“Water, water everywhere and not a drop to drink.” This quote from The Rhyme of the Ancient Mariner by English poet Samuel Taylor Coleridge came to mind recently while watching news feeds regarding a spectacular water contamination of toxic blooms along some of Florida’s most popular shorelines.

Life cannot exist without water and that’s why NASA’s primary test for life on other planets is evidence of water. But water is never pure. It’s the most common solvent, and the water in our lakes, rivers and seas can become extremely toxic—even deadly.

Toxic blooms that create adverse effects are called Harmful Algal Blooms (HABs). They grow naturally as a response to changes in the chemical content of water (like increases in nitrogen and phosphorus from fertilizer runoff) or changes in pH (how acid or alkaline the water is). HABs can also deplete the oxygen and block sunlight from water, thereby adversely affecting marine life.

HAB toxins also harm humans who come into contact with them. There are a couple of HABs that create the most havoc, but the most prevalent this year are Cyanobacteria (blue-green algae or pond scum).

There are both toxic and non-toxic strains of these algae. Spirulina is a type of blue-green algae that’s non-toxic, specifically because it’s free of microcystins (more on that in a minute). The toxic varieties (like what was reported in the news this past week) should never be ingested, even accidentally while swimming in contaminated waters.

Consumption produces abdominal cramps, nausea, diarrhea and vomiting. Prolonged skin exposure causes irritating rashes. More concentrated exposure can lead to liver damage and digestive problems. They also adversely affect the nervous system since they are neurotoxins (adversely affecting our brain and peripheral nerves).

Most varieties of Cyanobacteria (50–70%) are harmful, and that’s because they contain naturally-occurring neurotoxins in their cells. These toxins are called microcystins and are primarily responsible for the health issues associated with toxic blooms.

Microcystins are extremely stable (both to cold and heat as well as to changes in pH). For that reason, boiling water does not remove them. Ultra-filtration is the only safe way to purify water contaminated with such toxins.

So water is not only the giver of life. It can also take away life when there’s toxic baggage dissolved in or floating on that water. Stay safe this summer and avoid those areas of the beach that seem unusually colorful.

Thought? Comments? I’d love to hear them!