Acid ripples

Polluted sand is making Japan’s acid rain problem worse. Normally, sand blown
to Japan each spring from the Gobi and Taklamakan deserts of east Asia
neutralises the acidity of Japan’s soil. But researchers from the National
Institute for Environmental Studies in Tsukuba have shown that the sand is now
itself acidified because it picks up pollutants on its journey. These turn into
sulphuric and nitric acid on the grains’ surfaces. “This sand is blown across
the Pacific to Hawaii and the American mainland so the problem could be
widespread,” says team leader Masataka Nishikawa.