforce, but the traditional employment patterns of women have not changed significantly over the past 50 years (see Figure B-1). Twenty-one percent of all professional women are still engaged in teaching in secondary (i.e., below college-level) education. Women still dominate in