Water eutrophication has become a worldwide environmental problem in recent years, and understanding the mechanisms of water eutrophication will help for prevention and remediation of water eutrophication. In this paper, recent advances in current status and major mechanisms of water eutrophication, assessment and evaluation criteria, and the influencing factors were reviewed. Water eutrophication in lakes, reservoirs, estuaries and rivers is widespread all over the world and the severity is increasing, especially in the developing countries like China. The assessment of water eutrophication has been advanced from simple individual parameters like total phosphorus, total nitrogen, etc., to comprehensive indexes like total nutrient status index. The major influencing factors on water eutrophication include nutrient enrichment, hydrodynamics, environmental factors such as temperature, salinity, carbon dioxide, element balance, etc., and microbial and biodiversity. The occurrence of water eutrophication is actually a complex function of all the possible influencing factors. The mechanisms of algal blooming are not fully understood and need to be further investigated.
Animals ; Environment ; Eukaryota ; growth & development ; isolation & purification ; Eutrophication ; Humans ; Water ; analysis ; Water Microbiology

Karaj is an area with large influx of refugee people in Iran. To increase knowledge about parasitic infections, we carried out this research during 2006-2008. We recorded the stool examination results and some of their personal characteristics. A total of 13,915 human stools were examined, and 649 (4.7%) were positive for intestinal parasites. Among them, 13 (0.09%) had worm and 636 (4.6%) had protozoan infections. Maximum infections belonged to Giardia intestinalis, and 534 (3.8%) samples had this infection. Other parasitic infections included Entamoeba coli (0.39%), Entamoeba histolytica (0.021%), Blastocystis hominis (0.08%), Trichomonas hominis (0.1%), Iodamoeba butschlii (0.06%), Chilomastix mesnili (0.007%), Endolimax nana (0.05%), Enterobius spp. eggs (0.028%), Taenia proglottids (0.028%), and Strongyloides stercoralis larvae (0.03%). The maximum numbers of referred people to laboratories were in July and the maximum percentage of infections was in August. There is a point that all 5 Strongyloides stercoralis infections were pertained to 2008. With attention to the rate of parasitic infections (4.7%), it seems that we should take additional educational information to wide spectrum of people living in this city.
Adolescent ; Adult ; Animals ; Child ; Child, Preschool ; Cross-Sectional Studies ; Eukaryota/*isolation & purification ; Feces/parasitology ; Female ; Helminthiasis/*epidemiology/parasitology ; Helminths/*isolation & purification ; Humans ; Infant ; Intestinal Diseases, Parasitic/*epidemiology/parasitology ; Iran/epidemiology ; Male ; Middle Aged ; Protozoan Infections/*epidemiology/parasitology ; Seasons ; Young Adult

We examined stool specimens of the residents in the emigration camp in Tijuana, Mexico for helminth eggs or protozoan cysts with formalin-ethyl acetate concentration method in February and July 1992. Out of 92 examined samples, number of positive was 49 (53.3%). While number of cumulative positive was 66 (71.7%). Cysts of Entamoeba coli (29.3%) Giardia lamblia (9.8%), Entamoeba histolytica (7.6%), and eggs of Taenia spp. (6.5) were most frequently observed. Filtered water supply and chemotherapy were required in this camp.
Adolescent ; Adult ; Aged ; Animals ; Child ; Child, Preschool ; Concentration Camps ; *Emigration and Immigration ; Eukaryota/isolation & purification ; Feces/parasitology ; Female ; Helminths/isolation & purification ; Humans ; Intestinal Diseases, Parasitic/*epidemiology/parasitology ; Male ; Mexico/epidemiology ; Middle Aged

The incidence and etiology of parasite-associated gastroenteritis during 2004-2006 in Gyeonggi-do (province), South Korea was determined by means of antigen detection ELISA on 6,071 stool specimens collected from 6 general hospitals. At least 1 parasitic agent was detected in 3.4% (208/6,071) of the stool samples. Among these, Giardia lamblia was the most numerous (152 cases; 2.5%), followed by Entamoeba histolytica (25 cases; 0.4%), Cryptosporidium parvum (23 cases; 0.4%), and mixed infections (8 cases; 0.1%). Patients aged 1-5 years had the largest proportion (69.2%; 144/208) of parasite-positive stool specimens. Parasite-mediated gastroenteritis was most common from June to September. The detection rate gradually increased from 2004 to 2006. This study shows that parasite-mediated gastroenteritis may be significant among children in Korea and that parasite infection surveillance should be constantly performed.
Adolescent ; Adult ; Age Distribution ; Animals ; Child ; Child, Preschool ; Data Collection ; Eukaryota/*isolation & purification ; Feces/parasitology ; Gastroenteritis/*epidemiology/parasitology ; Humans ; Infant ; Protozoan Infections/*epidemiology/parasitology ; Republic of Korea/epidemiology ; Seasons ; Young Adult