[Epidemiological Survey on Intestinal Parasitic Infections in Lhasa City in 2014].

Objective: To investigate the prevalence of parasitic infections in Lhasa, Tibet. Methods: The residents in Chengguan District, Dangxiong County, Dazi County and Qushui County were selected to participate in the study in 2014, using the stratified random sampling method. Infections with the soil-borne nematodes in feces were examined in triplicates using the Kato-Katz method. Further, the Enterobius vermicularis were examined using the cellophane anal swab method in children aged 3-12 years, and the intestinal protozoa were detected by iodine staining. The parasitic infection was analyzed by sex, age, and occupation. Comparisons were made using Chi-square test. Results: A total of 1 015 residents（39.3±18.2 years: age range, 1-89 years） participated in the study, including 391 males（38.6%） and 623 females（61.4%）. Two hundred and forty-nine participants were positive for parasitic infections, with an overall infection rate of 24.5%（249/1 015）. The infection rate was 21.7%（220/1 015） for Taenia sp., 0.2%（2/1 015） for Trichuris trichiura and E. vermicularis respectively, 4.1%（42/1 015） for Entamoeba coli, 0.4%（4/1 015） for Giardia lamblia, 0.2%（2/1 015） for Iodamoeba butschlii. No infection was found for other parasites. There was no significant sexual difference in the infection rate of Taenia (male 21.2%, 83/391; female 22.0%, 137/624), T. trichiura (male 0; female 0.3%, 2/624), E. vermicularis (male 0.3%, 2/391; female 0.2%, 1/624), E. coli (male 5.4%, 21/391; female 3.4%, 21/624), G. lamblia (male 0.8%, 3/391; female 0.2%, 1/624), or I. butschlii (male 0; female 0.3%, 2/624) (P>0.05). The Taenia sp. infection rate in the age groups of 0-17, 18-29, 30-39, 40-49, 50-59 and ≥ 60 years was 10.9%（18/165）, 14.0%（18/129）, 23.0%（43/187）, 25.3%（61/241）, 26.5%（41/155）, and 28.3%（39/138）, respectively, with significant differences between groups of 0-17 and 40-49 years and between groups of 50-59 and ≥ 60 years (P<0.01). The infection rate of E. coli, T. trichiura and I. butschlii was highest in the age group of 50-59 years（6.5%, 10/155; 0.7%, 1/155; 1.3%, 2/155 respectively）. Among various occupations, farmers showed the highest infection rate for Taenia（44.5%, 147/330）, E. coli（6.4%, 21/33）, E. vermicularis （0.6%, 2/330） and I. butschlii（0.3%, 1/330）; housewives had the highest infection rate for T. trichiura（2.5%, 1/40）; and the students had the highest infection rate for G. lamblia (0.7%, 1/134). Conclusion: There are infections with various intestinal parasites in the participants of Lhasa City, among which taenia infection reaches 20.7% while others have a low level of infection.

Landfills in Jiangsu province, China, and potential threats for public health: leachate appraisal and spatial analysis using geographic information system and remote sensing.

Waste disposal is of growing environmental and public health concern in China where landfilling is the predominant method of disposal. The assessment of potential health hazards posed by existing landfills requires sound information, and processing of a significant amount of spatial data. Geographical information system (GIS) and remote sensing (RS) are valuable tools for assessing health impacts due to landfills. The aims of this study were: (i) to analyze the leachate and gas emissions from landfills used for domestic waste disposal in a metropolitan area of Jiangsu province, China, (ii) to investigate remotely-sensed environmental features in close proximity to landfills, and (iii) to evaluate the compliance of their location and leachate quality with the relevant national regulations. We randomly selected five landfills in the metropolitan areas of Wuxi and Suzhou city, Jiangsu province, established a GIS database and examined whether data were in compliance with national environmental and public health regulations. The leachates of the sampled landfills contained heavy metals (Pb, As, Cr(6+) and Hg) and organic compounds in concentrations considered harmful to human health. Measured methane concentrations on landfill surfaces were low. Spatial analysis of the location of landfills with regard to distance from major water bodies, sensible infrastructure and environmental conditions according to current national legislation resulted in the rejection of four of the five sites as inappropriate for landfills. Our results call for rigorous evaluation of the spatial location of landfills in China that must take into consideration environmental and public health criteria.