Monthly Archives: March 2019

Dust could be good for you

Posted by on March 28, 2019 Comments Off on Dust could be good for you

Could dust really be good for you?  Have a look at this.

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“Bad news, neat freaks: Dust could be good for you

Globe and Mail – click to read the original article

WENCY LEUNG

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.

What do you think? Does the thought of being surrounded by bits of skin make you want to clean your house more or less?”

Dust could be good for you

And here’s some more from Ask Doctor K …..

“Is dust dangerous?

Ask Doctor K –

DEAR DOCTOR K:
I keep a tidy house, but no matter how much I clean, there’s more dust than I’d like. Is dust dangerous to my family’s health?

DEAR READER:
Yes, depending on its contents, dust can be harmful to your health.

What is dust? It’s a little like sausage: You don’t want to know what’s in it. But I’ll tell you anyway.

More than half of household dust comes from soil either tracked into the home or wafting in as airborne particles through doors and windows. The remainder of dust is a hodgepodge that includes skin cells from family members, skin cells and fur from household pets, carpet fibers, kitchen grease — and more.

Household dust often contains remnants of household chemicals and possibly even heavy metals. It also contains bacteria, fungi and dust mite (insect) particles that can trigger allergies. In particular, the debris dust mites leave behind can provoke powerful allergic reactions.

The most vulnerable family members are the youngest: Infants are up to 100 times more susceptible to the health hazards of dust-borne pollutants than adults.

Perhaps the most effective way to control dust levels is with regular housekeeping. Frequent vacuuming, preferably using a vacuum cleaner with a high-efficiency particulate air (HEPA) filter, is a good place to start. It may be necessary to vacuum several times a week.

Cleaning can temporarily launch into the air dust that has settled on floors, carpets and furniture. People with respiratory allergies should consider wearing a mask that filters out dust when they clean. One way to capture the dust that gets stirred up is to clean higher surfaces first and then work your way down. Wiping floors and hard surfaces with a damp cloth or sponge will eliminate a lot of dust. You can also use products like Grab-it or Swiffer that are treated with chemicals to attract dust.

You should consider putting heavy-duty doormats in front of doorways to stem the amount of soil coming into your house. Even better: Remove your shoes upon coming inside.

Install weatherproofing around doors and windows to help keep out airborne particles. Filters on heating and air conditioning systems should reduce dust. Portable air cleaners with HEPA filters are another option. Air purifiers are a less effective option than HEPA filtration, and they may emit small amounts of ozone, a gas that can worsen asthma symptoms.

I’ve talked about how dust in the home can trigger allergies, so you’d think that dust is just plain bad. But it may not be that simple. New research indicates that newborns and very young children who grow up in relatively “dirty” surroundings, such as farms, may actually be protected against developing allergies and allergic diseases (such as asthma) later in life. I’m not urging you to keep a dusty home for the first few years of a child’s life, but someday you may hear that advice!”

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

 

The Science of Dust

Posted by on March 21, 2019 Comments Off on The Science of Dust

We are so busy trying to get rid of dust but Pablo Picasso loved it……… and here’s why.

(To read the original article please go to Brain Pickings)

The Science of Dust

“The Science of Dust, Picasso’s Favorite Phenomenon

“With every breath, we inhale a bit of the story of our universe, our planet’s past and future…”

BY MARIA POPOVA

It takes more than three centuries for a one-foot layer of dust to accumulate. The entirety of the Roman Empire is buried nine feet underground — that is, under nine feet of tightly compacted dust. This household nuisance is indeed one of nature’s most humbling phenomena and Earth’s most steadfast preserver. Picasso was fascinated by it. In a passage from Hungarian photographer Brassaï’s 1964 gem Conversations with Picasso (public library) — which also gave us the iconic artist on success and not compromising and intuition and where ideas come from — Picasso marvels the news of an excavation in which archeologists preserved a cross-section more than ten feet high, containing multiple layers built over the millennia. When Brassaï notes how moving it is that “in a glance, you can take in thousands of years of history,” Picasso responds enthusiastically:

And you know what’s responsible? It’s dust! The earth doesn’t have a housekeeper to do the dusting. And the dust that falls on it every day remains there. Everything that’s come down to us from the past has been conserved by dust. Right here, look at these piles, in a few weeks a thick layer of dust has formed. On rue La Boétie, in some of my rooms … my things were already beginning to disappear, buried in dust. You know what? I always forbade everyone to clean my studios, dust them, not only for fear they would disturb my things, but especially because I always counted on the protection of dust. It’s my ally. I always let it settle where it likes. It’s like a layer of protection. When there’s dust missing here or there, it’s because someone has touched my things. I see immediately someone has been there. And it’s because I live constantly with dust, in dust, that I prefer to wear gray suits, the only color on which it leaves no trace.”

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

Techniques to determine elements on dust

Posted by on March 14, 2019 Comments Off on Techniques to determine elements on dust

Techniques to determine elements on dust

There are a variety of techniques that are available to determine individual elements on dustfall out rate but for the purpose of this report only XRF (X – ray fluorescence) and ICP (Inductively coupled plasma) will be discussed and compared.

Definition of XRF Technology and ICP –MS

XRF Technology – XRF (X-ray fluorescence) is a non-destructive analytical technique used to determine the elemental composition of materials. XRF analysers determine the chemistry of a sample by measuring the fluorescent (or secondary) X-ray emitted from a sample when it is excited by a primary X-ray source. Each of the elements present in a sample produces a set of characteristic fluorescent X-rays (“a fingerprint”) that is unique for that specific element, which is why XRF spectroscopy is an excellent technology for qualitative and quantitative analysis of material composition.

ICP-MS – Inductively coupled plasma mass spectrometry (ICP-MS) is a type of mass spectrometry which is capable of detecting metals and several non-metals at concentrations as low as one part in 1015 (part per quadrillion, ppq) on non-interfered low-background isotopes. This is achieved by ionizing the sample with inductively coupled plasma and then using a mass spectrometer to separate and quantify those ions.

Comparison between XRF and ICP

One of the important distinctions between XRF and ICP is the fact that ICP only reveals individual elements where as XRF determines elements and their oxides, this makes it easy to extrapolate, analyse and compare with relevant standards. More explained below:

1.XRF Advantage: Simple, fast and safe sample preparation without chemical waste.

Measurements by XRF are carried out directly on the solid material with little sample preparations. XRF analyses any type of sample without the need for dilution or digestion and therefore no disposal of chemical waste is necessary. Transferring liquids in wet-chemical methods from one vessel to another can introduce contamination and/or loss of material.

Measuring relatively large sample volumes (100 mg up to 10 grams) results in a more representative characterization of the sample. Also, errors due to sample inhomogeneity are easily minimized by using larger sample volumes. XRF can measure gram quantities without any risk of cross-contamination and therefore the error in an XRF result is much smaller.

2.XRF Advantage: Non-destructive analytical technique

In benchtop XRF spectrometers the sample is excited using an X-ray tube and the characteristic X-rays from the sample are detected and automatically processed by the software. These low-power X-ray tubes don’t produce an extensive amount of X-ray photons or heat and therefore don’t damage the sample or alter its crystal structure. Irregularly shaped samples that fit into the spectrometer can be analysed without the need for destructive sample preparation, like cutting, crushing and grinding. The same sample that was analysed by XRF can later be analysed using other techniques for further investigation, if necessary.

3.XRF Advantage: Low cost of ownership

Taking into account the initial costs of instrument and infrastructure, and running costs of gasses, acids, electricity and waste disposal, XRF benchtop spectrometers are far more cost-effective than ICP. XRF does not require the use of expensive acids, gasses and fume hoods. The only requirement is electricity and in some cases the use of helium to boost the sensitivity for light elements in the sample. Also, the individual components in XRF spectrometers are not exposed to friction or heat and therefore last for many years.

For example, the analysis of oils only requires the use of inexpensive disposable liquid cups. Solid samples, like metals, can be measured ‘as is’ with no sample preparation.

4.XRF Advantage: Analysis at the production site (at-line)

Since no gasses, liquids, acids or fume hoods are necessary to operate the XRF benchtop spectrometer, the instrument can be placed in the production facility, right next to the production line for at-line process control. The instrument is easy to install and with a short and basic training on the software, the user can operate the instrument with confidence.

5.XRF Advantage: No need for daily re-calibration

The latest advances in excitation and detection technology make the current generation of XRF benchtop spectrometers very stable. In comparison with ICP, XRF doesn’t need gasses or liquids to operate. Therefore, changes in the calibrations due to the purity and stability of gasses are not an issue for XRF, making daily re-calibration of the XRF instrument unnecessary.

For XRF spectrometers, gradual instrumental drift over years is easily corrected in the software and does not need a full re-calibration each time the spectrometer is in operation.

  • Speed: Portable XRF analyzers enable quick decisions, including whether to drill or not to drill, equipment relocation considerations, where to focus on the grid, and when to take a proper sample for laboratory analysis.
  • Real-Time Reporting: Field analyses provide for faster delineation of drill targets for timely, defensible data for operational decisions and financial reporting back to management and/or investors.
  • Increased Sample Density: Running more assays in the field allows for finer grid resolution and the ability to send prequalified samples to an off-site laboratory. With improved statistics, this high-density analysis produces a more comprehensive picture of the target than the exclusive use of the traditional bag and lab method.
  •  XRF has a multitude of applications in mining. Exploration: Portable XRF analyzers provide fast acquisition of geochemical data for rapid delineation of anomalous zones and the in-depth, quantitative analysis of metal concentrations for geochemical mapping. Lead times are reduced, which can be critical if the exploration season is short. Quarry operations: Quickly obtaining accurate exploration assay data to guide mining operations is one of the biggest obstacles to optimal productivity. Portable XRF analyzers allow geologists to rapidly acquire and send XRF data to quarry laboratory and operations management personnel allows for easy collaboration and informed decisions. Oil and gas exploration: Portable XRF analyzers are valuable for upstream exploration and production, offering rapid, on-site chemical analysis of rocks, cuttings, and cores that can be used for identifying formations and determining mineral composition of the rock. Industrial minerals: Portable XRF analyzers are an emerging instrument of choice for in-quarry exploration and evaluating the composition of raw materials such as phosphate, potash, gypsum, and limestone for industrial use.
  • XRF is accurate with or without sample preparation. Handheld XRF analyzers are designed for simple point-and-shoot operation. Sample preparation may or may not be necessary depending on your application and acceptable accuracy. XRF without sample preparation can generate reliable data about many elements, particularly base metals, when decisions must be made on the spot. When higher accuracy is required, sample preparation can be accomplished in the field in minutes and then analyzed with portable instruments for lab-comparable results.
  • It keeps getting better! Advances are being made in XRF technology all the time, from improvements in light element analysis to even faster, more accurate results. Review these XRF products to find one that can improve your business. Are you using an XRF analyzer now? Let us know about your experience.

Since XRF measurements rely on quantity, there are limits on the measurements. The normal quantitative limit is 10 to 20 ppm (parts per million), usually the minimum particles required for an accurate reading.

XRF also can’t be used to determine Beryllium content, which is a distinct disadvantage when measuring alloys or other materials that might contain Beryllium.

ICP -MS

Advantages

  • Ability to provide elemental isotopic ratio information.
  • Roughly 25 elements can be analyzed in duplicate and with good precision in 1-2 minutes.
  • Large linear dynamic working range.
  • The effective combination of differing types of ICP instruments coupled with the many varied types of sample introduction allow for customization of techniques for a specific sample type or form of analytes.
  • The lower-cost ICP systems utilize single-quadrupole mass analyzer systems, which are inherently sequential systems, and have relatively low mass resolution.
  • Elements such as Ca and Fe are difficult to determine by conventional ICP.
  • Generally requires a clean room environment for ultra-low detection limits.

 

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

 

Fallout Dust Monitoring course

Posted by on March 9, 2019 Comments Off on Fallout Dust Monitoring course

Good day

The next Fallout Dust Monitoring course is in April 2019 in Pretoria

9 – 11 April 2019 – Pretoria

The costs are in the attached files, R4400 per person per day.

If you would like to attend or to send a representative, then please email chris@dustwatch.com or call 021 789 0847 or 082 875 0209 to reserve a place.

Please do not hesitate to contact me regarding any queries, comments, or suggestions.

Sincerely

Chris Loans

DustWatch CC – Precipitant Dust Monitoring

082 875 0209 or 021 789 0847 (Chris)

083 308 4764 (Gerry)

021 789 0847 (Cape Town)

011 083 8750 (Johannesburg)

+1 832 422 5031 (USA)

0866 181 421 (Fax – SA Only)

www.dustwatch.com

 

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Dust Hazards

Posted by on March 7, 2019 Comments Off on Dust Hazards

Dust is hazardous!  Here are a few articles regarding combustible dust and how to deal with it.
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Vacuuming Wood Dust Can be Hazardous

Environmental-Expert 

Courtesy of SafetySmart

“It’s well known that wood dust is highly combustible, but the practice of removing it with vacuum trucks can also be dangerous, because of the potential buildup of static electricity.

WorkSafeBC has issued a bulletin stating that “static electricity discharges can ignite wood dust and therefore must be eliminated or adequately controlled during vacuuming.”

When wood dust or other fine, dry materials are vacuumed through a hose or pipe, the friction between the dust and the hose can generate static electricity. If the hose is made of a material that conducts electricity and is properly grounded, the static charge will safely dissipate into the earth.

However, WorkSafeBC notes that if the hose is non-conductive, a static charge will build up on its interior surface and could discharge with enough energy to ignite wood dust or other combustibles. Since plastic does not conduct electricity, plastic hoses are not safe to use for vacuuming wood dust unless they are embedded with a static wire.

Also, hoses that have ridged or corrugated interior surfaces should not be used for vacuuming wood dust. Using hoses with ridged interior surfaces results in more physical interaction between the dust particles—and between the dust particles and the hose—than using hoses with smooth interior surfaces. This increased interaction results in a static charge with higher amounts of static energy, making static discharge more likely.

WorkSafeBC says when vacuuming wood dust or other dry combustible materials, use only conductive hoses, nozzles and connectors that are designed to be used with those types of materials. If you are unsure whether a hose or other equipment is safe to use for vacuuming wood dust, check the manufacturer’s instructions.

Following are some additional wood dust vacuuming safety tips from WorkSafeBC:

Ensure that trucks are grounded directly to the earth or another verified ground before vacuuming starts. Also, hoses and all other parts of the truck and vacuum system should be properly bonded to each other.
Pay particular attention to ensuring proper bonding in baghouses (air pollution control devices), where the risk of dust ignition is high because of high volumes of dust and air that flow through them.

Ensure that vacuum trucks are regularly inspected and properly maintained. Pay particular attention to potential problem areas such as hoses, baghouses, vacuum pumps, collection boxes and filtration systems. Conductive hoses should be tested regularly and removed from services if they have lost their conductivity.

Ensure that wood dust is safely removed before buildup of the dust could cause a fire or combustible dust explosion.

Ensure that workers follow manufacturers’ instructions, safe work procedures and occupational health and safety regulations, and are properly trained and supervised.”

Dust Hazards

Combustible Dust: It Doesn’t Take Much

Environmental Expert

Courtesy of SafetySmart

“A dust accumulation of 1/32 of an inch deep—about the thickness of a dime—covering just five percent of a room’s surface area doesn’t sound like much, but it’s enough to cause a catastrophic explosion, according to the National Fire Protection Association (NFPA).

Although good engineering and safety practices to prevent dust explosions have existed for decades, there are no government standards for general industry requiring and enforcing policies aimed at preventing combustible dust explosions, according to the US Chemical Safety and Hazard Investigation Board (CSB).

The CSB adds that many companies are not taking effective action to control dust hazards. Industries at risk for combustible dust explosions include food production, metal processing, wood products, pharmaceutical, chemical manufacturing, rubber and plastic manufacturing and coal-fired power plant operations.

Angela Blair, a former CSB investigator, says most solid organic materials will explode if the particles are small enough and they are disbursed in a sufficient concentration.

“What is so frustrating about dust explosions is that they are so preventable and I believe one of the reasons that dust explosions continue to occur may simply be a lack of understanding about the materials,” says Blair. “Some of the materials that could form combustible dust, and there are lots of them, could include coal, food products like sugar and flour, pharmaceuticals, many chemicals and even many metals.”

Like all fires, a dust fire requires fuel, oxygen and an ignition sources. A dust explosion requires two additional elements—dispersion and confinement. When the dust is confined within a structure or a piece of equipment, a powerful explosion can occur.

Dust may accumulate on surfaces such as floors, beams, rafters and lights and lie undisturbed for years. If a fire or explosion occurs, this accumulated dust can ignite in a series of explosions, with devastating results.

The chances of a combustible dust explosion occurring are greater during cold-weather months, because low humidity levels can make dust particularly easy to disburse and ignite.

The NFPA says preventing dust explosions involves designing facilities in such a way that combustible dusts cannot accumulate and migrate and performing rigorous housekeeping on a continuing basis to remove any dust that does build up.

The NFPA also recommends:

Vacuuming dust using specialized equipment designed for that purpose. Never use compressed air to clear dust accumulations because doing so can create a dust cloud that could easily explode in the presence of an ignition source.

Paying particular attention to out-of-the-way areas that might not be visible from the floor yet could contain dangerous buildups of combustible dust.

Having a laboratory test the potential for explosion of any materials in dust (powder) form that are present in your workplace.

In addition, your workers need to be trained to recognize and report combustible dust hazards so that they can be addressed before a disaster occurs.”