The Relationship between Petrol Station Density and Cord Blood Manganese in Taiwan

1. Taiwan Birth Panel Study (TBPS) 2004.3 - 2005.1 n=486 Taiwan Birth Cohort Study (TBCS) 2004.5 - 2005.7 n=1040 Total of these two cohort n=1526 Had completed questionnaires and blood sample n=1407 GIS data available n=1343 The Relationship between Petrol Station Density and Cord Blood Manganese in Taiwan Ying-Ying Lin, Jyung-Hung Liu, Hui-Chen Wu, Yue-Liang Leon Guo, Pau-Chung Chen, Yaw-Huei Hwang Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University,Taipei, Taiwan, R.O.C. Study aim Results Demographic data The average maternal age was 28 years old and most of them were educated at or above junior high school level. The boy proportion of neonates was 51%. Approximately a half of the newborns were the first children of the delivering women. The geometric means of cord blood manganese and lead concentration were 47.0 and 12.6 μg/L, respectively. Methylcyclopentadienyl manganese tricarbonyl (MMT) has been widely used as a substitute for lead containing anti-knocking additives in gasoline since 1992 in Taiwan. This study was set to investigate the relationship between the concentration of manganese in cord blood and the density of petrol station, a surrogate for traffic density. Materials and Methods • Study population • In total, 1526 newborns were randomly sampled by stratum from April 2004 to July 2005 (Fig. 1., Fig. 2.). Protocols used in this study were approved by the Institutional Review Board of the authors’ institutes. Informed consents were obtained from the newborns’ parents before they were included in the study. • Data collection • Questionnaire was administered to the mothers after childbirth to collect basic information, including date of delivery, parental ages, occupations, education, family income, nationality, etc. Additionally, gestation information, history of pregnancy, gestational age, home environment information, and use of western and herbal medicine were collected in this study. Nurses were responsible for the measurements of neonates, including birth weight, height, gender, head circumference, etc. • Sample collection and analysis • Cord blood samples were collected at birth and stored in EDTA tubes. The level of manganese and lead concentration were determined using inductively coupled plasma mass spectrometry (7500C, Agilent Technologies, Japan). • All the measurements were checked for accuracy with standard reference materials. If the concentration of a cord blood metal was not detectable, half value of the detection limit would be assigned to it instead in the further statistical analysis. • Exposure assessment • The residences of all newborns of the two birth cohorts in the present study were geocoded on GIS system. GIS layer data were obtained from the Taiwan Ministry of Transportation and Communications for data presentation and analysis, including county layer and petrol station layer. • Petrol station density (PSD) of a 10-km buffer zone of each newborn’s residence was used as surrogate for exposure to traffic related air pollution, for 1343 newborns using the Arc9 Geographic Information System. Discussion and Conclusion After adjusting for potential confounders, it was found that cord blood manganese concentration was associated with petrol station density. Although the explained variance, r2, of the multiple linear regression is only 0.072, it still imply the association of manganese level exposure resulting from gasoline consumption with the cord blood manganese level. Further study is warranted to explore the relationship of cumulative exposure to Mn by trimester through traffic related air pollution and cord blood manganese concentration. Fig. 1. Geographical locations of study subjects’ residence. Fig. 2. Taiwan Birth Cohort Study (TBCS) and Taiwan Birth Panel Study (TBPS) E-mail address: R97841015@ntu.edu.tw