Researchers of the St. Petersburg Federal Research Center of the Russian Academy of Sciences (SPC RAS) via an original technology for biological monitoring have revealed that diclofenac, a component of widespread painkillers, getting along together with human waste into reservoirs, can cause gastrointestinal diseases in their inhabitants. The substance can accumulate in water (especially in the autumn-winter period of low solar activity) and at high concentrations pose a threat not only to the health of organisms living in water, but also, possibly, to people using such water areas. A scientific paper was published in the professional journal Chemosphere (quartile Q1) (for hyperlink https://www.sciencedirect.com/science/article/pii/S0045653520323250?via%3Dihub).
Diclofenac is one of the major components in many painkillers. After application, along with the waste and wastewater, it penetrates into the soil and reservoirs and gets accumulated there. At the same time, the consequences of such processes for nature and man are not yet fully clear.
“To quickly establish the negative effects of diclofenac upon living organisms, we, jointly with specialists from Harbin Polytechnic University (PRC), used high concentrations of diclofenac in our experiments - about 10 thousand times more than that observed in the waters close to the world largest megacities, like, St. Petersburg”" says Sergey Kholodkevich Chief Researcher Head of the Laboratory of Bio-electronic Methods of Geo-ecological Monitoring of the Scientific Research Centre for Ecological Safety of the Russian Academy of Sciences (SRCES RAS- separate division of SPC RAS).
Experiments were executed in a container with diclofenac solutions of the required concentration, at that, red California crayfish were placed there (they are abundant in rivers and lakes of China, and exported all around the world). The functional state of the crayfish was assessed through the original bio-indication technology developed by the SPC RAS researchers (for hyperlink: https://spcras.ru/news/detail_news.php?ID_NEWS=480927) (based on physiological indicators of their cardio-activity), as well as by biochemical biomarkers of oxidative stress of the logical monitoring. Moreover, much attention was paid to the study of vital signs of the microbiota living in the crayfish digestive system.
"It turned out that at the used concentration diclofenac interferes with the intestinal microflora of crayfish. So, problems arise in the digestive tract. As a result, the crayfish vital systems are out of balance, what causes the animals’ death. We recorded signs of oxidative stress, that undermined the body at the cellular level”" explains Sergey Kholodkevich.
Further, the scientists want to find out at what minimal diclofenac concentrations, the health problems start in living organisms inhabiting the reservoirs. These studies are planned jointly with scientists from Harbin Polytechnic University (China).
Today, the technology of biological monitoring, developed in SPC RAS, is used to protect public health at all water intakes in St. Petersburg. Crayfish living in the North-West of Russia act as bio-indicators in these systems.