The rock is granite with a quartz content of 30%-70% according to the Arizona Geological Survey, which
means the neighborhood will be exposed to dust with a very high quartz content for the next 8 to 12 years.
Many lung diseases, including Silicosis, are known to be caused by long term exposure to quartz dust,
but exposure effects have only been studied in a workplace environment. MORE INFO
The Maricopa County Air Quality Department (MCAQD) is considering an air quality permit for this mine.
We presented studies to MCAQD that show how a hill like this generates faster, more turbulent winds
than the winds down here in the neighborhood. These winds, and the high quartz content of the granite
they will be mining, make this mine a very real and serious health hazard for everyone living within
a few miles of Twin Knolls in every direction.
MCAQD dust monitoring methods limit the opacity, or how much the dust obstructs visibility, to 7% or 20%.
Deadly quartz dust is too fine to be seen so these opacity limits are ineffective.
We compared MCAQD dust limits to those used for miners by the Mine Safety and Health Administration,
but MSHA limits for dust are based on the quartz % of the dust, and use limits for total particulates.
MSHA does not use opacity. MCAQD does not consider quartz % and when a particulate limit is used,
it's only an option. The mine operator can choose to use the opacity limit instead.
So, to make this comparison, we used MCAQD's particulate limit for crushing and screening.
MCAQD's limit is over 100 to 200 times higher than MSHA! MORE INFO
Of course, MSHA limits are for an occupational setting, but because of our unique situation, and absent
any applicable data from studies that have not yet been done, MSHA limits are the only reference we have.
And exceeding these limits by 100 to 200 times is not good.
And monitoring particulates is not a requirement. The mine operator can use opacity to monitor the dust.
We could be protected by the high-tech method of looking at the dust to see how thick it is.
This mine site is unlike anything MCAQD has ever granted a permit for.
We have requested that studies be done to determine how to control dust from this mine, if that's even
possible, and what the health risks are for this neighborhood and other communities in this area.
We have spoken with the EPA and confirmed that EPA can help with these studies if they are asked
to do so by MCAQD, but so far MCAQD has not responded to our requests to do this research.
Currently, no research data exists that can be used to establish an effective dust control plan
for a mine on top of a hill surrounded by people's homes.
Also, no research data exists to indicate what long term quartz dust exposure can do to families
living in such close proximity to a hilltop mine producing quartz dust.
If this mine begins operation, this will essentially begin a great experiment; the first experiment
exposing families, for 8-12 years, to an elevated quartz dust source towering over their homes.
The people in this neighborhood are not mine workers, and we are not lab rats.
We are people of all ages, some elderly, some with existing health issues, and some simply trying
to raise their children in a place where it's safe for them to play outdoors in their own back yard.
We are worried that in 10 years, or less, we will have countless residents, including children,
deathly sick with lung diseases.
Why bother with an air quality permit process if it doesn't protect people? What is the purpose?