Zufan Tao

Publications (3)2.6 Total impact

• Article: Cancer and non-cancer mortality among Inhabitants in the high background radiation area of Yangjiang, China (1979-1998).

  Zufan Tao, Suminori Akiba, Yongru Zha, Quanfu Sun, Jianming Zou, Jia Li, Yusheng Liu, Yongling Yuan, Shinji Tokonami, Hisashige Morishoma, Taeko Koga, Seiichi Nakamura, Tsutomu Sugahara, Luxin Wei
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  ABSTRACT: The present study aimed to evaluate the effects of high background radiation (HBR) on mortality. A cohort of 31,604 men and women aged 30-74 y living in the study area in Guangdong Province, China, was followed during the period 1979-1998. The information on deaths and migrations of cohort members was collected by visiting study areas every 3-4 y. Cumulative external radiation dose, lagged by 2 y for leukemia and 10 y for cancer excluding leukemia, was estimated for each individual based on hamlet-specific indoor and outdoor doses, and gender- and age-specific house occupancy factors. The follow-up study accumulated 736,942 person-years at risk and ascertained 6,005 deaths, including 956 cancer deaths and 4,525 non-cancer disease deaths. Mean cumulative radiation doses from natural radiation in the HBR and control area residents were 84.8 mGy and 21.6 mGy, respectively. Mortality due to leukemia (15 deaths) or cancer excluding leukemia (941 deaths) was not related to cumulative radiation dose. The excess relative risk (ERR) Gy of cancer excluding leukemia was estimated to be -1.01 (95% CI: -2.53, 0.95). In site-specific analysis, liver-cancer mortality was inversely related to the cumulative dose (p=0.002). Note, however, that liver cancer is well known for its difficulty in accurate diagnosis. The ERR Gy of cancer excluding leukemia and liver cancer was 0.19 (95% CI: -1.87, 3.04). Non-cancer disease mortality was not related to cumulative radiation dose either. The cumulative HBR dose was not related to the mortality due to cancer or all non-cancer diseases among residents in Yangjiang HBR areas.
  Health physics 02/2012; 102(2):173-81. · 0.92 Impact Factor
• Article: Cancer and non-cancer mortality among Inhabitants in the High Background Radiation Area of Yangjiang, China (1979–1998)

  Zufan Tao, Suminori Akiba, Yongru Zha, Quanfu Sun, Jianming Zou, Jia Li, Yusheng Liu, Yongling Yuan, Shinji Tokonami, Hisashige Morishoma, Taeko Koga, Seiichi Nakamura, Tsutomu Sugahara, Luxin Wei
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  ABSTRACT: Abstract—: The present study aimed to evaluate the effects of high background radiation (HBR) on mortality. A cohort of 31,604 men and women aged 30–74 y living in the study area in Guangdong Province, China, was followed during the period 1979–1998. The information on deaths and migrations of cohort members was collected by visiting study areas every 3–4 y. Cumulative external radiation dose, lagged by 2 y for leukemia and 10 y for cancer excluding leukemia, was estimated for each individual based on hamlet-specific indoor and outdoor doses, and gender- and age-specific house occupancy factors. The follow-up study accumulated 736,942 person-years at risk and ascertained 6,005 deaths, including 956 cancer deaths and 4,525 non-cancer disease deaths. Mean cumulative radiation doses from natural radiation in the HBR and control area residents were 84.8 mGy and 21.6 mGy, respectively. Mortality due to leukemia (15 deaths) or cancer excluding leukemia (941 deaths) was not related to cumulative radiation dose. The excess relative risk (ERR) Gy−1 of cancer excluding leukemia was estimated to be −1.01 (95% CI: −2.53, 0.95). In site-specific analysis, liver-cancer mortality was inversely related to the cumulative dose (p=0.002). Note, however, that liver cancer is well known for its difficulty in accurate diagnosis. The ERR Gy−1 of cancer excluding leukemia and liver cancer was 0.19 (95% CI: −1.87, 3.04). Non-cancer disease mortality was not related to cumulative radiation dose either. The cumulative HBR dose was not related to the mortality due to cancer or all non-cancer diseases among residents in Yangjiang HBR areas.
  Health Physics 01/2012; 102(2):173–181. · 1.68 Impact Factor
• Article: Cancer and non-cancer epidemiological study in the high background radiation area of Yangjiang, China

  Jianming Zou, Zufan Tao, Quanfu Sun, Suminori Akiba, Yongru Zha, Tsutomu Sugahara, Luxin Wei
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  ABSTRACT: The major objective of this study is to examine cancer mortality risk associated with low-level radiation exposure occurring in the high background radiation area (HBRA) in Yangjiang of Guangdong Province, China. The average annual effective doses received by the inhabitants from natural sources of external and internal exposures in HBRA are estimated to be 2.10 and 4.27 mSv, respectively, and the corresponding doses in the control area (CA) to be 0.77 and 1.65 mSv. We analyzed the mortality of non-cancer diseases as well in order to shed light on the comparability of the HBRA and the CA. We examined mortality for cancer and non-cancer diseases during the period 1979–1998. The prospective mortality study followed 125,079 subjects during the period 1979–1998, accumulated 1,992,940 person-years (PYs) at risk, and ascertained 12,444 deaths, including 1202 cancer deaths. The mortality of all cancer showed no difference between the HBRA and the CA [relative risk (RR)=1.00; 95% confidence interval (CI), 0.89 to 1.14]. When cancer deaths were limited to persons with pathological diagnosis, the RR changed only slightly (RR=0.99; 95% CI, 0.78 to1.26). The RR was not evidently modified by sex or age or follow-up period (1979–1986, 1987–1998). In site-specific cancer mortality analysis, only cancer of the esophagus showed a statistically significant excess in the HBRA (RR=2.61; 95% CI, 1.11 to 7.66). However, the observed excess mortality of esophageal cancer did not show a monotonic increase with external radiation dose or cumulative lifetime dose. The RR comparing non-cancer mortality in the HBRA with that in the CA was 1.06 (95% CI, 1.01 to 1.10), which was a statistically significant increase. However, the excess was limited to those aged under 50 and the latter half of the observation period (the period 1987–1998), suggesting that the excess mortality may be due to recent changes in lifestyles of the younger generations. In the cause-specific analysis of non-cancer deaths, disease of the digestive organs showed a statistically significant increase. This appears to be mainly due to liver diseases. In conclusion, the present study showed no increase of cancer mortality in the HBRA. However, it is difficult for the present study to support or deny the possibility that the radiation-related cancer risk associated with chronic exposure to low-dose radiation may be different from the risk associated with high dose ranges or high dose-rate exposure. The observed increase of non-cancer mortality in the present study is unlikely to be attributable to radiation exposure.
  International Congress Series 1276:97-101.