Formaldehyde-Associated Immunologic Responses among Exposed Nigerian Health Professionals

Abstract

Immunologic involvements have been reported over the years in association with formaldehyde exposure both in humans and animal models. This study was aimed at investigating immunologic responses among health professionals with occupational exposure to formaldehyde in Calabar, Nigeria. Eighty eight male and female subjects comprising anatomists, medical laboratory attendants, medical laboratory scientists and morticians occupationally exposed to formaldehyde in Calabar were enrolled in the study. Another group of eighty eight age and sex-matched individuals without formaldehyde exposure served as control subjects. Participants were between 24-52 years of age. Informed consent was obtained from all enrolled subjects. A structured questionnaire was utilized to capture the bio-data as well as allergic reactions experienced during working periods. Circulating immune cells were measured as neutrophil , lymphocyte, eosinophil and monocyte using automation. The total white cell count was also enumerated by automation. Itching, watery eyes and sneezing were part of the allergic reactions experienced by exposed persons. Total white blood cell (WBC), neutrophil and lymphocyte counts were significantly reduced (p<0.05), whereas eosinophil and monocyte counts increased significantly (p<0.05) among exposed persons. When viewed from the perspective of exposure setting, morticians (embalmers) had significantly (p<0.05) increased eosinophil count but reduced WBC, neutrophil and lymphocyte counts compared to medical laboratory staff. Findings from this study point towards formaldehyde possible impact on immune responses from skin, mucous membrane and even circulating immune cells among exposed persons particularly morticians.

Keywords: Formaldehyde, exposure, immune responses