Agricultural pesticide exposure and perinatal mortality in central Sudan

Abstract

Hospital- and community-based studies were conducted in central Sudan to investigate the association between pesticide exposure and perinatal mortality. The cases were 197 stillbirths in the hospital and 36 perinatal deaths in the community; the controls were 812 liveborn, normal-birth-weight infants in the hospital, and 1505 liveborn infants who survived for the first 7 days after birth in the community. The odds ratio (OR) of perinatal death associated with pesticide exposure was estimated using multiple logistic regression. There was a consistent and significant association between pesticide exposure and perinatal mortality in the hospital (adjusted OR = 1.9; 95% confidence interval (CI): 1.3-2.8) and the community populations (adjusted OR = 2.7; 95% CI: 1.1-6.4). The OR was significantly higher among women engaged in farming (3.6; 95% CI: 1.6-8.0), but not among women in nonfarming occupations (1.6; 95% CI: 0.8-3.3). The estimated attributable risks of perinatal death owing to pesticide exposure were 22.6% for hospital stillbirths and 15.7% for community perinatal deaths; but among women engaged in farming in the hospital population the attributable risks were substantially higher (34.5%).

PIP: Between March 1989 and June 1990, hospital and community based studies compared perinatal deaths with liveborn, normal birth weight infants who survived the neonatal period to examine the association between perinatal mortality and exposure to agricultural pesticides in the largest and oldest agricultural project in the Sudan--the Gezira Scheme. The main referral hospitals were in Wad Medani and Sennar. Data were gathered on all midwife assisted births at the 6 health centers between these 2 cities in central Sudan. The hospital, case control study included 197 perinatal deaths and 812 liveborn controls. The community based case control study included 36 perinatal deaths and 1505 liveborn controls. The researchers adjusted for any potential cofounders. Exposure to any pesticide spraying significantly increased the risk of stillbirth in the hospital population and of perinatal death in the community population (odds ratios [ORs] = 1.9 and 2.7 respectively). Pesticide spraying most significantly affected perinatal deaths in women engaged in farming (OR of fetal death = 3.6). The OR for nonfarmers indicated increased risk of perinatal death, but it was not significant (1.6). Pesticide exposure accounted for 15.7% of community perinatal deaths and 22.6% of hospital stillbirths. It attributed more greatly to perinatal deaths of women farmers than it did to women nonfarmers (34.5 vs. 10.7%). The association between exposure to pesticides and the occurrence of perinatal deaths was consistent in both the hospital and community studies as well as with findings of studies from India and Colombia. This association and the high attributable risks suggest that pesticide exposure causes perinatal mortality. These findings indicate the needs for pregnant women to be protected from exposure to pesticides and for awareness about safer use of chemicals to be increased.