A recent study claims that if vegetables are treated with human wastewater, they begin to absorb drugs in quantities that are not safe. Researchers of a reputed university has conducted this study, and primarily observed sweet potatoes and carrots. Their analyses show that both of these vegetables can absorb a drug metabolite and an anticonvulsant drug in an unsafe concentration.
The practice of irrigating crops with human wastewater is becoming popular in many parts of the US. In fact, many states have launched specialized programs in this regard. The World Health Organization does have concerns with this, and so they published a report about potential problems which many arise when wastewater is used for agricultural purposes.
The researchers told the press that they traced about 14 common medicines and two drug metabolites in irrigation water and in the eatable parts of various crops. They grew sweet potatoes and carrots using the same wastewater, which is used by local farmers. Concentrations of the drugs were measured in water, soil and the plants with the help of liquid chromatography. Caffeine and epilepsy drugs were detected in the two vegetables. After this, the toxicity levels of the drugs were measured by using a standard technique.
The analysis shows that an adult person will have to eat hundreds of kilograms of these veggies on a daily basis in order to reach the TTC level of caffeine and carbamazepine, which is an epilepsy drug. As for a child, they will need to eat about 90 grams of sweet potatoes to cross the TTC levels. In the case of carrots, just eating half of one carrot will increase the toxicity levels in their bodies.
An analytical chemist at a reputed university stated that this study is the first one ever to be conducted based on TTC levels and the associated health risks. The chemist added that the study also should focus on other drug metabolites and not only the parent compounds. This will present a more concrete picture and highlight the risks associated in a better manner.
So should wastewater be used for agricultural purposes? In light of the current analyses, probably not but a more in-depth study might bring up more solid facts. For right now, it is better to refrain from this practice and be safe.