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Death by Volcanic Laze1 119

Figure CS7.1 Volcanic laze at an ocean entry in Hawai‘i Volcanoes National Park

makes this a case of interest, however, is that it was and US$9507 for personnel costs. Volcanic hazards
the first known incident of its nature in Hawai‘i and at the Eruption Site and in the vicinity of the
that it specifically highlights a potential global ocean entry are not always recognized, and access
hazard present in locations where lava enters ocean to the area is not restricted. However, warning
waters (Figure CS7.1). Conditions near the ocean signs and safety messages should be strongly
entry typically involve exposure to volcanic laze, a heeded by all visitors.
dense hydrochloric acid (HCl) mist that is formed
when hot lava enters the ocean (Stephenson et al, Note
1991; Hansell and Oppenheimer, 2004; Hansell et 1 This chapter was modified from Heggie, T. W.,
al, 2006). This laze is often mistakenly referred to as Heggie, T. M. and Heggie, T. J. (2009) ‘Death by
a steam plume. Heat from the lava entering the Volcanic Laze’, Wilderness and Environmental
ocean rapidly boils and vaporizes seawater, producing Medicine, vol 20, pp101–103.
a large white plume. This plume contains a mixture
of HCl and concentrated seawater that is a brine References
with a salinity about 2.3 times that of seawater and Hansell, A. and Oppenheimer, C. (2004) ‘Health
a pH of 1.5 to 2.0 (USGS, 2008). Moreover, dense hazards from volcanic gases: A systematic literature
laze plumes are known to contain as much as 10 to review’, Arch Environ Health, vol 59, pp628–639
15ppm of HCl (USGS, 2008). The density of the Hansell, A. L., Horwell, C. J. and Oppenheimer, C.
plume decreases as it moves away from the ocean (2006) ‘The health hazards of volcanoes and
entry, but acid rain commonly precipitates on geothermal areas’, Occup Environ Med, vol 63,
individuals and land near the plume’s proximity pp149–156
(USGS, 2008). Hence, following the inhalation of Stephenson, R., Burr, G., Kawamoto, M. and Hills, B. (1991)
the laze, the bodies of the victims were exposed to ‘Exposures to volcanic emissions from the Hawaiian
extreme heat and acidic conditions during the volcanoes: A NIOSH health hazard evaluation’, Appl
maximum 48 hours they were at the ocean entry. Occup Environ Hyg, vol 6, pp408–410
United States Geological Survey (USGS) (2008)
Lessons ‘Volcano Hazards Program. When lava meets the
sea: lava haze or laze air pollution’, volcanoes.usgs.
In addition to the loss of life, the final cost of this gov/Hazards/What/VolGas/Laze.html, accessed 5
incident included US$3025 for aircraft assistance August 2008

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