I'm not certain that you pick up the irony in my comment, Terry, nor am I
certain that there has ever been a sign that our use of dichromates in gum
printing presents any greater hazard to our health than, say, smoky air or
the ordinary darkroom. (I read somewhere that photographers have a 1/3
higher cancer rate than the mainstream, and recall that Garry Winogrand,
for instance, died of liver cancer.)
I happen to have on hand a copy of a letter exchange on this very topic in
Darkroom User, Winter 1995, from Keith Dugdale, Penzance; Peter Charles
Fredrick (spelled "Frederick," which is it?) of Southend; Dr. Graham
Matthews of Cheltenham; David Richardson of Sheffield; Dave Whitehead of
Manchester, and with a reply by Dr. Dunstan Perera.
Highlights:
Dugdale: If used responsibly in the minute quantities required for
photographic use, I cannot see what harm it can do to the environment....
Can Perera really say that [in 125 years] the authorities will not come
up with yet more chemical legislation that may throw doubt on a chemical
consitutent of his process... [which Dugdale notes cannot be assessed
because it is not revealed].
A large petrochemical company...dumps approximately 50 tons of toxic waste
into the North Sea every week... This is 175 million times the amount a
photographer making a 10x8 inch print will add.... Even Dunstan himself
has been using dichromates for the last 40 years or so and he is still as
bright as a button....
Fredrick:
I find it very sad that my friend ...denigrates the use of 'dichromate
based' processes in an attempt to promote his Heliochrome process ....
Yes, dichromate is a toxic substance and a non-biodegradable heavy metal,
but so is silver...and in fact silver nitrate is far more lethal!...
I have approached the National Health and Safety Executive on this issue
and they can see no reason why these chemicals cannot be used if normal
chemical hyugiene procedures are adopted. Also, I have been in contact
with Dr. Graham Matthews, toxicologist to H.M. Government and World
Health Authority consultant....he says that as a toxicologist he would be
loathe to state that any chemical is absolutely safe, but in the small
quantities used in the Dichromated Colloid Processes there should be no
real health hazard...
Dr. Graham Matthews:
The warning which comes with the chemical will be based mainly on the
fact that an increased risk of cancer, mainly of the respiratory tract
occurred amongst very heavily exposed workers, mining ore, etc. in the
past.....This does not mean there is any risk in the Gum Bichromate
process... It is not clear whether the danger is from the chemicals, or
at least mainly from abrasive particles of ore...the risk may be due
specifically to calcium chromate....[and] the exposure of miners
used to be huge and on a daily basis....
[Matthews continues about the risk of dermatitis and urges that we warn
students about care, hygiene, spillage. Doctor, we do try!]
Since my server is wont to cut me off at times like this, I will continue
in part 2.
Judy