Elemental Analysis Laboratory

Why Is Hair Used in Environmental Biomonitoring

Key Takeaways

Hair is used in environmental biomonitoring because it may reflect long-term exposure to selected elements present in the environment. Due to its stable structure and the possibility of measuring multiple elements simultaneously, hair analysis is used in toxicology, environmental research, and monitoring exposure to heavy metals.

What Is Environmental Biomonitoring?

Environmental biomonitoring is the assessment of human exposure to chemicals and elements present in the environment.
Different biological materials are used in biomonitoring studies, including:

bloodBLOOD
urineURINE
nailsNAILS
hairHAIR

The aim of biomonitoring is to analyze the body’s exposure to selected environmental substances such as:

toxic pbHEAVY METALS
elementsTRACE ELEMENTS
industrial toxicINDUSTRIAL POLLUTANTS
toxicTOXIC SUBSTANCES PRESENT IN THE ENVIRONMENT

International organizations such as the World Health Organization (WHO), the US EPA , and the Agency for Toxic Substances and Disease Registry (ATSDR) describe biomonitoring as an important tool supporting the assessment of environmental exposure in populations.

Why Is Hair Used in Biomonitoring Studies?

Hair has several characteristics that make it a useful biological material in environmental and toxicological research.
The most important include:

  • the possibility of assessing long-term exposure,
  • easy sample collection,
  • non-invasive sampling,
  • material stability,
  • the ability to measure multiple elements simultaneously.

During hair growth, various elements present in the body and environment may become incorporated into the hair structure.
Since hair grows on average about 1 cm per month, a hair segment may reflect exposure from several weeks or months.

Hair vs Blood Testing — Different “Exposure Windows”

One reason hair is used in biomonitoring is the difference between hair and blood regarding the time frame of reflected exposure.

bloodBLOOD TESTS

  • show the current state of the body,
  • reflect short-term changes,
  • are regulated by homeostatic mechanisms.
bloodHAIR

  • may reflect long-term trends,
  • allows analysis of exposure over a longer period,
  • is less affected by short-term fluctuations.

For this reason, in environmental toxicology, hair is sometimes used as a complementary material alongside other biomonitoring methods.

Which Elements Can Be Measured in Hair?

Hair mineral analysis can assess both:

  • nutritional elements,
  • trace minerals,
  • selected elements considered potentially toxic.


The most commonly analyzed elements include:

  • zinc,
  • magnesium,
  • calcium,
  • selenium,
  • iron,
  • copper,
  • arsenic,
  • mercury,
  • cadmium,
  • lead.

The scope of analysis depends on the laboratory method and procedures used.

The Use of Hair in Environmental Toxicology

In environmental toxicology, hair analysis is used, among others:

  • for occupational exposure assessment,
  • in population studies,
  • in environmental exposure analysis,
  • in epidemiological projects,
  • in monitoring exposure to heavy metals.

Hair is particularly useful in assessing chronic exposure because it may accumulate elements over a longer period.

For this reason, hair analysis has been used in numerous studies concerning:

  • mercury,
  • arsenic,
  • lead,
  • cadmium.

The Importance of Laboratory Methods

The reliability of biomonitoring results depends on the quality of the laboratory process.
In hair analysis, important factors include:

  • sample collection method,
  • washing procedures,
  • sample preparation,
  • instrument calibration,
  • method validation,
  • quality control systems.

The most commonly used analytical techniques include:

  • ICP-OES,
  • ICP-MS.

These methods allow simultaneous multi-element analysis with high analytical sensitivity.

Why Is Standardization So Important?

Hair is a biological material susceptible to external influences.
Results may be affected by:

  • cosmetics,
  • hair dyeing,
  • environmental contamination,
  • sample collection method,
  • analyzed hair length.

Therefore, standardization is very important in biomonitoring studies, including:

  • sample collection,
  • washing procedures,
  • hair length,
  • laboratory protocols.

Without proper standardization, results between laboratories may be difficult to compare.

HTMA as a Biomonitoring Tool

Hair Tissue Mineral Analysis (HTMA) is used as a method for assessing the elemental composition of hair.
In practice, HTMA may be used for:

  • observing mineral trends,
  • environmental exposure analysis,
  • monitoring changes over time,
  • assessing long-term exposure to selected elements.

However, it should be emphasized that:

  • HTMA is not a diagnostic test for diseases,
  • results require careful interpretation,
  • hair analysis does not replace medical diagnostics.

Practical aspects of HTMA interpretation are described in more detail in LifelineDiag educational materials.

The Role of Laboratory Quality

In biomonitoring studies, the laboratory’s experience with biological material is critically important.
A reliable laboratory should apply:

  • validated procedures,
  • quality control systems,
  • regular instrument calibration,
  • standardized sample preparation protocols.

In laboratories performing hair analysis, understanding the specific characteristics and interpretative limitations of biological material is also essential.
Information regarding sample collection and result interpretation is available in the LifelineDiag knowledge center.

Frequently Asked Questions (FAQ)

Because it may reflect long-term exposure to selected environmental elements and substances.

No. Hair and blood provide different types of information and have different applications in biomonitoring.

Hair analysis may allow the assessment of exposure to selected heavy metals such as mercury, arsenic, lead, and cadmium.

No. HTMA is a biomonitoring and mineral trend observation tool, not a diagnostic disease test.

Results may be influenced by factors such as:

  • sample preparation methods,
  • laboratory procedures,
  • analytical techniques,
  • quality control standards.

Summary

Hair is an important biological material used in environmental biomonitoring and toxicology.
Its importance results from:

  • the possibility of assessing long-term exposure,
  • easy and non-invasive collection,
  • material stability,
  • the ability to analyze multiple elements simultaneously.

At the same time, result reliability depends on:

  • laboratory procedure quality,
  • standardized sample preparation,
  • quality control,
  • responsible interpretation.

Therefore, hair analysis should be treated as a biomonitoring and environmental exposure assessment tool rather than a standalone diagnostic method.

References

  1. Kempson IM, Lombi E. Hair analysis as a biomonitor for toxicology, disease and health status. Chemical Society Reviews. 2011.
  2. Rodrigues JL, Batista BL, Nunes JA, Passos CJ, Barbosa F Jr. Evaluation of the use of human hair for biomonitoring the deficiency of essential and exposure to toxic elements. Science of the Total Environment. 2008.
  3. Harkins DK, Susten AS. Hair Analysis: Exploring the State of the Science. Environmental Health Perspectives. 2003.
  4. World Health Organization (WHO). Environmental Health Criteria and Biomonitoring Guidance.
  5. ATSDR. Toxicological Profile and Environmental Biomonitoring Guidance.
  6. Seidel S et al. Assessment of commercial laboratories performing hair mineral analysis. JAMA.
  7. Bass DA et al. Trace element analysis in hair: Factors determining accuracy, precision and reliability. Biological Trace Element Research.

Hair Tissue Mineral Analysis (HTMA) is a functional and educational tool. It does not replace medical diagnostics or professional medical consultation.

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