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  Discussion on Iron Content in Water
Author Message
Member:
Dianeky

Posted on Thursday, Feb 24, 2005 - 11:46 am:

Hi Dr. O.,
I have quickly perused the discussions and articles referenced therein, and I don't know how to make the conversion from ppm to mg/l.
We have recently moved and I had the well tested because of a metallic smell and brownish color in the water. The test results, with regards to iron content, came back as 7.55 mg/l. The maximum acceptable levels for human consumption are listed as 0.3 mg/ml.

Given that information, I realize that the iron content is quite high but do not know the toxicity level in mg/ml. My concern is not only for the older horses (6 yrs to 18 yrs) but also for a broodmare getting ready to foal as well as a yearling. Once I realized that the iron was so high, I began giving the broodmare water from a different source in her stall, but she was getting the water in question when tuurned out.

Should I be concerned about the health of the unborn foal?

Thanks,
Diane
Member:
Christos

Posted on Thursday, Feb 24, 2005 - 5:22 pm:

Diane,
0,3 mg/L is a maximum level for horses too. Not because Iron is toxic at that level, but because it will dramatically reduce palatability and water consumption.
Member:
Christos

Posted on Thursday, Feb 24, 2005 - 5:34 pm:

Oops, there's an article:
Care of the Horse >> Nutrition >> Water, water quality and watering horses.
Moderator:
DrO

Posted on Thursday, Feb 24, 2005 - 6:36 pm:

I think you misread your lab results Diane: 7.55 mg / liter (L) is pretty low compared with the acceptable limits. Remember there are 1000 milliliters in a liter. So dividing both sides by 1000 gives us: 0.00755 mg iron / 1 ml of water. Far below (appx 1/50th) the undesirable levels.

Ppm's of solutes in water are pretty easy to handle in the metric system whose weights are based on the volume of water. The two key facts are that:
1) A ppm is equal to a 1 mg / 1 kg. Or said another way 1 kg equals a million mgs.
2) A liter of water weighs one kg.
So 1 mg of iron (or any solute) in a liter (1 kg) of water is 1 ppm by weight.
DrO
Member:
Imogen

Posted on Friday, Feb 25, 2005 - 8:33 am:

Diane, just a bit of reassurance. We have high iron and manganese in our water to the extent that we have sand filters to take it out before it gets to the house otherwise we get brown everything, especially underwear that has been washed!

If you stand a glass of our untreated water for an hour, rust will start to DrOp down to the bottom (because of the exposure to oxygen). Despite this the water is well within the WHO limits for humans/horses. And sand filters are damn cheap to build and maintain.

All the best

Imogen
Member:
Christos

Posted on Friday, Feb 25, 2005 - 8:36 am:

DrO, the table in your article suggests 0,3 mg/L as an upper limit. Then you say 7,5 mg/L is pretty low. I do not understand.
Member:
Dianeky

Posted on Friday, Feb 25, 2005 - 11:10 am:

Dr. O.

Sorry, I had a type-o in the results I posted.

The iron level in our water is 7.55 mg/l and the report lists 0.3 mg/l as acceptable limit. (I had originally posted the acceptable as
0.3 MG/ml.

Sorry for the confusion. So then you don't believe that I have to worry about the unborn foal? Should I keep it from this water as a neo-nate, since there is evidence that high iron can be fatal in a newborn?

Thanks to all who posted here. Any and all info is greatly appreciated.

Thanks Dr. O.,
Diane
Moderator:
DrO

Posted on Friday, Feb 25, 2005 - 5:29 pm:

Whoops...great math skills but crappy thinking. I had used the normals in her lab report as the acceptable limit which have now been corrected. I should have checked them (or read your post more closely Christos). Thanks for the corrections.

Diane I suspect everyones impressions above are correct that twice the normal level of iron is not a big deal as long as the horse is drinking it. But with the high levels you have to consider it as part of the iron intake of the total diet. What if there are other sources of high iron intake?

Perhaps the easiest way to look at this is to see what this is likely to add to the diet and compare it with the toxic levels listed in our article. Lets say your horse drinks 40 L of water a day, probably a little more than the average size horse takes in on an average day. You are adding just a hair more than 300 mg of iron. This same average horse probably consumes a bit more than 10 kg of dry matter a day. So you have added 30 ppm to the diet. The toxic level is listed as 2000 ppm, so een if we add this to the highest levels likely in the other food stuffs you are well below the toxic levels assuming there are no other sources of iron like supplements or environmental contamination.
DrO
Member:
Dianeky

Posted on Saturday, Feb 26, 2005 - 9:37 am:

Dr. O.,
Makes sense!!!! I will check labels on bags to make sure that we are not going over 2000 ppm.

Great for older horses but I still haven't heard any info regarding the toxicity to a foal. I was under the impression that the toxic level for a 24-36 hour old is much lower than for adult horses. My mare should foal within a week and I want to make sure I don't have any complications that I can avoid. (I am the one with the weanling from last year that was diagnosed with pemphigus but is responding to allergy treatment). A lttile GUN SHY perhaps?????

Thanks,
Diane
Moderator:
DrO

Posted on Saturday, Feb 26, 2005 - 10:30 am:

It is, but your 24 to 36 hour foal should not be consuming either water or food stuffs other than milk, right? Iron poisining in neonates has only been reported when iron was orally supplemented or injected into the foal.
DrO
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