Another day, another depressing insight into the world’s oceans.
A recent study has found that chemicals from your cleaning products, cosmetics, and plastics are making their way into the bodies of bottlenose dolphins in Florida. As reported in the American Geophysical Union journal GeoHealth this week, researchers discovered evidence of exposure to chemical compounds called phthalates in over 70 percent of dolphins in Florida. This is the first time these chemicals have been documented in the urine of wild marine mammals.
Phthalates are everywhere. They are a group of chemicals added to plastic products and packaging to make them more flexible or durable, although they can also be found in products like paints, nail polish, hair spray, shampoo, soaps, perfumes, food, you name it. However, scientists are only just starting to understand the risk they pose to human health.
In this study, the researchers tested the urine of 17 dolphins in Sarasota Bay between 2016 and 2017 for phthalates and their metabolites. Phthalate metabolites were detected in at least 12 of the dolphins’ urine, including two phthalates often used in commercial manufacturing – diethyl phthalate (DEP) and di‐2‐ethylhexyl phthalate (DEHP).
“We are looking for metabolites. These are indicators that the dolphins have been exposed somewhere in their environment and that the body has started to process them,” lead author Leslie Hart, a public health professor at the College of Charleston, said in a statement.
“These chemicals can enter marine waters from urban runoff and agricultural or industrial emissions, but we also know that there is a lot of plastic pollution in the environment.”
A fair few studies have linked phthalate exposure to a number of wide-reaching health problems in humans, although exactly how much risk they pose is not crystal clear. The US Centers for Disease Control and Prevention (CDC) currently states that the effects of low-level exposure are “unknown”, although they highlight that research has linked phthalates to fertility problems in mammals. A number of studies have also demonstrated how phthalates can affect levels of sex hormones and other hormones by stimulating or inhibiting the endocrine system. Although, once again, more research needs to be done before any firm conclusions are reached.
The risk to dolphins and marine mammals is even less clear. Nevertheless, health risks aside, phthalates are still a form of contamination introduced to the environment by humans. At the very least, this still goes to show how far-reaching the unwieldy impacts of industrialized humans can be.
“Any animals in the near shore environment with similar prey are probably being exposed as well,” said Gina Ylitalo, an analytical chemist at the NOAA Northwest Fisheries Science Center (who was not involved in the study).
“The dolphins are great sentinels of the marine environment.”