Objective To understand the ability of the CDC to detect ammonia nitrogen in drinking water in Hubei Province. Methods The blind samples of two concentration levels were tested in the laboratories of the disease control institutions in the province, and the test results were evaluated by double-sample Z score. Results The satisfaction rate was 76.29% (74/97), the problem rate was 15.46% (15/97), and the dissatisfaction rate was 8.25% (8/97). Conclusion The detection ability of ammonia nitrogen in drinking water in laboratories of disease control institutions in Hubei Province is generally high，however，some laboratories need to be further improved.

Objective: To investigate the association between blood pressure and all-cause mortality in Shanxi, China. Methods: The '2002 China Nutrition and Health Survey' baseline data in Shanxi province was used. A retrospective investigation was performed in 2015. The effects of SBP and DBP on the all-cause mortality were analyzed using the Cox regression model. The hazard ratio ( Results: The follow-up rate was 76.52% over 13 years, while the cumulative mortality rate for all participants was 917.12/100,000 person-years. The mortality rose with an increasing SBP ( Conclusion Adults with SBP > 160 mmHg and DBP > 100 mmHg had a higher mortality risk. Sex and age difference was noted in both DBP and mortality risk.
Adolescent ; Adult ; Aged ; Blood Pressure ; China ; Cohort Studies ; Female ; Health Surveys ; Humans ; Hypertension/mortality* ; Male ; Middle Aged ; Mortality/trends* ; Proportional Hazards Models ; Young Adult