From Cows to Concrete

In the United States, crushed meat-and-bone meal from slaughtered cows is almost all recycled into hundreds of goods, including fish food, fertilizer, linoleum, and lubricants. In Britain, however, the fear of mad cow disease has rendered discarded parts from cows, sheep, and pigs—such as bone and intestine—unsalvageable. "We used to sell all these bits; now we have to destroy them," says Martin Grantley-Smith, a nutritionist and head of planning at the British Meat and Livestock Commission. So more than a million tons of bone and offal end up as waste in Britain every year. Most is dumped into landfills, but some is burned in power stations to provide electricity. Grantley-Smith asked the country's Building Research Establishment to test ash from the incinerated animals for use in bricks, road-building, and bridges. Incineration should completely destroy the deformed proteins, or prions, that cause mad cow disease, he adds, and nothing will be built without extensive safety tests. "There's absolutely no reason to think that there is any danger left in the material," he says. "Of course, the bone in bone china is animal bones. So it's not a new concept at all."