Determination of LC50 from Daphnia magna in treated industrial waste waters and non-treated hospital effluents

The ecological risks associated with the effluents from 10 different factories and 3 hospitals in the Puebla area of Mexico were assessed using bioassays of Daphnia magna. Five factories discharged toxic effluents in terms of LC50 and 2 of the 3 hospitals discharged toxic waters. The results encouraged the introduction of toxicity bioassay using Daphnia magna into standard norms to assess water pollution in Mexico. The results showed a sensitivity close to that reported elsewhere.