I disagree for the brain. Decline only begins post-puberty, in the early twenties. The brain is still in development until puberty is initiated, after which further changes are no longer caused by its structural development, but rather as a result of the influence of hormones.

As far as animals affected by particulates in the water supply go, isn't that why Alex Jones was saying they were turning the frogs gay? Sure, he can be a nutjob and not always present all the evidence required to convince the population at large, but there's usually some grounding behind his claims. I also remember hearing about some other animals that are hermaphrodites, that can change sex, that were beginning to have an overrepresentation of females in their populations. I guess it is possible that this was caused by plastic rather than oestrogen, though.