A study by the Superior Institute of Engineering of Porto (ISEP) confirmed that the drugs are not eliminated by the processes of the WWTP discharge.
Researchers of ISEP have a focused study in three antibiotics (amoxicillin, tetracycline and trimethoprim) and an anti-inflammatory (ibuprofen), because they are more drugs consumed by the general population. The results indicate that the products are not completely removed, in particular ibuprofen, by treatment with anaerobic sludge, even by prolonging the process. This means that in addition to the contamination of watercourses where do these discharges effluent WWTP, also irrigated soils may be contaminated by passing the pharmaceutical compounds.
The scenario can be worrisome considering that sometimes in the vicinity of discharges are not only small family farms but also playgrounds, getting the whole surrounding environment and, consequently, the population exposed to the negative effects of contamination. The problem of multi-resistance to antibiotics may be just one of the consequences. Therefore, drugs are currently classified as arising pollutants.
"There has been an awareness of this type of problem. We speak often of contamination of water, rivers and seas, but very little of soil. Sometimes, there are nearby the WWTP's small gardens, some of which even to produce biological products. But the truth is that soils can hide all sorts of problems, among them the existence of residues of drugs, "explains Valentina Domingues, teacher and member of the ISEP research team.
The problem is not unique to Portugal and that is why the scientific community has come to look into this matter. The WWTP reveal weaknesses in the process of wastewater treatment, particularly in relation to pharmaceutical compounds. "This is a global problem and it is difficult to improve the efficiency of treatment plants. We have to solve the problem upstream," advocates the researcher.
In this context, the results now obtained by the study of ISEP are part of a larger project, funded by the Foundation for Science and Technology, entitled "rehabilitation of soils contaminated with pharmaceuticals." The goal is to create mechanisms to minimize the impact of pharmaceutical compounds in the environment and consequently the health of populations.
"Part of the diagnosis is made. In Portugal the presence of pharmaceuticals in the environment is a reality, making it urgent to find remediation techniques to rehabilitate soils", says Valentina Domingues. There are some more classical solutions being developed to be an alternative methodology greener and low cost. "The preliminary results seem to be promising. This problem associated with the lack of legislation to soil quality, for which we have been warning, means that little is done to reverse the situation, despite being available to various treatment technologies. It is urgent to take this step towards environmental protection, "concludes the researcher of ISEP.
