The drawbacks of clean air

One of the things people like about New Zealand is that it is (relatively) "clean and green". We have plenty of forests, cleanish water (though nowhere near as clean as we'd like to think), and (except in Christchurch) clean air.

Unfortunately, the latter also seems to have some drawbacks. Most noticably, less smog means less UV light absorbed in the atmosphere, which means higher UV levels and therefore higher skin cancer. Bugger.