Contaminants of Emerging Concern (CECs)

---

CECs have been defined by the European Commission and the US Environmental Protection Agency  as having the following characteristics: 

CECs are pollutants that may cause adverse ecological or human health effects, are not regulated under current environmental laws, and are generally not undergoing monitoring by periodic sampling and analytical testing of groundwater. Many CECs have been entering the environment for years, even decades, but their presence and extent have only recently been under investigation. 

There are many pharmaceuticals, personal care products, industrial chemicals such as PFAS, and flame retardants that act as so-called endocrine disruptors (EDCs). EDCs are compounds that adversely alter the normal functions of hormones. EDCs can cause reproductive effects in aquatic organisms, and evaluating these effects typically require analytical testing methodologies not readily available along with endpoints not previously evaluated using current guidelines.

Pharmaceuticals include antibiotics, anti-inflammatories, analgesics/pain relievers, antiepileptics, antidiabetics, beta-blockers (for heart disease and high blood pressure), and lipid regulators (lipids are fats and vitamins that store energy).

Personal care products include non-medicinal consumer chemicals such as cosmetics, deodorants, cleansers (soap, shampoo, toothpaste), moisturizers, perfumes, sunscreens, hair styling sprays and foams, and shaving creams. Household cleaning products include laundry detergents.

Existing data indicates industrial chemicals may comprise the most voluminous known category of CECs. The following are the most commonly-known: per- and polyfluoroalkyl substances (PFAS), pesticides, plastics and their common constituent bisphenol A (BPA) and phthalates, and explosives compounds. The following are lesser-known yet significant industrial chemical CECs: 1,4-Dioxane, used in pharmaceutical purification, and plastics production; the cleaning solvent trichloropropane; N-nitroso-dimethylamine (NDMA), which forms during the production of antioxidants and rocket fuel and the chlorination of waste and drinking water; and perchlorate, a widespread component in fireworks, explosives, and rocket propellant.

 Brominated flame retardants (BFRs) are an enormous category of CECs, used to reduce flammability in computers, plastics, furniture and clothing.

Cyanotoxins are toxic chemicals released from bacterial blooms that can proliferate in surface water or groundwater as a result of additions of nitrogen and phosphorus from fertilizer runoff and detergents in urban areas. The toxins are generally poorly documented; they reduce water quality and can adversely affect wildlife and humans.

Nanomaterials, or nanoparticles, are used in hundreds of consumer products and biomedical applications. They are typically 1-100 nanometers (a nanometer is one-millionth of a meter), and examples are metals such as aluminum or silver, or carbon fiber.

Bisphenol A (BPA) is a common constituent of many types of plastic. It is a confirmed endocrine disruptor, which means it can have adverse health effects on hormone function in humans and animals.

PFAS compounds are in Teflon, Gore-Tex, aqueous fire fighting foam [AFFF], also known as aqueous film forming foam, and metal plating baths. PFAS are a widespread emerging class of compounds whose toxicity is still being defined, but its cancer-causing (carcinogenic) effects have been confirmed.. 

As the CECs move through the environment or through wastewater treatment plants or drinking water filtration systems, by-products are routinely formed. Definition of the make-up and toxicity of these by-products is lacking.

Countries should strive to: a) control the release of these CECs to the environment at the source, b) implement regular oversight of manufacturers’ constituents used in their products; and c) implement groundwater monitoring in drinking water wells for (at least) those CECs such as PFAS that have the highest certainty of causing human health problems. Countries should follow the lead of the European Commission as they finalize legislation to eliminate the widespread release of PFAS compounds in biosolids from wastewater treatment plants that are used as soil amendments for agricultural areas, as the PFAS compounds currently continue to leach into underlying groundwater.