The water in Norwegian lakes has become less polluted, but also browner. Here’s why

The water in Norwegian lakes has become much better and less polluted in the last 25 years, but at the same time, it has become much browner. There is a natural explanation for that.

Twenty-five years after the last nationwide lake survey in 1995, researchers have updated the status of many lakes in the country.

After a thorough survey was conducted in 2019, the results are now available. 

Perhaps the most important finding is that the water is less acidic, has less nitrate, and is generally less polluted by heavy metals than was the situation 25 years ago.

The cause? International agreements probably helped reduce sulfur emissions to the atmosphere, leading to reduced air pollution.

Less acid rain

“Instances of acid rain have decreased sharply and are now down to levels we had around the 1920s. 

“Emissions of toxic heavy metals such as lead and cadmium to the environment have been reduced. 

“It is gratifying that we now see that this affects the health of lakes throughout Norway,” Øyvind Garmo in the Norwegian Institute for Water Research (NIVA) noted in a press release.

Cleaner air

Although it may sound strange that the water in the lakes has become cleaner, at the same time browner, this is actually related to the fact that the air has become cleaner. One reason for the water’s color change is the reduction in acid rain.

“Less acid rain has contributed to more dissolved organic material – what we call humus – ending up in the water in these areas. This causes the water to be browner,” NIVA researcher Heleen de Wit said.

Although there are several good developments, the NIVA researchers pointed out that large areas in Southern Norway are still strongly affected by acidification. 

Source: © NTB Scanpix / #Norway Today / #NorwayTodayNews

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