- Research Article
- 10.3390/environments13030172
Long-Term Effect of Oral Exposure to Hexavalent Chromium on Gastrointestinal Cancer Mortality—An Ecological Study in Greece
- Mar 19, 2026
- Environments
- Konstantinos Katsas + 3 more +3
Hexavalent chromium (Cr(VI)) is a highly toxic and carcinogenic trace element. While carcinogenicity through inhalation is well-established, gastrointestinal (GI) carcinogenicity via oral ingestion remains contentious. This study aimed to measure GI cancer mortality at Oinofyta, Greece, where the toxic waste of industries was discarded in the village’s water source for a long time. An ecological study was carried out at the Oinofyta municipal unit, where the primary water supply had been contaminated with Cr(VI) for approximately three decades. Mortality data of all residents of Oinofyta for the period 2000–2021 were obtained from the Hellenic Statistical Authority, and causes of death were classified according to the ICD-10. Standardized Mortality Ratios (SMRs) were computed, stratified by five-year age groups, biological sex, and calendar year, using the population of the entire Voiotia regional unit as the reference population. A higher all GI cancer SMR was observed during the second decade (SMR = 1.44; 95%CI = 1.03, 1.95), but not the first (SMR = 0.98; 95%CI = 0.64, 1.44). Overall, the SMR was evidently higher for males (SMR = 1.35; 95%CI = 1.0, 1.8), but not for females (SMR = 0.97; 95%CI = 0.6, 1.49). A borderline higher SMR was also observed for colorectal cancer in males (SMR = 1.63; 95%CI = 0.93, 2.65; p = 0.08). Additionally, the SMR for all GI cancers demonstrated a significant increasing trend from 2000–2009 to 2010–2021 (0.98; 95%CI = 0.64, 1.44 to 1.44; 95%CI = 1.03, 1.95). This ecological study presents a population-level association between Cr(VI)-contaminated drinking water with certain GI cancers, suggesting further research for etiological associations.
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