Objectives: The impact of occupational hazards on erythrocyte and hemoglobin levels and menstrual cycle characteristics in women exposed to aromatic hydrocarbons was studied. The investigated cohort consisted of 110 women exposed to benzene, toluene, xylene and styrene while working in the transport and storage of petrochemical products (TSPP), the laboratory for the control of aromatic hydrocarbons (LCAH), and rubber and latex (RL) production at the biggest petrochemical plant in Bulgaria, Neftochim. Controls consisted of 45 women from the administrative personnel in the same plant.
Methods: Questionnaires were administrated to all participants to obtain self-reported demographic data, data on characteristics of the menstrual cycle, and psychosomatic symptoms. Erythrocyte counts (RBC) and hemoglobin (HGB) levels were determined by the semiautomatic hematology analyzer Serono System 190, USA. All subjects had signed an informed consent.
Results: The mean RBC counts and HGB levels of the women from the LCAH and TSPP departments were statistically significantly lower than those of the control group. We found statistically significant differences in all exposed groups in comparison with controls when the dose-response relationship was investigated. No statistically significant differences were found in menstrual cycle characteristics (duration of the menstrual cycle, days and quantity of bleeding) between the subjects exposed and the controls in all age groups investigated, but the numbers were too small to allow definite conclusions.
Conclusions: The lowering of HGB levels and RBC counts in the investigated women were mainly due to the direct influence of aromatic hydrocarbons in the working environment on hematopoiesis. The studied group was too small to enable us to determine the impact of aromatic hydrocarbons on menstrual cycle characteristics, and the possible combination of these effects.