Kadmiyum (CdCl 2.H 2O), arsenik (AS 2O3) ve kadmiyum-arsenik karışımının Daphnia magna (Straus 1820) (Cladocera, Crustacea ) üzerine akut toksik etkilerinin araştırılması

Bu calismada kadmiyum (CdCl2.H2O), arsenik(AS2O3) ve karisimlarinin Daphnia magna  (Straus 1820) (Cladocera, Crustacea) uzerine etkileri arastirilmistir.  Elde edilen sonuclar istatistiki olarak Probit analiz (SPSS 17.0) yontemine gore hesaplanmis ve D. magna uzerine; kadmiyumun 24 saatlik LC50 degeri 44 µg/L, arsenigin LC50 degeri 509 µg/L bulunmustur. Ayni zamanda Behrens-Karber yontemi ile hesaplanan sonuclarin 24 saatlik LC50 degerleri sirasiyla 46µg/Lve 509µg/L oldugu saptanmistir. Bu iki yontemin sonuclari karsilastirildiginda degerlerin cok benzer oldugu gorulmustur. Elde edilen sonuclar kadmiyumun arsenige gore D. magna uzerine daha toksik oldugunu gostermistir. Tek basina agir metallerin ve agir metal karisimlarinin toksisite siralamasi % 90 Cd + % 10 As > Cd > % 50 Cd + % 50 As > % 10 Cd + % 90 As > As olarak bulunmustur. Sonuc olarak % 90 Cd + % 10 As karisiminin tek basina kadmiyuma gore D. magna uzerine daha toksik oldugu bulunmustur. Karisimdaki bilesenlerin birbirleri uzerine olan etkilerini (sinerjistik-antagonistik) anlamak amaciyla Toksik Birim (TUs) ve Additional Indeks (AI) degerleri kullanilmistir. Bu calisma sonucunda tum karisimdaki bilesenlerin etkileri sinerjistik bulunmustur.Abstract  In this study the acute toxicities of cadmium chloride (CdCl2.H2O), arsenic trioxide (AS2O3) and their mixtures to Daphnia magna were investigated employing the statistic method of aquatic toxicity. The data obtained were statistically evaluated with Probit Analysis method (SPSS 17.0) and the 24h LC50 of cadmium and arsenic to D. magna were estimated for Cd to be 44µg L-1, and for As 509µg L-1, respectively. Also, the 24h LC50 of these metals was found to be 46µg L-1 and 509µg L-1, respectively with Behrens-Karber method. The two methods were found to be in good agreement. The results suggested that D. magna is more sensitive to the 90% Cd + 10% As mixture than cadmium alone. Toxic Units (TUs) and Additional Index (AI) showed that all mixtures were synergistic. The order of toxicity was found as 90% Cd + 10% As > Cd > 50% Cd + 50% As > 10% Cd + 90% As > As. The results showed that D. magna is more sensitive to 90% Cd + 10% As mixture than individual cadmium. Toxic Units (TUs) and Additional Index (AI) used to understand the effect of components in the mixture whether synergistic or antagonistic to D. magna. In this study, it was found that the combined effects of all mixtures were synergistic.