The long term effects of pharmaceuticals in the environment may affect survival and reproduction of such organisms. However, levels of medical drug waste in the water is at a low enough level that it is not a direct concern to human health. However, processes, such as biomagnification, are potential human health concerns. On the other hand, there is clear evidence of harm to aquatic animals and fauna. Recent advancements in technology have allowed scientists to detect smaller, trace quantities of pharmaceuticals in the ng/ml range. Despite being found such low concentrations, female hormonal contraceptives have been documented to cause feminizing effects on male vertebrate species, such as fish, frogs and crocodiles. A promising model has been developed to further study the effects on the aquatic environment. The "biological read across model" combines the concepts of the mechanism of action (MoA) and adverse outcomes pathway (AOP). In other words, the species being studied needs to have similar mechanisms by which the pharmaceutical acts on the species and reach similar concentrations that would be enough to cause an effect in humans. Studying these relations may give us more quantifiable information on the effects of pharmaceuticals in the environment. Currently, research is being done on various methods of reducing chemical waste in the environment. In addition, the U.S. Food & Drug Administration (FDA) established guidelines in 2007 to inform consumers should dispose of prescription drugs. When medications do not include specific disposal instructions, patients should not flush medications in the toilet, but instead use medication take-back programs. This aims to reduce the amount of pharmaceutical waste that gets into sewage and landfills. If no take-back programs are available, prescription drugs can be discarded in household trash after they are crushed and/or dissolved and then mixed in a separate container or sealable bag with undesirable substances like cat litter or other unappealing material (to discourage consumption).