10 things you must know about Phosphate pollution

Last week, the media reported the alarming situation in Bengaluru city's Varthur lake as polluted foam from the lake spilled into the roads and surrounding areas. Similar reports appeared in the press about Bellandur lake pollution.

The following are the 10 things you must know about phosphate pollution in lakes and streams:

1. Phosphate along with nitrogen is a known naturally occurring ‘nutrient’.
2. Phosphorus helps in the growth of plants like algae in aquatic ecosystems like lakes. Fish and other species feed on algae.
3. Higher levels of phosphorus lead to faster growth of aquatic plants like algae. If you see weed like growth covering a large portion of a lake nearby, you can suspect nutrient pollution.
4. Such growth of algae results in toxic algal blooms that are recognized by changes in the color of water.
5. Faster plant growth in water bodies reduces the concentration of oxygen in these waters, and results in a condition called ‘Hypoxia’.
6. Hypoxia results in the death of animals like fish in aquatic systems severely polluted by phosphorus and nitrogen.
7. Eating seafood from lakes or streams high in algal blooms is a risk to human health. The effects reported include deaths and neurotoxicity.
8. High levels of phosphorus reaches water bodies from agricultural actives, fertilizer overuse, untreated sewage, human waste, and storm water runoff.
9. Household detergents, pet waste, and lawns in urban areas contribute to phosphorus pollution.
10. It took more than 40 years to reduce phosphorus pollution into the severely polluted Lake Erie.