What Does Contaminants of Emerging Concern Mean?

If you take a keen interest in environmental or scientific topics, you may have come across the term “contaminants of emerging concern” before. This broad umbrella category refers to hundreds (or perhaps even thousands) of chemicals that are present in our environment and used in our everyday activities – but about which we know very little.

It’s important to note that the chemicals themselves are not emerging, since they have been in widespread circulation for decades. However, as our ability to analyse water and our knowledge of their behaviours – and, in particular, their ability to persist in the natural world – has grown, so too has our concern over their long-term effects on the human body and the environment. It’s for this reason they are termed contaminants of emerging concern.

What exactly are contaminants of emerging concern?

This is a difficult question to answer, mainly because there are nearly 100,000 chemicals in circulation in our environment, many of which are completely unregulated. These are used in a wide variety of household products and processes and over time, they can become leached into the environment.

For many years, scientists believed that this contamination posed little problem because the concentrations of such substances was miniscule at the outset. Indeed, the mantra that “dilution is the solution” held firm, until it was observed that certain chemicals do not biodegrade easily (or at all) in the natural world. As a result, they are capable of bioaccumulating and reaching concentrations that could pose a problem for plant, animal and human life.

Where do contaminants of emerging concern come from?

It’s highly likely that you interact with products containing contaminants of emerging concern on a daily basis. They have a wide range of sources, including agricultural chemicals such as pesticides and herbicides, grass care products, pharmaceuticals, personal care products, industrial chemicals, surfactants, heavy metals and more.

When we consume or use these products, a certain percentage of the chemicals contained therein are washed down the plughole, excreted through our bodies or else washed into sewers, rivers and lakes from excessive rainfall. They are then capable of withstanding the filtration processes at most wastewater treatment plants, thus allowing them to infiltrate the environment relatively intact.

What are the potential impacts of contaminants of emerging concern?

As the name suggests, our research into these contaminants has only begun to take shape in recent years. For that reason, we simply do not know the full impact that such chemicals could have on ecosystems over a prolonged period of time. However, it is known that some contaminants can imbalance nutrient levels in aquatic environments, promoting the growth of certain species to the detriment of others. Meanwhile, it’s also been observed that other chemicals can disrupt the feeding, breeding and navigational abilities of some marine life.

From a human perspective, we’re even less confident about the long-term ramifications of exposure to contaminants of emerging concern. While some chemicals have been labelled as likely carcinogenic and others as endocrine disruptors, we have no way of knowing the full extent of their impact on our bodies. That’s especially true of those which only reveal their effects later in life. Research is ongoing.