microcontaminants

A microcontaminant is an impurity found at very low concentrations in environmental media such as surface water, groundwater, air, or food. These substances are typically identified at concentrations below the regulatory limits of conventional pollutants but can accumulate in ecosystems or in human and animal bodies over time. Common microcontaminants include trace pharmaceuticals and personal care products (e.g., analgesics, sedatives, fragrances), endocrine‑disrupting chemicals (e.g., bisphenol A, phthalates), pesticides, industrial chemicals (e.g., polychlorinated biphenyls), and emerging contaminants such as microplastics and nanomaterials.

Sources of microcontaminants are diverse. Human activities such as improper disposal of medicines, agricultural runoff, industrial discharges, and the use of detergents and cosmetics contribute to their introduction into the environment. Natural processes can also release microcontaminants; for example, some bacteria and plants produce natural compounds that may reach low concentrations in water or soil.

Detection of microcontaminants requires specialized analytical methods. Techniques such as liquid chromatography coupled with mass spectrometry (LC‑MS) or gas chromatography (GC‑MS) allow identification and quantification at nanogram‑per‑liter levels. While the presence of a single microcontaminant may not pose an immediate health risk, combined exposure can lead to chronic effects, including endocrine disruption, antimicrobial resistance, and sublethal toxicity to aquatic organisms.

Regulatory responses vary worldwide. Some jurisdictions have established guidelines for specific microcontaminants, whereas many adopt a precautionary approach and invest in research to better understand exposure pathways, health outcomes, and mitigation strategies. Water treatment plants are exploring advanced oxidation, adsorption, and membrane technologies to reduce microcontaminant levels, yet removal efficiency depends on the chemical nature of each contaminant. The scientific community continues to evaluate long‑term ecological and human health implications, as well as cost‑effective remediation technologies, in the emerging field of microcontaminant management.