title: Microbial and heavy metal contamination of treated hospital wastewater in Thailand.
abstract: OBJECTIVE
  To determine the microbial and heavy metal contamination of treated hospital wastewater
  
  
  METHODS
  Methods of treating wastewater were acquired by questionnaires. Chlorine concentration, pH, bacteria and parasites in treated wastewater were tested in the individual hospitals. Heavy metal concentrations were measured by atomic absorption spectrophotometry.
  
  
  RESULTS
  In 2002, 72 hospitals were included in the present study. The common methods of treating wastewater were activated sludge and oxidation ditch. Bacteria exceeded standard numbers, pathogenic bacteria and parasites were found in two-thirds of the hospitals. Heavy metals, namely lead, chromium and cadmium, in the hospital effluent did not exceed standard concentrations.
  
  
  CONCLUSIONS
  Micro-organisms exceeding standard levels were found in treated wastewater in two-thirds of the hospitals. Lead, chromium and cadmium levels in hospital effluent were in an acceptable range.
authors.affiliation: Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok. sisdc@mahidol.ac.th
authors.forename: Somwang
authors.initials: S
authors.lastname: Danchaivijitr
authors.forename: Wichai
authors.initials: W
authors.lastname: Wongchanapai
authors.forename: Susan
authors.initials: S
authors.lastname: Assanasen
authors.forename: Duangporn
authors.initials: D
authors.lastname: Jintanothaitavorn
mesh_terms: D000818:Animals; D001419:Bacteria / Q000302:isolation & purification*; D002104:Cadmium / Q000032:analysis; D002857:Chromium / Q000032:analysis; D006801:Humans; D007854:Lead / Q000032:analysis; D008284:Maintenance and Engineering, Hospital / Q000592:standards*; D019216:Metals, Heavy / Q000032:analysis*; D010271:Parasites / Q000302:isolation & purification*; D018570:Risk Assessment; D013785:Thailand; D014865:Waste Disposal, Fluid / Q000592:standards*; D014867:Water / Q000469:parasitology*; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D002104:Cadmium; D014867:Water; D002857:Chromium; D007854:Lead