Are Micropollutants on the Rise?

Sometimes termed as emerging micropollutants or contaminants of emerging concern,  micropollutants have been an increasingly hot potato in scientific and policymaking circles in recent years. Although they have been around for millennia and increasing in concentration in our environment for centuries, it’s only now that we’re beginning to get a grasp of what the consequences of their existence may be.

Defined as substances which are leached into the environment in extremely low concentrations, usually (but not exclusively) through anthropogenic activity, micropollutants might not sound like a significant problem at first glance. However, their ability to persist in the environment for years, decades or even centuries – along with the difficulties involved in monitoring and removing them from the water, air and soil – mean that they’re a tricky proposition that’s certainly on the rise.

The bane of bioaccumulation

The fact that micropollutants are emitted into the natural world in such low concentrations could prompt you to think that there’s no point in worrying about them. However, many such substances do not biodegrade in the environment of their own account at a fast pace or even at all, meaning they can persist for a long, long time.

Of course, this leads to the phenomenon known as bioaccumulation, whereby small concentrations gradually build up to larger ones in the natural world, including inside flora and fauna. Given the extremely long half-lives of many micropollutants, they are, by very definition, on the rise at all times.  Generally, they will end up in water sources such as rivers, streams and lakes, as well as reservoirs, underground aquifers and other drinking water sources.

Wastewater woes

Ideally, they should theoretically be tackled at the filtration stage of wastewater treatment. However, current processes of purifying wastewater are insufficient to deal with the vast majority of micropollutants, meaning they are freely emitted back into the environment unperturbed. That’s because when most of our wastewater treatment plants were designed and commissioned, very little (if anything at all) was known about the issue of micropollutants.

Obviously, this only compounds the problems raised by the bioaccumulation of the substances. If they do not break down via natural processes – and we are not able to extract them from the natural world using the best scientific methods available to us – then they are undoubtedly going to accumulate ad infinitum, posing some very serious problems in the long run.

What is being done?

Clearly, such a scenario cannot be allowed to come to pass and the good news is that environmentalists, researchers and politicians are acutely aware of the problem. Studies are ongoing into the best methods of monitoring micropollutants, as well as advanced techniques to ultimately remove them from effluent streams and from the environment altogether.

However, it would be far more preferable to prevent these unwanted substances from entering our waterways in the first place. For that reason, legislation is also being drafted which will limit the concentration of known micropollutants in consumer products such as cosmetics, pharmaceuticals and agricultural additives, thus addressing the issue at its source.