MineWatch December Meeting 2021 - AIR Impacts

Special Guest Speaker and Respiratory Therapist, Pam Heard takes a detailed look at Rise Gold's reports as they relate to air pollutants that put our lungs at risk, including diesel exhaust, radon, silica, and asbestos.


This virtual community meeting was hosted by CEA Foundation and community partners on December 16, 2021.

6:15 Project Update

The meeting begins with CEA Foundation president Ralph Silberstein giving a progress report on the effort to oppose the mine. He provides an update on the Centennial project, tells us the Nevada County Supervisors approved the costs and consultant selection for an Economic Study, and tells us the Draft Environmental Impact Report is now guesstimated for arrival in late January 2022.

11:25 Air Concerns: Mining vs Cancer Risk

Respiratory Therapist, Pam Heard talks about the dangers of diesel exhaust, radon, silica, and asbestos, educates us on how each of them play a role in the rocks and geology in our area, and reviews the assumptions and inconsistencies found in Rise Gold's reports. See the full transcript below.

53:45 - Questions and Answers. Part 1

1:09:45 - Questions and Answers. Part 2

Pam Heard answers a number of questions from the audience.

1:04:30 - Take Action

CEA Foundations' Christy Hubbard and Laurie Oberholzer talk about what the community can do to take action, including letter writing, sharing on social media, canvassing in the new year, and making a tax-deductible donation in 2021.



Air Concerns: Mining vs. Cancer Risks

Slide: Airborne Pollutants

November was Lung Cancer Awareness Month. It was also the anniversary of our first discussion about air quality here in Nevada County. Now is the perfect opportunity to talk about exposure to airborne pollutants that will be released during mining processes and how those exposures will impact the health of our community.

All of the pollutants you see on this slide have the potential to cause respiratory problems, acute and chronic, from both short and long-term exposures.

Rise Gold’s Brunswick site is just a half mile southeast of the city limit – so any pollutants that are released will funnel into the Brunswick Basin and the City of Grass Valley.

The question is, which pollutants will be released if the Idaho-Maryland Mine reopens? To try to answer that, I took a deep dive into Rise Gold’s technical reports. Tonight, I will share with you what I found and what the potential health impacts could be. What I found was surprising and concerning, especially as it relates to 4 of these pollutants: diesel emissions, radon, silica, and asbestos. These pollutants will be the focus on my presentation tonight.

Slide: Health Risks

Before we get into the specifics, I’d like to set the stage for WHY we are so concerned. It’s critical to know that Nevada County already has compromised air quality. The EPA has classified Nevada County to “serious” nonattainment for 8- hour ozone levels. California Air Resources Board, CARB has designated Nevada County as a nonattainment area for the state O3 and PM10 standards. The American Lung Association has given Nevada County an F, a failing grade for air quality due to its high ozone and particle pollution levels.

In September of this year, the World Health Organization revised their air quality guidelines for the first time in 15 years in recognition of the harmful effects of air pollution on human health. They lowered limits for PM2.5, PM10, ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide.

Nevada County also has a vulnerable population. According to the 2020 census, in NC, nearly a third, 28.6% of our population is 65 years or older, compared to the statewide rate of 14.3%. So, we have an older demographic here. The 2019 Health Assessment for NC revealed that our mortality rate for Chronic Lung Disease is twice that of the statewide rate (69 deaths/100,000 people for the county vs 35 deaths/100,000 for the state). Our Heart Disease Mortality rate is 1.5 times higher than the statewide rate. The bottom line is that we have a vulnerable population with chronic conditions that will be exacerbated by exposure to these pollutants.

Slide: Diesel Emissions

The first pollutant encountered will be diesel emissions, including both exhaust and particulate matter, or DPM.

The impact of these emissions on public health is serious. Approximately 70% of all airborne cancer risk in California is associated with diesel particulate matter.

Diesel particulate matter has other public health effects as well. Because it is part of PM2.5, DPM contributes to the same non cancer effects as PM2.5 exposure. These effects include premature death, ER visits and hospitalizations for exacerbated heart and lung disease, asthma and it may affect the immune system increasing the risk of allergies and susceptibility to infectious diseases.

Diesel emissions will be constant throughout the life of the project starting with the remedial action on the Centennial site, followed by the construction phase of the Brunswick site, then delivery and placement of engineered fill on the Centennial site, and ongoing operations at Brunswick site.

This project will require heavy duty diesel engines for earth moving equipment along with trucks for the delivery and dispersal of materials: bulldozers, graders, compactors, generators, haul trucks, delivery trucks with explosives, water, diesel fuel and cement, fuel storage tanks, explosives, gold concentrate and aggregate removal trucks.

Now you should know that, the Rise report states that all diesel equipment “owned” by them would be equipped with Tier 4 Final engines, which is the current emissions standard for new trucks, requiring engine manufacturers to reduce particulate matter and oxides of nitrogen (NOx) by 50-96% as compared to Tier 3 engines. But if you look closely at the plans, you can easily see there are several loopholes. For instance, another section of the report states that “If these engines are not ‘commercially available’, then they will use CARB certified Tier 3 engines with the most effective Diesel Emission Control Strategies available for the engine type. “Commercially available” will take into consideration factors such as critical path timing of construction and geographic proximity of the equipment location to the project site. What isn't covered is the question about what the “Tier” status will be for leased equipment and outside vendors. These trucks will travel the same roads as our residents and school buses. They’ll be bringing explosives, fuel oil and cement to the mine.

In other words, there are no guarantees that Tier 4 engines will be used exclusively…

Slide: Diesel Exhaust Contributes to Formation of Ozone and Acid Rain

These emissions break down into two parts: gases (released through exhaust), and particulate matter. The gas phase contains mostly carbon dioxide, carbon monoxide, nitrogen oxides (NO, NO2), sulfur oxides, and hydrocarbons, including polycyclic aromatic hydrocarbons. Some of these gases react in the atmosphere with UV light to form ozone and acid rain. These pollutants will have devastating effects on both our terrestrial and aquatic environments- which are already stressed from drought and climate change.

Slide: Diesel Particulate Composition

The emissions also create diesel particulate matter, or DPM, which is also known as soot. Soot is made up of particles such as carbon, organic compounds (including PAHs) and traces of metallic compounds. It contains more than 40 known organic cancer-causing compounds such as benzene and formaldehyde which coat the soot particle.

More than 90% of DPM is <1 micron in diameter. Due to its small size, it is inhaled deeply into the lungs where the lung is most susceptible to injury

Slide: Particulate Matter Deposition in the Lungs

Let’s take a close look at what’s really happening to our lungs. This is a diagram of the respiratory system. It’s like an upside tree starting with the trachea (trunk) which branches into the bronchi, then smaller bronchioles and down to the alveoli. These air sacs are where respiration, or gas exchange, takes place with the bloodstream similar to leaves with the environment.

Our bodies take in oxygen and release carbon dioxide through the alveoli while trees respire by taking in carbon dioxide and releasing oxygen to the environment.

As you can see, the smaller the particle, the deeper it is able to penetrate into the lungs and cause damage.

Slide: Radon

Diesel emissions aren’t the only high-level pollutants that affect respiratory health…

We also have to consider radon, a radioactive gas that increases the risk of lung cancer. In this section, I’ll explain what it is, then share what I found about it when reviewing Rise Gold’s reports.

Slide: Understanding Radon

  • According to WHO, “Radon is a radioactive gas that emanates from rocks and soil and tends to concentrate in enclosed spaces like underground mines and homes”.

  • You cannot see it, smell it or taste it.

  • It is generated from the decay of radium. Radium is a decay product of uranium and thorium which are naturally occurring in rocks and soils.

  • Because it is a gas, it moves freely in the air spaces between rocks and in soils. And because it is heavy (7.5 X heavier than air), it accumulates in low places like mines, basements, and the ground floor of homes.

  • Factors that can affect radon levels include local geology, construction materials and how the home was built.

  • Levels can vary from home to home, it’s very unpredictable.

What’s the risk?

  • After smoking, radon is the second leading cause of lung cancer in the United States

  • For non-smokers, radon is the leading cause of lung cancer

  • The US EPA estimates that radon causes about 21,000 lung cancer deaths each year.

  • There is a linear relationship between radon and lung cancer: As radon levels increase, the risk of lung cancer increases

Slide: California Radon Zones

Let’s start by looking at our current radon levels.

  • The national average of radon is 1.3 pCi/L

  • California average is 0.85 pCi/L

  • Now look at Nevada County, our average is 3.1 pCi/L

What do these numbers mean? Well, you should know that the EPA action level is 4.0 pCi/L. In other words, you should already be taking action today to lower your exposure.

Slide: Nevada County Radon Levels

· Now, we’ll look more closely at our County’s levels.

· The California Department of Public Health analyzed results of radon tests last updated in 2017. Here in Grass Valley, tests on 315 homes revealed that 66 homes had levels ≥4.0 pCi/L (21% of the total). The highest level recorded was 29.5 pCi/L.

· The Idaho Maryland Mine project is located in this same zip code, 95945.

Slide: How Radon Enters A Home

So just how does radon enter your home?

Radon seeps into your home from several sources: fractured bedrock, groundwater, soil and well water.

Slide: Questions about Radon

· So this is a critical question: How will the reopening of the IMM affect radon levels in Grass Valley and in our homes? How could radon impact our groundwater and wells? Rise Gold did test groundwater from some drains and the New Brunswick shaft for radon and emitting particles, including measurements known as Ra226 and Ra228. All published test results were below the maximum level, measuring under 5pCi/L for both types of radium combined.

But in 2006, the state of California adopted new Public Health Goals for Ra226 and Ra228. The new goal for Ra226 is 0.05 pCi/L and the new goal for Ra228 is 0.019 pCi/L. The combined value of 0.069 is below the current detection level

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but these new goals demonstrate that the state recognizes the health risk for lung cancer from radionuclides exposure. Now looking at the groundwater test results under this criterion, all Ra226 and Ra228 results meet or exceed these PHGs.

And here’s another question: What will be the effects on miners and surface workers when this radioactive gas is released during constant dewatering and mine ventilation?

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Over the last decade, several studies have concluded that elevated radon concentrations could be a sign of an imminent earthquake. Radon is released from cavities and cracks in the rocks and soil due to “a slight compression of pore volume that causes gas to flow out of the soil”.

1900 pounds of explosives will be detonated every day during mining! Will the continuous explosives use and tunnel excavations lead to increased rock fractures and fissures thereby increasing radon levels in our community?

Slide: Recommendations

Here are my recommendation on radon…

Nevada County should have an action plan that will…

1. Obtain baseline radon level in homes and businesses

2. Maintain ongoing monitoring programs in the mine and all structures in the community

3. Mitigate radon levels as necessary

Slide: Toxic Air Contaminants

Radon isn’t the only thing from our local geology that may prove hazardous to our health. Silica and asbestos will be released to the environment from all phases of mining: blasting, excavating, skipping, crushing, milling and transporting to various sites.

· Both of these materials belong to the category of toxic air contaminants

A substance is considered toxic if it has the potential to cause adverse health effects in humans, including increasing the risk of cancer upon exposure, or acute (short-term) and/or chronic (long-term) noncancer effects. A toxic substance released into the air is considered a TAC.

To be clear, Rise Gold claims that measures will be taken to reduce the release of these contaminants, but a “reduction” in the release of toxic air contaminants is not the same thing as no release at all.

Slide: Rise Gold’s Report

This is the only technical report found on the Rise Gold website (www.risegoldcorp.com) for their investors. It’s really a great report, only 179 pages in length, that details the history, gold production and most importantly, the geology of our region.

Within it, there are 115 mentions of quartz and over 70 mentions of serpentinite.

Why are there so many mentions of these materials? Because that’s where most of the gold is found…in quartz veins along the contact points with serpentinite. These are the buzzwords that excite investors.

Rise will be excavating tons of quartz and tons of serpentinite. And you guessed it, these are the rocks that contain silica and asbestos.

So, let’s look at quartz first

Slide: Silica Exposure Risks

Quartz contains Respirable Crystalline Silica (RCS), which is defined as a particle with an aerodynamic diameter size of 4 microns, so it is able to penetrate deep into the lungs.

The risks from exposure to crystalline silica are well known: lung cancer, silicosis, emphysema, chronic bronchitis, respiratory failure, premature death. It has been implicated in bladder and kidney disease along with some autoimmune disorders

Research indicates that “Freshly ground quartz has been found to be much more cytotoxic than aged quartz because grinding or fracturing quartz particles is thought to break the silicon-oxygen bonds, generating silicon and silicon oxide radicals on the surface of the particles. (Vallyathan et al. 1988,1995: Vallyathan, 1994, Shoemaker et al, 1995)”.

Slide: Proportions Matter - Especially in Mining

So, just how much silica will we be exposed to?

Our geology is igneous in origin with later metamorphosis and alteration. One way to classify igneous rock is according to their silica content:

This graphic displays the different categories of igneous rock. All of these rock types are present in our geology. Proportions matter… especially in mining.

FELSIC has a silica content greater than 65% by weight such as quartz and plagioclase feldspars

FELSIC TO INTERMEDIATE has greater than 20% quartz by volume and between 65-90% plagioclase feldspar such as granodiorite

INTERMEDIATE has a silica content between 55-65% by weight such as andesite (52-63%) and diorite

MAFIC has a silica content between 45-55% by weight such as gabbro (48%) and diabase

ULTRAMAFIC has a silica content less than 45% such as serpentinite

What’s most remarkable in Rise Gold’s report is the assumption that 98% of the rock mined will be meta-andesite rock with a silica content of 60%. This percentage was obtained from the geology 101 textbook definition of andesite rock as being between 52-63% silica. Just how accurate is this number?

First of all, this is meta-andesite rock not just andesite.…it has undergone metamorphosis becoming altered in composition. In the book, The Gold Quartz Veins of Grass Valley, referenced in the Technical Report of Idaho-Maryland Project Johnston (1940) stated: “The degree of metamorphism may vary in this unit, such that parts of it have been referred to as amphibolite schist, porphyrite, diabase, and quartz porphyrite.”

The laboratory that Rise used for all metals analyses, ACZ Laboratories, is certified to perform both silica and silicon dioxide tests yet not a single sample was analyzed for this parameter. Why is this important? To quote Sara Seager, a planetary scientist: “When you are working on such enormous scales, the smallest mistake can be amplified into massive miscalculations” (Sara Seager, planetary scientist/astronomer, The Smallest Lights in the Universe)

For example, mining 1000 tons ore/day at 60% silica would yield 600 tons of silica (1,200,000 pounds)

But mining 1000 tons ore/day at 65% silica would yield 650 tons of silica- an additional 100,000 pounds (1,300,000 pounds)

And this difference would be compounded every day.

Slide: Sample Population Metals

The thing we need to keep in mind is that Rise selected the sample drill locations, selected the samples to be tested and selected the tests to be performed on those samples.

We don’t have the drill logs but let’s look at what information we are given from those drill cores…

· From 2017-2019, Rise drilled 19 core samples during their exploratory phase for a total of 67,500 linear feet

· Metals analyses were performed on 47 crushed core samples

· These 47 samples were selected from just 5 of those cores (26% of the total): I-18-11(1), B-18-02(1), I-18-10(3 200), I-18-12(2, possibly mislabeled) and I-19-13(40) core

· The procedure went like this: for every 90-100 feet drilled, a 10 ft sample was obtained for testing. A one gram sample from each 10 ft segment was then analyzed for metals content. The total footage for all segments combined equals 456.5 ft. (0.68% of the 67,500 total drilled)

· 40 Samples (85% of the overall total) were selected from a single core, I-19-13 here shown in red. This core began at 167 ft bgs to a final depth of 4774.6 ft (4607.6 ft).

· Sampling was consistent from 167 ft to 3227 ft. Then large segments (of 350 to 450 ft) started missing: 365 ft between 3227-3583 depth, another 343.3 ft between 3969.7-4313 depth and lastly 444.9 ft between 4323.0-4767.9 depth (1144.2 ft).

· These missing segments add up to over 1100 ft or 25% that is absent from that core.

· Why are these segments unaccounted for? Are they quartz or serpentinite? What else are we not being told?

Slide: Rise Gold Projections

For those who really like to understand how it works, these charts lay it out.

· Rise will mine 500 tons of barren rock per day and 1000 tons of ore rock per day.

· The rock will be crushed to a 6 inch size in the jaw crusher, then conveyed to the silo.

· The ore rock will then be sent to the processing center to be milled in multiple stages, ground down to a small size that will enable them to separate the gold out by gravity flotation.

· After removal of the gold, this material is known as “tailings” or sand tailings. 500 tons will be used in cement paste backfill while the remaining 500 tons will be mixed with barren rock to become “engineered fill”.

· The pie chart shows the percentage of rock types that will be mined each day…there is no mention of quartz.

· The bottom chart shows the breakdown in size for the sand tailings.

· The engineering firm, NV5, stated in the Centennial Geotechnical Report that: “We understand that the sand tailings will likely have a gradation similar to the historical gradation presented in the table below, and will typically have a large proportion of quartz.” Hmmm

· The quartz sand has been graded according to size and percentage of total for each size. Twelve percent will be less than 44 microns in size. The human eye can only see down to 50 microns, so these particles will be invisible. Just what amount of this 12% is less than 10 microns, of a respirable size, is unknown.

· The engineered fill composed of sand tailings and barren rock will be loaded and transported to Centennial site for placement, grading and compaction.

· There will be 6 fans in the ore processing facility exhausting 1 gram/second at a flow rate of over 21,000 ft3/min 24 hours per day.

· What are these fans exhausting to the environment and in what quantities?

Slide: Hours of Operation

A close look at this proposed schedule gives us a good sense of the extent of the risk.

  • Mining and ore processing will occur 24 hrs/day for 7 days a week.

  • Hauling of engineered fill will occur 16 hrs/day for 7 days a week

· Placement, grading and compaction of the engineered fill will occur 8 hrs/day for 5 days a week.

· There will be 50-100 haul truck trips per day with each load weighing 20 tons. (50=3 trips/hr, 100=6 trips/hr)

· Since placement, grading and compaction only occurs 8 hrs/day, 5 days a week, there will be significant stockpiles of this material building up before 7 am and after 3:30 pm and throughout the weekends.

· Rise maintains that there will be negligible fugitive silica dust because they will sprinkle the material with water twice a day, or cover it with a tarp. We are very concerned about fugitive dust.

Are there any protections for our community?

Well, there are some regulatory standards for workers exposed to silica

· The OSHA, Occupational Safety and Health, regulatory standard for permissible exposure level (PEL) for RCS is 50 ug/m3 TWA over an 8 hour day

· The MSHA, Mine Safety and Health Administration, regulatory standard for permissible exposure level (PEL) is 100 ug/m3 TWA over an 8 hour day. This standard was adopted in 1969 and is double the current OSHA standard.

· BUT OUR COMMUNITY WILL BE EXPOSED 24 HOURS A DAY, 365 DAYS PER YEAR, forevermore from multiple sources to this toxic air contaminant

In 2005, California adopted a “safe limit” for non-occupational exposure. This chronic reference exposure level is 3 ug/m3 for ambient respirable crystalline silica. However, there is no enforcement of this statute and the exposure level falls below the NIOSH 7500 test detection level of 5 ug/m3. (In other words, the accepted method for sampling and testing is not sensitive enough to reach the state limit of 3 ug/m3)

Note: A chronic reference exposure level is a concentration, at or below which no adverse health effects are anticipated in the general human population from long-term (up to a lifetime) exposure. OEHHA, 2000

Slide: Asbestos

And still the community has yet another TAC to be concerned about …asbestos

According to the World Health Organization, “No level of asbestos exposure is safe. Excess rates of cancer are found at all asbestos fiber concentrations. ” WHO

Exposure is linked to several diseases: cancer of the lung, larynx, and ovaries and mesothelioma (cancer of the pleura and peritoneal linings). Exposure is also responsible for asbestosis, COPD, and pleural effusions.

It generally has the worst effects when a person is exposed to an intense concentration of it or they are exposed on a regular basis over a long period of time.

Chrysotile, serpentine asbestos, is the type found in IMM

An asbestos fiber is defined as a particle longer than or equal to 5 microns with a length to width ratio of greater than or equal to 3:1

Thus, the fibers are invisible, readily airborne and inhaled deep into the lungs.

Slide: Mining Will Occur Along Faults Associated with Serpentinite

· Here is a geologic map from the Hydrology report

· The black dotted line represents the mineral rights boundary with different rock types denoted by color

· The purple area is serpentinite, which can contain asbestos

· The red dotted lines trace the Morehouse, Idaho and 6-3 faults through the serpentinite deposit.

Slide: Rise Gold’s Asbestos Sampling Locations Again in this map, the gray area represents the mineral rights boundary with serpentinite traced in purple. Green is porphyrite (meta-andesite), orange is diorite, coral is granodiorite with meta-sedimentary deposits shown in blue

Slide: Inconsistencies Raise Questions

And here is an expanded view of the previous map showing the drill core locations where asbestos sampling was done…

· 42 samples were analyzed: 2 blanks, 2 tailings from Centennial site and 40 core samples

· Core samples were from 6 different cores out of 19 total: 9 samples from I-18-11, 1 from I-18-12? (labeled I-19-12 on map), 9 from I-19-13, 7 from I-19-13A, 8 from I-19-14, and 4 from I-19-14A

· Asbestos was encountered in serpentinite at final drill depth for 3 cores I-18-11, I-19-13, I-19-13A where drilling stopped. So, the thickness and width of the serpentinite layers are unknown.

· Two distinct methods of analysis with different sample prep, instrumentation, magnification and counting methods were used. Forty samples were analyzed by Polarizing Light Microscopy while the remaining two samples were analyzed by transmission electron microscopy. The results by TEM were 3.1% for one sample and 2.0% for another. PLM had two detections at 0.75% and 2.5%.

· Overall, asbestos was detected in four samples. For quality control, duplicate analyses were performed: this is when you analyze two samples from the same location. The results were <0.25% PLM(Y962847) and 2.0% TEM (Y962981)

e.g. TEM used a magnification of 15,000X vs PLM at 50-1000X, usually 400X. Higher resolving power enables TEM microscopists to distinguish and identify finer particle and fibers not seen with the use of PLM

The differences between these sample duplicate results could be due to different analysis methods, lack of sample homogeneity (one sample was received as pulp) or both. Regardless, there is a very big difference between no detection of fibers and 2.0% by weight results.

Slide: No Guidelines for Specimin Collection - Stats Not Representatitive

In fact…

Regarding asbestos sampling, the California Geologic Survey states: “Because no exact guidelines exist for determining the number of specimens that should be collected, any statistics that are computed using the quantitative results from analysis of these specimens cannot be interpreted to be “representative” of the entire NOA population. Guidelines for Geologic Investigation of Naturally Occurring Asbestos in California, California Geologic Survey

For example, suppose the analytical results for three samples are 0%, 5% and 10% asbestos. The mean, or average, of these three values is 5%, but the variability is considerable. Simply reporting the average value, 5%, says nothing about this variability. It is not correct to say that the average NOA concentration for the entire site is 5% because it is not known, nor can it be known, that the three specimens are representative of the entire population.”

Rise did use a “weighted” average for the 12 serpentinite samples used for asbestos weight % determination. Four of those samples, 25% of the total, contained asbestos ranging from 0.75-3.1% by weight. The core lengths ranged from 3.6” to 13”, with over half of the samples at <5” length.

Based on 12 samples, Rise calculated the content of asbestos as 1.08% by weight and the asbestos emissions are based on the 1% of serpentinite to be mined each day.

Is this an accurate percentage based on the limited sampling done, testing limitations and the asbestos variability in serpentinite deposits?

Slide: So much Serpentinite in the Mining Area

Here is a closer look at some of the deposits that are proposed or targeted sites for mining…

· The diagram on the left is “The Rose Garden”. According to the Technical Report on the Idaho-Maryland Project this deposit “is hosted solely in serpentinite. Serpentinite within the Idaho fault zone, east towards the 6-3 Fault and west of the 3 Vein may host mineralization similar to the Rose Garden.”

· On the right is a view of the Idaho #3 Vein System. You can trace the gold vein along the serpentinite contact, here in purple

Slide: More Serpentinite

And here are portions of the Idaho #1 and #2 Veins adjacent to the Morehouse fault… again with the gold vein tracing alongside the serpentinite contact

Rise states that only 1% of daily mined material will be serpentinite.

  • However, as you can see from the previous Rise Gold maps, gold mineralization has a strong association with serpentinite

  • Rise plans for the additional serpentinite material (besides the content taken to the Centennial site) to be placed in a separate compartment of the concrete silo. It will also be used to backfill stopes (empty tunnels).

  • Rise claims that 90% of asbestos fibers will be captured by filters on the ventilation system, water curtains, or other methods. The remaining 10% will be exhausted to the ambient environment. For reference, the main ventilation fan exhausts to the ambient environment at 200,000 ft3/minute from a height of 165 ft.

  • In the Health Risk Assessment section of the Air Quality Report is the following statement: “The average asbestos content of the total ore is of primary concern, rather than the speculative potential of blasting particularly asbestos rich rock, since asbestos does not have established acute noncancer effects (OEHHA).”

  • In other words, Rise will not have to account for fibers released during blasting of asbestos rich rock simply because there are no immediate proven cancer health effects from acute exposure…what a nice loophole

  • This statement may be true for the miners but there will be safeguards in place to limit their exposure: respirators, PPE, working a short shift and being monitored to ensure they don’t exceed Permissible Exposure Levels according to regulations. At the end of their shift, they will decontaminate themselves and go home.

  • Rise claims that by protecting their employees, they will….by default …be protecting the community. But there is a fatal flaw to their logic in this argument. The primary way that Rise will protect their workers is by ventilating the mine. But ventilating the mine to the ambient air is the primary way our community will be contaminated with asbestos.

  • Once these fibers are in the environment, they persist forever and the community exposure will be every minute of every day.

  • Just where can we expect these fibers to go once airborne?

Slide: Particles Travel Easily - Grass Valley is at Risk

We’re almost done now, but before we conclude, let’s consider how far these toxic contaminants might travel in the air.

We know that both respirable crystalline silica and asbestos emissions are microscopic, less than 5 microns in size. But any particles less than 10 microns can be inhaled into the lungs

· Here are some charts based on Stoke’s Law showing particle distances travelled according to wind speed and particle size.

· Keep in mind that the Brunswick site is <2 miles from downtown Grass Valley

· The average hourly wind speed in Grass Valley is 5.7 mph WeatherSpark

· Here is one last statement from the Air Quality Report: “Based on the PM10 emissions estimated and the lab sample results, emissions of asbestos, silica, and heavy metals were estimated for purposes of this HRA (Health Risk Assessment).”

· The consultant is using estimations of estimates to predict the future health of our community. It may take 10-20 years for diseases to appear from radon, silica and asbestos exposure. But the effects will be devastating.

· A bigger question is…. How will we monitor these airborne pollutants? PM10 studies will only indicate quantity, they will not distinguish the amounts of the individual components AND… Nevada County is already in nonattainment status for PM10.

· The fugitive dust mitigation plans are not adequate to prevent the release of airborne microscopic silica and asbestos into our environment.


Diesel, radon, silica and asbestos…OH MY!

Rise has said that each of these pollutants will have a “less than significant effect on our community. They maintain that they will be able to mitigate or diminish the effects with strategies such as using Tier 4 diesel engines, filters on the mine ventilation fan, and wetting down the “dust”.

How can spewing pollutants from thousands of gallons of diesel fuel daily, trucking rock and sand tailings laden with asbestos and silica around town 16 hours per day, building two sites with this material, plus the daily operations of the mine for 80 years have a “less than significant effect” on our community?

I am concerned that the rise operation will constitute a public health and an environmental health crisis.

All the gold in the world can’t buy good health. Please join with CEA to Stop the Idaho Maryland Mine!

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