As such, they are a bioindicator species whose presence may demonstrate that the water is relatively unpolluted.

It is relatively unpolluted, and its landscapes composed of green hills like Santo Amaro.

The planet's entire population is forced to migrate from southern to northern hemispheres and back again each year to stay in relatively unpolluted, winter environments.

From Ruggell one can stroll along the Rhine River, which is still narrow and relatively unpolluted here.

The light outside was a clean, clear, dawn light-as if even the relatively unpolluted air of the tropic outdoors had been recently washed by a rain shower.

They are relatively unpolluted and provide fish for locals and tourists.

Due to its relatively unpolluted image, various locations within Kodaikanal are used for movie shootings as well.

The results showed that it was relatively unpolluted and was well aerated.

Thanks to its relatively unpolluted waters and abundant fish, the Hwang is home to a population of endangered European otters.

Sithalapakkam was a relatively unpolluted place, however, due to factories and human settlement its pollution levels have increased dramatically.