In general, hair analysis results can provide limited qualitative insights into environmental exposures and rarely can
answer questions about potential health effects. The following table gives some examples of the utility of hair
sampling:
Is Hair Sampling Useful?
Study Objective
To determine whether women of
Yes. Data are available linking concentrations of methyl mercury in hair of
childbearing age have been recently
exposed to methyl mercury at levels of expecting mothers to developmental effects in their children.
concern by eating contaminated fish.
No. ATSDR is unaware of any data in the peer-reviewed literature linking
To demonstrate that chromium
chromium levels in
hair to
any adverse health effects, including birth defects.
detected at trace levels in drinking
In these cases, toxicologic evaluations of exposure point concentrations
water was resulting in birth defects.
would likely be a better tool for commenting on public health implications of
exposure.
To assess whether local residents were
No. Considering typical hair growth rates and how often most people cut
exposed to metals from a facility that
their hair, hair analysis will not characterize exposures that occurred more
closed 4 years ago.
than 1 year ago for most subjects.
To quantify environmental exposures
No. Exposure doses cannot be calculated from hair analysis results. More-
over, metals in hair can come from multiple sources (e.g., diet) other than
among residents who live near a
plating shop.
Most likely not. Because reliable data are not available on "background" hair
To determine whether residents near a concentrations, hair sampling cannot detect elevated exposures. Use of a
smelter are exposed to elevated levels control (or not exposed) population in the study could assess the relative
magnitude of
exposures. However, quantitative conclusions could not be
of metals.
drawn on actual exposure doses, even if hair concentrations were lower in the
control population.
No. Hair sampling methods currently focus on metals and organo-metallic
To characterize any exposures to
compounds. Little information is available on whether hair sampling can
volatile organic compounds (VOCs).
characterize exposure to VOCs and their metabolites.
Where can I get more information on the state of the science for
hair analysis?
ATSDR recently convened an expert panel to discuss the current state of the science for hair analysis. The meeting
summary report documents the experts' discussions and includes a long list of relevant references identified during a
literature review. You can get a copy of this report by calling ATSDR: 1-888-42-ATSDR (or 1-888-422-8737). The
report is available on ATSDR's Web site at "www.atsdr.cdc.gov/HAC/hair_analysis." We can also send you a fact
sheet we prepared to explain the pros and cons of hair analysis to community members.