In order to carry out long-term follow-up of the residents’ health and the epidemiologic study, the cohort study is needed. Based on community-level local health service and support from National Taiwan University Hospital Yunlin Branch, we have tried to establish an epidemiological model for environmental cohort study in this year. Until June 2010, we have conducted 11 times of mass health screenings in Baojhong, Taisi, Sihhu, Dongshih, Mailiao, Lunbei, and Huwei. A total of 2006 subjects with questionnaire data, 2008 subjects with pulmonary function examination data, 1508 subjects with health screening data, and 1252 subjects with biological monitoring samples were collected.
In the epidemiological point of view, our data revealed that (1) If we set that reference group is Taisi, the five pulmonary function indices (percent-predicted FVC, percent-predicted FEV1, FEV1/FVC, percent-predicted FEF25-75% and percent- -predicted PEF) in subjects were better in Huwei, Dongshih and Erlun. If we set that reference group is Mailiao, the five pulmonary function indices (percent-predicted FVC, percent-predicted FEV1, FEV1/FVC, percent-predicted FEF25-75% and percent-predicted PEF) in subjects were better in Dongshih, Sihhu, Huwei and Erlun. (2) We used HPLC to test urinary metabolites of PAH (1-hydroxypyren, 1-OHP). The result showed that the 1-OHP concentrations in Baojhong, Taisi, Dongshih, and Mailiao were higher than that in Huwei.
In this study, we used environmental sampling and literature review of epidemiological database. There were 255 kinds of air-born chemicals related to the No. 6 Naphtha Cracker Complex of Formosa Petrochemical Corporation. In these chemicals, 132 were acute or chronic carcinogens. Sulfur dioxide, nitrogen oxide, PM10, and PM2.5 were also related to the No. 6 Naphtha Cracker Complex of Formosa Petrochemical Corporation, as well as 97 kinds of volatile organic compounds (VOCs, SVOCs), 19 kinds of heavy metals, and 12 kinds of PAHs.
In the environmental monitoring study, the VOCs sample collection results showed that the highest concentration was 128.38 ppb, which was collected in Sihhu Junior High School in March 2010. The second highest concentration was 54.57 ppb, which was collected in Erlun Junior high School in September 2009. The rest results were all below 50 ppb. 1,2-dichloroethane and 1,3-butadiene only was collected in Taisi Junior High School and Fengan Elementary School. The main materials were toluene and benzene in the VOCs sample collection. The dimethyl benzene and ethyl benzene concentrations were higher in Lunbei and Erlun Junior high School than that in other in November 2009.The methyl chloride and dichloromethane concentrations were higher in Mailiao Junior high School than that in other in September 2009.The Solvents of Polarities sample collection results showed that the acetone and ethanol were main materials, found in all sampling collecting spots. In fourth collection, the Methyl tert-butyl ether (MTBE) concentrations was highest in Sihhu Junior high School，the second highest was Fengan Elementary School. The second highest concentration was collected in November 2009, in Mailiao and Erlun Junior high School than that in other. We found the acetaldehyde pollution in Huwei and Cihtong Junior high School.
When the wind blows from exposure zone to non-exposure zone, we could find PAHs concentrations were higher in exposure zone, including Benzo(a)anthracene, Benzo(a)pyrene, Benzo(ghi)peryene, Benzo(k)fluoranthene, Chrysene, Fluoranthene, Indeno(1,2,3-cd)pyrene, Naphthalene and Pyrene. Although the wind does not blow easterly, we could also find three kinds of PAHs higher in exposure zone, including Acenaphthylene, Anthracene and Phenanthrene. When the wind blows from exposure zone to non-exposure zone, we could find 10 kinds of heavy metals, including Sr, Mn, Ba, Ga, As, V, Cr, Li, Se and Ni were higher in exposure zone, rather than non-exposure zone. After analyzing the data from air quality monitoring station, the results showed that the SO2/NO2 concentrations were lower in Taisi than that in Douliou and Lunbei before 2000. But after 2000, SO2/NO2 concentrations were higher in Taisi than in Douliou and Lunbei. The annual average concentration of PM10 is about 60 ~ 80 μg/m3 and the eighth largest daily average concentration of PM10 is about 110 ~ 200 μg/m3. Both of them are much higher than the WHO guideline standard. In Yunlin County, the ozone concentration increased year by year. The data from Taisi photochemical station showed that TVOC did not change significantly between 2007 and 2009.
In conclusion, out data showed that the No. 6 Naphtha Cracker Complex would influence ambient air quality, pulmonary function and 1-OHP in residents nearby. We would need continuous follow-up of this environmental to identify multiple health effects in a more detailed manner.
