For another clustering approach, we classify the PPCP molecules depending on their environmental effects (see Figure ). The main environmental effects, according to several publications (see SI Table ), are toxicity towards (aquatic) organisms, impact on the endocrine system of aquatic organisms, induction of behavioral changes in animals (leading to a reduced relative fitness of these animals), development of multi-resistant microbes and toxicity towards sludge bacteria (thus compromising wastewater treatment plants (WWTP)). It has to be noted that some PPCPs impact the environment in more than one way, therefore double counting is present in this representation to some degree. Substances that are toxic towards (aquatic) organisms, impact their endocrine systems or induce behavioral changes affect local ecosystems by altering population levels and thus influence food chains and other complex environmental mechanisms. However, these effects are, in the most cases, of a more local nature receding with distance from the contaminated water bodies. Zeolite frameworks that could find local application to remove preferably PPCPs that are toxic towards (aquatic) organisms are the MTW, IFR or BEA frameworks. An enhanced ability for the removal of endocrine disrupting substances can be seen for the CFI, AFI, MOR and BEA framework. Even though the TON framework shows a strong affinity towards species with this environmental effect, due to the narrow pores only Metformin, an antidiabetic drug that impacts the endocrine system of zebrafish, can fit into the pores while the other compounds with similar effects (mainly, but not exclusively, steroid hormones) cannot be adsorbed. The strongest increase in relative IE between PPCPs that induce behavioral changes in animals and zeolite frameworks is shown for the CFI and MOR framework. As the compounds in this effect class are often hormones which also show endocrine disrupting effects, the rather pronounced correlation between the endocrine disruption and the behavioral change is unsurprising.