I have personally worked with polyacrylamide in labs. Did a (very) shallow research on its use in agriculture.Â
Â
To put it short, It's somewhat important to use a hyper absorbant polymer ment for soil conditioning.
Â
Main points:
The polyacrylamide (PAM) must have been purified well for precursers (acrylamide [AMD])
The polyacrylamide must be in its anionic form, as the neutral and cationic species have a higher toxicity.
polyacrylamide in anionic form is very little toxic to humans.
There MIGHT be issues with PAM degrading into AMD, but studies on the subject has not observed this.
Â
"PAM does not revert to AMD on degradation (MacWilliams, 1978). Furthermore, AMD is easily metabolized by microorganisms in soil and biologically active waters, with a half-life in tens of hours (Lande et al., 1979; Shanker et al., 1990). Bologna et al. (1999) and Barvenik et al. (1996) showed that AMD is not absorbed by plant tissues and apparently breaks down rapidly when exposed to living plant tissue."
Â
Source:Â
http://eprints.nwisrl.ars.usda.gov/43/1/1196.pdf
Â
Â
So PAM used correctly should be of no danger when used as a soil conditioner.
Â
I havn't researched much what polymer is typically used in diapers, but a quick googling yielded that is is some derivative of PAM. Most likely anionic PAM, as it is generally safer.
Â
"While nonionic and especially cationic PAM formulations pose some risk to aquatic organisms at low concentration (Biesinger and Stokes, 1986; Hamilton et al., 1994), the anionic formulations do not. "