Oral ingestion of hexavalent chromium through drinking water and cancer mortality in an industrial area of Greece - An ecological study

Abstract

BackgroundHexavalent 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.MethodsWe 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.ResultsA 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.ConclusionsElevated 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.

Environmental Pollution Effects on Mortality in an Industrial and a Non-industrial Municipality, in Voiotia Prefecture, Greece

“…In addition, our results regarding increased mortality from all cancers and specific cancer sites including lip, oral cavity and pharynx, liver, stomach, pancreas, prostate, colon and kidney and other genitourinary organs among females are in consistence with relevant epidemiological and animal studies, which indicated carcinogenesis after long-term consumption of drinking water contaminated with Cr(VI) (Beaumont et al, 2008;Linos et al, 2011;NTP, 2008). Similar to our outcomes, Linos et al (2011) showed that citizens residing in the industrial area of Oinofita were more likely to have higher mortality rates from primary liver (SMR = 1104.2, 95% CI 405.2-2403.3) and lung cancers (SMR = 145.1, 95% CI 100.5-202.8) in both males and females as well as kidney and other genitourinary organs among females (SMR = 367.8,3) compared to the population of the surrounding prefecture.…”

“…Yet, the California Environmental Protection Agency proposed the Public Health Goal of 0.02 μg of Cr(VI) per liter of drinking water (Office of Environmental Health Hazard Assessment [OEHHA], 2011). Such threshold was relied on the study of Linos et al (2011), which supported the hypothesis of Cr(VI) carcinogenicity via the oral ingestion pathway of exposure.…”

“…Such evidence has been collected since 2007 through measurements in wells and public drinking water supply, made by three independent sources: the Institute of Geology and Mineral Exploration (Giannoulopoulos, 2008), the Economic Geology and Geochemistry Department of the University of Athens (Vasilatos, Megremi, Economou-Eliopoulos & Mitsis, 2008) and Oinofita's Municipal Office (Linos et al, 2011). During 2007-2008, all independent sources detected high Cr(VI) concentrations, ranged from 8.3 to 156 μg/l (Linos et al, 2011). Also, in early 2009 the main drinking water supply was diverted from Asopos River to Mornos Lake (reservoir), which is part of the drinking water supply network of Athens.…”

“…This study was focused on the municipality of Oinofita, one of the rare areas worldwide, where population has been exposed to hexavalent chromium Cr(VI) through drinking water due to dense industrial activity (Linos et al, 2011). In addition, the levels of air pollution have been increased, a fact that has recently given rise to concerns for adverse effects on public health and especially children (Papadimitriou, Riza, Pililitsis, Petralias, & Linos, 2012).…”

“…However, when Kerger, Butler, Paunstenbach, Zhang and Li (2009) compared the Cr(VI)-exposed population with demographically similar populations, concluded that there was no significant risk of human mortality from all cancers attributed to Cr(VI) exposure. More recently, Linos et al (2011) performed an ecological study focusing on the municipality of Oinofita, where residents were exposed to Cr(VI)-contaminated drinking water. Their results indicated that there was a statistically significant increase in mortality from primary liver cancer, lung cancer and cancer of the kidney and other genitourinary organs among women, in Oinofita compared to the population of the surrounding prefecture.…”