diatomaceous earth

[saysfaa]

I've seen claims DE is bad here on this forum, yet nobody seems to provide any specifics or experiences as to why it's so bad other than opinion. On the contrary I can find many posts, chicken guides, even scientific articles supporting the use and benefits of DE around chickens (for example: https://www.sciencedirect.com/science/article/pii/S0032579119420300)

This references skin irritation and risks to the respiratory system due to particle inhalation but doesn't focus on that. It may be helpful for how to most effectively use DE and how it compare to some other options. Link to the published study

An outbreak of 75 deaths with no clinical signs of illness in a layer flock was determined to be caused by poor ventilation and chicken-house dust produced by scattering the diatomaceous earth were inducing factors. Link to the published report

"...One drawback: diatomaceous earth is very harmful if inhaled (by bird or human) and may pose a threat to your flock’s respiratory health. Research is still divided as to the efficacy of this product for parasite control...."
Link to source - University of New Hampshire

I haven't yet found what evidence they use as the basis of their claims. Partly, maybe, because I'm not willing to pay for access to full text versions. These three allowed free access.

Edit (several hours later) to add...

This study compared crystalline free silica (cristobalite), amorphous free silica (diatomaceous earth), and amorphous silicate (volcanic glass) in hamster lungs. It found "...Total silica content per lung increased linearly throughout at least 21 months in each experiment...although atmospheric dust concentrations were roughly comparable for the three preparations, the total amount of silica accumulated varied inversely with the degree of tissue damage occurring. Thus, the maximum total content of the crystalline silica reached only 68 mg per lung, while that of the amorphous silica and silicate was 120 mg and 465 mg, respectively..."
Link to the abstract

This says "Human epidemiologic studies have found that silicosis may develop or progress even after occupational exposure has ended, suggesting that there is a threshold lung burden above which silica-induced pulmonary disease progresses without further exposure...." This study in rats supports this suggestion. It also found some indications that the damage done is not limited to the lungs. They used crystalline free silica (DE heated to 1,000F), not amorphous free silica (DE); other studies indicate this will change the amounts needed for the different immune system responses but not the types of effects if the different amounts are given.
Link to abstract

 

[saysfaa]

I've seen claims DE...

I'm not convinced either way yet.

A first look into any research I can find seems to indicate there is more to using it beneficially than simply adding some or spreading some - as a separate issue than what disadvantages there might be. It matters how much is used, how often, for how long, where/how extensively, and maybe in other ways.

Edit, several hours later, to add...
After looking a many more studies, it seems clear DE can cause damage. The next step is finding how much is needed for the risk of damage to be significant. Or the risk to outweigh the likely benefit.

I don't know either how much is needed to cause damage (temporary or permanent) or how much is needed to get a benefit. I may look for both kinds of info. Or not. I don't see much reason to use DE instead of the other available options in any case.

 

[raingarden]

WedMD says, "Inhaled amorphous silicon dioxide particles can accumulate in the lung tissue, bronchi, pulmonary alveoli, and lymph nodes. Continued inhalation of diatomaceous earth has been tied to several diseases, including lung cancer, silicosis, and nonmalignant respiratory diseases.".

 

[CapricornFarm]

Don't waste your time and money.

 

[YourChickHasAPastyButt]

WedMD says, "Inhaled amorphous silicon dioxide particles can accumulate in the lung tissue, bronchi, pulmonary alveoli, and lymph nodes. Continued inhalation of diatomaceous earth has been tied to several diseases, including lung cancer, silicosis, and nonmalignant respiratory diseases.".

Just from what I saw... it cakes with very little moisture, and even when conditions dried, it stayed caked hard on some surfaces, so I can see how this would be cumulative in the lungs. I just dumped that dirt I removed from under the coop around some of our blueberry plants.

To each his own.