The research progress in water supply and latrine improvement as well as its effects on controlling intestinal infectious diseases in rural areas of China were reviewed in the present paper. It showed that China had significant gains in rural water supply and sanitary latrines over the past two decades. By the end of 2005, 94.06% of the rural population had benefited from the improved water supply, 61.32% of the rural residents were supplied with the running water and 55.31% used the sanitary latrines. As a result, the occurrence of the intestinal infectious diseases had significantly declined. To develop a perfect disease control system in the rural areas in China, the role of government will be important and critical.

Indoor microbial contaminants may induce the eye stimulation, asthma, allergic dermatitis and pneumonia and infectious diseases as well, even to die due to the serious infection. The main contamination source is constructional materials (especially the decorative materials) of the inner space of the building as well as the electric appliance (especially the center air conditioner system). Not only the direct stimulation from the chemicals released, but also all of them provide a suitable environment for some pathogenic microorganisms in the inner space of room. Using the anti-microorganism decorative materials to inhabit/decrease the microorganisms may improve the indoor air quality.

The studies on environmental cadmium (Cd), lead (Pb), arsenic (As) pollution and health impact on exposure population in China were reviewed in the present paper. The related reports said the main pollution sources of serious environmental Cd, Pb and As pollution in China were mining and smelting of nonferrous metals, these pollutants were discharged into the environment and caused the pollution of water, atmosphere, soil and biological species and caused a series of acute and chronic diseases in the exposed people, but the relationship between malignant tumors and environmental cadmium, lead, arsenic pollution is not well understood up to now. The researches should focus on the assessment of environmental pollution and health impact through the effect identification, dose-effect assessment, exposure evaluation and description of risk characteristic.

Objective To know the drinking water safety for students and teachers in urban and rural boarding schools in Guangxi, further to prevent and control the water-borne diseases. Methods The random stratified cluster sampling method was used to select 100 schools in 10 counties of Nanning, Liuzhou and Guilin cities. The drinking water samples were collected and tested according to Sanitary Standard for Drinking Water Quality2001. The epidemic situation of intestinal infectious diseases was investigated. Results The total qualified rate of drinking water quality in 100 boarding schools of 10 counties cities was only 27.00%, as for the water supply provided for themselves with disinfection, the qualified rate was 47.37%, without disinfection, it was 16.95%. 24 outbreak events of intestinal infectious diseases occured in 100 boarding schools in 2000-2005, 2 339 of school teachers and students were attacked, including 13 outbreak events of typhoid and paratyphoid 54.17% with 1 280 cases 54.72%, 6 outbreak events of bacterial dysentery25.00% with 829 cases35.44%, 4 outbreak events of infectious diarrhea 16.67% with 225 cases 9.62%, 1 outbreak of hepatitis A 4.17% with 5 cases 0.21%. These 24 epidemic events were caused by drinking water, the morbidity was higher in the schools where there was no disinfection facility in water supply. Conclusion Some of water supply for some urban and rural boarding schools have been polluted with bacteria in Guangxi, so drinking water disinfection should be done to ensure water safety and prevent the related diseases in these schools.

Objective To understand the status of the sanitary quality in some areas of countryside in Guangxi. Methods The investigation on the type of water source and the water supply was carried out in 9 counties.10 sampling points were established in each observed county.91 water samples were collected totally for the measurement of water quality ,then their sanitary quality was assessed based on the Criteria for Implementing the Hygienic Standards for Drinking Water in Countryside. Results In the observed 9 counties ,15.33% of total population drank water supplied with surface water,and 84.67% with ground water source. Drinking water from centralized water supply system was supplied to 43.16% of total population.In the centralized water supply system,the finished water completely treated by sedimentation and filtration was supplied to 10.57% of the total population,the disinfected finished water was only supplied to 2.96% of the total population,the raw water was directly supplied to 68.66% of the tap water-supplied population without any treatment.The completely-qualified rate of water samples was 20.88% for total 91 water samples,14.81% for surface water samples and 23.44% for ground water samples respectively.The qualified rate of bacterial indexes was 32.61% for water samples collected from centralized water supply system and 20.00% for those from decentralized water supply system. Conclusion Most of the peasants in the investigated 9 counties hadn't been supplied by safe and health drinking water.Contamination of drinking water by microorganisms was the main sanitary problem in water supply in countryside of Guangxi.

Objective To know rural drinking water safety and the affecting factors in Guangxi Zhuang Autonomous Region.Methods The survey was conducted through a combination of census and spot-checks during January to May 2005,taking villages as the survey units,the basic situation of water supply,coverage of tap water,running of water supply facilities,and the distribution and types of water sources,pollution of water sources,water sources and beneficiary population were investigated.The water samples were collected and tested with related standard methods on July and November,2005.Results The total rural population in Guangxi Zhuang Autonomous Region was 41.424 0 million,13.858 1 million people were served with central water supply,accounted for 33.45%.There were 14 260 township and village level central water supply systems.Of these systems,only 1 157 had water purification facilities,accounted for 8.11%.A total of 475 water samples were tested,the eligible was 25.68%.The eligible rates were 23.71% and 27.57% in rainy and dry seasons,respectively.The bacteriological indexes were the main noneligible indexes,as for total coliform,the eligible rate was less than 40%.The rural population consuming unsafe drinking water was 17.768 6 million,accounted for 42.9%.Conclusion The drinking water safety in rural areas in Guangxi Zhuang Autonomous Region is to be solved urgently.Special focus should be paid to the construction and management of rural drinking water safety projects.

Objective To know the drinking water quality,latrine improvement and fecal,domestic garbage,sewage treatment in the rural areas in Guangxi Province.Methods The survey was carried out according to "National Scheme on Current Situation of Rural Drinking Water and Sanitation" from July to December,2006.The water samples were collected in rain season(August 2006).2 414 houses were investigated in 241 administrative villages of 23 counties.Results In the rural population,31.66% was served by central supply,68.34% was served by non-central supply in Guangxi Province.22.22% of the people used surface water and 77.78% used ground water.The eligible rate of water quality was 21.58%.As for surface water,the eligible rate was 32.76%,as for ground water,it was 18.03%.As for central water supply,the eligible rate was 24.06%,as for non-central water supply,it was 18.52%.The eligible rate of total count of bacteria and total coliform was only 62.24% and 29.88% respectively.The sanitary latrine rate was only 43.79%.The treatment rate of domestic garbage was 45.57%,industrial garbage was 80.17%.No domestic sewage was treated,the treatment rate of production wastewater was very low(only 1.59%).Conclusion The drinking water quality and sanitation in the rural areas in Guangxi Province should be improved as early as possible.

Objective To understand and master the dynamic changes and contributing factors to Guangxi rural drinking water quality. Methods No less than 25% of counties in Guangxi Zhuang Autonomous Region were randomly selected according to the proportional stratified sampling method to build the monitoring network for the dynamic monitoring of rural drinking water quality. The sampling time was arranged in the rainy (July or August) and dry season (March or November) in 2007 and 2008, respectively. The test methods were those documented in the standard (GB 5750-2006). Results The coverage rate of rural centralized water supply was 35.72% in 2008, higher than that in 2007 (31.80%) by 3.92%; the eligible rate of water quality in 2007 and 2008 were 20.57% and 24.59% respectively. The eligible rate of water quality in dry season was higher compared with that in the rainy season. Among all the monitoring indexes, the microbiological index ranked the lowest in terms of eligible rate, ranging from 34.76% to 80.68% for central water systems, and from 21.43% to 66.57% for non-central water supply. Conclusion Microbiological pollution is the main influencing factor for drinking water quality in rural areas in Guangxi Zhuang Autonomous Region.

Objective To know the current situation of drinking water quality and the influencing factors of provided for oneself water supply in rural schools in Guangxi.Methods According to the randomly proportionate stratification (economic,geography and topography etc.),43 and 50 counties were selected in 2007 and 2008 and the monitoring sites from 3 rural schools with provided for oneself water supply facility were taken out based on the proportion of water sources and technical patterns coverage in each county.The survey on water supply technical patterns,water sources and their coverage was conducted.One hundred and thirty,one hundred and fifty-three monitoring sites in rain season (July or August) and dry season (March or November) were monitored separately in 2007 and 2008.The monitoring results of drinking water were assessed according to Sanitary Standards for Drinking Water Quality (GB5749-2006).Results The groundwater was main drinking water source,which were 84.03% and 90.75% in 2007 and 2008.Most of water supply had not any water treatment,which was 75.86% in 2007 and 64.22% in 2008.The qualified rate in rain season (18.02%) was significant lower than dry season (31.80%) (P

Objective To investigate the quality of drinking water produced by safe drinking water projects in rural areas of Guangxi.Methods A survey of water quality was conducted from January to October 2008,in the drinking water projects funded by treasure bonds in 89 counties (cities and districts) of Guangxi.The water samples were collected from waterworks and tap water in dry season (March) and rainy season (July to August),respectively,and evaluated for aesthetic,microbiologic and chemical indexes.Results A total of 1 327 drinking water projects were surveyed.58.25% had a daily output under 100 tons,and only 2.71% had an output over 1 000 tons (enough for 10 000 persons).Only 12.28% adopted comprehensive water treatment process (i.e.coagulation,sedimentation,filtration and disinfection),whereas 62.85% did not provide any treatment.Up to 79.80% had no disinfection equipment and 90% failed to provide effective disinfection.25.21% and 21.48% of finished water,and 25.78% and 20.59% of tap water samples tested up to the standard respectively in the dry season and rainy season.Over 88% of water samples met the aesthetic,chemical and toxicological standards (100% up to standard for chronic,arsenic and fluoride),while 73.16%-80.78% met the standard for bacterial count,30.86%-36.17% for fecal coliforms and 41.86%-47.73% for thermotolerant coliforms.Conclusion The study results indicate that the inadequate supply of safe water,absence of water treatment facilities and poor drinking water quality have represented a potential health risk in Guangxi rural areas.