It sure looks nice but who can tell
On Guanabara Bay?
Waters glisten and sailboats glide,
And so it's hard to say.
The mountains rise, the clouds hang low
Across a blue-gray sky
While cable cars to Sugarloaf
Are slowly riding by.
It all rests easy on the eyes _ 
Of that, there's no dispute.
There clearly seems no need to don
 A high-tech hazmat suit.
No trash befouls the gentle waves,
No stench assaults the nose.
The smell is one that's of the sea
If not quite like a rose.
The water's free of furniture
And fish too ill to swim.
No mattresses, no carcasses,
No disconnected limb. 
But microbes lurk, and all is not
What it appears to be.
For the devil's in the details
And in the deep blue sea.