Oral ingestion of hexavalent chromium through drinking water and cancer mortality in an industrial area of Greece - An ecological study
1 Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias str., Athens, 11527, Greece
2 Institute of Preventive Medicine, Environmental & Occupational Health, Prolepsis, 7 Fragoklisias str., Maroussi, 15125, Greece
3 Department of Statistics, Athens University of Economics and Business, 76 Patission str., Athens, 10434, Greece
4 Cyprus International Institute for Environmental and Public Health in association with Harvard School of Public Health, Cyprus University of Technology, Eirinis 95 str., Limassol, 3041, Cyprus
5 Department of Environmental Health, Harvard School of Public Health, 401 Park Drive str., Boston, MA, 02215, USA
6 The Biostatistics Center, George Washington University, 6110 Executive Boulevard, Rockville, MD, 20852, USA
7 Hellenic Cancer Registry, Hellenic Centre for Disease Control & Prevention, 3-5 Agrafon str., Maroussi, 15123, Greece
8 Department of Community and Family Medicine, Section of Biostatistics & Epidemiology, Dartmouth Medical School, 1 Medical Center Drive, Hanover, NH, 03756, USA
Environmental Health 2011, 10:50 doi:10.1186/1476-069X-10-50Published: 24 May 2011
Hexavalent chromium is a known carcinogen when inhaled, but its carcinogenic potential when orally ingested remains controversial. Water contaminated with hexavalent chromium is a worldwide problem, making this a question of significant public health importance.
We conducted an ecological mortality study within the Oinofita region of Greece, where water has been contaminated with hexavalent chromium. We calculated gender, age, and period standardized mortality ratios (SMRs) for all deaths, cancer deaths, and specific cancer types of Oinofita residents over an 11-year period (1999 - 2009), using the greater prefecture of Voiotia as the standard population.
A total of 474 deaths were observed. The SMR for all cause mortality was 98 (95% CI 89-107) and for all cancer mortality 114 (95% CI 94-136). The SMR for primary liver cancer was 1104 (95% CI 405-2403, p-value < 0.001). Furthermore, statistically significantly higher SMRs were identified for lung cancer (SMR = 145, 95% CI 100-203, p-value = 0.047) and cancer of the kidney and other genitourinary organs among women (SMR = 368, 95% CI 119-858, p-value = 0.025). Elevated SMRs for several other cancers were also noted (lip, oral cavity and pharynx 344, stomach 121, female breast 134, prostate 128, and leukaemias 168), but these did not reach statistical significance.
Elevated cancer mortality in the Oinofita area of Greece supports the hypothesis of hexavalent chromium carcinogenicity via the oral ingestion pathway of exposure. Further studies are needed to determine whether this association is causal, and to establish preventive guidelines and public health recommendations.