Don’t dump drugs in trash, toilet; it may come back in your food — study
After finding traces of pharmaceuticals in sea squirts in Mediterranean and Red seas, Tel Aviv University researchers urge public to take unused medicines to clinics, pharmacies
Sue Surkes is The Times of Israel's environment reporter
After finding residues of three commonly used drugs in marine creatures in both the Mediterranean Sea and the Red Sea, Tel Aviv University researchers called on the public Sunday to deposit used drugs in special containers at pharmacies and medical centers and not to flush them down the toilet or throw them in the trash.
The call came after they found significant concentrations of the drugs at 10 out of 11 sampled sites along the Israeli coast. The drugs were Bezafibrate, which helps to lower LDL cholesterol and triglyceride in the blood and increase HDL; carbamazepine, which is used to treat epilepsy and is among treatments for schizophrenia and bipolar disorder; and diclofenac, a common anti-inflammatory drug sold under brand names such as Voltaren.
Because these pharmaceuticals are not fully metabolized in the body, large amounts of the active compounds are excreted out. Sewage treatment facilities are unable to break them down properly and their concentrations after sewage treatment has been completed are not monitored. From the treatment facilities, they enter the sea.
The problem is exacerbated by people throwing unused drugs down the toilet or into the garbage.
“Many of these compounds are very stable,” said Prof. Noa Shenkar of the university’s School of Zoology and the Steinhardt Museum of Natural History, who led the research, together with graduate student Gal Navon. The research was published this month in the journal Marine Pollution Bulletin.
“They take a long time to degrade in the marine environment and the damage they cause to marine life could be extreme, since these pharmaceuticals are designed to affect biological systems in the human body.
“The medications we use end up in the sea, mainly through sewage discharge, and cause great damage to the marine environment, indirectly affecting humans, who feed on sea foods that are exposed to such contamination.
“There are different ways to tackle this problem. On the individual level, we recommend that the population as a whole takes personal responsibility, disposing of unused pharmaceuticals into designated containers – which can be found at pharmacies and health maintenance organizations’ facilities.”
The research team, which also included the university’s Porter School Water Research Center Hydrochemistry Lab, headed by Prof. Dror Avisar, will be probing the impact of the drugs on the organisms tested and will be expanding the list of common drugs to be researched.
The drug residues in marine ecosystems — including antibiotics, anti-inflammatory drugs, analgesics and anti-depressants — is a worldwide problem.
Studies performed at sites around the world have shown that estrogen, present in birth control pills, damages fertility in certain species of male fish by encouraging the development of female features. Prozac triggers increased aggressiveness and risk-taking in crustaceans (shellfish). And anti-depressants have been found to impair memory and learning in cuttlefish.
The Israeli researchers looked for evidence of the three drugs in ascidians – invertebrate filter feeders just a few centimeters long that attach themselves to hard surfaces such as rocks, piers or breakwaters, where they feed on small particles. Of the 11 sites tested, nine were along the Mediterranean coast (Achziv, Acre, Haifa Marina, Sdot Yam, Hadera power station, Accadia beach in Herzliya, HaSela beach in Bat-Yam, Ashdod Marina and Ashkelon Marina) and two were in the Red Sea (Eilat Marina and Dolphin Reef).
Shenkar and and Navon found all three substances in filter feeders at four sites — Ashdod, Ashkelon, Sdot Yam and Haifa. Two of the drugs were present at five sites — Achziv, Acre, Herzliya, Bat-Yam and the Eilat Marina. Diclofenac and Bezafibrate were found at “especially high concentrations” in Acre, Ashdod and Ashkelon and a “concerning concentration” of diflofenac was identified at Eilat’s Dolphin Reef.
The only ascidians without traces of the drugs were near the Hadera power station, where they were collected from deep water.