[Impact of liver cancer deaths on life expectancy in 14 counties (districts) from the Huai River Basin, 2013: relationship between the water environment and liver cancer].

OBJECTIVE: To investigate the relationship between liver cancer and the water environment, we analyzed the life expectancy in 14 counties (districts), which form the Huai River Basin with respect to liver cancer deaths in 2013 and changes in the surface water quality from 2004 to 2010.

METHODS: The study area included the 14 counties (districts) of the Huai River Basin in China. We obtained surveillance data for all causes of death in the study area during 2013, as well as data for International Classification of Diseases,Tenth Edition(ICD-10) code C22 or liver cancer. Life expectancy and life expectancy after elimination of liver cancer were then calculated. Based on water quality monitoring data from the China Environment Yearbook 2005-2011, we analyzed the water environment of the Huai River Basin, and changes in the water quality. According to the " Encyclopedia of Rivers and Lakes in China" (Huai River Basin section), we divided the river basin into five categories: upstream basin (upstream); midstream, north shore of the basin (midstream-north); midstream, south shore of the basin (midstream-south); downstream basin (downstream); and the Yishusi River Basin. To calculate the life expectancy and life expectancy after elimination of liver cancer in the study area, we used the Nemerow Pollution Index (NPI), to investigate the relationship between liver cancer and the water environment.

RESULTS: Life expectancy in the 14 study districts varied from 68.99 years (Shenqiu County) to 78.85 years (Jinhu County). Gains in life expectancy after elimination of liver cancer varied from 0.86 to 0.31 years. Midstream-north showed the greatest improvement, with overall gain in life expectancy of 0.77 years; this gain was 1.04 years for males and 0.40 years for females. Yishusi River Basin showed the least improvement, with overall gain in life expectancy of 0.41 years; this gain was 0.54 years for males and 0.24 years for females. For the 7 years from 2004 to 2010, midstream-north had the highest annual NPI values, at 2.08, 1.74, 1.64, 1.81, 1.41, 1.26, and 1.06, respectively. There was a positive correlation between NPI and life expectancy gain for both males and females (r=0.64, P=0.014). There was positive correlation between NPI and life expectancy gain among males alone (r=0.64, P=0.014); there was no significant correlation between NPI and life expectancy gain among females (r=0.44, P=0.115).

CONCLUSION: Liver cancer had a significant impact on life expectancy in the Huai River Basin. The gain in life expectancy was higher for males than for females. There is a possible relationship between liver cancer deaths and the water environment in the research area, but this study did not infer a causal association.