Analysis of Trace Metals for Occupationally Exposed Workers
As many as 4 million U.S. workers may be exposed to toxic
metals
and other elements in such occupations as painting, welding,
soldering, electroplating, alloying, mining, and
electronic-component
manufacturing and in facilities that produce brass, bronze, drugs,
dyes, textiles, rubber, glass, batteries, and ceramics and
enameling.
Lung disease and dermatologic problems among these workers have
resulted from exposure to metals and their compounds (1).
Traditionally, industrial hygiene samples taken to evaluate the
exposures of these workers have been analyzed for a limited number
of
elements; each elemental analysis often required a separate
sample-preparation procedure and, consequently, a separate sample.
As
a result, developing a profile of occupational exposure for a
worker
or group of workers was expensive and time-consuming. Now,
however, a
method combining new analytic instrumentation and techniques for
sample preparation has been developed and is described below.
This method, called inductively coupled plasma-atomic emission
spectroscopy (ICP-AES), allows simultaneous, multi-element analysis
and has been successfully applied to industrial hygiene samples
collected from workplace atmospheres (2). The technique has also
been
adapted and extended for biologic monitoring by the National
Institute
for Occupational Safety and Health (NIOSH). Trace metals are first
extracted from urine samples with a polydithiocarbamate resin (3).
This resin is well-suited for such extractions because of its
unique
characteristic of complexing with trace metals while showing little
significant affinity for the alkali or alkaline earth elements
(e.g.,
sodium, potassium, and calcium), which occur in large quantities as
dissolved salts in urine. After extraction, the resin is digested;
the metals are dissolved in a small volume of acid; and ICP-AES
analysis is conducted. This procedure allows the simultaneous
quantitative measurement from a single sample of 17
elements--aluminum, barium, cadmium, chromium, copper, iron,
lanthanum, lead, manganese, molybdenum, nickel, platinum, silver,
strontium, tin, titanium, and zinc).
Reported by Methods Research Br, Div of Physical Sciences and
Engineering, National Institute for Occupational Safety and Health,
CDC.
Editorial Note
Editorial Note: In addition to the 4 million workers
occupationally
exposed to elements or their alloys, a significantly larger number
is
exposed to the salts and aerosols of these metals. This new
methodology provides a means for readily establishing baseline data
for trace metals in urine samples of both exposed and nonexposed
workers. With quantitation of several elements from a single
sample,
these biologic monitoring data can be collected considerably more
efficiently than with traditional analytic methods. In addition to
establishing baseline data, the methodology can also be used in
screening to determine whether unsafe levels of toxic metals exist.
The methodology developed from this work is included in the NIOSH
Manual of Analytical Methods, Third Edition (4).
References
Department of Health, Education, and Welfare. Occupational
diseases--a guide to their recognition. Cincinnati, Ohio:
Department of Health, Education, and Welfare, 1977; DHEW
publication no. (NIOSH)77-181.
Hull RD. Multielement analysis of industrial hygiene samples.
Paper No. 68, presented at the American Industrial Hygiene
Conference, Portland, Oregon (1981).
Barnes RM, Genna JS. Concentration and spectrochemical
determination of trace metals in urine with a
polydithiocarbamate
resin and inductively coupled plasma-atomic emission
spectrometry. Anal Chem 1979;51:1065.
CDC. Availability of NIOSH Manual of Analytical Methods, Third
Edition. MMWR 1984;33:467-8.
Disclaimer
All MMWR HTML documents published before January 1993 are electronic conversions from ASCII text into HTML. This conversion may have resulted in character translation or format errors in the HTML version. Users should not rely on this HTML document, but are referred to the original MMWR paper copy for the official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices.
**Questions or messages regarding errors in formatting should be addressed to mmwrq@cdc.gov.
