Why should sewage sludge not be used as a soil builder if it has not been properly tested?

Using sewage sludge that has not been properly tested can pose significant risks to soil and vegetation. One of the primary concerns is that untreated or inadequately tested sewage sludge can contain elevated levels of toxic metals, such as arsenic, lead, cadmium, and mercury, among others. When this sludge is applied to soil, these metals can accumulate in plants, potentially entering the food chain and posing health risks to humans and animals. This accumulation can lead to toxic effects and decrease the overall safety and quality of the crops grown in such soils.

Proper testing of sewage sludge is essential to ensure that it meets safety standards and does not contain harmful substances that could adversely affect plant health or soil ecosystems. Therefore, without adequate testing, the use of sewage sludge as a soil builder is risky due to the potential for increased levels of toxic metals within vegetation, which emphasizes the importance of rigorous testing protocols in managing and utilizing sewage sludge safely.