IARC MONOGRAPHS ON THE EVALUATION OF CARCINOGENIC ...

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1.4 Occurrence
1.4.1 Natural occurrence
Naphthalene, discovered in 1819 by A. Garden (BUA, 1989), is a natural constituent
of coal tar and crude oil, which are major contributors to its presence in the environment.
They contain up to 11% and 1.3% of the chemical, respectively (BUA, 1989; O’Neil
et al., 2001). Forest fires also contribute to the presence of naphthalene in the environment,
as the chemical is a natural combustion product of wood (Agency for Toxic
Substances and Disease Registry, 1995a).
1.4.2 Occupational exposure
IARC MONOGRAPHS VOLUME 82
Table 4. Consumption of naphthalene by major region (thousand tonnes) a
End use
Japan USA Western Europe
1995 1999 1995 2000 1995 2000
Phthalic anhydride 137 124 66 66 42 45
Naphthalene sulfonates b
16 9 21 27 34 45
Pesticides c
2 1 17 14 15 22
Dyestuff intermediates 22 23 – – 14 11
Other d
16 15 2 3 14 10
193 172 106 109 119 133
Total e
a From Lacson (2000)
b Includes alkylnaphthalene sulfonates and naphthalene sulfonate–formaldehyde condensates
(NSF). NSF includes concrete additives and synthetic tanning agents.
c Includes carbaryl and moth repellents.
d Includes diisopropyl naphthalene, naphthalene dicarboxylic acid, tetrahydronaphthalene
(Tetralin), decahydronaphthalene (Decalin) and chloronaphthalenes.
e Totals may not equal sums of the columns because of independent rounding.
From the National Occupational Exposure Survey conducted between 1981–83, the
National Institute for Occupational Safety and Health (NIOSH) estimated that approximately
113 000 workers, about 4.6% females, in 31 major industrial groups were potentially
exposed to naphthalene in the USA. The top six industries, by total workers,
accounted for over 50% of the total potentially exposed workers. The petroleum and coal
products and oil and gas extraction industries were among the top three industries and
comprised about 21.4% of the workers potentially exposed to naphthalene. An estimated
1840 agricultural services workers were exposed to naphthalene; over 87% were females
(National Institute for Occupational Safety and Health, 1990; National Toxicology
Program, 1992).