Researchers on Aug. 19 unveiled the results of a computer simulation showing that acid-rain-causing pollutants produced in not only northeastern China but also in southern China can affect Japan.

The simulations, conducted at the National Institute for Environmental Studies, are the first to focus on acid rain in East Asia, the researchers said.

The active use of coal in southern China is said to be responsible for the high output of sulfur oxide and other pollutants in the region. The simulations show for the first time that such pollutants are a possible cause of acid rain in Japan, the researchers said.

When a lower pressure system born near Taiwan passes south of Japan, the simulations show, pollutants over China are carried by air to Japan, which sees an increase in the density of sulfate ion, they said. The simulations also reveal that acid rain-causing pollutants like sulfur oxide produced in China become heavier in density over Japan when a seasonal rain front goes south, they said.