Cancer Mortality Study In Fertilizer Workers

• Main Authors: KUNG,CHEN-YI, 龔真儀
• Other Authors: CHEN,PAU-CHUNG
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/62235459304662514713

碩士 === 國立臺灣大學 === 職業醫學與工業衛生研究所 === 88 === Fertilizer manufacturing was one of the most important industries in Taiwan. It has been confirmed that fertilizer workers who expose to high concentrations of nitrate at work are likely to have high concentration of nitrate in the saliva. It might cause an excess risk of stomach cancer. About 60﹪ of one and half million tons of sulfuric acid available in Taiwan annually is used to manufacture fertilizer. It has been indicated that there is moderate association between mist containing sulfuric acid (MSA) and laryngeal cancer, but little evidence in support of a relationship between the exposure of MSA and lung cancer. We used a retrospective cohort study design to analyze cancer mortality among fertilizer workers. We selected employees at a major fertilizer company including 6 factories for this study. We obtained the employees’ insurance information from the Bureau of Labor Insurance and the Government Employees’ Insurance Department of Central Trust of China to establish the cohort of fertilizer workers. The cohort consisted of 6799 males and 624 females. Individuals exclusions were individuals with no identification numbers, employed after January 1, 1994, and with less than 1 year of employment. The 1985-1998 death registration data from the Department of Health, delayed death registration data from the Department of Health, 1980-1997 death registration data from the Ministry of Interior, and household registration system from the Ministry of Interior were linked. We used NIOSH PC LTAS program to analyze cancer standardized mortality ratios (SMRs). Besides, we observed cancer standardized rate ratios (SRRs) by the duration of employment using controls with employment of less than 1 year as reference. Referring to general population, overall mortality for male workers was lower (SMR=0.71, 95% CI=0.67-0.76), so was the mortality from all cancers (SMR=0.78, 95% CI=0.69-0.87). The corresponding measurements for female workers were 0.72 (95% CI=0.50-1.00) and 1.37 (95% CI=0.82-2.13). A significant elevated mortality from ovarian cancers (3 cases, SMR=7.98, 95% CI=1.64-23.33) for female workers was revealed. Using individuals with employment of less than 1 year as reference, the SRR for death from brain cancer increased as the duration of employment increased. In conclusion, no excess mortalities for this fertilizer work related cohort were found from all cancers, larynx cancer and nasopharyngeal cancer. The excess deaths from the ovarian cancer and brain cancer for this cohort deserves further investigation.