[ad_1]
According to a new study by the company, bottlenose dolphins are exposed to chemical compounds added to many cleaning products, cosmetics, personal care products and common plastics. GeoHealth, a journal of the US Geophysical Union.
The new research found exposure to these chemical compounds, called phthalates, in 71% of the dolphins tested in Sarasota Bay, Florida, in 2016 and 2017. Previous studies have detected phthalate metabolites in fat or the skin of some individual marine mammals. A new study is the first to document additives found in the urine of wild marine mammals.
Some phthalates have been associated with hormonal, metabolic and reproductive problems in humans, including low sperm count and abnormal reproductive organs. The study's authors do not know what health impact phthalates may have on dolphins, but the presence of chemical byproducts in the urine of animals indicates that they have stayed long enough in the body to treat them.
"We focused on urine in dolphins because in previous studies on humans, this matrix was the most reliable for indicating short-term exposure." Leslie Hart, professor of public health at the College of Charleston and lead author of the new study.
Studies have established a link between human exposure to phthalates and the use of products containing these additives, such as personal care products and cosmetics, but Hart said that the source of the drugs is the same. exposure of dolphins to phthalates is not yet known. High concentrations in dolphin urine of a specific phthalate compound most often added to plastics have alluded to plastic waste as a possible source of exposure for dolphins, she said. .
"These chemicals can get into 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," said M Hart.
According to the study's authors, the understanding of exposure in dolphins gives scientists an overview of the contaminants present in local waters and what other animals, including humans, are exposed to.
Gina Ylitalo, analytical chemist at NOAA's Northwest Fisheries Science Center who did not participate in the study, said that dolphins are good indicators of what's happening in coastal waters.
"All animals in the near-shore environment with similar prey are probably also exposed," she said. "Dolphins are great sentinels in the marine environment."
Ubiquitous contaminants
Phthalate compounds are added to a wide variety of products to provide flexibility, durability and lubrication. Some phthalates interfere with body systems designed to receive messages from hormones such as estrogen and testosterone. This can disrupt the natural responses to these hormonal signals.
Phthalate exposure tests look for the metabolites of the compounds, the products of the initial degradation of the compounds by the liver.
"We are looking for metabolites – these are indicators that dolphins have been exposed somewhere in their environment and that the body has started to treat them," Hart said.
About 160 dolphins live in Sarasota Bay, a subtropical coastal lagoon located between the barrier islands and the towns of Sarasota and Bradenton, on the southwestern coast of Florida. The Sarasota Dolphin Research Program of the Chicago Zoological Society has been tracking individual dolphins since 1970, monitoring their health, behavior and exposure to contaminants. Dolphins are residents of the region all year round, over several decades, with individuals living up to 67 years old.
In 2016 and 2017, Hart and his colleagues have tested the urine of 17 wild dolphins in and around Sarasota Bay for nine phthalates. They found phthalate metabolites in the urine of 71% of the dolphins tested.
Hart compared dolphin data with the CDC's NHANES, which includes behavior and diet information, the American population. She found that concentrations of one type of phthalate metabolite, monoethyl phthalate (MEP), were much lower in dolphins than in the human population studied by NHANES, but concentrations of another phthalic metabolite, mono-, were equivalent to or greater than levels found in humans.
"If you look at the main uses of the original compounds, the mother of MEP is commonly used in cosmetics and personal care products, including shampoos and body cleansers, while MEHP is a metabolite of A compound commonly added to plastic ".
Indicator species
Understanding what dolphins are exposed gives researchers and the public a better sense of what's in the environment.
The study is particularly useful because of the long-term data available on the health and behavior of Sarasota dolphins, Ylitalo said. Bottlenose dolphins are good indicators of pollutant exposure in whales and dolphins, which can not be easily sampled.
"We will not get urine samples from killer whales in my part of the country," Ylitalo said. "They do not know what the health effects are, but if a group can do it, these are the people who will start doing it."
Documenting the exhibition was an important first step, Hart said. She wants to expand the size of the sample to continue studying the extent and potential impacts of exposure on health and start looking for possible sources. Ultimately, she hopes this research could help reduce sources of contamination.
"We have introduced these chemicals, they are not natural toxins, and we have the ability to reverse them, clean them." Hart said.
Source link
