An environmental engineer says he knows why some endangered trees on Japan’s UNESCO World Heritage Yakushima Island are dying.  And he is pointing the finger at Japan’s rapidly industrializing neighbor.

Located off Japan’s southwestern coast of Kyushu, Yakushima Island earned its UNESCO status because of its incredible natural beauty.  The island is covered with Cedars and greenery that have been largely untouched by the outside world.  One popular Cedar is 2,600 years old.  The island was the inspiration for the landmark Hayao Miyazaki film “Princess Mononoke”.

But a species of Pine found only on Yakushima and a neighboring island is in trouble.  Yellow, dying trees dot the otherwise unbroken green moss-carpeted forests on the mountainsides.

Osamu Nagafuchi of the University of Shiga says the problem is China.  He’s been studying the island for two decades, ever since he first found blackened snow particles on a mountaintop during a hiking trip in 1992.  Like a good scientist, he took samples and found the grunge was made of silicon, aluminum and other byproducts from the burning of coal, which is used to heat homes in China.  Then he studied maps of winds, and discovered the pollutants were carried there from China, across the East China Sea.

That poison particulate matter is in the news a lot lately, as the gray, soupy air of China’s industrial interior causes panic when it wafts Japan.  Several cities declared air quality alerts already this year.

That’s making it easier for Nagafuchi to get the word out on his findings, which were initially rejected by the Japanese Government.  Not every official believes his theories, but they now listen as he presents a decade’s worth of data from a series of pollution monitors he established on Yakushima.

Many islanders are already believers, and they worry that the pollutants may be threatening their health.  “We are starting to feel like the canary in a coal mine,” said Yakushima Island’s mayor, Koji Araki. “Our island is right downwind from China, so we get the brunt of it.”