Contaminants of Emerging Concern (CECs) are a broad class of chemicals that have been recently identified as potential threats to environmental and human health. They include pharmaceuticals, personal care products, microplastics, flame retardants, and industrial chemicals that persist in our waterways and oceans.
What Makes a Contaminant "Emerging"?
The term "emerging" doesn't necessarily mean the chemical is new. Many CECs have been in use for decades. What's emerging is our understanding of their environmental presence and potential harm. Advances in analytical chemistry now allow scientists to detect chemicals at parts-per-trillion concentrations — levels previously invisible.
A contaminant is considered "emerging" when it meets one or more of these criteria:
- Recently detected in the environment for the first time
- Newly recognised as potentially harmful at environmental concentrations
- Not yet regulated or inadequately covered by existing frameworks
- Increasing in prevalence due to changing production or consumption patterns
Categories of CECs
Pharmaceuticals and personal care products (PPCPs) — antibiotics, hormones, antidepressants, UV filters from sunscreens, and antimicrobials like triclosan enter waterways through household drains and hospital discharges.
Per- and polyfluoroalkyl substances (PFAS) — the "forever chemicals" used in non-stick coatings, food packaging, firefighting foam, and waterproof clothing. Over 12,000 individual PFAS compounds exist.
Microplastics — tiny plastic particles under 5mm from the breakdown of larger plastics, synthetic textile fibres, and manufactured microbeads.
Flame retardants — brominated and organophosphate compounds added to electronics, furniture, and building materials to reduce flammability.
Endocrine-disrupting chemicals (EDCs) — substances that interfere with hormonal systems, including bisphenol A (BPA), phthalates, and certain pesticides.
Why Do CECs Matter?
Even at very low concentrations, CECs can have significant biological effects. Endocrine disruptors can alter reproductive development in fish at parts-per-trillion levels. Antibiotics in the environment contribute to antimicrobial resistance. Microplastics act as vectors, absorbing and transporting other pollutants into organisms.
The "cocktail effect" — where organisms are exposed to multiple CECs simultaneously — can produce effects greater than any single chemical alone. This makes risk assessment particularly challenging.
What Is Being Done?
The EU's Chemicals Strategy for Sustainability is driving regulatory reform. The revised Urban Wastewater Treatment Directive will require advanced treatment for CEC removal at large treatment plants. Research projects like CONTRAST are developing new tools to detect, assess, and address CEC contamination in marine environments.
What Can You Do?
Educate yourself about the products you use daily. Dispose of pharmaceuticals at designated collection points. Choose products free from known CECs. Support policies that address chemical pollution at source. And explore the resources on A New Formula to deepen your understanding.
This article is part of the CONTRAST project, funded by the European Union under Horizon Europe. Views expressed are those of the author(s) only.