While a material may be healthy in it's final state it may be harvested through processes that are dangerous and or unhealthy for the workers, and nearby residents. For instance, people who live near mines, farms, manufacturing plants or refineries may suffer due to their proximity to such locations. Water pollution, air born toxins can cause cancer, breathing detriments, birth defects etc. A material must be evaluated for extraction process, manufacturing, installation, useful life, disposal and the associated transportation at any stage of it's life cycle. For instance, gold, a material that is clean, non-corroding, and recyclable. Mining enough gold for one wedding band creates roughly 20 tons of mine waste including cyanide and or mercury. Also we must look at the energy put into smelting process.