Early-life PFAS exposure linked to reduced bone mineral density in adolescents

Overview

The health evidence base for per- and polyfluoroalkyl substances (PFAS) continues to expand, and the latest findings carry direct implications for how contaminated land professionals assess risk at legacy sites. A new longitudinal study published in the Journal of the Endocrine Society has linked early-life exposure to specific PFAS compounds with reduced bone mineral density (BMD) in adolescents. Researchers tracked 218 children from birth to age 12, identifying PFNA, PFHxS, and PFOS as primary drivers of reduced BMD in the whole body, total hip, and femoral neck. For practitioners conducting human health risk assessments under Australian regulatory frameworks, these findings signal that acceptable exposure thresholds for PFAS are likely to continue tightening.

Key details

The study represents one of the most detailed longitudinal investigations into the developmental effects of PFAS exposure on the skeletal system. The key findings include:

• Compounds of concern: PFNA (perfluorononanoic acid), PFHxS (perfluorohexane sulfonate), and PFOS (perfluorooctane sulfonate) were each independently associated with reduced bone mineral density. These are among the most commonly detected PFAS in Australian groundwater and soil at legacy contamination sites, particularly those associated with firefighting foam (AFFF) use.
• Exposure window: The critical exposure period identified was early childhood, with effects measurable at age 12. This highlights the importance of developmental exposure pathways in risk assessment, rather than focusing solely on adult exposure scenarios.
• Dose-response relationship: The study identified a dose-dependent relationship, meaning that higher PFAS concentrations in blood serum correlated with greater reductions in BMD. This is significant for risk assessors because it supports the derivation of quantitative toxicity reference values.
• Mechanism: The researchers propose that PFAS compounds interfere with endocrine signalling pathways that regulate bone mineralisation during growth. This endocrine disruption mechanism is consistent with other PFAS health effects and strengthens the biological plausibility of the findings.

Australian context

Australia’s regulatory framework for PFAS is anchored by the PFAS National Environmental Management Plan (PFAS NEMP), currently in its third version (NEMP 3.0). The NEMP references health-based guidance values developed by Food Standards Australia New Zealand (FSANZ) and the Australian Department of Health. These values are periodically reviewed as the global toxicological evidence base grows.

The National Environment Protection (Assessment of Site Contamination) Measure 2013 (NEPM 2013) provides the overarching framework for contaminated site assessment, including human health risk assessment (HHRA). Health Investigation Levels (HILs) and Health Screening Levels (HSLs) are derived using toxicity reference values that draw on international data. Developmental endpoints, including effects on children and adolescents, have historically been the drivers for setting conservative guideline values.

In practical terms, this study adds to the body of evidence that will inform future revisions to Australian PFAS guidelines. State regulators, including the NSW EPA, Victorian EPA, and Queensland Department of Environment, Science and Innovation, will likely factor skeletal developmental effects into their assessment of acceptable exposure levels. Sites with known PFAS contamination in areas where groundwater is extracted for potable or domestic use, or where residential land use involves sensitive receptors (children, pregnant women), will face increased scrutiny.

The Department of Defence’s PFAS Investigation and Management Program, which covers dozens of current and former defence sites across Australia, will also need to consider these findings in its ongoing risk assessments and remediation planning.

Practical implications

For contaminated land consultants and site owners, the practical implications are significant:

• Risk assessment updates: Practitioners conducting HHRAs at PFAS-affected sites should ensure their toxicological reviews capture the latest developmental endpoint data. Relying solely on current screening levels without considering the trajectory of the science leaves site owners exposed to future regulatory changes.
• Conceptual site models: CSMs for PFAS-affected sites must account for the likelihood that guideline values will continue to decrease. This influences the assessment of exposure pathways, particularly ingestion of groundwater and consumption of home-grown produce irrigated with affected water.
• Remediation planning: Sites that currently meet existing criteria may not meet future, more stringent thresholds. Proactive remediation planning that anticipates tighter standards can avoid costly re-mobilisation and additional community engagement.
• Community communication: The finding that children are a particularly sensitive receptor group requires careful communication with affected communities. Environmental consultants should work with their clients to ensure risk communication is transparent and evidence-based.

References and related sources

• Original source article – AJMC
• PFAS National Environmental Management Plan (PFAS NEMP)
• Department of Defence PFAS Investigation and Management Program

How iEnvi can help

iEnvi’s contaminated land specialists have extensive experience in PFAS site investigations and human health risk assessments across Australia. We work within the PFAS NEMP framework and apply the latest toxicological data to ensure our assessments are robust and defensible. Our remediation team designs and implements PFAS management strategies that account for both current regulatory requirements and anticipated future changes. If you need expert witness support for PFAS-related litigation or regulatory proceedings, our team can provide independent, evidence-based opinions. Contact iEnvi to discuss your PFAS management needs.

This is an iEnvi Machete news summary. Prepared by iEnvi to summarise the source article for contaminated land, groundwater, remediation, approvals and site risk professionals.

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