Silica Sand Mining & Health
The recent increase of silica sand mining in Minnesota is raising
community concerns about possible health risks. The Minnesota
Department of Health (MDH) is working to develop public health
responses and tools to support citizens and communities as they
consider impacts from mining activities.
How people are exposed to silica sand and the health concern.
Silica sand is a common part of our natural environment, found mostly
in soil and rocks. Silica sand naturally occurs with either a crystalline or
amorphous structure. Silica in a crystalline form is much more toxic to
human health. Crystalline silica becomes of concern to human health
only when it is released into the air in small particles.
Dust-sized silica particles, invisible to the naked eye, are generated
during the mining process when they can be breathed into the body and
deep into the lungs. Once in the lungs, these particles can be coughed
up, or pass from the lungs to other organs in the body through the blood
stream, or stay stuck in the lungs.
Silica Sand is…
a material that forms rock,
soil, sand, and other parts
of the earth. Over many
years, silica in the soil can
form into crystalline silica
due to natural heat and
pressure.
Silica Sand is used for…
industrial and commercial
processes like glass-making,
road-building, , hydraulic
fracturing for oil and gas
production, water filtration
and even electrics.
Exposure to silica sand particles from mining is of greatest concern to:
• People who work in the fracking or mining industry. They can be
exposed to crystalline silica during the course of their work
(occupational exposures).
• People living in communities near silica sand mining and
processing operations. They can be exposed to crystalline silica
sand emitted to the air as a result of general mining activities
(environmental exposures).
Possible health concerns from exposure to crystalline silica.
The health effects of crystalline silica have been well characterized in
occupational settings. Diseases associated with occupational
crystalline silica exposure include:
o
o
Diseases of the lungs including silicosis, emphysema, chronic
obstructive pulmonary disease, tuberculosis, and lung cancer.
Immune system diseases
Disease risk is related to both the levels and duration of crystalline silica
exposure. The onset of disease may occur long after the exposure has
stopped. Lung cancer, chronic bronchitis, silicoproteinosis and several
autoimmune diseases have been linked to long term or very high
exposures to crystalline silica.
Silica sand mines may pose
some risk to groundwater
and surface water, either
from chemical releases or
changes to natural water
systems.
For more information about
environmental impacts
from silica sand mining,
see the MDH website at
http://www.health.state.m
n.us/divs/eh/hazardous/
topics/silica/index.html
The effect of high levels in air of crystalline silica in humans has been
Site Assessment and Consultation Unit
Phone: 651-201-4897 or toll-free 1-800-657-3908
Email: [email protected]
www.health.state.mn.us/divs/eh/hazardous/index.html
Updated June 2014
Silica Sand Mining & Health – Page 2
well studied. The US Occupational Safety and Health Administration have set a permissible exposure limit for
crystalline silica for occupational exposures. The National Institute for Occupational Safety and Health also
has a recommended exposure limit. There is research which suggests the current occupational limits may not
be protective enough.
Few studies have been done on environmental crystalline silica exposures, and health effects resulting from
these low level exposures have not been documented. It is known that a small amount of crystalline silica is
naturally present in ambient air throughout the world, and that people breathe in small amounts of crystalline
silica throughout the course of their lifetime during normal daily activities. At this time, there is no evidence that
exposure to low-levels of breathable crystalline silica in air has adverse health effects. This continues to be an
area of on-going research.
Minnesota Department of Health (MDH) Health Based Guidance for Crystalline Silica
MDH completed a review of breathable (respirable) crystalline silica and released an air quality chronic healthbased value (HBV) of 3 micrograms per cubic meter (µg/m3) in July 2013. This guidance was developed by
MDH because there are no federal or state guidelines or standards for respirable crystalline silica in ambient
air.
MDH guidance is focused on human health. Crystalline silica is toxic to human health when inhaled because
of how it damages tissues in the lungs. Crystalline silica is not a concern for human health in other places in
the environment, such as surface water or groundwater, because it is not breathed in from these
sources. Therefore, the focus of MDH’s health-based guidance is on crystalline silica that is found in the air,
and may be breathed into the lungs.
For more information about MDH Health Based Guidance for Crystalline Silica, see the MDH website at
http://www.health.state.mn.us/divs/eh/hazardous/topics/silica/index.html
Addressing Community Concerns: Health Impact
Assessment
Community concerns related to general mining
activities include impacts to air quality and non-mining
industries (i.e. tourism) and increased traffic, noise,
and risk of accidents. Health Impact Assessment
(HIA) is a process that could lead to a more complete
evaluation of all of the risks associated with silica
sand mining and processing.
MDH supports HIA as a tool to ensure that health is considered in these and other important decisions. HIA is
a systematic process used by organizations and community groups to provide decision-makers with
information about how any policy, program or project may affect the health of people. HIA emphasizes a
comprehensive approach to health, which includes economic, political, social, psychological, and
environmental factors that influence people’s health.
For more information, see the MDH website at http://www.health.state.mn.us/divs/hia/
Site Assessment and Consultation Unit
Phone: 651-201-4897 or toll-free 1-800-657-3908
Email: [email protected]
www.health.state.mn.us/divs/eh/hazardous/index.html
Updated June 2014