Why We Are Safe To Use
CROPAID NPA is produced using Thiobacillus subspecies bacteria and minerals in a special formula which is totally natural and safe for the environment.
There is no (or little) information on the hazards of Thiobacillus, because there are not thought to be any.
As a rule of thumb, thiobacilli - not all of which have been re-labelled as Acidothiobacillus - are ubiquitous. Introducing them into the environment will have no impact (other than perhaps accelerating the inevitable eg ARD production).
Twardowska (sp?) showed some years ago that viable (ie living but not growing) Thiobacillus could be isolated from Polish coal spoil, at pH7.2. This surviva at circumneutral pH was by organisms that grow optimally at pH2 or less (for leaching types). Frank Roberto of the then INEEL presented at a Minerals Engineering conference about ten years ago that viable Thiobacillus could also be isolated from deep drill core taken from an undeveloped copper sulphide mine. These were genetically different isolates from surface isolated Thiobacillus above the same ore body, were in what was up until then unbroken rock (ie with no air, no moisture) and were almost certainly not doing anything as a result, but were still there, and were not surface contaminants. The implictaion being that once you expose sulphide compounds at surface, leaching organisms are very close by.
The second issue is one of pathogenicity. Perhaps start with the NIH listing in the US of microorganisms (ie algae, fungi, and bacteria) that are safe for use in schools and colleges. Thiobacilli that are involved in the S cycle are included on that list, albeit at a higher school level, reflecting a higher degree of complexity in their cultivation.
In the context of bioleaching etc, the organisms involved are typically regarded as obligate acidophiles and obligate autotrophs. This means they only grow in acid and with inorganic materials as food. As noted above, growth is not the same as survival. However, as far as human (or indeed animal) pathology goes, the only source of an acid environment where these organisms could conceivably grow is the gut. And it’s the wrong acid (HCl not H2SO4), as chloride will take out the bacteria (as opposed to sulphate), not to mention the organics, etc.
The other issue to consider then is non oral routes of infection, such as respiration. Not so much with respect to growth in the body but possible allergic reactions. In this case the acid and metal associated with leaching operations etc is definitely a much bigger issue. Plus, with the cavalier labelling of leaching bacteria as Thiobacillus, you would never prove cause and effect for any susceptible human who could be allergic to any given bacterium or compound (you would probably be more at risk from using latex rubber gloves to protect you from acid etc, as latex is a known allergy risk to lab workers [please don’t ask about condoms, because I don’t know!]).
Certainly, antibodies have been raised against these bacteria for use in testwork, so the mammalian immune system does react against them, but these antibodies are generated under somewhat artificial conditions, and an active immune system is generally a good thing.
As to the other organisms mentioned, shaking hands with someone who has been to the toilet and not washed can lead to infection with E coli. This is a proven route, as too infection in washed salads using non potable water, or in frozen ice cubes in drinks. It can be that simple. Not ridiculously scary in outcome but quite infective nonethelss and the odd strain will “dehydrate you”, quite quickly. Listeria on the other hand is one reason pregnant women are advised not to eat soft cheeses during pregnancy. The veracity of this can be debated, but the advice is there. Finally, Salmonella might not be quite as “infective” as E coli, in that you need to be contaminated with (much) more material, under different conditions, but the effect can be life threatening. And most years probably is, somewhere in the world. Altogether, a completely different ball park, re risk, compared with Thiobacillus.