Microcystins – Blue Green Algae- Cyanobacteria
Your Drinking Water
The first step in understanding
this situation is it is important that you understand the source of your
drinking water. Is the source a surface water
reservoir, stream, river, or groundwater source and if you are part of a
municipal or regulated water supply or if you are a private water supply
system. The second step is to review
available water testing information on the quality of the water. If you have not gotten any data in the mail
and you do not get a water bill, it is likely that you are on a private system
and need to get your WATER Tested Yourself.
If you get an annual report, you would want to look at issues related to
general quality and the source of your water.
If the report says that the source is a lake or reservoir and there is a
Water Treatment Plant that filters the water, it is likely your source could be
influence by Microcystins and Blue-green Algae.
So what happened in Ohio and what
is microcystin?
In Toledo, Ohio -Toledo's Collins Park
Water Treatment Plant found two sample readings for microcystin in excess of
the one-microgram-per-liter (1 ug/L or 1 ppb or 0.001 mg/L). First – they did not mention if this was in
the raw or finished (treated) water. It
would make sense is was the level in the finished or treated drinking water.
There is no federal drinking
water standard for microcystin, but there is a WHO (World Health Organization) has
a provisional standard for
Microcystin-LR of 1 ug/L. Microcystins
are not regulated by USEPA in drinking water, but are unregulated microbial
drinking water contaminants listed on the USEPA's Contaminant Candidate Lists
(CCLs) 1 and 2 as cyanobacteria and their toxins. Specific varants, Anatoxin-A, Microcystin-LR
and Cylindrospermopsin, are on the USEPA's Contaminant Candidate Lists 3-
CCL3. Minnesota analysis of acute
response suggests a guidance limit of 0.04 ug/L, but the method detection limit
for the available method is 0.15 mg/L.
What are blue green algae
(cyanobacteria)? (Yes we are talking
about POND SCUM!)
Blue green algae lives in a wide
range of environments including freshwater, saltwater, brine, soil and even in
very brackish water. They are among some
of the oldest “organisms” on the planet and probably responsible for the fact
we actually have oxygen. They can live in freshwater, salt water, or in mixed
“brackish” water. They are called
blue-green algae, but they come in a wide range of colors including red, brown,
orange, and green (Strange – They do not come in BLUE). These blue green algae can actually be many
colors including green, red, orange, or brown. Because these organisms have characteristics
similar to bacteria they are called or known as “cyanobacteria.” Cyanobacteria are one of the oldest microorganisms on Earth, predating predators, 3.5 billion years ago.
What causes these organisms to form
“blooms”?
Well for some the answer is Climate
Change, but for them the answer to most things is climate change. The real reason why we have blue green algae
blooms is because these organisms have an advantage. When they do not have enough nitrogen to
grow – they can fix the nitrogen directly from the atmosphere. Just think – you would have an advantage over
others if you could PRINT MONEY. For
these organism, this happens when there is so much phosphate in the water the
growth rate of the organism is no longer limited by the phosphate, but limited
by nitrogen. When this occurs, these
organisms have the advantage and then out-grow and shade out all the other
algae. The second advantage they are big
and small fish and zooplankton do not like to eat or can not eat.
What causes some blooms to be
toxic?
Only some blue-green algae produce
microcystin toxins. Why? You will not like this answer, but we do not
know. My guess is it is a defense mechanism
to prevent predation by zooplankton or it could be just part of the metabolite
process they developed. There are thousands of blue green algae species and
many more are still being discovered. Most do not produce toxins that are
harmful to people or animals. However, some types of blue green algae produce
toxins within their cells which are released when the cells die off or are
ruptured. It is not clear why blue green algae make these toxins.
A microcystin is?
A toxin produced by bacteria of the genus
microcystis (planktothrix cyanobacteria (i.e.,
some filamentous blue green algae), a type of blue-green algae, or cyanobacteria. Only certain
species of blue-green algae form toxins, for reasons that aren't fully
understood. Microcystins are toxic peptides, i.e.,
peptides are short chains of amino acids linked together via peptide bonds. These peptides are produced in large quantities during blooms. Microcystins typically persist even after the
collapse of the algal blooms.
Microcystin can produce hives or blisters from direct contact with the
skin. Swallowing it can cause headaches, fever, nausea, vomiting and diarrhea.
Large-scale ingestion can damage the liver.
What environment factors lead to
formation?
Microystin is associated with
blooms of Cyanobacterial, i.e., blue-green algae. The primary environmental factors that lead
to this condition high levels of phosphorous (source direct discharges,
non-point sources, and internal cycling from the sediments), growth limiting
nutrient is nitrogen not phosphorous, temperatures in the 5 to 30 C and related
to the condition within the surface water source, such as a lake that recent
was “turned over” and is not a complete mix system. Is this caused by climate change – the
science is not in yet – My Scientific Opinion Based on Available Data is NO,
but I am open to Facts!
Microcystin toxins are nonvolatile,
hydrophilic (i.e., have an affinity for water- “Makes Sense”, and stable in
sunlight, and stable over a wide temperature and pH range. Factors affecting
toxin production are light and temperature, with optimum temperatures from
cyanobacteria ranging 20 to 25 C- as the algae becomes more productive the
levels of microcystin increase. Elevated
levels may persist for up to 2 months following the decline of the algal
populations.
YOU may have a problem with your
lake or reservoir, if:
Based on these studies - Current
recommendation are as follows:
1. Monitor you lake quality, parameters such as pH,
conductivity, phosphate, secchi depth, and alkalinity.
2. Monitor the vertical profile of the lake or reservoir and
understand how it changes overtime.
3. Avoid contact with blue-green algal blooms.
4. The greatest risk may be when the water transparency or secchi
depth is low (< 0.5 m), pH > 9.0, or when distinct surface scums are visible.
5. If you have the budget, hire a professional to assist with
conducting a lake and watershed assessment to understand the
sources and sinks for nutrients and the food-web for the system.
6. Test for chlorophyll a, conduct phytoplankton and zooplankton
counts, and test the water for mirocystin.
Websites
http://water.epa.gov/scitech/drinkingwater/dws/ccl/
