Archimedes Plutonium wrote:
But I suspect the carcinogen claim or claim of bad chemicals in the
shingles are false claims. People think there are bad chemicals but
have no data.

Pitch has long been used by coopers to seal water casks, and is still in
use by many orchardists to seal pruning wounds on fruit trees, so I don't
expect anyone is going to drop dead any time soon through either of these
uses. Most of us spend much of our life inhaling the vapours given off by
hot pitch slowly baking in the summer sunshine as we drive along streets and
highways. This is not to say the risk this poses is diminished one iota just
because everyone is doing it. With the realisation that many risk factors
are cumulative, others may choose not to invite any additional risk -- no
matter how small it may be -- through needlessly introducing pitch to their
organic gardening. That you have chosen otherwise is not of my concern, but
in your post you failed to indicate any cognizance of disregarding the risks
here. I made amends for your omission in my response by drawing attention to
the known toxins in tar to give balance to your endorsement of using such
roof tiles in the garden. While mulching is an excellent idea, for some
people there may be preferable alternatives than the one you have
recommended.

(Both arsenic and chloroform were common ingredients in popular cold
medications until their carcinogenic properties were recognized, and I'd
post a warning about these chemicals were someone to endorse their usage
nowadays, too.)

Can you list, John, a list of the top five bad chemicals in these roof
shingles that you claim would end up in the soil. Again, I would
estimate that all the chemicals would be degraded and altered by the
time the shingles became soil.

It would have taken you far fewer keystrokes to find this out for
yourself on google, instead of trying to get others to do every bit of
homework for you.

Now what was that old adage? -- You can point a twit to google but you
cannot make him click. Something like that.
--
John Savage (my news address is not valid for email)