The evidence is building that the chemicals present in contraceptives are harmful to the environment and to animals — such as human beings — who live in the “environment”, i.e., drink from the water supply:

In the case of oral contraceptives, the key ingredients are synthetic hormones known as progestins, which mimic progesterone, either alone or combined with estrogen. When used therapeutically in contraceptive pills or in hormone replacement treatments for menopause, these synthetic hormones make their way into the water supply after being excreted in the patients’ urine. As environmental contaminants, these are referred to as endocrine-disrupting chemicals (EDCs), due to the fact that they interfere with the endocrine systems of humans and animals alike following exposure.