As early as 5,000 years ago, people living in California’s Channel Islands waterproofed baskets with bitumen to create water bottles. Recently, using oral tradition, researchers tried to re-create two types of water bottles the ancient Channel Islanders made. One bottle basket was lined with soft bitumen, known as “malak,” which seeps up from the ocean floor and washes ashore. A second was lined with hard bitumen, known as “woqo,” which is found on land.
Unfortunately, a byproduct of warming bitumen, polycyclic aromatic hydrocarbons (PAH), is known to be linked to cancer, fertility problems, and developmental impairments. The finished water bottles did not seem to have sufficient PAHs to cause health problems. However the fumes from the fires used to soften and prepare the bitumen did have extremely high levels of PAHs. And since bitumen was also used to waterproof boats, tools, and food-storage vessels the total exposure might have been high enough to affect Channel Islander’s health.
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