# Cyanobacterial toxins?



## trystianity (Jul 21, 2005)

This is kind of a weird question but a lot of people here seem to be really knowledgeable about algae so I thought I would give it a shot. I remembered reading a few sources that mentioned toxins in BGA that can harm fish, but also pose certain risks to mammals including people as well. Effects I remembered reading about were contact dermatitis in people with sensitive skin (swimmers itch) and things like that. I was cleaning a few spots of BGA from one of my tanks today (my own fault for not keeping up with KNO3 dosing). Almost immediately afterward I noticed an itchy red rash breaking out on my hands that I am familiar with as contact dermatitis (I get it a lot), I have had this happen before when I've handled BGA in the past but never thought about it much. This sparked a lightbulb in my head so I decided to find out more about toxins and BGA.

This is a subject that's particularly important to me because I suffer from Multiple Chemical Sensitivity and Fibromyalgia. Because of that, I have to be very careful about exposure to anything that might be even slightly toxic, even at normally safe levels of exposure. Without going too far into it, I am hypersensitive to a lot of chemicals that most people wouldn't have problems with. No I am not crazy, ask my doctor. 

Anyway, I took some antihistamines and decided to do a bit of reading about cyanobacteria. I found a few really interesting abstracts and articles about the effects of BGA on humans. Most of them reported symptoms of contact dermatitis in people exposed to various types of cyanobacteria, and a few cases of serious reactions to consumption of cyanobacterial toxins (not so relevant to me, I have no desire to eat the stuff, but still interesting) here are a few I found especially good:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=pubmed

http://www.ncbi.nlm.nih.gov/entrez/...d&dopt=Abstract&list_uids=11769249&query_hl=3

http://www.fwr.org/cyanotox.pdf

http://bodd.cf.ac.uk/BotDermFolder/BotDermA/ALGAE.html

http://www.bioremediate.com/algae.htm

http://www.euro.who.int/watsan/Publications/20031021_12

After reading up on it a bit it doesn't sound like something I want to be in contact with! :shock: I think it probably did cause my rash after handling it, has anyone else experienced this or have any comments?

I have decided to treat the infected tank with erythromycin to obliterate it, after that I promise I will be more careful with my KNO3 dosing habits. Hopefully I won't have to deal with it again but until the erythromycin kills it and just in case I have to manually remove the evil slime in the future, I need some ideas to protect myself while handling it. I have some dust masks that I use for cleaning and I should be able to find some gloves to protect my hands from it. Is there anything else anyone can suggest? I always wash my hands really well before and after they are in my tanks but in this case it doesn't seem to help that much. 

And of course I suppose this means no drinking my tank water or chewing on spots of BGA I pull out......not that anybody needed to tell me that.


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## plantbrain (Jan 23, 2004)

Do not assume that the one single species that infest our tanks is a banlket statement for all BGA's..........

We only deal with one species of BGA, Oscillitoria.
I've never seen any associated deaths related to the this species, it might be from something else, like not cleaning the filter, reduced water current, poor environmental conditions etc, but not the BGA.

Regards, 
Tom Barr


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## trystianity (Jul 21, 2005)

plantbrain said:


> Do not assume that the one single species that infest our tanks is a banlket statement for all BGA's..........
> 
> We only deal with one species of BGA, Oscillitoria.
> I've never seen any associated deaths related to the this species, it might be from something else, like not cleaning the filter, reduced water current, poor environmental conditions etc, but not the BGA.
> ...


All of my filters are cleaned every 2 weeks, media is rinsed, filters are taken apart monthly for a thorough cleaning. On this tank in particular I have a lot of current, turnover rate is 15X per hour through the HOB filter and an additional about 15X from a powerhead. Water is changed 25% weekly and the tank is understocked, planted, etc. The water condition in the tank is fine. I put my hands in the tank twice to three times a day to feed the fish (they are hand fed), the only time I have ever noticed any rash has been when handling BGA itself. When it happened today, I was pulling some BGA out then noticed the rash right away.

From what I understand of Oscillatoria it is known to irritate the skin and cause contact dermatitis, gastrointestinal problems and other symptoms in swimmers. I haven't seen any deaths reported for it either. One CDC paper I looked at reported an incident with it in New Hampshire:



> In one outbreak (New Hampshire, August 2001), 42 children became ill with nausea, vomiting, and diarrhea after swimming in a state park lake. Oscillatoria was isolated from the lake water in high concentrations, which was consistent with the clinical symptoms manifested.


http://www.cdc.gov/mmwr/preview/mmwrhtml/ss5308a1.htm

I don't mean to be alarmist or anything, nor do I doubt your experience, I would personally just rather not take a risk with it. I'm not suggesting that this would be of much, if any concern to most people. As I said in the post above I have health problems that make me extremely sensitive to many chemicals and toxins, it's probable that it wouldn't be a problem for most people. In my case, however, I think it would be best to play it safe even if that means being a little overly cautious. So, on that note, what kind of measures would you recommend to be absolutely sure this isn't going to be an issue for me?


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## HeyPK (Jan 23, 2004)

If you want to keep from having contact with bluegreen algae, (1) wear gloves, (2) you can syphon out water and suck out globs of it with the syphon, (3) give your tank a prolonged dim (room) light period until the snails and fish (browsing fish, such as guppies, mollies, etc) have eaten all of the BGA. In low light, such as ordinary room light, the BGA is not able to produce its protective toxins, and becomes edible after four or five days for snails and fish. (5) Keeping your nutrient levels up, especially nitrate at 5-10 ppm, discourages BGA.


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## plantbrain (Jan 23, 2004)

trystianity said:


> In my case, however, I think it would be best to play it safe even if that means being a little overly cautious. So, on that note, what kind of measures would you recommend to be absolutely sure this isn't going to be an issue for me?


Let me put it another way, the likyhood you have a specific reaction to this one species is a risk, my advice if you are truly this sensitive, don't keep aquariums at all................your health is more valuable than a hobby........

No one has ever reported a rash or other skin related issues due to BGA, I know folks that have gotten bacterial resistent life threatening issues from tanks............one of out local members in fact.........

I'd be far more worried about the other bacteria in the tank rather than the BGA which do get lots of press.........

Look, if you are this worried, find another hobby truthfully, the hobby is great and all, but if this risk is something that you feel is a risk, it's not worth it. And I'd definitely say the aquatic microbes are far more worrisome than the one species of BGA..............you did read the cdc article correct??

The BGA was found where precisely and high level of what else where found there? That does not imply the BGA, the species in our relatively clean tanks causes your reaction.

I do not pretend to know your conditions but I'm good with infectious diseases, there are much worse things than BGA, that much I can assure you, and you'll never see them..................

I've known a dozen folks over the years that have gotten some serious infections, but not one due to BGA.............everyone that keeps planted tanks are exposured pretty much every time they stick their arms in the tank............

Killing BGA is simple:

See the Blackout method I've suggested for years.
3 days total blackout(cover the tank so that no light gets in)
Turn off CO2 etc,
Do 50% water change
Remove all the BGA you can
Add 1/4 teaspoon per 20 gallon of tank of KNO3

Wait 3 days
Do another 50 WC and add the same amount of KNO3 back.
Hook up the CO2 back.
Turn light on.
Add KNO3 at this rate 1-2x a week etc thereafter.

Everything has a risk, the risk that it's BGA is very low.
BGA is in neveryone's tank BTW, just not at visible levels till the NO3 drops too low or the tank is really flithy. Anyway, you can kill it back and prevent easily. Spores (air born) generally take a about 1 month or so to land and reinfest a new tank

Then you can remove that variable as a potential cuase.
If you still have the issue later, then you'll know it's not the BGA.
They make long gloves also for reef tank/SW folks.

Regards, 
Tom Barr


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## trystianity (Jul 21, 2005)

> I'd be far more worried about the other bacteria in the tank rather than the BGA which do get lots of press.........


I think I failed to explain the problem correctly. For me infectious diseases aren't much more of a risk than they would be for most people, it's hypersensitivity to a variety of chemicals that in most cases wouldn't affect people especially at the levels of exposure that affect me. To explain it really basically (and I apologize because there is a lot that is still unknown about internal processes that cause this), there is apparently some kind of problem in the CNS that causes the brain to essentially overreact to environmental stimuli and a lot of unrelated chemicals. When this happens it manifests in a number of physical symptoms, rashes, stomach upset, muscle pain, headaches, asthma, etc. For me, I usually have problems related to household cleaners, perfumes, mold, dust, solvents, certain foods, food additives, etc., and all of this has been medically documented. For some reason I have what some people would describe as an "overactive immune system," related to a few immune system disorders I have. Think of it in terms of "sensitive skin" or something taken to the extreme where the effects can sometimes be serious.

As I said I doubt this would be relevant to most people. I did contact my doctor about it, she said that most types of algae including cyanobacteria are known to cause allergic reactions in some people so it is definitely possible that my rash was caused by some chemical in the BGA. A quick check of the literature confirmed that oscillatoria is a known offender for causing immune system reactions in sensitive people. Her advice was to limit my exposure to it as much as I can, wearing gloves while handling it directly and one of my dust masks to prevent inhalation of it when I pull visible chunks of it out of the tank and also to keep me from touching my face and mouth when I've been handling it. Basically if I can smell it I shouldn't be breathing it in. If I do have a reaction despite my precautions I can take some antihistamines and that should be OK. It would be unpleasant but should be over in a couple of hours and it's something I'm used to dealing with anyway.  I do know a couple of hobbyists with really similar health issues to mine, and I'm going to tell them to be careful when handling BGA just to be on the safe side.

As far as keeping tanks goes I'm not going to let a little BGA stop me, I've had aquariums around since I was 5.  Not going to let health issues stop me either, if I totally eliminated everything that could cause problems for me I would have to live in a sterile bubble.

HeyPK, thanks for the ideas. siphoning does sound like a great way to remove it manually while keeping as far away from it as I can. Tom, the long armed gloves you mentioned look good too, the reef gloves look a bit thick and heavier than I would need so I'm going to look around for something a bit thinner.

The BGA in this tank is suffering from the erythromycin, the patches that are left are turning brown and looking really unhealthy. So far it seems to be working really well and I've already got my NO3 up where it should be again. There wasn't a whole lot of it, just a few patches in between the substrate and glass but it should be gone in a few days. I have dealt with it before but this is my first time trying the maracyn for it. Blacking the tank out works most of the time and I'm usually very hesitant to dose my tanks with anything but I wanted to test it out and see what happens with it. So far so good.


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## plantbrain (Jan 23, 2004)

EM will kill it for a few days, weeks, but it'll be back from air born spores(about 20-35 days).

So just keep the conditions good in the tank. Do aquatic plants cause rashes etc? Might be the plant, not the algae, BGa etc at all. 

There are a lot of unknowns there.................
I'd not be so ready to point the finger...........

But rather, reduce the risk...........I'm glad you feel strongly and have kept fish etc for many years, but the approach if you are determined to do it, should be of optimal health for the fish, plants, that will likely minimize the risk while increasing the pleasure which..........makes all those risk worth it.

Blackout, then KNO3 and then regular maintenance.

Regards, 
Tom Barr


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