Microbial contamination and environmental factors of drinking water source for households with children under five years old in two South China ethnic groups
The article aimed to find the causes of microbial contamination of drinking water source, by exploring the influencing factors of water on the incidence of diarrhea in children. Random stratified-cluster sampling was used to study Li and Han communities of rural Lingshui County with regard to water quality and environmental sanitation. Water samples were evaluated for microbial contamination using National Standard of the People's Republic of China and World Health Organization drinking water standards. Data were compared between ethnic groups. Li communities had more contamination than Han. The correlation between the frequency of diarrhea among children and the presence of microorganisms in the water was positive, for both total coliforms and Escherichia coli (E. coli). Regression analysis showed the substandard risk factors of total coliforms for source water were type of water supply (OR = 3.508) and garbage disposal methods (OR = 2.430). For E. coli, risk factors included the source of water supply (OR = 2.417); depth of wells (OR = 0.536) and distance of wells from the cesspit (OR = 0.723). The content of bacterium in drinking water source was high in the rural county. Water from open wells had higher contamination rates than water from centralized systems and tube-well sources. Improvement of water supply and environmental hygiene would decrease diarrheal diseases among children under five.