Similarly, air pollution can be a problem on busy weekends when up to 5,000 vehicles travel to the summit each day. Fortunately, some tourists use public transport, especially trekkers and birders. Social Impacts Besides its economic and environmental impacts, ecotourism can have social effects. At Doi Inthanon, more than 4,000 people, including Thais, Karen, and Hmong, inhabit some 600 villages located in the park. Hilltribe villagers earn a living by growing rice and cash crops, such as ornamental flowers and strawberries, which are often sold in nearby cities.
Villagers raise additional revenue by selling garden produce and handicrafts to tourists.
If hilltribes can benefit economically from ecotourism, they may support habitat-protection initiatives and depend less on unsustainable uses of park resources. Currently, around one-third of all tourists stop at the hilltribe villages, where their contact with residents is mostly restricted to the souvenir trade. The exception are trekkers whose goal is to experience village life and interact with the locals. For hilltribe villages, the impacts of tourism include increased commercialization, altered food habits, and the substitution of traditional dress for Western clothing such as t-shirts. By contrast, the impact of ecotourism is generally more benign.