The environmental causes of cancer distribution in Syria

In the last decade Syria witnessed a boost in cancer incidences, as well as high mortality ratios. This research aims to illustrate the geographical distribution of cancer over Syria in details and to trace the expansion of incidence through time according to risk factors like age, gender, human behaviour. The paper consists of four parts: 1- Introduction to the topic (cancer and the environmental influence of its distribution) and explanation of the used terms. 2- The relationship between cartogeographical sciences and the topic of the paper. 3- Building a Geographical Information System according to the major district in Syria. 4- Building a Geographical Information System for the southern part of Syria (the most infected place). 5- Results and discussion. The study employed the geographical tools to investigate the geographical distribution of cancer disease and the environmental factor that controls this distribution. The used methods are the statistical, systematic, analytical descriptive, comparative and the cartographical which were employed differently according to the data characteristics. Personal and spatial data were collected from treatment points in a questionnaire that allowed adjusting each of them on the electronic interactive map. Data was analysed statistically and cartographically depicted. Accordingly parallel descriptive and comparative data were added for reaching the final conclusions. Thematic maps were the final product of using GIS. The cartographical product helped to analyse the epidemiological cluster and the accumulated risk factors. The resulted maps were an analytical tool revealing the concepts of spatial data. Natural risk factors were the main focus in addition to people nutrition habits. The studied factors were depicted in three map scales. The recorded incidences for 2002 till 2008 were depicted as well. The output is an atlas of: 1- 1/2000,000 Syria maps showing the big clusters of the disease and the risk factor. 2- 1/2000,000 Choropleth maps showing the ratio of incidence to the census of each Syrian district, 3- 1/200,000 for the southern part of Syria which showed the highest incidence ratios (Al-Souida county). The study showed many clusters based on the kind of cancer and the kind of risk factor and drew the attention to some risk factors that people disregard (the frequent relative marriage in the region of Al-Souida) and some uncommon ones like rock type (Al-Souida). Tracing pollution in time line helped to link the earlier influences and the accumulated factor to the recent incidence. the geographical risk factors were the minor reasons for the cancer clusters (elevation height, solar radiation, rock type, polluted gases in the atmosphere and water wells), meanwhile people habitual activities were the major reason (kind of job, smoking and nutrition system). Considerably some urgent risk factor caused the small clusters up on different groups of people (eating food exported to the city of Dier al-zor which was polluted by radiation)