Assertion: nutrient pollution | /r/HasProperty | the number-one threat
Facets:
value: to water quality
type: TRANSITIVE-OBJECT
value: worldwide
type: LOCATION
Source sentences:
text: Nutrient pollution, caused by excess nitrogen and phosphorus in water or air, is the number-one threat to water quality worldwide and can cause algal blooms, a toxic soup of blue-green algae that can be harmful to people and wildlife.