Michael Banks on mon 10 may 99
I've been sort of lurking for a day or two to see if anyone else more
knowledgeable will answer this from downunder, as I'm am not in possession
of any hard stats. But it seems to me that, although Australia and New
Zealand have among the the world's highest skin cancer incidence, it is a
complex issue, including factors in addition to ozone depletion.
1. These countries have a degree of atmospheric clarity unparalleled in the
northern hemisphere, which transmits more solar UV radiation, irrespective
of ozone. This is because of a low concentration of heavy industry, cars
etc, and latitude (especially for New Zealand), being in the path of
globe-circling westerly winds.
2. Perihelion (Earth's closest approach to the sun) coincides with the
southern summer. The Southern Hemisphere has a higher UV flux in the summer
(when people wear reduced clothing), than in the Northern Hemisphere.
3. Imperfect epidemiological data base for other southern countries e.g.:
4. A large percentage of the population down-under, has fair skin, unlike
in South America.
5. A "sports-mad", beach and outdoor culture which encourages infants and
children to be taken outdoors often. The degree of Infant exposure to solar
radiation appears to be related to later skin cancer incidence.
6. Over-selling of the horrors of ozone depletion by over-zealous
environmentalist groups in the northern industrialised countries. In
Germany for example, it seems to be "common knowledge" that a trip outdoors
in New Zealand without a hat is tantamount to suicide. Not so. People
still sunbathe here without getting burnt, though it is discouraged
officially and may lead to skin problems in later life.
I do acknowledge your very important point that the ozone layer is being
seriously depleted and that chlorine is the worst offender, released by the
dissociation of chlorofluorocarbons. Whether polystyrene foam (Styrofoam)
is still being manufactured that has been blown-up wth freon, is a moot
point, but there does seem to be a lot of it still about. It does not seem
worth all the risks to fire it in a kiln.
BTW, Nelson has the highest sunshine hours annually (most years) in New
Zealand, so I'd better try and find my hat!
>Aside from the toxic fumes, I believe that something like 20,000 cubic
>cms. of the ozone layer is destroyed for every one cubic cm. of
>styrofoam that we burn. Of course, incinerators are doing this for us
>all the time, but I like to think of ceramists as back to the earth
>types, not prone to this appalling practice.
>P.S. I have been told that in Australia and New Zealand people who do
>not use sun screen are considered stupid. Ozone depletion is so bad that
>people get skin cancer from even a little exposure. Perhaps some of our
>friends thereabouts could verify this.