Hair Analysis Panel Discussion: Section 7.0
On both days of the panel discussions, observers were given the opportunity to provide input on issues related to the charge questions and panel deliberations. Observer comments received during the meeting are summarized below, alphabetized by observer's name. A full list of observers and their respective positions and affiliations is included in Appendix F. Observers were asked to provide appropriate references and data to support their statements where possible. Statements provided without reference are included, but have not been verified or validated by ATSDR or the panel. In some cases panelists responded to a particular observer comment or question; such responses are summarized in this section as well.
Observers were also encouraged to provide written comments after the June 12–13, 2001, panel discussions. Appendix G includes written comments from two individuals.
Erik Auf der Heide
Dr. Auf der Heide commented that considering sensitivity, specificity, and predictive value is as important as the reference range when interpreting laboratory data.
Dr. Amler, a pediatrician, stressed her observations of over-interpretation and misinterpretation of hair analysis results.
She noted that a lack of knowledge exists among health care providers in terms of how to use hair analysis, citing two examples. She described a case of an autistic child with reportedly high levels of mercury in his hair. The physician presumed that the elevations were due to his immunizations and ordered chelation in hopes of improving the autism. In another case, the interpretation of hair analysis results of a Down's Syndrome child as a dietary insufficiency led to the administration of high vitamin doses and an unusual diet. (Dr. Clarkson raised the point that misuse or misinterpretation of laboratory tests is not unique to hair analysis.)
Dr. Campbell emphasized the need to clearly define "normal" and
"reference" ranges and to describe how these ranges are developed
in the various laboratories. Understanding the meaning and derivation
of such ranges is very important to individuals who need to interpret
site-specific hair analysis results and understanding whether results
may be elevated. Further, Dr. Campbell questioned what is known
about possible geographical or regional differences in background
concentrations of various substances in hair.
Dr. Jones requested that the panel and ATSDR consider the following:
- Evaluate substances on a species-specific basis, not just
on an element basis. Looking at the form in which elements such
as arsenic, mercury, and selenium are present in hair may help
to distinguish exposures due to the form released from a Superfund
site from exposures to a form originating from another source.
- If ATSDR is considering hair analysis in its public health
assessments, begin the process of generating substance- and
species-specific quality control reference materials as soon
as possible. Generation of such reference materials can take
- Include handling procedures and short- and long-term storage
requirements (e.g., container and climatic conditions) in any
- Do not standardize hair analysis procedures too highly or you risk stifling innovation by laboratories. Strict standardization will not guarantee good quality control. Specific procedures or technologies should not be required as long as the laboratory can demonstrate the quality of its results. Proficiency systems (daily and longer-term), as recommended by the Clinical Laboratory Improvement Act (CLIA), are encouraged.
CDC/National Institute for Occupational Safety and Health
Dr. Kawamoto presented a schematic that integrated many of the concepts and issues being discussed by the panel (see Figure 7-1). She explained the interface between the many compartments within the body and how different testing methods help piece exposure information together. Specifically, Dr. Kawamoto discussed how different methods help assessors identify potential (environmental media sampling), external (wipes, breathing zone air samples, hair), and internal (hair, blood, urine) exposures to a particular substance and how that information may be integrated to evaluate potential health effects. She emphasized the importance of establishing a framework under which to conduct exposure and health effects evaluations, including clearly identifying the problem and the hypothesis under which you will proceed, identifying study design issues, and understanding sampling and analytical issues.
In reference to the arsenic conference held in San Diego in 2000, Dr. Mellard commented on a study in which a single volunteer showered in arsenic-contaminated water to help better understand internal versus external contamination. The study revealed that up to a certain level, no change in arsenic levels in hair were observed. Dr. Mellard suggested that perhaps further study is worthwhile to see if, for relatively low levels of arsenic in water, hair could be used as a measure of internal contamination, without worrying about external contamination.
Dr. Kosnett responded with a few words of caution: In vitro
experiments have shown that external absorption is dependent on
time. Therefore a single showering episode may not reflect a longer-term
exposure or exposure through bathing. Having reviewed the literature,
indicated that he is not convinced yet that any cut-off point exists at which there is no element of external uptake of arsenic in hair from bathing.
Dr. Quig, from Doctor's Data (a commercial laboratory), expressed
extreme gratitude for being invited to this meeting and offered
his opinion on a variety of topics related to analytical methods
and factors affecting the interpretation of laboratory results:
- As a screening tool, no one laboratory test exists that
is absolutely definitive. It is critical that hair analysis
results be looked at in careful consideration of patient symptoms
and exposures. Hair analysis is not a test to end all tests.
- A targeted approach is necessary for certain elements. There
is no question, for example, that chromium is extremely difficult
to measure. One laboratory using high-resolution mass spectrometry
is getting closer to being able to measure Cr6+ in
blood. However, interference problems do not exist for all
- Hair treatment is an important issue and clearly affects
hair analysis results. Dr. Quig has worked on a study of 150
hair products (pre-published status); the most common contaminants
identified include tin, aluminum, silicone, and phosphorous.
Only two products have been found to contain mercury and arsenic
(Denorex and Aquanet), which could confound hair analysis for
- Ethnicity/race needs to be factored in when evaluating hair
analysis results. For example, the reference ranges for Caucasians
should not be used for African Americans. The basic profile
is very different between the two.
- With respect to growth rates, the difference between the
very young and the very old is significant.
- Distinguishing internal versus external levels is impossible.
Some laboratories claim they have an algorithm for making such
distinctions. Any such claim should be seriously questioned.
- In Dr. Quig's experience, laboratories do take into account
the type of container in which samples are stored.
- Using hair analysis for an individual can be acceptable
and useful—for example, when tracking occupational exposures
of a particular person over time (e.g., a worker exposed to
- Washing procedures are a critical part of the hair analysis
protocol (with the possible exception of methyl mercury testing).
It would not be desirable, for example, to test unwashed dreadlocks.
- The only time Dr. Quig has seen significantly elevated mercury
in hair levels in non-fish-eating individuals is with dentists
exposed occupationally to mercury vapor. In questioning whether
this was internal or external contamination, a comparison of
scalp and pubic hair confirmed equally high levels; this suggested
internal exposure. Again, it is critical to look at hair analysis
screening in context of other measurements (e.g., blood).
- As indicated by the panel, it is important to realize that
the presence of organic toxins (e.g., DDT) is not "normal."
It is equally important to recognize that we are all subjected
to exposure to a variety of organic compounds and toxic metals.
It is therefore important to consider multiple exposures.
- Standardization of laboratories is a necessity. The same methods and sensitivities should be required. It is not surprising that Seidel et al. (2001) found different reference ranges across the laboratories studied, because the laboratories used different analytical methods (i.e., ICP-MS versus OES) that have a 1,000-fold difference in the detection limits. This discrepancy should not be used as a reason for not using hair analysis, but as the impetus for advocating standard protocols.
Dr. Quig provided more comments toward the end of the second day of the meeting. His stated opinions are summarized below:
- If done correctly, hair analysis can be a useful tool.
- No question exists that gross ineptness has been observed
at some commercial laboratories. The issue of interlaboratory
differences is not sufficient reason, however, to conclude that
hair analysis is not of value. It is simply a question of tightening
up sampling/analytical protocols and QA/QC procedures.
- Regarding quality control issues, Doctor's Data has been
pressing for the establishment of standardized procedures for
hair analysis under CLIA and the Health Care Financing Administration.
The fact that procedures are not yet in place is not a reason
not to do hair analysis; it is a matter of the organizations
catching up with the needs of the time.
- Regarding washing protocols: A laboratory should produce
a reasonable report describing its washing protocol. The user
of the data should look for this information before interpreting
- A standardized procedure can and should be set for sample
- Statements by panelists regarding the over-interpretation
and misuse of hair analysis were not relevant to the specific
charge of this meeting and should not be of concern to ATSDR.
- Doctor's Data only accepts hair samples from licensed physicians
or for research purposes. Dr. Quig agreed that hair samples
should only be submitted by trained practitioners.
- Dr. Quig suggested looking at research conducted by Needleman
(University of Pittsburgh) and Masters (Dartmouth) before dismissing
the utility of hair analysis for evaluating lead exposures.
- Sound literature does exist on manganese and aberrant behavior,
although the literature is criticized by the panel. Dr. Quig
referenced a follow-up study comparing manganese levels in prisoners
committing violent versus nonviolent crimes. With regards to
the symptoms and the neurotoxicity of manganese, psychological
effects range from apathy progressing to violent reactions and
loss of tolerance. The physiology of manganese toxicity is well-established
in the literature. Manganese has a high propensity to bind to
myelin pigmented dopaminergic neurons in the brain.
- Reference ranges are not based exclusively on small data pools (e.g., "n=2"), as suggested during some of the panel discussions. Available reference ranges are based on 28 years of doing hair analysis. As methods improve, so will reference ranges. Data sets are expanding to include documentation of variations in levels of elements between Caucasians and African Americans, as well as transcontinental differences.
Dr. Sample speculated on the possible value of measuring wash solutions as well as washed hair in attempts to further distinguish between internal and external exposures. Wash solution may provide a better sense of external levels and the hair may provide a better indication of the total internal burden. At a minimum, Dr. Sample suggested incorporating wash evaluation into any standard protocol.
Based on his experience looking at drugs, Dr. Sample acknowledged that data may not exist to set the "normal range." In order to do so, one needs to understand the different rates and methods of incorporation into the hair. He suggested that there may be some value, in an occupational setting, in developing an individual reference range.
In response, Dr. Kosnett commented that workers may not be the best population to study for normal ranges because of the potential for external exposures in various work places. Dr. Seidel noted that further research is needed into the utility of studying wash water. Studies suggesting that easily removed fractions represent exogenous sources and the not so easily removed fraction represents endogenous sources have been disproved.
Dr. Schaffer, a trained industrial toxicologist with an interest in criminal justice and forensics, explained that Pyschemedics performs hair analysis as part of workplace drug testing. He asked participants to keep an open mind and consider the science of hair analysis very carefully. Knowledge gained from the last 10 years of testing hair for drugs of abuse can, he said, be used to enhance the knowledge base for using hair analysis for environmental/public health evaluations. He stressed that his experience in the drug testing arena has revealed that hair analysis is not totally unreliable. Good science and good analyses have supported legal cases. If the proper analytical tools and washing procedures are used, valid interpretations can be made.
Dr. Schaffer recognizes that drugs of abuse are different than trace metals. Working with mass spectrometry, metabolite profiling has helped identify uniquely internal measures of the substance of concern. It has taken 10 years, but such tools are now available.
Dr. Schaffer stressed that hair offers a unique matrix, recognizing that there is much that is not known or understood. In time, he feels, hair analysis will likely provide a lot of useful information.
Dr. Schaffer expressed concern that some of the statements made during the panel discussions could be misinterpreted or used inappropriately. Specifically, he wanted to make certain that caveats were provided with panel conclusion statements so that it is clear that hair analysis for substances of abuse is appropriate and based on good science; the conclusions drawn by the panel should apply to environmental contaminants only.
Dr. Schaffer also responded directly to Dr. Baratz's overview of the Ditton paper.5 He took exception to the implication that hair analysis may not be suitable for testing drugs of abuse. He stated that conducting hair testing with the proper safeguards is defensible and has been upheld by the courts. He noted that no hair color or ethnicity bias exists. In vitro studies have shown incorporation of drugs in different types of hair, but those drugs can be removed by washing as quickly as they are bound to hair. The Department of Health and Human Services (Substance Abuse/Mental Health Services Administration) is currently writing draft guidelines for the incorporation of hair analysis into the federal workplace drug testing program. A pilot proficiency survey is also available to help address quality control issues; the model is urine drug testing.
Subsequent to the June 12—13, 2001, panel discussions, Dr. Schaffer submitted additional comments and supporting literature. He provided (1) a partial listing of those cases demonstrating judicial acceptance of the Psychemedics hair analysis method, (2) information on hair testing and racial or color bias, and (3) information on the effectiveness of Psychemedics' washing procedures for ruling out external contamination. (See Appendix G.)
Colorado Department of Public Health and Environment
Ms. Schonbeck questioned whether hair analysis would be a valid consideration at an arsenic exposure site (soil pica/soil ingestion) where urine sampling is already planned.
Dr. Kosnett commented that a hair assay could reveal the potential
for exposure, but that environmental and urine data will have already
provided that information. It is not likely that hair analysis would
provide additional insight. Dr. Baratz re-emphasized that one must
examine the clinical utility before considering hair analysis. Does
it have any predictive value? Without symptom or disease history,
or unless you have a quantifiable dose-response relationship, hair
analysis data will not help. Dr. Baratz expressed concern that collecting
hair samples as another means of documenting exposure will only
muddy the waters. Dr. Seidel suggested collecting, analyzing, and
archiving the data, but being clear with the community up front
what the data can and cannot be used for. Dr. White emphasized the
distinction between medicine and public health, which can sometimes
cause confusion and tension in the community. That is, medicine
is looking at the individual and treatment options, while public
health is looking at populations and possible risk factors.
Association of Occupational Environmental Clinics
Rocky Mountain Center for Occupational and Environmental Health
Dr. Suruda questioned whether nails are more susceptible to external contamination by metals than hair. In response, Dr. Kosnett noted that, in some forensic investigations, the distal portions of nails have shown correlation with poisoning. Some studies have investigated whether the inner surface of the nail may be less likely to contain elevated levels of arsenic as a result of external contamination. Study findings suggest that external contamination of nails is an issue as it is in hair. For example, a study that measured arsenic in nails over time following arsenic ingestion revealed the following: (1) elevated levels of arsenic were measured in distal segments of unscraped nails (believed to be deposited by sweat); (2) scraped nails during the same period did not reveal elevated levels; and (3) samples of scraped nails taken later in time showed elevated arsenic levels (as a result of the ingestion episode). As with hair, it is questionable whether methods exist to clearly distinguish between externally and internally deposited contamination.
Dr. Suruda indicated that he was requested to evaluate an individual with peripheral neuropathy 9 months after possible exposures to lead and arsenic. Total arsenic urinalysis had been performed closer to the time of exposure, but not a fractionated analysis. To evaluate past exposures, a toenail sample was taken down to the growth plate, which was negative. These results were used to conclude that the individual had not been exposed to arsenic within the past year.
Dr. Suruda noted that the charge to the panel was to examine aspects of hair analysis related to public health assessments. Dr. Suruda commented that he is more often faced with questions from individuals (practitioners, community members) looking for assistance in interpreting hair analysis results. He expressed hope that the panel and ATSDR will consider the utility of hair analysis in the assessment of public health as well as for individual assessment. Dr. Suruda noted that ATSDR's toxicological profiles and other agency documents have great credibility within the scientific community and that he looks forward to further guidance (e.g., biological monitoring guidelines) to assist in his evaluations. Even if all the answers are not available, Dr. Suruda said, hair analysis should be ranked with other methods of monitoring (e.g, blood, urine).
Regarding research needs, Dr. Suruda indicated the need for a
population-based study on how hair analysis is used and what impact
it has had. Questions to consider include: Can it be used to identify
poisoned individuals? How many people are unnecessarily alarmed
or mistreated on the basis of hair analysis? What type of reports
do practitioners receive on hair analysis? Dr. Suruda expressed
concern regarding what he referred to as "junk science." For example,
he pointed to a laboratory report that indicated "lead is slightly
above detection limit" and that the "zinc to mercury ratio is extremely
high." The report indicated that these ratios do not indicate disease;
however, it also indicated that research has shown that this "will
eventually lead to other disturbances in metabolic function." Physicians
and other practitioners need to recognize that they do not often
know what results mean and should be cautious in what they report.
5Dr. Baratz clarified that his purpose in presenting the Ditton paper was to summarize some of the key aspects and possible pitfalls of hair analysis. Dr. Baratz noted that the author, a chemist, has done studies on drugs of abuse and has shown the validity of hair analysis for testing drugs of abuse.