There’s a gap in public health surveillance that I believe will eventually have to be addressed if we want the march of progress in population health to continue. Current surveillance relies heavily on biological fluids (blood serum and urine) to monitor population exposure to environmental contaminants. While these matrices effectively capture recent exposures and water-soluble compounds, they frequently fail to reflect the total body burden of persistent toxicants.

This gap exists because many critical pollutants do not remain in circulation; they sequester in specific tissue compartments over a lifetime, and they can be tricky to measure. Lipophilic compounds like PCBs and pesticides partition into adipose tissue, mercury builds up in nervous tissue, lead accumulates in the skeleton, and so on. Consequently, relying solely on fluid biomonitoring creates a pharmacokinetic blind spot, risking a significant underestimation of the toxicological drivers behind chronic diseases, and especially those with long latency periods such as neurodegenerative disorders and renal pathology.

Recent post-mortem analyses underscore the urgency of addressing this gap. Studies have confirmed the presence of per- and polyfluoroalkyl substances (PFAS a.k.a. “forever chemicals”) in human brain tissue, challenging previous assumptions about the blood-brain barrier. Furthermore, the detection of black carbon in airway macrophages serves as a dosimeter for lifetime particulate exposure that ambient air monitors cannot replicate. These findings suggest that the body acts as a historical archive, recording exposures that fluid analysis misses entirely.

To progress public health surveillance, we must move beyond the snapshot provided by blood samples and access the archive stored in tissues. This does not require a return to widely practiced complete autopsies. The emergence of Minimally Invasive Tissue Sampling (MITS), which utilizes needle biopsies to collect samples from key organs, offers a scalable, cost-effective, and culturally acceptable alternative. MITS is currently being used mostly for post-mortem analysis of infectious cases, but in theory could be adapted to analysis of persistant toxicants with little extra work involved.

By integrating toxicological screening into MITS protocols, epidemiological data collection can evolve to capture the true burden of environmental toxicity. This shift is essential for establishing causal links between chronic exposure and non-communicable diseases, ultimately driving more effective environmental health policy.

History and Implementations

National Human Adipose Tissue Survey (NHATS) (1970-1989)

This program was conducted between 1970-1989 by the EPA of the United States. It collected adipose tissue samples from sugeons and medical examiners across the U.S. to monitor the prevalence of lipophilic toxic substances. It provided critical baseline data on the body burden of persistent organic pollutants like PCBs and organochlorine pesticides. It was discontinued in 1989 as the focus shifted to the National Health and Nutrition Examination Survey (NHANES) which relies on blood and urine samples (more convenient but missing important tissue data).

Child Health and Mortality Study (CHAMPS) (2015 - Present)

Founded in 2015 by the Melinda Gates Foundation, CHAMPS is a global health surveillance network dedicated to determining the definitive causes of death in children under five and stillbirths in high-mortality regions within Sub-Saharan Africa and South Asia. Moving beyond standard verbal autopsies, CHAMPS utilizes a “ground truth” protocol that combines clinical records with Minimally Invasive Tissue Sampling (MITS)—using biopsy needles to collect brain, lung, and liver tissue—which are then reviewed by a multidisciplinary panel to assign a precise cause of death. While the network currently prioritizes infectious diseases and malnutrition, its established infrastructure for collecting and banking solid organs seems to me like a potential candidate for future environmental toxicological surveillance.