Temporal-Spatial Distribution Changes of Cancer Villages in China

A Cancer Village is the village whose cancer morbidity or mortality is remarkably higher than the national averages,which is the reflection of high incidence of cancer in the village-level spatial scale. The appearance of Cancer Village is a result of the evolution of man-land relationship,the spatial-temporal distribution and changes of those is a Health Geography problem. From the viewpoint of Health Geography,according to the definition of Cancer Village,through the construction ofDatabase of Cancer Villages 1980- 2011in Chinaand the utilization of spatial-temporal analysis methods of ArcGIS,this paper analyses the spatial-temporal distribution and change of Cancer Villages in China since 1980. The results show that: 1) the first Cancer Village in China appeared in 1954,and 351Cancer Villages were found by the end of 2011. The number of Cancer Villages increased slowly before 1988,but rapidly since then,so that 186 Cancer Villages,accounting for 53% of the total,newly occurred in the decade between 2000 and 2009,which may be called as a decade of Cancer Villages in clusters and groups. 2) The spatial distribution pattern of Cancer Village in China was congregating,but the regional difference was significant,generally,the number of Cancer Villages in the eastern zone was more than the central zone,and the central zone more than the western zone. According to the number of Cancer Villages per 10 000 square kilometers at provincial level,China could be divided into four levels: rather dense area of Cancer Villages,relatively dense area of Cancer Villages,sparse area of Cancer Villages and blank area of Cancer Villages. 3) In the last thirty years,the gravity centers of Cancer Villages in China kept shifting in the border of Hubei and Henan provinces,and generally there was a tendency of moving from west to east,while the gravity center of Cancer Villages added every five years also kept shifting in the border regions of Hubei,Henan and Anhui provinces,but there was a tendency of moving from northeast to southwest. 4) The distribution of Cancer Villages had a very close correlation with rivers,nearly 60 % of Cancer Villages located within a distance of three kilometers from rivers,and 81% within five kilometers. 5) 95. 16 % of Cancer Villages in China were caused by chemical carcinogenic factors,1. 99 % by virus carcinogenic factors,and 1. 14 % by physical carcinogenic factors. Environmental pollution,especially the water pollution,was the chief cause of Cancer Villages.