ASSOCIATION OF PETROCHEMICAL EXPOSURE WITH SPONTANEOUS-ABORTION

Objectives-To assess the association between petrochemical exposure an d spontaneous abortion, a retrospective epidemiological study in a lar ge petrochemical complex in Beijing, China was conducted. Methods-Plan t employment records identified 3105 women who were married, were 20-4 4 years of age, and had never smoked. Of those, 3070 women (98.8%) rep orted at least one pregnancy. From this group, 2853 (93%) of the women participated in the study. According to their plant employment record , about 57% of these women workers reported occupational exposure to p etrochemicals during the first trimester of their pregnancy. Trained i nterviewers administered a standardised questionnaire to this group of women and their husbands, collecting information on :reproductive his tory, pregnancy outcomes, employment history, occupational exposure, s moking habits, alcohol consumption, indoor air pollution, and demograp hic variables. The results from the womens' first pregnancies were ana lysed. Results-There was a significantly increased risk of spontaneous abortion for women working in all of the production plants with frequ ent exposure to petrochemicals (8.8%; range of 5.8%-9.8%) compared wit h those working in nonchemical plants (2.2%; range of 0.0%-7.1%). Also , when a comparison was made between exposed and non-exposed groups wi thin each plant, exposure to petrochemicals was consistently associate d with an increased risk of spontaneous abortion. The overall odds rat io (OR) was 2.7 (95% confidence interval (95% CI) 1.8 to 3.9) after ad justing for potential confounders. When the analysis was performed wit h the exposure information obtained from the women' interview response s for (self reported) exposures, the estimated OR for spontaneous abor tions was 2.9 (95% CI 2.0 to 4.0). The analysis was repeated by exclud ing those 452 women who provided inconsistent reports between recalled exposure and work history, and a comparable risk of spontaneous abort ion (OR 2.9; 95% CI 2.0 to 4.4) was found. In analyses for exposure to specific chemicals, an increased risk of spontaneous abortion was fou nd with exposure to most chemicals, and the results for benzene (OR 2. 5; 95% CI 1.7 to 3.7), gasoline (OR 1.8; 95% CI 1.1 to 2.9), and hydro gen sulphide (OR 2.3; 95% CI 1.2 to 4.4) were significant. Conclusion- An increased risk of spontaneous abortion was found associated with th e exposure to petrochemicals, including benzene, gasoline, and hydroge n sulphide.