This study was conducted to determining the values of LC50, mortality rates and DNA damages (Daphnia magna) of species exposed to pozzolanic cement concentrations of 50, 100, 150, 200, 250, and 300 mg/L for 24 h. To compare the effect of increased pH value associated with the addition of cement, a NaOH group was also formed in Gammarus komareki individuals. As a result, the LC50 values in D. magna and G. komareki were calculated as 118.57 and 197.24 mg/L/24 h, respectively. It was observed that, unlike the G. komareki individuals, cement particles were accumulated on D. magna. In the comparison trial (NaOH) performed on G. komareki individuals, 60% mortality was determined. The number of deaths from cement and NaOH in the experimental groups with the same pH values were found similar. There was not statistically significant difference between control and experimental groups for DNA damage on D. magna. As a result, it has been determined that cement has a toxic effect on D. magna and G. komareki due to increasing the pH value of water.