Epidemiologic Study for the Association between Phenol Contaminated Drinking Water and Poor Pregnancy Outcomes in Taegu City

Park, Jung Han; Lee, Ju Young

Abstract

From 14 to 17 March 1991 the Nakdong River which is a major source of drinking water for Taegu was contaminated with phenol that was spilled out of a factory in Gumi industrial park. Many people who drank the contaminated water complained of various symptoms and were apprehensive of possible adverse effect to the fetus. This study was conducted to examine the effect of drinking water contaminated with phenol on pregnancy outcome in Taegu. All of livebirths and stillbriths delivered in the 5 General Hospitals in Taegu during 1 year from 1 April 1991 were included for this study. For this duration, total number of babies delivered in the 5 General Hospitals was 21,196. Among them, 77.7%(16,468) were delivered from women living in Taegu and it accounted for 47.5% of 34,688 livbirths registered in Taegu during the same period. The babies born to the women living in Taegu were divided into phenol-exposed and unexposed groups. Exposed group was the residents of the area where contaminated water was supplied and they accounted for 81.4% of the women included for this study. Unexposed group was the residents of the area where drinking water was not contaminated with phenol and they accounted for 18.6% of the study subjects. Data were abstracted from the hospital records. All the rates were adjusted for the maternal age and parity by direct method. The abortion rates for the exposed group was 1.7 per 1,000 abortions and livebirths and 1.6 for the unexposed group. The stillbirth rate for the exposed group was 10.5 per 1,000 livebirths and stillbirths 20 weeks of gestation and 9.5 for unexposed group. The early neonatal death rate(within the 1st week after birth) for the exposed group was 7.8 per 1,000 livebirths and 5.4 for the unexposed group. The perinatal death rate for the exposed group was higher as 14.1 per 1,000 livebirths and stillbirths 28 weeks of gestation than 10.8 for the unexposed group. The proportions of intrauterine growth retardation(IUGR) were 2.7% for the exposed group and 3.3% for the unexposed group. Congenital anomaly incidence rates per 1,000 livebirths was 7.4 for the exposed group and 8.4 for the unexposed group. The low birthweight incidence rate for the exposed group was 6.6% and 6.5% for the unexposed group. These differences between two groups were not statistically significant. The premature birth rate(< 37 completed gestational week) was 6.0% for the exposed group and 4.8% for the unexposed group and the difference was statistically significant(p<0.05). Monthly variation of these indices did not show any clue that suggested concurrent change with the phenol contamination of the drinking water. There were no sufficient evidence that could support the hypothesis of adverse effects of phenol contaminated water on pregnancy outcome, such as abortion, stillbirth, premature birth, IUGR, congenital anomalies and early neonatal death.