Are there any benefits to dust in your home?  Most of us would instantly say “No!”  But Wendy Leung makes a good argument for the opposite – read her article from The Globe and Mail  – This article was published more than 9 years ago. Some information in it may no longer be current.

“Bad news, neat freaks. All that work you’ve done to keep your homes dust-free may be counter-productive.

A new study has found that household dust actually purifies the air by neutralizing harmful ozone, according to The Canadian Press.

The gross part is it’s the flakes of human skin in dust that gives it its ozone-fighting power.

Researchers from the American Chemical Society found that dust containing high amounts of squalene, a component in human skin, can reduce up to 15 per cent of ozone in the air. (Ozone, when present in the air we breathe instead of high up in the atmosphere, is a pollutant that can damage our lungs, The Canadian Press explains.)

“Dust is parts of…people that have been in that room,” researcher Charles Weschler told The Canadian Press. “I mean, that’s a gross way of thinking about it.”

Squalene is present in the oils of our skin, which makes humans “remarkably good ozone sinks,” Dr. Weschler said.

Humans shed up to 500 million skin cells per day, so just think of all the ozone-neutralizing bits of your body that are scattered around your home.

The Canadian Press warns you may not want to retire your feather duster just yet, though.

Sure, it may clear up some of the ozone in the air, but the dust itself can leave allergy-sufferers wheezing.”

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Dust Monitoring Equipment – providing equipment, services and training in dust fallout management to the mining industry.

This is a great article by Josh Thomas of Enviro-tech on the importance of monitoring dust in the workplace.  Enjoy the read!

Please note that the regulations stated are applicable in the United Kingdom.

“Why monitor dust in the workplace?

Almost any place of employment can present a potential threat to health and safety from airborne particulates and aerosols. It is important to note, however, that dust hazards are not necessarily visible to the human eye and that the finest particles can represent the greatest threat because of their ability to travel deepest into the lungs. Effective monitoring is therefore key to the implementation of an effective risk management strategy.

There are two major reasons for monitoring dust in the workplace; to enable air quality management, and for regulatory compliance. The immediate effects of dust can be irritation to eyes, headaches, fatigue, coughing and sneezing. As such, poor indoor air quality can lower employee performance and cause increased absenteeism through sickness. In addition, particulates are known to create long-term deleterious effects, contributing to serious illnesses. In combination with outdoor exposure (to pollution form vehicles for example), the Government has estimated that 29,000 premature deaths occur in the UK every year as a result of particle pollution. This means that, particularly in urban areas, natural ventilation may not necessarily improve indoor air quality.

Employers are responsible for ensuring that staff and visitors are not exposed to poor air quality in the workplace, so it is necessary to conduct monitoring. Accurate and effective monitoring data can be used to check exposure levels and to help identify safe working practices.

Monitoring also helps to demonstrate compliance with relevant regulations. COSHH is the law that requires employers to control substances that are hazardous to health. According to the Health & Safety Executive (HSE), employers can prevent or reduce workers’ exposure to hazardous substances by finding out what the health hazards are; by deciding how to prevent harm to health; by providing effective control measures; by providing information and training; by providing monitoring and health surveillance, and by planning for emergencies.

In order to evaluate workplace safety, monitoring data is compared with Workplace Exposure levels (WELs) which prescribe the maximum exposure level to a hazardous substance over a set period of time. Failure to comply with COSHH and WELs can result in financial penalties, prosecutions and civil claims.

Indoor air quality is affected by both internal and external factors. Air pollution may arise from external sources such as neighbouring factories, building and development activities, or from vehicles – especially those with diesel engines. Internally, air quality is affected by working practices and business processes. For example, dust may arise from raw materials such as powders, or it may be produced by processes that generate particulates; including dust, mist, aerosols and smoke. In all cases, internal and external, it is important to identify both the source and the seriousness of the problem, so that appropriate and effective mitigation measures can be implemented. These might include, for example, ventilation, process dust prevention, the management of shift patterns, personal protection equipment (PPE) and alarm systems.

Regulatory Requirements to Monitor

Under the Workplace (Health Safety and Welfare) Regulations 1992, employers have a legal duty to ensure, so far as is reasonably practicable, the health, safety and welfare of employees. Furthermore, the Management of Health and Safety at Work Regulations 1999 require employers to assess and control risks to protect their employees. A key element of this is the requirement to comply with the COSHH Regulations. The HSE says that exposure measurement is required:

• For COSHH assessment, to help select the right controls

• Where there is a serious risk to health from inhalation

• To check that exposure limits are not exceeded

• To check the performance of exposure controls

• To help select the right respiratory protection equipment

• To check exposure following a change in a process

• To show any need for health surveillance; or

• When an inspector issues an ‘Improvement Notice’
requiring monitoring

The COSSH Regulations include dust, mist, vapour, fumes and chemicals, but they do not cover Lead or Asbestos. Specific requirements exist for certain industries such as construction. Generally, WELs relate to particulate diameter because the health effects of particulates are heavily influenced by their size.

Inhalable dust is that which enters the nose or mouth during breathing and is available for deposition in the respiratory tract. It includes particles with a width between 2.5 and 10 microns (PM2.5 – PM10), and the WEL for this fraction is 10 mg/m3 as an 8-hour Time Weighted Average (TWA).

Respirable dust is the fraction that penetrates deep into the gas exchange region of the lungs. It includes particles with a width between 1 and 2.5 microns (PM1– PM2.5), and the WEL for this fraction is 4 mg/m3 as an 8-hour TWA. Lower specific WELs exist for particulates that present a greater threat to health. For example, Silica dusts have a WEL of just 0.1 mg/m3 respirable dust as an 8-hour TWA.

The Costs of Non-Compliance

In addition to the enormous numbers of premature deaths that result from exposure to outdoor air pollution, there are also numerous well-documented instances demonstrating the harm caused by exposure to indoor pollution from dust, smoke, aerosols and vapour. For example, a 46-year-old cook developed breathing problems after working with flour in a school kitchen with poor ventilation. Her breathing problems became so severe that she could hardly walk and had to sleep sitting up. She became severely asthmatic and had to retire early on health grounds. With the support of her Union she made a compensation claim on the basis that decent working conditions were not provided, and the council admitted that it had not taken sufficient action despite repeated complaints. Consequently, the courts awarded the cook £200,000 in damages.

In another example, between 1995 and 2004, a solderer was exposed to rosin based solder fumes and suffered health deterioration and breathing problems including asthma. An investigation conducted by the HSE found that the company did not have adequate control measures in place and failed to install fume extraction equipment. Furthermore, the company did not employ rosin-free solder until December 2003, despite an assessment having identified the need in 1999. The company was subsequently fined £100,000 with £30,000 costs, a punishment which attracted both local and national media attention.

Monitoring Dust

A wide variety of methods exist for the measurement of dust, and the choice of equipment is dictated by the application. For example, it is obviously important to employ a technology that is able to measure the particulates that will be present. In addition, it will be necessary to determine whether monitoring should be continuous, at a single point, or whether portable instruments are necessary to check multiple locations. Monitoring might be conducted in a work space, or personal sampling might be undertaken in order to assess the exposure of an individual over an entire shift.

Personal Sampling Pumps represent the preferred method for workplace exposure monitoring where it is necessary to demonstrate regulatory compliance or where legal dispute is a possibility. An HSE document (MDHS 14/4) provides workplace exposure monitoring guidance for collecting respirable, thoracic and inhalable aerosol fractions. The samples collected by this process are analysed in a laboratory, which means that chemical analysis is also possible. However, the sampling method incurs a delay and incurs extra cost.

In response to the wide variety of applications and monitoring requirements, Ashtead Technology stocks a comprehensive range of monitors for both sale and rental, providing customers with complete financial and technical flexibility. As a TSI Gold Partner, Ashtead Technology provides a comprehensive range of maintenance and calibration services; helping customers to ensure that their monitoring equipment remains in optimal condition. Ashtead’s fleet of rental equipment includes large numbers of the latest TSI instruments, supported by the highest levels of service and technical assistance. Employing advanced light-scattering laser photometers, the TSI products are supplied with a calibration certificate and provide real-time, direct-reading aerosol monitoring and analysis of different particulate fractions in workplace, cleanroom, HVAC, fugitive emissions and environmental monitoring applications.

The TSI range of dust monitors is continually being developed to bring new levels of functionality to the market. For example, the new lightweight AM520 Personal Dust Monitor is able to measure and log PM10, Respirable (PM4), PM5 (China Respirable), PM2.5, PM1 or 0.8µm Diesel Particulate Matter (DPM), providing real-time audible and visual alarms, and running from a rechargeable battery for up to 20 hours. For outdoor applications, the MCERTS approved Environmental DustTrak is web-enabled, providing a quick and easy dust monitoring solution for applications such as building and development projects.”

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Dust Monitoring Equipment – providing equipment, services and training in dust fallout management to the mining industry.

Agricultural activities can cause a lot of dust – but what is it that is in that dust?  Tom Philpott reports for Mother Jones on the topic of what is carried in the dust from factory farms.

“Dust From Factory Farms Carries Drugs, Poop Bacteria, and Antibiotic-Resistant Genes Far and Wide

Ever approached a feedlot teeming with thousands of cattle? Unlike industrialized hog and chicken farms, where huge enclosed buildings trap at least some of the smell, cattle feedlots are open-air—as anyone who has driven Highway 5 between Los Angeles and San Francisco can testify. Turns out, when you inhale the aroma, you’re not just getting a blast of ammonia and other noxious fumes. You’re also probably breathing in tiny particles of antibiotics, bacteria from cows’ “fecal matter and  gut flora,” and antibiotic-resistant gene sequences. That’s the conclusion of a new study from Texas Tech researchers, who analyzed air samples taken just downwind of ten cattle feedlots in Texas and states to the north, each containing between 20,000 and 50,000 cows.

The team placed portable air samplers 10-20 yards upwind and downwind of feedlots in the fall and winter months, when temperatures are mild and wind is moderate, and analyzed the particulate matter. Monenisin, an antibiotic growth promoter widely used on beef and dairy feedlots, turned up in 100 percent of samples, at much higher rates downwind (mean: 1,800 parts per billion) than upwind (below the level of measurement.) Now, monenisin isn’t used in human medicine, meaning that it doesn’t directly contribute to antibiotic resistance that affects us. But tetracycline antibiotics—used commonly to treat urinary tract infections and pink eye—showed up in 60 percent of the downwind samples and 30 percent of the upwind samples, again at much lower levels upwind.

To put these findings in perspective, the authors note they found antibiotics in the air outside of these feedlots at levels similar to those typically found within large enclosed hog operations—meaning that finding yourself 20 yards from a giant cattle lot is a lot like being inside a hog house.

They also found bacteria “common to fecal matter and gut flora” at significantly higher levels downwind than upwind, including several that can cause human infections, including including corynebacterium, Leptospira, Clostridia, Bacteroides, and Staphylococcus.

And they picked up gene sequences that confer resistance to tetracycline at rates ranging from 100 to more than 1,000 times higher downwind than upwind. And get this: Those tetracycline-resistant genes appeared at much higher rates than those typically found in the liquid manure lagoons that build up in beef feedlots—meaning that wind may be even more prolific than water at spreading antibiotic-resistant genes from the farm to the surrounding region.

So how is all this nasty stuff moving from the feedlot to the surrounding air? The authors offer a simple explanation: The ground in feedlots “consists primarily of urine and fecal material,” the study notes. In the morning, all of that … stuff is relatively stable, held more or less in place by moisture from humidity. But after hours of sunlight, the floor material “becomes dry and brittle, thus becoming source material for fugitive dust.”

So what does this all add up to? The study doesn’t comment on whether the particles the researchers found are at high enough levels to directly cause human harm. But that’s not the main concern—most of us don’t spend much time near massive concentrated cattle operations. (Feedlot workers are another story.) The larger issue is those antibiotic genes, traces of antibiotics, and fecal microbes that are being scattered far and wide. The authors note that of the nation’s 2,100 large-scale (1000 head or greater) cattle feedlots, more than three-quarters are in the region of area study, the southern Great Plains (a swath stretching from northern Texas through parts of Oklahoma, Kansas, Nebraska, and Colorado)—the very region with the “highest frequency of dust storms in the United States.” The region’s semi-arid conditions—as well its its propensity for prolonged droughts—provides an ideal environment for the “wind scouring of dry soils,” and “aerial transport and deposition” of feedlot particles into “surrounding soil surfaces, water surfaces, vegetation, and other living organisms.”

And that’s under calm weather conditions. “Fronts and other major weather patterns frequently sweep through this region, and are often associated with exceedingly high wind velocities which themselves transport significant masses of particulates into the atmosphere and across the region and continent,” they add. And once in the environment, resistance genes can jump from bacteria that don’t pose a threat to humans to ones that do, the authors note.

The study is yet another reminder that the massive amounts of waste generated on factory farms don’t stay on factory farms.”

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Dust Monitoring Equipment – providing equipment, services and training in dust fallout management to the mining industry.

Do we know what kind of harm our cars are doing to the environment? The University of Pennsylvania did a fascinating study of roadside dust.  Take a read.

Analyzing roadside dust to identify potential health concerns
by University of Pennsylvania

https://phys.org/news/2018-09-roadside-potential-health.html

“Everyone knows that cars contribute to air pollution. And when most people consider the source, exhaust is usually what comes to mind.

However, new research led by the University of Pennsylvania’s Reto Gieré, working with collaborators across the world, is helping to illuminate another significant culprit when it comes to traffic-related air pollution: Tiny bits of tires, brake pads, and road materials that become suspended in the air when vehicles pass over.

“More and more I’ve noticed that we don’t know enough about what is on our roads,” says Gieré, professor and chair of Penn’s Department of Earth and Environmental Science in the School of Arts and Sciences. “If you have lots of traffic, cars, and trucks driving by, they re-suspend the dust on the roads into the atmosphere, and then it becomes breathable. To understand the potential health implications of these dust particles, it’s really important to understand what’s on the road.”

While regulatory efforts have helped make cars cleaner and more efficient, those restrictions do not address the pollution that arises from tire and brake wear. Increasing urban congestion stands to aggravate these as sources of pollution and possibly adverse health effects.

“About 4 million people die prematurely from air pollution each year,” says Gieré. “From unsafe water the number is 2 million. Yet we have a United Nations Sustainable Development Goal about water pollution but not one about the air.”

To shed light on the contents of traffic-related dust and the conditions that make it more likely to accumulate, Gieré has teamed with German colleagues from the Federal Highway Research Institute, the German Meteorological Service, and the University of Freiburg to sample and analyze the air along roadsides. In 2017, they published the findings of a year-long sampling effort along two highly frequented motorways in Germany, one subject to more stop-and-go traffic and another in a more rural area bordered by agricultural fields.

To passively collect the dust along the roadsides, they used customized cylindrical samplers with a transparent sticky foil at the bottom to trap particles that make their way in. The researchers checked the collection points and switched out the sticky “trap” weekly.

Using optical microscopy to analyze the collected airborne particles, the team found that the site with busier traffic patterns had 30 percent more particles overall, with a greater fraction derived from tire wear. Weather factored significantly into the patterns they observed; dry and warm conditions were associated with a greater build-up of particles.

“At higher temperatures we saw more tire abrasion, more pollution than at intermediate temperatures,” Gieré says. “This was exactly analogous to what two laboratory studies found.”

With higher temperatures and more dry spells predicted under climate change, Gieré notes that this problem of tire abrasion may only get worse, “which is significant,” he says, “because nearly 30 percent of the microplastics released globally to the oceans are from tires.”

In a more recent study, published last month in Aerosol and Air Quality Research, Gieré and colleagues used powerful scanning electron microscopy to more precisely identify the make-up of the particles collected from the two motorways studied in the 2017 report as well as a third collection site, at an urban highway with slower-moving traffic.

“The optical microscope gives us a first approximation,” Gieré says, “while the scanning electron microscope allows us to distinguish between tire abrasion, brake abrasion, carbon, or find out if there are minerals in there.”

Taking a further step, the team also ran samples through an analysis that provides information about the elements that compose each specimen, called energy-dispersive X-ray spectroscopy.

This study focused on the “super coarse” particles collected, those greater than 10 micrometers in size. (For comparison, a human hair is roughly 75 micrometers in diameter.) While still tiny, these particles pose less of a health threat than those even smaller, which are more easily inhaled. Still, these larger particles can wind up in waterways and soil, affecting wildlife or possibly even agricultural crops.

Ninety percent of the dust particles collected from the three sites were traffic-related and the researchers again saw differences between the sites. The slower-moving traffic on the urban road generated fewer particles from brake wear but more from tires; they noted that the tire rubber became encrusted with minerals and other materials from the roads. The highway with more stop-and-go traffic generated more brake particles.

Tire and brake pad manufacturers do not disclose all the contents of their products, but it’s known that zinc, lead, antimony, silicates, cadmium, and asbestos are used by some. These are chemicals that can pose a health risk if they get into the environment or, if the tires are burned as they sometimes are by coal plants, the atmosphere.

“These coarse particles aren’t going to be transported very far, so pollution is going to be restricted to the vicinity of these roads, especially during congestion,” Gieré says. “But they do also collect on the road and then wash into rivers. Our team believes that’s a major pathway of how microplastics get into waterways.”

One way to reduce this avenue of pollution would be traffic-calming measures, such as coordinated traffic lights, that reduce the amount of starting and stopping that drivers must perform. Gieré and colleagues, including Ph.D. student Michael O’Shea, are also performing similar experiments on the streets of Philadelphia and comparing the pollution levels between different neighborhoods to see what is happening a little closer to home.”

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Dust Monitoring Equipment – providing equipment, services and training in dust fallout management to the mining industry.

Here are two opposing articles to read on the subject of adding rock dust to your garden / agricultural land.  Take a read – what do you think?  Rock dust – good or bad?

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Topping Soil With Rock Dust Could Suck Billions of Tons of CO2 From the Air and Increase Crop Nutrients

By Andy Corbley -Jul 14, 2020

Good News Network

“Spreading the dust of basalt rock over fallow fields could drain billions of metric tons of CO2 out of the atmosphere every year, says a new study published in Nature.

According to a team of primarily English scientists, mitigation of the worst effects of human-caused climate change will require both cutting carbon emissions, and the gradual removal of already existing greenhouse gases.

Soils normally absorb carbon from the atmosphere, but when mixed with the dust of basalt, which is rich in calcium and magnesium and also very abundant (as a mining and mineral by-product) you get a 2-fold benefit—crop production that is more nutrient, and an accelerated absorption of CO2.

The mixing of dust and soil increases the alkalinity, dissolving CO2 into non-organic carbon forms such as hydrogen carbonate ions: HCO3. These carbon-sequestering ions are removed via rainwater, and transferred to the ocean through runoff and drainage systems where they will act as carbon-prisons for 100,000 years.

“The logistical infrastructure to apply basaltic rock dust to managed croplands already exists owing to the common need to apply crushed limestone to reverse soil acidification resulting from intensive cropping,” write the authors in their study. “Thus, rapid deployment at large scale appears to be feasible…and has important ancillary benefits including mitigation of ocean acidification.”

If this can also cut the acid level in the ocean, which puts coral at risk, the idea now has a 3-fold benefit—a win-win-win.

“CO2 drawdown strategies that can scale up and are compatible with existing land uses are urgently required to combat climate change, alongside deep emissions cuts,” said Prof David Beerling, of the University of Sheffield, a lead author of the study. “ERW [dust spreading] is a straightforward, practical approach.”

Dust is even better than trees
Their modeling and analysis found that the emissions of serious CO2 producers Germany and Japan could be offset by treating half the world’s cropland with basalt dust, which would in theory be cheaper than other CO2 extraction strategies, with costs varying on local labor rates.

Tree-planting is mentioned in the study as a great way to extract CO2 from the atmosphere, but while mass-planting is often cheaper, the benefits are not as strong. Further they rely on the trees surviving a certain number of years for the benefits to fully take hold which is never a certainty.

Speaking with the Guardian, Prof. Breeling said of the basalt dust mixing: “If you could demonstrate to farmers in China and India, for example, that they are going to get crop yield increases and get paid $100 a ton for removing CO2, then it becomes really attractive.”

“Mining generates a continuous, but often discarded, finely powdered silicate by-product that is utilizable for dust mixing,” reads the study. They point out that it would require little to utilize existing silicate powders because of already existing mining infrastructure, potentially eliminating the CO2 generation from constructing tipper trucks, roads, or additional mines to produce the dust. Finally the authors mention that nations only need make an inventory of how much silicate byproduct they possess.

These numbers could then be plugged into their models and a more accurate and real-world assessment could be made on how far basalt dust mixing could go to reducing the effects of climate change.

And because it’s good for cropland, there are plenty of private sector incentives as well.”

(The article below has not been printed in full here – please follow the link to read the complete article)

Rock Dust – Can It Remineralize the Earth?

By: Robert Pavlis

Garden Myths

“Rock dust is a very popular soil additive especially with organic and permaculture groups. It is full of nutrients and adding it to soil will replenish all of the nutrients that agriculture has taken out of our soil. This process of adding nutrients back to soil is known as mineralization.

This seems to make a lot of sense. We remove food from the land, and the food contains lots of minerals. At some point we need to put them back into the soil or else we will have soil that won’t grow anything. This seems logical but is it really true? Is our soil losing fertility? If it is deficient, can rock dust be used to solve the problem? How effective is rock dust and which type of rock works the best? Time to crush some myths about rock dust.

To be effective the rock needs to be ground into a very fine powder. That way it is more easily used by microorganisms and decomposed by environmental elements.

Two common forms of rock, namely limestone and phosphate rock have been used for a long time to amend soil. Although these products are correctly called rock dust, they are usually not included when gardeners talk about rock dust, and I will exclude them from this post.

Is Rock Dust a Fertilizer?
Some commercial products call themselves a fertilizer and I even found one that was labeled like a fertilizer showing an NPK of 0-0-1, but by most legal definitions rock dust does not contain enough NPK to qualify as a fertilizer.

Claims Made for Rock Dust
Rock dust is claimed to add all kinds of minerals back to soil. These are the nutrients that plants need to grow. Because of this, rock dust products make all kinds of claims for growing bigger plants, producing higher yields, increasing disease resistance, etc. These are all valid claims if the soil is deficient of one or more nutrients and rock dust adds the missing nutrient.

There are two clear questions we must answer to validate these claims and I’ll do that in the rest of this post.

Does rock dust add plant available nutrients to soil?

Is soil deficient of nutrients?

If the answer to either question is no, rock dust will not help plants grow.

Mineral Content of Rock Dust
Rock dust does contain a lot of minerals. I have seen claims ranging from 60 up to 90 different minerals. Azomite is a common product and their analysis list of 74 minerals can be seen here.

I don’t dispute the claims, but there is no evidence that plants need all of these minerals. They use about 20 minerals – that’s it. The other 40 to 70 are not needed by plants.

Rate of Decomposition of Rock Dust
Earlier in this post, I posed the question, does rock dust add nutrients to soil. There is no doubt that adding rock dust adds the minerals, but I can also do that by laying a big bolder on top of the garden. The bolder will not help plants grow but it does add minerals to the garden. Unless the minerals in the rock decompose to release the nutrients in a form plants can use, there is little point in adding the rock dust.

For this reason I think that one of the most important questions we need to ask is, how quickly does rock dust decompose?

Some of my early reading on the matter indicated time frames of a hundred years. I have searched on many web sites selling rock dust and none have any claims or data to show decomposition happens even after 100 years or more. No one in the industry wants to put a number on this important property.

The best information I have is a casual comment that it is about 100 years. At that rate the product is essentially useless.

Are Soils Nutrient Deficient?
This is also an important question to ask. Do we have a problem that needs to be fixed?

I had a closer look at this question in a previous post called Is Soil Fertility Decreasing? My conclusion was that our soils are not losing fertility. They are not nutrient deficient. Therefore, rock dust, assuming it actually works, is a product that tries to solve a problem that doesn’t exist.

What Does Research Say?
Some papers report some improvements in plant growth with some soils but many show no change. There is limited field work done – it is almost all lab work. I did not find a single paper that measured the chemical characteristics of soil before and after adding rock dust to the field – maybe you can find one for me.

There is some evidence that rock dust may provide an important source of potassium in regions like Africa that tend to have soils which leach nutrients quickly and where fertilizer costs are very high.

Rock dust is used extensively in Brazil and now Embrapa, the Brazilian Agricultural Research Corporation, has come out and said, “there is not enough scientific information to recommend silicate agrominerals as a source of nutrients, especially potassium, or soil conditioners for agriculture.”

The science does not support the use of rock dust for most agricultural areas and even the suppliers of rock dust suggest it has no value in alkaline soil.”

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Dust Monitoring Equipment – providing equipment, services and training in dust fallout management to the mining industry.