ABSTRACT
Objective:To explore the potential suitable distribution area and the high-quality distribution area of <italic>Sabia parviflora</italic>. Method:Combined with the distribution information and environmental factors，the maximum entropy （MaxEnt） model and ArcGIS software were used to predict the potential suitable distribution area of <italic>S. parviflora</italic>. Based on the correlation between environmental factors and total saponins，total flavonoids，quercetin-3-<italic>O</italic>-gentiobioside，camellianoside，tsubakioside A，kaempferol-3-<italic>O</italic>-rutinoside and isobariclisin-3-<italic>O</italic>-rutinoside，the quality regionalization was conducted by using spatial interpolation method and fuzzy superposition function in ArcGIS software. Result:<italic>S. parviflora</italic> is mainly distributed in Yunnan，Guizhou，Guangxi province in China. The medium and high suitable areas accounts for about 2.88% of the national area. The precipitation in October and November，the precipitation in the warmest and driest seasons，the standard deviation of seasonal changes in temperature and altitude are the main environmental factors that affect the distribution of <italic>S. parviflora</italic>. Slope，precipitation，solar radiation and temperature change had great influence on the accumulation of secondary metabolites. Based on the results of potential suitable distribution and spatial interpolation of each component，the high-quality areas of <italic>S. parviflora</italic> are mainly concentrated in the southwest of Guizhou，with Qinglong，Guanling，Zhenning，Pu'an，Xingren county and other areas as the core. Conclusion:This study provides a scientific guidance for the site selection of artificial planting and the procurement of medicinal materials for <italic>S. parviflora</italic>.
ABSTRACT
Objective To evaluate the inverse distance weighted(IDW) in revealing the characteristics of spatial distribution of water fluoride in Heze City,Shandong Province.Methods A geographic information system (GIS) database of water fluoride was established in Heze City of Shandong Province using the data of endemic fluorosis surveys collected by Endemic Disease Prevention Institute in Shandong Province during 2005-2007.IDW spatial interpolation was applied to predict the distribution of fluoride in drinking water in 139 towns of Heze City.Sensitivity and specificity were calculated.Results Mean water fluoride levels in 10 counties of Heze City were all higher than 1.0 mg,/L,and the water fluoride in Cao County,Juye,Mudan District and Juancheng were higher than 2.0 mg/L.Of all 139 townships of Heze City,129 were higher fluoride townships where fluoride was ＞ 1.0 mg/L,10 were lower fluoride townships(≤ 1.0 mg/L).IDW spatial interpolation showed that the water fluoride of most areas in Heze City were ＞ 1.0-2.0 mg/L.The areas with water fluoride of ＞ 2.0-3.0 mg/L were mainly located in eastern Juancheng,northern Mudan District,north-central Chengwu,central and southern Juye,southeastern part of Caoxian and eastern part of Shan Town.Regions of water fluoride ＞ 3.0 mg/L were mainly distributed in Xieji and Wanfeng towns of Juye County,Jishan town of Juancheng County,Sunlaojia town of Caoxian and Dusi town of Mudan County.The internal verification results showed that the sensitivity,specificity and overall accuracy rate of IDW used for predicting water fluoride content was 100.00％ (129/129),10.00％ (1/10) and 93.53％ (130/139),respectively.While the external verification results showed that the sensitivity,specificity and overall accuracy rate of IDW for predicting water fluoride content was 100.00％(31/31),11.11％(1/9) and 80.00％(32/40),respectively.Conclusion With the application of IDW interpolation,it is feasible to infer the overall spatial distribution based on the monitoring data,and to reveal the spatial characteristics of water fluoride in Heze City,Shandong Province.
ABSTRACT
Objective To establish a new method for assessing the effects of environmental factors on human health.Methods Based on the environment part of the frame for comparative risk assessment(CRA) of WHO,the frame and index system for environmental contamination risk assessment which accorded with the situation in China was developed.With the prevalence of different exposure level,RR and the choice of counterfactual scenario,the potential impact fraction(PIF) was estimated.Then an example on the study of liver cancer related with water pollution was used to show the new frame.In this example,the contaminated water was regarded as the environmental factor,incidence of liver cancer was regarded as variable of health,and the analysis was performed with spatial interpolation,counterfactual analysis and CRA theory.Results The quantity of COD of river water in this area was estimated with ordinary Kriging interpolation,and the accumulated exposure of COD was calculated with the trend of annual COD,and the number of population exposed to COD was estimated at same time.In accordance with the different level of pollution and the RR relate to liver cancer,the trend with monotonically increasing showed.At same time,the values of PIF illuminated that 75.72% in male and 66.39% in female would avoid death for liver cancer if the level of contaminated water could be reduced to the level of the control areas.Conclusion The frame includes CRA,spatial analysis and counterfactual analysis is a good approach to assess the health effects of environmental factors.