Immunotoxicity: The Hidden Health Risk

Why immunotoxicity matters? 

Immunotoxicity refers to harmful effects on the immune system caused by exposure to certain chemicals. Substances like PFAS (per- and polyfluoroalkyl substances) often found in industrial runoff and BPA (bisphenol), used in plastics, have been linked to reduced vaccine effectiveness, increased infection rates and even higher cancer risks.
What makes immunotoxicity especially concerning is its subtle, cumulative nature. Unlike immediate toxic effects, immune system damage builds up silently over time, often remaining undetected until it leads to serious or irreversible health outcomes. This is particularly alarming during critical stages of development like childhood or pregnancy, when even low-level exposure can have lifelong consequences. Yet, despite the mounting evidence, immunotoxicity is still not a standard endpoint in chemical safety evaluations. Regulatory frameworks like the EU’s REACH mandate testing for carcinogenicity and several other endpoints, but immunotoxicity is only addressed when specific concerns are raised, leaving countless chemicals unexamined for their potential immune harm. This is a regulatory blind spot of public health concern that demands immediate and systematic action.

What is required? 

To address the gap in water safety, a tiered testing strategy is recommended, starting with broad bioassays and narrowing down to high-risk chemicals. The authors urge the establishment of effect-based thresholds (EBTs) to guide decisions, prioritisation of under-tested substances, development of standardised immunotoxicity tests, and continued research on how chemical mixtures impact the immune system.