Navigating the Complex Landscape of Emerging Contaminants

1. Introduction

In the realm of environmental science and management, one of the most pressing and complex issues we face today is the emergence of new contaminants. These are substances that, due to advancements in detection methods, newly recognised exposure pathways, or evolving scientific understanding, are now being identified as potential threats to our environment and public health.

Emerging contaminants aren’t necessarily new in their creation or use. In fact, many have been part of our industrial, agricultural, and domestic landscapes for years, even decades. However, their environmental presence or significance is only recently being recognised. This could be due to advancements in scientific techniques that allow us to detect these substances at lower concentrations, or it could be due to new research revealing previously unknown pathways through which these contaminants can enter and affect our ecosystems.

One of the most prominent examples of such contaminants is Per- and polyfluoroalkyl substances (PFAS). These substances, often referred to as “forever chemicals” due to their longevity and persistency, have been used in various industries for their resistance to heat, water, and oil. Despite their widespread use, our understanding of their environmental and health risks is still developing, making them a prime example of emerging contaminants.

Fire Fighting Foam – a common source of PFAS in the environment

However, PFAS are just one piece of the puzzle. The landscape of emerging contaminants is vast and varied, encompassing everything from pharmaceuticals and personal care products to industrial chemicals and pesticides. Each of these substances presents its own unique challenges in terms of detection, risk assessment, and management.

Navigating this complex landscape requires a deep understanding of the science behind these contaminants, as well as the tools and strategies available for their management. It also requires us to stay abreast of the latest research and developments in the field, as our understanding of these contaminants is constantly evolving. In the following sections, we will delve deeper into these topics, exploring the global impact of emerging contaminants, the role of legislation in their management, and the future directions in this critical field of environmental science.

2. Understanding the Global Impact of Emerging Contaminants

Emerging contaminants, due to their pervasive nature and potential for long-term environmental and health impacts, have become a global concern. Their presence is not limited to specific regions or countries; they are found in various environmental media across the world, from the soil in our backyards to the deepest parts of our oceans.

Microplastics in Sediments

The global impact of these contaminants is multi-faceted. On one hand, they pose a direct threat to our ecosystems. Many emerging contaminants, such as PFAS, are persistent, meaning they do not break down naturally over time. This allows them to accumulate in the environment, potentially causing harm to wildlife and damaging delicate ecosystems. Some of these contaminants can also bioaccumulate, building up in the tissues of organisms over time, which can lead to harmful effects up the food chain.

On the other hand, emerging contaminants also pose a significant risk to human health. Many of these substances can make their way into our food and water supplies, leading to potential exposure. While the health effects of many emerging contaminants are still not fully understood, research has linked some of these substances to a range of health issues, from hormonal disruption to increased risk of certain types of cancer.

The global nature of this issue also means that it is influenced by a range of factors, from industrial practices and waste disposal methods to climate change and population trends. For instance, more extreme weather events, driven by climate change, can impact how contaminants behave in the environment and affect their spread and concentration.

Understanding the global impact of emerging contaminants is a crucial step in navigating this complex landscape. It allows us to see the bigger picture, highlighting the urgency of this issue and the need for coordinated, global action. In the next sections, we will explore how legislation plays a role in managing these contaminants and delve deeper into specific examples, such as PFAS, to better understand the challenges and potential solutions in this field.

3. The Role of Legislation in Managing Emerging Contaminants

As we navigate the complex landscape of emerging contaminants, one of the most critical tools at our disposal is legislation. Laws and regulations play a pivotal role in managing these substances, providing the framework for their detection, monitoring, and control.

Different countries have different approaches to this issue. For instance, in the UK, the approach to managing contamination is chemical agnostic. Rather than having a specific list of chemicals to monitor and regulate, the UK legislation tasks local authorities to examine any and all substances in, on, or under the land. This broad approach ensures that no potential hazardous substances are overlooked, providing a more comprehensive protection of public health and the environment.

In the event that a substance poses a high level of risk, remediation efforts are mandated to reduce these risks. This process includes a range of actions like removing contaminated materials, using technologies to reduce the concentration of contaminants, and controlling the risk to prevent further harm.

However, legislation is not a static entity. It must adapt and constantly update based on new scientific findings, environmental discoveries, and public health studies. This is particularly true for emerging contaminants, where our understanding is constantly evolving. As scientific techniques and monitoring capabilities improve, we may identify more such substances, and our understanding of their risks and how best to manage them will continue to develop.

For emerging contaminants that don’t yet exist, our first line of defence is legislation like the REACH legislation, whether it’s at a UK level or an EU level. The challenge there is the flow of new substances coming onto the market, which is probably overwhelming. But these are our first lines of defence.

In the following sections, we will delve deeper into specific examples of emerging contaminants, such as PFAS, and explore the challenges and potential solutions in managing these substances.

4. Emerging Contaminants: A Closer Look at PFAS

Per- and polyfluoroalkyl substances (PFAS) serve as a prime example of emerging contaminants. These substances, often referred to as “forever chemicals” due to their longevity and persistency, have been used in various industries for their resistance to heat, water, and oil. Despite their widespread use, our understanding of their environmental and health risks is still developing.

PFOS Molecule

PFAS encompass a large number of individual chemicals, often quoted as numbering in the thousands. While some, such as PFOA and PFOS, are relatively well-studied, many others are not. Our understanding of the environmental and health risks posed by these less-studied PFAS is limited, which fits into the definition of emerging contaminants.

What makes PFAS particularly challenging is their persistence in the environment and their potential for bioaccumulation. They are resistant to degradation, which means they can remain in the environment for a long time after being released. Moreover, they can accumulate in the tissues of living organisms, including humans, leading to potential health risks.

Efforts are underway to better understand and manage the risks associated with PFAS. For instance, the PFAS guidance project led by professionals from ALS, and LQM is a valuable effort towards understanding the impact and risk management of PFAS in soil and water. Additionally, the planned launch of CIRIA’s PFAS forum later this year will provide a platform for the scientific and industrial communities to share knowledge, learn from global best practices, and discuss potential strategies to mitigate the risks posed by PFAS.

However, the challenge of managing PFAS is significant. With over a thousand pages of substance-specific environmental risk assessments and risk management options analysis, the task of understanding and managing these substances is complex. This complexity underscores the importance of a robust and adaptable approach to managing emerging contaminants, a topic we will explore further in the following sections.

5. The UK’s Approach to Contaminant Management

The United Kingdom has a unique approach to managing contaminants, including emerging ones. Unlike some other countries, the UK’s approach is chemical agnostic. This means that instead of having a specific list of chemicals to monitor and regulate, the UK legislation tasks local authorities to examine any and all substances in, on, or under the land. This broad approach ensures that no potential hazardous substances are overlooked, providing a more comprehensive protection of public health and the environment.

LCRM – One of the main sources of guidance for management of contamination in the UK

The UK’s contaminated land legislation breaks down the issue into four key areas: historic contamination, new contamination, ongoing land use, and changes in land use. This breakdown clearly illustrates how contamination can occur and evolve over time, and the different facets that need to be addressed when managing contamination.

In the event that a substance poses a high level of risk, remediation efforts are mandated to reduce these risks. This process includes a range of actions like removing contaminated materials, using technologies to reduce the concentration of contaminants, and controlling the risk to prevent further harm.

However, the UK’s approach is not without its challenges. One of the key challenges is the need to constantly update the list of hazardous substances based on new scientific findings, environmental discoveries, and public health studies. This is particularly true for emerging contaminants, where our understanding is constantly evolving.

In the following sections, we will delve deeper into the challenges and potential solutions in managing emerging contaminants, using specific examples such as PFAS, and explore the importance of preliminary risk assessment in land contamination risk management.

6. The Challenge of Identifying and Characterising Emerging Contaminants

One of the most significant challenges in navigating the landscape of emerging contaminants is their identification and characterisation. Emerging contaminants can include a wide range of substances, from industrial chemicals and pharmaceuticals to personal care products and pesticides. Each of these substances presents its own unique challenges in terms of detection, risk assessment, and management.

For instance, the examples of polybrominated diphenyl ethers (PBDEs) and 1,2,3-trichloropropane (TCP) underscore the complexities around defining emerging contaminants. Both PBDEs and TCP have been studied extensively enough to understand their chemical properties and toxicological impacts, and even have set regulatory standards. Yet, they appear on the list of emerging contaminants. This paradox might be due to ongoing uncertainties around their environmental fate, interactions, and long-term effects, or evolving concerns around their presence in the environment.

Another intriguing case is that of Bisphenol A (BPA), a widely used industrial chemical that is currently under scrutiny for its potential health impacts, particularly regarding food safety. Despite being a well-studied chemical, its status might shift towards being an emerging contaminant due to changing understandings of its safe levels of exposure.

In all these cases, the challenge for environmental management is not just identifying and characterising new contaminants, but also keeping up with changing understandings of known substances and their risks. This includes staying informed about evolving exposure pathways, detection methods, toxicological data, and the potential for unexpected interactions between contaminants.

In the next sections, we will explore the importance of preliminary risk assessment in land contamination risk management and discuss future directions in navigating the complex landscape of emerging contaminants.

7. The Importance of Preliminary Risk Assessment in Land Contamination Risk Management

As we navigate the complex landscape of emerging contaminants, one of the most critical steps in the process is the preliminary risk assessment (PRA). This process involves understanding the nature and location of different site activities, which forms the basis of a conceptual site model. Without a good understanding of the historical uses of the land, it can be challenging to accurately assess the risks and manage liabilities associated with contamination.

A PRA is particularly important when dealing with emerging contaminants, where our understanding is constantly evolving. For instance, substances like PFAS, which are persistent in the environment and can bioaccumulate in organisms, require a thorough understanding of their distribution, behavior, and potential impact on the environment and human health.

The PRA process includes identifying potential sources of contamination, evaluating the pathways through which contaminants can move in the environment, and assessing the receptors that could be affected. This process helps to identify areas of concern and prioritise efforts for further investigation and remediation.

However, PRA is not a one-time process. As new information becomes available, the risk assessment needs to be updated to reflect the current understanding of the contaminants and their potential risks. This iterative process is crucial for effectively managing emerging contaminants and protecting public health and the environment.

In the final section, we will discuss future directions in navigating the complex landscape of emerging contaminants, focusing on the need for a more quantitative, interdisciplinary, and communicative approach to managing these challenges.

8. Future Directions

As we look towards the future, navigating the complex landscape of emerging contaminants will require a multifaceted approach. The challenges we face are not just scientific or technical, but also regulatory, societal, and economic. Therefore, our strategies for managing these contaminants must be equally diverse and adaptable.

One of the key future directions in this field is the development of more advanced detection and monitoring techniques. As our ability to detect and quantify contaminants at lower concentrations improves, we will be better equipped to identify and manage emerging contaminants. This will also allow us to better understand their behavior in the environment and their potential impacts on human health and ecosystems.

Another important direction is the development of more effective remediation technologies. While traditional remediation methods can be effective for some contaminants, emerging contaminants often require more innovative solutions. This could include advanced chemical treatments, biological remediation methods, or even the use of nanotechnology.

Eight potential EA approaches for PFAS plumes. EA, enhanced attenuation; PFAS, per‐ and polyfluoroalkyl substances

However, technical advancements alone are not enough. We also need to improve our regulatory frameworks to better manage these contaminants. This includes updating our legislation to reflect the latest scientific understanding, as well as developing more effective strategies for enforcing these regulations.

Finally, we need to enhance our communication and collaboration efforts. Navigating the complex landscape of emerging contaminants is a collective effort, requiring the cooperation of scientists, policymakers, industry professionals, and the public. By working together, sharing knowledge, and learning from each other, we can develop more effective strategies for managing these contaminants and protecting our environment and public health.

In conclusion, while the landscape of emerging contaminants is complex and challenging, it is also an area of great potential. By leveraging our scientific understanding, technological advancements, regulatory tools, and collective efforts, we can navigate this landscape and work towards a safer and healthier future.

Published: 26 May 2023