Mortality analysis on wastewater exposure in Shijiazhuang, Hebei, China, from 2007 to 2011

The study investigated the age-adjusted mortality rate and disease odds among deceased residents living in areas exposed to wastewater and cleanwater from 2007 to 2011, in Shijiazhuang, China. Mortality data for eight villages exposed to wastewater and 16 villages not exposed to wastewater were collected and crosschecked from multiple sources. Overall mean age-adjusted mortality rate for wastewater areas was 798/105 (95% Confidence Interval (CI) = ± 68), insignificantly higher than the mean mortality rate for cleanwater area, 726/105 (95% CI = ± 46), p > 0.05. Malignant neoplasms and respiratory mortality and disease odds were higher in wastewater areas than in cleanwater areas, OR = 1.7 (95% CI = 1.3-2.2, p < 0.01) and OR = 1.9 (95% CI = 1.1-3.4, p < 0.05), respectively. Wastewater area mortality and disease odds for Lung and Stomach cancers after adjustments were OR = 1.6 (95% CI = 1.1-2.4, p < 0.05) and OR = 1.8 (95% CI = 1.2-2.7, p < 0.01), respectively, significantly higher than those of cleanwater areas. There is a possibility that exposure to wastewater might be associated with cancer and respiratory disease mortality. The study recommends that the use of wastewater be limited, discouraged, or discontinued.