US lakes have increased threat of toxin

By JW Dowey - 06 Aug 2014 8:12:0 GMT
US lakes have increased threat of toxin

The Great Lakes have never been immune to human effects. Lake Erie is one of many water bodies throughout the world that has now succumbed to regular and dangerous cyanobacterial blooms; Port Ryerse image; Credit: © Shutterstock

Toxic cyanobacteria don't sound dangerous enough, but their prevalence in many US water bodies and even worldwide is causing an extremely dangerous situation to build. From California and Lakes Erie and Ontario across to Kansas and North Carolina, no state is safe. Global warming has raised average temperatures in many lakes and that is enough to change conditions for the growth of microorganisms.

The threat to water supply and recreational lakes is made worse by torrential rains and the presence nationwide of high concentrations of agricultural fertilizers in many states' rivers. Ohio has been in the news this week because of the toxins from these so-called "algae" in shallow Lake Erie. The waters warmed up quickly in the spring and the combination of nitrogen and phosphorus concentrations and optimum heat created the bloom. Strong winds may have driven the cyanobacteria deep into the lake where water intakes are situated. We previously noted the 2011 blooms in - Lakes Erie and Huron Suffering.

For the residents, 2 days without water around Toledo, Ohio was enough to allow the microcystin poison in their water supply to dissipate. We're quite lucky that other towns don't seem to have had elevated levels of the toxin in their water. Bottled water sales in the area peaked and then ran out. The Environmental Protection Agency (EPA) considered this kind of situation in its National Lakes Assessment of 904 water bodies (excluding the Great Lakes.) No recommendations however could be made for regulations.

With no federal regulations or standards laid down, the need for bottled water could arise again anywhere. Boiling this poison has no effect as it would with bacterial contamination. The US Geological Survey has data on these blue-green algae and microcystin contamination levels, which become critical above 20 parts per billion even in recreational bodies of water. Other problems from the algae include production of foul smelling gas and great loss of life for wild animals.

Florida suffered marine contamination in 2013 with the loss of large numbers of manatee, with California's sea lions being brought into rehabilitation centers and record fish deaths this year Health effects on people or animals can be deadly, but begin with paralysis and seizures. Advice from medical personnel is essential immediately if anybody is thought to have drunk contaminated water. Water shortage in many US states also means that this situation could impact on future supplies. It is likely the water wars that have been predicted in many regions of the earth will apply to inter-state relations in the near future!