Apply outside with good air exchange. Leave alone after application and
> go somewhere else. Rinse part in a container for later proper disposal
> of the effluent. Limit exposure to a few minutes in a 24-hour period.
>
> All in all, it might be simpler to have someone bead-blast the part, or
> use oleum to remove the carbon (a longer process, but using a mild
> caustic material with fewer health side effects).
Excellent advice... in a general sense you probably want to minimize your
exposures to organic solvents over your lifetime. Some studies have
suggested a link between occupational exposure to methylene chloride and
liver cancer and others have not supported a definitive link. Perhaps its
better to err on the side of caution. Carcinogenesis is a complex
multistep process that occurs over a period of several years to a lifetime
and involves several different genes and mechanisms. Only one out of 10
smokers gets lung cancer but 9 out of 10 asbestos workers who smoke get
mesothelioma. There are multiple exposures involved and some are
cumulative (like radiation) while others may have a threshold. Incidently,
irradiated meat would pose no excess cancer risk, assuming that there is
no radioactive contamination in the food, and would effectively kill
bacteria and viruses, but probably not the so-called "mad cow" agent. We
don't yet understand the long-term effects of chronic exposures to low
doses of potential carcinogens like dioxin, which is omnipresent. But we
do know that dioxin, like methelyene chloride is capable of causing
cancer in mice when they are give high doses. Humans metabolize
methelyene chloride differently than mice, however vinyl chloride is a
VERY good carcinogen in humans... and the jury is still out on the
polychlorinated biphenyls (PCBs) for which exposures in humans may explain
the high rates of breast and prostate cancer in industrialized countries.
Interestingly, lung cancer recently surpassed breast cancer as the #1
cancer killer of women in the USA. Lung cancer in men in the USA has had
that distinction since the 1950's, afterall, this is Marlboro country...
"http://www.cancer.org/statistics/cff98/graphicaldata.html#aacdrm";
Sincerely
-Kevin O'Driscoll, Ph.D.
Asst. Prof. of Molecular Neuro-Oncology
Herbert Irving Cancer Center
Columbia-Presbyterian Medical Center
New York
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