SIAM REAP, Cambodia — A thousand years ago, they were temples so sacred only high priests were allowed to enter — the spiritual epicenter of a powerful empire that dominated Southeast Asia.
Now, millions of tourists climb among the elaborate, enchanting ruins. In this poor, struggling nation, they arrive at Angkor Archaeological Park's ticket counter via decades-old tour buses that belch dark, toxic fumes.
Here, air pollution is at its worst.
At the 18 ticket counters, visitors — led by Chinese and Koreans — take refuge from the exhaust clouds by covering their noses with scarves.
The aging tour buses are resuscitated from back when Japan or Korea themselves were struggling, unable to afford clean modern technology. The tired vehicles can no longer be sold there, so they end up here.
Also contributing to the noxious ambiance are tuk-tuks — Cambodia's answer to rickshaws, pulled by rickety motorbikes.
No one bothers to turn off the engine while waiting for clients at the ticket counters.
It’s not just bad air that’s assaulting this world-class archeological site. The sheer weight of millions of tourists has long taken its toll. Wooden stairs have been installed to protect the original ones underneath. Some areas are limited to 2,000 tourists per day.
But for the air pollution that worries scientists, no quick fix is in sight.
Research suggests that a decade ago, air pollution here in Siem Reap, a city of about 250,000 inhabitants that accommodates temple tourists, was worse than in Thailand's capital Bangkok, a city of more than 8 million.
“[T]he pollution of the Angkor Park has been getting worse during [the past] ten years” and will continue to deteriorate, says Dr. Shinji Tsukawaki, a professor at Japan's Kanazawa University who researches air pollution in the Angkor Archaeological Park, the official name for the UNESCO World Heritage site that contains several capitals of the mighty Khmer Empire, built between the 9th and 15th centuries.
More than ten years ago, when the annual visitor numbers were around 300,000, UNESCO warned of the expected surge in tourists. Not only were the ancient stones crumbling under the steady beat of the millions that were expected, but mounting air pollution had caused acid rain that darkens the stone, and eventually leads to its decay.
“It is obvious that pollution and acid rain will affect the stone,” says Anne Lemaistre, UNESCO country director.
Acid rain — basically pollutants trapped inside water droplets in clouds that rain down — causes erosion that will forever erase the ancient carvings of lions and female dancers that adorn the crumbling temples. Furthermore, the discoloration is noticeable.
“And this is not just for the stone, but what about the local population?” Lemaistre says, pointing to the thousands of people who have called the World Heritage Site their home for decades.
In a shack of thatched hay, suspended by wooden sticks and covered with a corrugated metal roof, Veng Ken, 53, lives with her children and grandchildren, about 500 yards from the vast Angkor Wat.
She remembers her childhood, when the Angkor temples were her playground, empty ruins overrun with weeds that her family's cows and buffalo would graze on.
“It was beautiful. It was quiet and clean, and it was empty. I can't remember seeing many tourists, and I think the foreigners who came were researchers,” she says.
Like most of the 200 families in her village, she lives off selling fruit and noodles to tourists, and collecting the garbage left behind.
“That's what I like about the tourists. But it has also destroyed the nature, and the air is getting worse and worse. Before, nobody here was coughing. Now, everybody coughs, our grandchildren and us, too,” she says.
UNESCO has long advocated for a sustainable, long-term solution for the park's ever-increasing traffic and air pollution issues, a means of transportation that is self-reliant but does not produce toxic fumes.
7Makara, a Cambodian-Korean company, has achieved at least one of two ideals by operating about 20 electric, golf-cart-style vehicles.
They have, however, major disadvantages that make them unfit as a long-term means of mass transportation. The battery that powers the carts can be charged around 1,000 times before it has to be replaced. And the carts run on conventional electricity, which is already scarce in the ever-expanding city.
Limited availability isn't the only issue. In one of the world's poorest countries, electricity costs around 25 cents per KwH, higher than the US average.
Enter France's solar-powered Blue Solutions electric vehicles, already successfully introduced as a car-sharing project in Paris, with cities such as Indianapolis next in line.
Last year, Blue Solutions set up Siem Reap's first solar-panel farm next to a new ticket center that will be able to accommodate the growing number of tourists. Two electric buses as well as electric cars are already standing under a wooden bus station.
They are prototypes from other cities that were used to showcase the functionality of electric vehicles during the park's International Coordinating Committee (ICC) meeting last year.
“Here we have so much sun and are so close to the equator, it would be stupid not to use [solar power],” Blue Solutions Cambodia CEO, Vincent Calzaroni, says.
Currently, an expert commission of the ICC is working on a master plan for a large-scale introduction of electric vehicles in the park that will be announced late this year.
“If air pollution is already a problem now, and the condition of the temples is getting worse, imagine in a few years when there'll be 5 million tourists,” Calzaroni says.