The data shows that levels of copper and zinc are rising by as much as 10% a year in counties (in the u.s.) where Animal waste is being applied to land in large volumes.???[14]; ???Because Pigs cannot digest all the nutrients, their manure is rich in nitrogen and phosphorus and laced with heavy metals such as copper and zinc, which poison the soil when they accumulate.???[15] In the e.c. the level