For this reason, a buildup of toxic heavy metals in soils is often dismissed as irrelevant. But in the real world, farmers go out of business while acid precipitation keeps soaking soils with dilute acid year after year. Sheep eating cabbage grown on sludge developed lesions of the liver and thyroid gland. In grazing, these animals may pull up plants by the roots and thus ingest substantial quantities of soil. From a public health perspective, any unnecessary addition of dioxin to human food chains is unthinkable and unacceptable.
Sewage sludge is produced in the huge quantities day after day, year after year.
Sludge never takes a holiday. Municipalities find themselves under relentless pressure to get rid of the stuff, day after day after day. It is exceedingly expensive to treat it to clean it up. Towns and cities have every inducement to cut corners, skimp on tests, fudge the numbers, claim that their sludge is cleaner than it really is. Only an aggressive, independent oversight agency can protect public health.