What happens to your old cellphones and computers when you throw them away? For a long time, much of the world’s e-waste ended up in China. But last year, China’s leaders banned e-waste imports because of environmental concerns, and now the garbage is flowing into neighboring Thailand. E-waste, which contains hazardous elements such as lead, mercury, and cadmium, is arriving in Thailand at a rate of about 16,000 tons per month, more than three times the amount imported last year, according to Thai officials. The increase has strained recycling firms, which import the waste for the valuable metals, such as copper and gold, extracted from the devices. Environmentalists worry that shifting electronic trash from China to Thailand, where regulations are more lax, could create an environmental catastrophe. “E-waste is made of literally thousands of toxic chemicals,” says Ted Smith of the International Campaign for Responsible Technology, an environmental group. “It can contaminate soil and groundwater, leading to birth defects and chronic illnesses for people and animals.”