Nowadays, we use and produce more chemicals and in increasingly higher amounts. Many chemicals are later found in the marine environment, such as the Baltic Sea. But what and how much do we know about the chemicals present in the Baltic Sea? Researchers at ACES set out to answer this question in a new study published in the journal Environmental Science – Processes and Impacts. They conclude that while we are good at finding and monitoring well-known and regulated chemicals present in the Baltic Sea, we are largely unaware of many other chemicals that are also there.
“It is a great challenge for society to manage the risks of all the partly known, but mostly unknown, chemicals that are emitted to the environment. Environmental monitoring and analysis of chemicals in various samples such as water or fish, is a crucial part of this work since it provides knowledge on what chemicals are present in the environment, and if their concentrations increase or decrease. An important question is whether we can observe effects of measures taken to reduce emissions of chemicals,” says Anna Sobek, Associate Professor at ACES who co-authored the study.
The researchers compiled data from research and monitoring collected from Baltic Sea fish between 2000-2012.
“We found that it was mostly well-known and already regulated chemicals that were being reported or studied in fish over and over again. These chemicals are, for instance, PCBs (polychlorinated biphenyls) and dioxins. The most commonly studied chemicals in Baltic Sea fish are, to a large extent, already regulated by, for example, EU’s REACH, the Stockholm Convention on persistent organic pollutants or EU’s Water Framework Directive,” says Anna Sobek
Prioritising chemicals is biased
Since measuring concentrations of chemicals in environmental samples is expensive and time-consuming, it is often deemed important to prioritize chemicals.
“Our study shows a bias towards prioritizing previously studied chemicals or chemicals that are known to be a risk to humans and the environment. Even though there are good arguments for monitoring these substances in the environment, we must realize that this prioritization leads to lack of information about the majority of chemicals present in the environment,” says Anna Sobek.