Foto: Marcel Burkhard /Wikimedia Commons

When EDCs are noted in politics or in the media, the discussion is often about human health hazards. But within environmental research, concern is growing that even wildlife is likely to be more negative than has been thought so far.

In the report, Endocrine Disrupting Chemicals in the Marine Environment, researchers from the ACES Institute at Stockholm University have compiled the knowledge situation and demonstrates the risk of adverse effects on marine animals.

– It is primarily about the impact on animal reproduction, such as reduced fertility. In toxicity studies, EDCs have also been linked to effects on the immune system and metabolism, and also with cancer, says ACES researcher Marlene Ågerstrand.

Researchers are now worried that EDCs are likely to be a much greater threat to marine animals than is known at the present time.

– We are particularly concerned about the persistent substances that accumulate in the marine environment and in the large predators at the top of the food web, says Marlene Ågerstrand.

The problem is that there are still large knowledge-gaps. A major difficulty in studying EDCs is that their hormone-affecting effects often appear first long after exposure. Even if the animal is exposed to EDCs already in the ovary or fetal stage, the effect can first be detected much later when the animal itself is given offspring.

Another problem is that the legislation is lagging behind in relation to how chemicals are used in society today, says Marlene Ågerstrand

– The test requirements we have are generally low, and the tests required for different chemicals do not capture hormone-destructive effects. This means that in the end we do not have the knowledge we need to determine the possible harmful effects of different chemicals, she says.

In the Baltic Sea, in the 1970s, eyes were raised for what the researchers now call "classical" persistent EDCs, such as PCB and DDT. These substances were used on a large scale and caused very serious damage to, among other things, the seal and sea eagle populations.

Nowadays, most "classical" substances are regulated and banned. But at the same time, the production and use of other and, in many cases, similar chemicals have increased sharply. Today, the marine environment is burdened with thousands of new substances, of which science knows little or nothing about.

– We are not yet seeing the effects of all the new chemicals we use. And we do not want to come there either. When you see clear effects in the environment and on the animals, then it has gone too far. Instead, we must learn from the mistakes and work preventively, says Marlene Ågerstrand.

Text: Henrik Hamrén