Americans have managed to befoul their natural resources on a scale unparalleled in history.
From the time.com
Let's not befoul this newsletter with garbage like this.
From the dallasnews.com
Its compounds create smog, cause cancer and respiratory disease, and befoul rivers, lakes and coastal waters.
From the sacbee.com
The crude emanating from BP's well threatens to befoul a number of alliances between energy conglomerates and environmental nonprofits.
From the heraldtribune.com
Many stores now label the phosphate content of detergents that they sell, thus encouraging housewives to choose a brand less likely, after sewage treatment, to befoul waterways.
From the time.com
Most right-minded people can agree that politicians are plain awful, that Republicans are inveigling demons sent to befoul our souls, and that Democrats are nincompoops.
From the ideas.time.com
More examples
Foul: spot, stain, or pollute; "The townspeople defiled the river by emptying raw sewage into it"
(befouled) made dirty or foul; "a building befouled with soot"; "breathing air fouled and darkened with factory soot"
(befoulment) the state of being polluted
To make foul; to soil; To entangle or run against so as to impede motion