Vol 21 No 1-4 (1992)

Articles

  • XML | PDF | downloads: 57 | views: 123 | pages: 1-10
    Natural sources of water contain some halogenated organic compounds after disinfection by chlorine. Trihalomethanes are one group of the chlorination by products that suspected of being carcinogenic inhuman unfortunately, these compounds are in finished water of all treatment plants that use chlorine as a disinfectant. In this study, the concentration of total THMS of water treated in the water treatment plant No.1 of Tehran had been measured by spectrophotometric method, along the month of June, 1371. Results of experiments have shown that organic contents of Tehran drinking water were not considerable in the period of survey. The mean concentration of TTHMS in water samples is estimated to be 28 micrograms per liter and none of the analyzed samples was considered polluted.
  • XML | PDF | downloads: 120 | views: 108 | pages: 11-28
    This research was done in order to determine the basic criteria for “Tehran Oil Refinery Effluemt TreatmentUnit” to prove the feasibility of the application of powdered activated carbon in aeration zone of activated sludge System. The main stages of this research included: determination of qualitative and quantitative characteristics of raw wastewater preparation of two pilot scale units of activated sludge (As) and powdered activated carbon technology (PACT), study of correlation between independent variables of powdered activated carbon concentration, hydraulic detention time, and microbial detention time with the concentrations of COD, B0D5 and TSS of the effluent. Results indicated the efficiency increase of Tehran oil refinery effluent treatment by PACT process , which besides increasing COD5 , BOD5 , Oil and TSS removal, improves also nitrogen and phosphorus removal Conditions and activated sludge sedimentation, comparing as system.
  • XML | PDF | downloads: 62 | views: 125 | pages: 29-38
    This Survey was carried out from June to October 1990, in order to evaluate the prevalence of intestinal parasites in the residents. A total of 2227 persons were selected from 44 Villages by using linear Systematic Sampling Method. The Samples of stool from these people were examined by formalin - ether concentration procedure. The collected data were analyzed by spss package. The result showed that 69.2% of the specimens were infected with intestinal parasites, which 58.4% of them were pathogenic (33.8% 16.9%, and 7.7% were infected with 1,2 and 3 species intestinal pathogen parasites respectively). Infection rates with intestinal pathogen parasites was higher in mountains (71.4%) than plain areas (49.6%). and also higher in age groups 5-14 years (68.0%) than other age groups. The difference of the infection rates was nonsignificant between males and females. Prevalence of different intestinal parasites was as follows: Protozoa; E.Coli 27.9% G. lamblia 17.2% I.butschlii 7/0% E.histolytica 5.9% E. hartmann 2.9% E. nana 2. 1% D. fragilis). 6% and C.. mesnili 0.4% Helminths; T. trichiura 26. 8% A. lumbricoides 17.8% Hook worm 8.9% S. stercoralis 8.5% E. vermicularis 3. 6% T.saginata 1. 4%, H.nana %1.0 and Trichostrongylus sp. 0.7%
  • XML | PDF | downloads: 62 | views: 121 | pages: 39-52

    The genetics and mechanism of malathion resistance in the adults of An. stephensi (BAN-S), Was studied. Nine successive generations of malathion selection in the adults resulted in an increase in LTSO of about 3-fold. The crossing experiments indicated that the resistance is inherited as partially dominant character with no indication of sex linkage. The results of back-crosses suggested that probably more than one genetic factor are responsible for malathion resistance. Synergist study with TPP and PB indicated that the involvement of carboxyesterase as the main resistance factor in An. Srephensi. The cross- resistance spectrum of malathion resistance with pirimiphos- methyl, DDT and dieldrin were studied in the selected strain. The results did not show any relationship between resistances to malathion, DDTand pirimiphos- methyl. Dieldurin test on the selected and uselected strains showed that malathin resistance could increase dieldrin resitance.

  • XML | PDF | downloads: 62 | views: 107 | pages: 53-68

    One thousand children from 20 day care centers were studied for intestinal parasites in Tehran. The stool samples Collected from 0 - 6.6 years old Children and examined by formalin ether concentration method for parasitic ova and cyst. Cellophane tape technique (Graham’s method) also applied for Enterobius vermicularis diagnosis, of these 454 children were positive. E.vermicularis with the rate of 272 per thousand)Giardia lamblia (204) per thousand) and Entamoeba Coli (55 per thousand)were the Commonest parasites found. The prevalence rate of other parasites present included Hymenolepis nana (13); E. histolytica (9); Ascaris lumbricoides (7); E. hartmanii, Endolimax nana (5); Dientamoeba fragilis (6); lodamoeba butchelii, Chi1omastix meseneli (3); and Trichurjs trichiura, Trichomonas hominis (1) per thousand. There were no difference in.the rate of infections between boys and girls with exception for E. histolytica. The significantly higher precvalence rate of E. vermicularis was found in age group of 4-6 years. There was no difference between various age groups of other parasites.

  • XML | PDF | downloads: 245 | views: 104 | pages: 53-68
    115 couples with consanguineous marriage, who had experienced reported abortions or still births either in their close relatives (3 couples) or themselves (1 couple) were exposed to genetic counseling (at the Shahid Akbarabadi hospital) Cytogenetic studied were carried out using both conventional staining and G.T.G banding for all the cases studied. The investigation demonstrated various forms of balanced translocation as fully discussed in the presented paper. During genetic counseling, information5 were also given to each couple regarding the Probability of having healthy or affected offspring’s, and also concerning prenatal diagnosis of the futures during pregnancies.