Pharmaceutical residuals pose a serious threat to Marine life
A study by Tel Aviv University reveals worrying evidence of environmental contamination
A study led by Prof. Noa Shenkar and graduate student Gal Navon, from the Tel Aviv University (TAU) School of Zoology and the Steinhardt Museum of Natural History, has found significant concentrations of residual pharmaceuticals at 11 sampled sites along the Israeli coastline. These substances have been found in ascidians – marine, filter-feeding, sessile invertebrates. This study was conducted with the participation of the Hydrochemistry Lab of the Water Research Center of the Porter School of the Environment and Earth Sciences, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, headed by Prof. Dror Avisar. The study was published in the journal “Marine Pollution Bulletin”, in August 2020. The study involved sampling of ascidians from 9 different sites along the Mediterranean coastline (Achziv, Acre, Haifa Marina, Sdot Yam, Hadera power station, Acadia beach in Herzliya, HaSela beach in Bat-Yam, Ashdod Marina and Ashkelon Marina) and 2 different Red Sea sites (Eilat Marina and Dolphin Reef). Ascidians are marine invertebrates, few centimetres in size that attach to hard surfaces – such as rocks, peers or breakwaters. Since ascidians feed on small particles found in the water, large quantities of particles from the marine environment accumulate in their bodies over time – including different pollutants. The researchers have performed chemical analysis of the collected ascidians, searching for active compounds of three frequently used pharmaceuticals: Bezafibrate, which reduces blood lipids content; Carbamazepine, an antiepileptic, and mood stabilizer; and Diclofenac, an anti-inflammatory agent present in the well-known medicine Voltaren. These three substances are extremely durable, are hardly degraded by sewage treatment facilities, and last long in the marine environment. The findings are extremely worrisome: in 10 out of 11 sampled sites significant concentrations of the tested pharmaceuticals have been found.
- All three substances have been detected at 4 of the tested sites (Ashdod, Ashkelon, Sdot Yam and Haifa).
- Residuals of two of the pharmaceuticals have been detected at 5 of the tested sites (Achziv, Acre, Herzliya, Bat-Yam and the Eilat Marina).
- One site – Eilat Dolphin Reef, has shown signs of one pharmaceutical only – Diclofenac, though at a concerning concentration
- Ascidians collected from deep water at the Hadera power station were the only ones to show no traces of pharmaceuticals.
- Especially high concentrations of Diclofenac and Bezafibrate were found in Acre, Ashdod and Ashkelon.