An Introductory Overview of the Epidemiological Study on the Population at the High Background Radiation Areas in Yangjiang, China

Abstract

The epidemiological study on the residents of the high background radiation areas in Yangjiang, China was started by Chinese scientists in 1972 and continued until 1986. In 1991, Japanese scientists recognized the importance of the work and a joint feasibility study was conducted with revised protocols. The feasibility study matured to a cooperative project involving both Chinese and Japanese scientists in 1992, which currently is still in progress. The project was divided into three phases; the first being from 1992 to 1995, the second from 1995-1998 and the third from 1998 to 2001. The results of the first phase were reported previously in 1996. The present paper is a historical overview of the studies before the cooperation and the first two phases. Remarks are made on the detailed data on dosimetry, cytogenetic studies and cancer epidemiology of a series of the papers in this supplemental issue. Some problems such as paradoxical observations between cytogenetic results and cancer mortality, and the importance of the high background study in risk assessment are discussed.

A pilot study for dose evaluation in high-level natural radiation areas of Yangjiang, China

“…A China-Japan cooperative study was organized and radiological and epidemiological studies were carried out [2,[5][6][7][8][9][10]. These studies did not find any statistically significant excess mortality due to cancer or non-cancer diseases [8,9].…”

Smoking and Hormesis as Confounding Factors in Radiation Pulmonary Carcinogenesis

“…Residents near Yangjiang in Guangdong province, China, receive an annual background dose of 6.4 mSv. The PROFAC was 0.19, while the ERR per Sievert for lung cancer was -0.68 under the apparently inappropriate LNT assumption (Wei 1997;Wei and Sugahara 2000). Use of the LNT function seems inappropriate in that a PROFAC > 0 implicates a hormetic dose-response.…”

“…The USEPA estimates the average indoor radon level nationwide is 1.3 pCi/L (City of Fort Collins 2005). The relative rates of cancer in most native populations of Iran, India, and China that are exposed to high levels of background radiation have, in most cases, appeared to decrease (Wei 1997;NCRP 2001). Residents near Yangjiang in Guangdong province, China, receive an annual background dose of 6.4 mSv.…”

La controverse sur les effets des faibles doses de rayonnements ionisants et la relation linéaire sans seuil

“…Les études conduites dans des régions où l'irradiation naturelle est nettement plus élevée qu'en France ne montrent pas de lien entre le niveau d'irradiation naturelle et la mortalité par cancer bien que l'on observe des stigmates biologiques de l'effet des radiations sur les lymphocytes circulants : -province indienne du Kerala, jusqu'à 70 mSv par an (Nair et al, 1999) ; -région chinoise du Yangijang, avec suivi comparatif depuis dix ans de 100 000 habitants de zones à 6 mSv, 4 mSv et à 2 mSv par an (Sugahara et Watanabe, 1994 ;Tao et al, 2000 ;Wang et al, 1990 ;Wei et Sugahara, 2000) ; -Japon, irradiation due au radon (Mifune et al, 1992 ;Noguchi et al, 1986 ;Sobue et al, 2000).…”