Environmental and ecological factors of stomach cancer incidence and mortality: a systematic review study on ecological studies.

A total of 157 potentially relevant articles were identified from the initial search 38 of which met the eligibility criteria; finally, 34 articles were included in the systematic review. The results revealed that soil arsenic exposure, coal and other opencast mining installations, living near incinerators and installations for the recovery or disposal of hazardous waste, installations for the production of cement, lime, plaster, and magnesium oxide, proximity to a metal industry sources, dietary iron, ingested asbestos, farming, arsenic in soil, altitude, organochlorines and environmental exposure to cadmium and lead have positive associations with SC incidence or death. Most of the ecological and environmental factors such as living near the mineral industries, the disposal of hazardous waste, metal industry sources and environmental exposure to cadmium and lead are positively related to SC mortality and incidence. However, solar UV-B, heat index and dietary zinc can be taken into account as protective factors against SC mortality and incidence.