Monthly Archives: May 2017

Occupational and Environmental Lung Disease

I found this article at Health, Environment & Work – some interesting info on how lungs function and the health effects of dust and gasses.

“The lungs and skin (including nose and eyes) are the organs of first contact for most environmental exposures (excluding ingestion). This aid to learning also includes an introduction to wider harmful consequences as exemplified by the effects on cellular respiration. It will exclude infection and consequences of radioactivity. It complements other modes of learning in the module.

Relevant Fundamentals of Lung Structure and Function

The airways of the lung derive from the trachea (wind pipe) downwards by progressive division into two (or more) branches. Those airways beyond the trachea that contain cartilage are called bronchi. The airways lacking in cartilage beyond the bronchi are the bronchioles. These lead into hollow spaces called alveoli which have a diameter of about 0.1 mm each. There are approximately 300 million alveoli and their total surface area is about 140 m2. The conducting airways are lined by cells with cilia (small motile surface projections). Interspersed between these cells are mucus secreting cells. Secreted mucus spreads over the cilia which direct it upwards to the larger airways by rhythmic undulating movements, thus helping to clear deposited dusts.
The respiratory units, i.e. the alveoli and the smallest bronchioles called respiratory bronchioles are responsible for the exchange of gases. They are lined mainly by flat, extremely thin cells which permit easy diffusion of oxygen through them from the air in the alveolar spaces to the blood in the capillaries and easier diffusion of carbon dioxide in the opposite direction. Alveolar macrophages are very abundant, mobile and phagocytic cells mainly responsible amongst other functions for the ingestion of foreign matter. The lining of the outside of the lung and the inside of the chest wall is called the pleura.

Deposition and host defence of inhaled dusts and mists

Aerosol is an all-embracing term including all airborne particles small enough to float in the air. Dusts are solid particles dispersed in air. Mists are liquid droplets formed by the condensation of vapours, usually around appropriate nuclei or the ‘atomisation’ of liquids. The aerodynamic diameter of a particle is the diameter of a sphere of unit density that would settle at the same rate.
When airborne particles come in contact with the wall of the conducting airway or a respiratory unit they do not become airborne again. This constitutes deposition and can be achieved in one of four ways:
Sedimentation is settlement by gravity and tends to occur in larger airways.

Inertial impaction occurs when an airstream changes direction especially in the nose but also in other large airways.

Interception applies mainly to irregular particles such as asbestos or other fibrous dusts which by virtue of their shape can avoid sedimentation and inertial impaction. However they are intercepted by collision with walls of bronchioles especially at bifurcations or if the fibres are curved.

Diffusion is the behaviour of very small aerosol particles which are randomly bombarded by the molecules of air. It significantly influences deposition beyond the terminal bronchioles.

Most compact particles larger than 20 microns aerodynamic diameter and about half of those of 5 micron aerodynamic diameter are filtered within the nose during breathing at rest. However there is a wide variation in the efficiency of this among apparently normal subjects.

Moreover conditions which favour mouth breathing, (e.g. high ventilation rates and obstructive disease of the nasal airways) will cause large particles to bypass this filter. Alveolar deposition is appreciable at particle diameters of between 1 and 7 microns (respirable particles) and probably maximal at aerodynamic diameter of between 2 and 4 microns. During regular breathing at rest only about 10% of compact particles of 0.5 to 1 micron diameter are deposited in the lung (alveoli), the bulk being again exhaled.

During exertion, increase in tidal volume (i.e. the volume of air inspired with each breath) and particularly in respiratory minute volume (i.e. the product of tidal volume and the number of breaths per minute) is the single most important determinant of the total load of particles in the alveoli and hence the total volume of particles deposited for a given aerosol. Several other factors may influence particle deposition. Insoluble particles deposited in the conducting airways are propelled towards the larger airways by the cilia and then rapidly coughed or swallowed. This may be delayed by factors such as tobacco smoking. In the respiratory units, ingestion by macrophages is necessary before the particles are carried to the larger airways. Particles may also penetrate the deeper lung tissue where they may stay for years or be transported by macrophages to the lymph nodes.

Vapours and gases

Vapours are substances in the gaseous phase at a temperature below their boiling point. Gases produce their harmful effects in the following ways (as described below):
(1) They can cause asphyxiation (deprivation of oxygen to the tissues);

(2) They can cause irritation of the airways and the lungs;

(3) After entering the body through the lungs they can cause damage to other tissues of the body.

Health Effects of Dusts, Gases and Vapours

Nuisance dusts are relatively inert and, by definition, cause no serious health effects although they may be irritant to the upper airways. Examples include chalk, limestone, and titanium dioxide (provided they are free of toxic impurities). They may cause radiographic changes without disease. Dusts should be considered as nuisance dusts only when there is good evidence that they are inert and free from significant health effects not when evidence for an effect is lacking. Moreover there is now good evidence that ultrafine particles of dusts previously considered inert, such as titanium dioxide can be toxic.
Diseases Mainly of the Respiratory Units


Pneumoconiosis is the non-neoplastic (i.e. excludes cancer) reaction of the lungs to inhaled mineral or organic dust and the resultant alteration in their structure. It also excludes diseases mainly of the airways like asthma, bronchitis and emphysema (although destruction of alveoli as in emphysema can be caused by dusts). Two important pneumoconioses are coal workers pneumoconiosis and silicosis.
Coalworkers’ pneumoconiosis (cwp) is a pneumoconiosis caused by inhalation of coal dust and is more prevalent in underground workers exposed to higher concentrations of dust than in surface workers. The lung is destroyed by fibrosis and emphysema.

Silicosis is a pneumoconiosis caused by inhalation of quartz (or some other crystalline forms of silicon dioxide) which is lethal to macrophages that ingest it and releases their enzymes. In its early stages it is similar to cwp but the nodules in the lung tend to be denser. It is a serious and progressive disease. A number of exposures such as grit / sand-blasting with silica have essentially been banned because of the risk of this serious condition.

The term mixed dust fibrosis describes the pulmonary disorder caused by the inhalation of silica dust simultaneously with another non-fibrogenic dust. Other mineral pneumoconiosis may be caused by beryllium, talc, kaolin and mica.

The image alongside shows a quarry worker gently pushing an explosive charge down a hole bored in the rock. The reel next to his right foot contains a cable to permit detonation from a safe distance. As well as the obvious trauma hazard, this procedure (shot-blasting) can generate large concentrations of silica dust.

Environmental Lung Disease

Asbestosis, and other asbestos-related lung disease

Asbestos is such an important cause of lung disease that it is now discussed on a separate page in this website: Asbestos and Disease.

The accompanying image shows asbestos bodies in human bronchoalveolar fluid obtained through bronchoalveolar lavage by the author for diagnostic and research purposes from a symptomatic worker who had significant exposure to asbestos (note alveolar macrophage cells adherent to the larger body, close to a large multinucleated giant cell, while in the bottom right hand corner a smaller body has probably been engulfed by a couple of the cells).
Asbestosis is often classified separately from pneumoconiosis even though asbestos is a dust -but it is a special form of fibrous dust. Like silicosis, asbestosis is a serious condition which is incurable and can result in death at an early age. However, as is the case with many harmful substances it does require a certain inhaled dose of asbestos before there is a measurable risk of asbestosis.

Extrinsic allergic alveolitis

Extrinsic allergic alveolitis can be caused by sensitisation to many organic dusts mainly fungal spores, e.g. farmer’s lung and malt worker’s lung. It tends to affect the respiratory units of the lung rather than the conducting airways and may have ‘flu’ like symptoms in addition. In some respects it is similar to humidifier fever which might be caused by sensitisation to amoebae or algae.
Inhalation of oil mists may cause asthma, airways irritation, lipid pneumonia or other conditions depending on their composition.

Diseases Mainly of the Airways

Irritant effects of gases

Examples: Sulphur dioxide, Nitrogen dioxide, Ozone, Ammonia and Chlorine
These gases produce their harmful effect by irritating eyes, airways and even the respiratory units of the lungs. Many of them may be detected by their smell and irritant effect, but if evasive action is not taken in time, and if exposure is high enough they can produce severe damage throughout the lungs.

Occurrence: Exposure to ammonia and chlorine occurs as a result of industrial accidents. High levels of nitrogen dioxide can be encountered in agriculture (silo filling), during arc welding, as a result of shot firing in the mines and in the chemical industry. It can achieve high levels in the vicinity of internal combustion exhausts. Ozone is usually a secondary pollutant. Sulphur dioxide results from the combustion of sulphur containing substances.

Symptoms: Sulphur dioxide, chlorine, and Ammonia are highly irritant and cause pain in the eyes, mouth and chest. In high concentrations they can produce inflammation of the lining of the lungs and this causes breathlessness and may be fatal. (See chronic effects below).

Nitrogen dioxide has less effect on the eyes, nose and mouth but can cause severe inflammation of the lungs. It is important to realise that although symptoms at first may be mild, serious breathing problems may follow later if the exposure is high enough.


Asthma is a condition characterised by inflammation of the lining of the airways and intermittent spasm of the underlying smooth muscle. Comparatively more is known about the cause of asthma caused by work (occupational asthma) than about other forms of asthma. It is often but not always the result of allergy to an inhaled dust or vapour in the workplace. Its symptoms include cough, wheeze, chest tightness and shortness of breath which improve on days off work or longer holidays but the association with work may be difficult to establish in some cases. In the UK there are probably more than 2000 new cases every year and there have been a few fatalities from agents such as isocyanates or reactive dyes.
Important causative agents include:-

Isocyanates (e.g. in twin-pack spray paints), Hardening/curing agents e.g. anhydrides, Rosin (colophony) fumes from soldering flux, Dusts from various cereals (including flour), Animals such as mammals (rats, mice) but also arthropods (such as locusts), Wood dusts – various e.g. Canadian red cedar, Aldehydes e.g. formaldehyde or glutaraldehyde, Cyanoacrylates (as in “superglue”), and Antibiotics.

In the home, exposure to allergens from house dust mites can be a contributing factor in the development of asthma as well as a cause of its symptoms. Other allergens from pollen, moulds, animal dander etc can cause asthmatic symptoms. Outside the home in the general environment increase in asthmatic symptoms has been attributed to exposure to soya bean dust and to oil seed rape. The contribution to the causation of asthma by irritant gases such as sulphur dioxide, nitrogen dioxide and ozone is still unclear, although it is known that these substances can certainly aggravate symptoms in those who are already asthmatic.

Chronic Bronchitis

The best documented and probably most important environmental cause of chronic bronchitis is tobacco smoke. Other substances could cause bronchitis but this is not yet clear. Certainly many substances (such as sulphur dioxide) can aggravate the symptoms of bronchitis and cause premature deaths from this condition, as occurred in the smogs that affected many big cities in the early 1950’s.

Bronchial cancer

(“lung” cancer)
The single most important known environmental respiratory carcinogen by far in man is tobacco smoke. However lung cancer may also be caused by other agents e.g. asbestos, certain compounds of nickel, polycyclic aromatic hydrocarbons (PAH) e.g. benzpyrene, arsenic trioxide and chromates.


Exposure to asbestos dusts probably of all kinds but especially of blue asbestos (crocidolite) causes mesothelioma which is a cancer of the pleural lining of the lung (besides an increased risk of lung cancer in the bronchus as with smokers). Hundreds of ex-workers still die of these diseases in the UK every year.
Cancer of the nose or nasal sinuses might be caused by certain dusts from hard woods, leather processes and nickel refining.

Systemic Effects


Some dusts e.g. lead of its salts can be absorbed into the body after inhalation or skin contact. They can then have harmful effects on other organs e.g. the nerves or the blood forming organs. Ultrafine particles might travel through the alveoli to produce harmful effects elsewhere.
Systemically toxic gases and vapours

Examples: Methylene chloride, various chloroethanes and chloroethylenes. The effect of methylene chloride is similar to the effect of vapours given off by organic solvents (e.g. trichlorethylene). Initially they might cause a feeling of well being similar to that produced by alcohol. At higher concentrations they cause unconsciousness. Repeated exposure can lead to permanent brain damage.
Simple Asphyxiant gases

Life depends on an adequate supply of oxygen reaching the tissues of the body. Oxygen present in the air breathed into the lungs passes into the blood and is carried to the tissues. Simple asphyxiants may interfere with this process either by displacing oxygen from the air breathed in. Examples: Methane, Nitrogen. This happens usually in enclosed, poorly ventilated spaces particularly underground where methane can be produced by naturally occurring processes or where natural oxygen has been depleted. Symptoms include breathlessness due to lack of oxygen. Carbon dioxide also causes rapid breathing, headache and sweating. Eventually, loss of consciousness and death can result.
Chemical asphyxiants gases

These cause asphyxia by interfering with oxygen transport. Examples: Carbon monoxide, Hydrogen cyanide, Hydrogen sulphide. See toxicology – toxicodynamics.


Companion page on Occupational and Environmental Skin Disease

Information about the reported incidence of occupational lung disease in the UK and the Republic of Ireland is collected by SWORD and other surveillance schemes which are part of the THOR network at the University of Manchester.”

Have a great day!  Regards, Chris

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


What are the Effects of Dust on the Lungs?

Here’s an interesting article from the Canadian Centre for Occupational Health and Safety on what effects dust have on the lungs. Enjoy the read!

What are the lungs?
The lungs are the organs of breathing: they are responsible bringing oxygen from the atmosphere into the body through a series of branching air tubes (Figure 1 below) and exchanging it for carbon dioxide that is released back into the atmosphere.

What are the Effects of Dust on the Lungs?
The lungs are constantly exposed to danger from the dusts we breathe. Luckily, the lungs have another function – they have defense mechanisms that protects them by removing dust particles from the respiratory system. For example, during a lifetime, a coal miner may inhale 1,000 g of dust into his lungs. When doctors examine the lungs of a miner after death, they find no more than 40 g of dust. Such a relatively small residue illustrates the importance of the lungs’ defenses, and certainly suggests that they are quite effective. On the other hand, even though the lungs can clear themselves, excessive inhalation of dust may result in disease.

What happens when we breathe in dust?
The lungs are protected by a series of defense mechanisms in different regions of the respiratory tract.

When a person breathes in, particles suspended in the air enter the nose, but not all of them reach the lungs. The nose is an efficient filter. Most large particles are stopped in it, until they are removed mechanically by blowing the nose or sneezing.

Some of the smaller particles succeed in passing through the nose to reach the windpipe and the dividing air tubes that lead to the lungs.

These tubes are called bronchi and bronchioles. All of these airways are lined by cells. The mucus they produce catches most of the dust particles. Tiny hairs called cilia, covering the walls of the air tubes, move the mucus upward and out into the throat, where it is either coughed up and spat out, or swallowed.

The air reaches the tiny air sacs (alveoli) in the inner part of the lungs with any dust particles that avoided the defenses in the nose and airways. The air sacs are very important because through them, the body receives oxygen and releases carbon dioxide.

Dust that reaches the sacs and the lower part of the airways where there are no cilia is attacked by special cells called macrophages. These are extremely important for the defense of the lungs. They keep the air sacs clean. Macrophages virtually swallow the particles. Then the macrophages, in a way which is not well understood, reach the part of the airways that is covered by cilia. The wavelike motions of the cilia move the macrophages which contain dust to the throat, where they are spat out or swallowed.

Besides macrophages, the lungs have another system for the removal of dust. The lungs can react to the presence of germ-bearing particles by producing certain proteins. These proteins attach to particles to neutralize them.

Dusts are tiny solid particles scattered or suspended in the air. The particles are “inorganic” or “organic,” depending on the source of the dust. Inorganic dusts can come from grinding metals or minerals such as rock or soil. Examples of inorganic dusts are silica, asbestos, and coal.

Organic dusts originate from plants or animals. An example of organic dust is dust that arises from handling grain. These dusts can contain a great number of substances. Aside from the vegetable or animal component, organic dusts may also contain fungi or microbes and the toxic substances given off by microbes. For example, histoplasmosis, psittacosis and Q Fever are diseases that people can get if they breathe in organic that are infected with a certain microorganisms.

Dusts can also come from organic chemicals (e.g., dyes, pesticides). However, in this OSH Answers document, we are only considering dust particles that cause fibrosis or allergic reactions in the lungs. We are not including chemical dusts that cause cancer or acute toxic effects, for example.

What are the reactions of the lungs to dust?
The way the respiratory system responds to inhaled particles depends, to a great extent, on where the particle settles. For example, irritant dust that settles in the nose may lead to rhinitis, an inflammation of the mucous membrane. If the particle attacks the larger air passages, inflammation of the trachea (tracheitis) or the bronchi (bronchitis) may be seen.

The most significant reactions of the lung occur in the deepest parts of this organ.

Particles that evade elimination in the nose or throat tend to settle in the sacs or close to the end of the airways. But if the amount of dust is large, the macrophage system may fail. Dust particles and dust-containing macrophages collect in the lung tissues, causing injury to the lungs.

The amount of dust and the kinds of particles involved influence how serious the lung injury will be. For example, after the macrophages swallow silica particles, they die and give off toxic substances. These substances cause fibrous or scar tissue to form. This tissue is the body’s normal way of repairing itself. However, in the case of crystalline silica so much fibrous tissue and scarring form that lung function can be impair. The general name for this condition for fibrous tissue formation and scarring is fibrosis. The particles which cause fibrosis or scarring are called fibrogenic. When fibrosis is caused by crystalline silica, the condition is called silicosis.

What are the factors influencing the effects of dust?
Several factors influence the effects of inhaled particles. Among these are some properties of the particles themselves. Particle size is usually the critical factor that determines where in the respiratory tract that particle may be deposited. Chemical composition is important because some substances, when in particle form, can destroy the cilia that the lungs use for the removal of particles. Cigarette smoking may alter the ability of the lungs to clear themselves.

Characteristics of the person inhaling particles can also influence the effects of dust. Breathing rates and smoking are among the most important. The settling of dust in the lungs increases with the length of time the breath is held and how deeply the breath is taken. Whether breathing is through the nose or mouth is also important.

What are the diseases of dusty operations?
The classic diseases of “dusty” occupations may be on the decline, but they have not yet disappeared. Workers today still suffer from a variety of illnesses caused by dust they inhale in their work environments. For practical purposes, we limit this document to dust. We do not take into consideration combined effects arising from exposures to dusts, gases, fumes and vapours.

Some types of lung diseases caused by the inhalation of dust are called by the general term “pneumoconiosis.” This simply means “dusty lung.”

The changes which occur in the lungs vary with the different types of dust. For example, the injury caused by exposure to silica is marked by islands of scar tissue surrounded by normal lung tissue. Because the injured areas are separated from each other by normal tissue, the lungs do not completely lose their elasticity. In contrast, the scar tissue produced following exposure to asbestos, beryllium and cobalt completely covers the surfaces of the deep airways. The lungs become stiff and lose their elasticity.

Not all inhaled particles produce scar tissue. Dusts such as carbon and iron remain within macrophages until they die normally. The released particles are then taken in again by other macrophages. If the amount of dust overwhelms the macrophages, dust particles coat the inner walls of the airways without causing scarring, but only producing mild damage, or maybe none at all.

Some particles dissolve in the bloodstream. The blood then carries the substance around the body where it may affect the brain, kidneys and other organs.

The table below summarizes some of the most common lung diseases caused by dust.

The OSH Answers document Extrinsic Allergic Alveolitis has more information about diseases from exposure to organic dusts.

Some types of pneumoconiosis according to dust and lung reaction
Inorganic Dust Type of Disease Lung Reaction
Asbestos Asbestosis Fibrosis
Silica (Quartz) Silicosis Fibrosis
Coal Coal Pneumoconiosis Fibrosis
Beryllium Beryllium Disease Fibrosis
Tungsten Carbide Hard Metal Disease Fibrosis
Iron Siderosis No Fibrosis
Tin Stannosis No Fibrosis
Barium Baritosis No Fibrosis
Organic Dust  
Mouldy hay, straw and grain Farmer’s lung Fibrosis
Droppings and feathers Bird fancier’s lung Fibrosis
Mouldy sugar can Bagassosis Fibrosis
Compose dust Mushroom worker’s lung No Fibrosis
Dust or mist Humidifier fever No Fibrosis
Dust of heat-treated sludge Sewage sludge disease No Fibrosis
Mould dust Cheese washers’ lung No Fibrosis
Dust of dander, hair particles and dried urine of rats Animal handlers’ lung No Fibrosis


How can we protect the lungs from dust?
To avoid respiratory or other problems caused by exposure to dust, hazardous substances should be substituted with non-hazardous substances. Where substitution is not possible, other engineering control methods should be introduced. Some examples are:

Use of wet processes
Enclosure of dust-producing processes under negative air pressure (slight vacuum compared to the air pressure outside the enclosure)
Exhausting air containing dust through a collection system before emission to the atmosphere
Use of vacuums instead of brooms
Good housekeeping
Efficient storage and transport
Controlled disposal of dangerous waste
Use of personal protective equipment may be vital, but it should nevertheless be the last resort of protection. Personal protective equipment should not be a substitute for proper dust control and should be used only where dust control methods are not yet effective or are inadequate. Workers themselves, through education, must understand the need to avoid the risks of dust.

A respiratory protection program is discussed in OSH Answers – Personal Protective Equipment under Respirator Selection and Respirator Care.

Enjoy your day further!  Dust Monitoring Equipment – providing equipment, services and training in dust fallout management to the mining industry.


Dust helps regulate Sierra Nevada ecosystems

Dust helps regulate Sierra Nevada ecosystems, study finds

Article sourced from Phys Org

“Collecting dust” isn’t usually considered a good thing.

But dust from as near as the Central Valley and as far away as the Gobi Desert in Asia provides more nutrients—especially critical phosphorus—than previously thought to sustain the vegetation in the Sierra Nevada, a team of scientists has found.

Dust helps regulate Sierra Nevada ecosystems
A new study released today (March 28) in the journal Nature Communications indicates it’s important to understand how dust helps vegetation thrive, especially in light of the changing climate and land-use intensification.
It is well known that dust is an important source of nutrients for highly weathered and old landscapes like the island of Kauai, where intensive chemical weathering and leaching have depleted the underlying bedrock of life-sustaining elements, including phosphorus, potassium, calcium and magnesium, UC Merced Professor Stephen Hart and his collaborators wrote.
Because of the mostly phosphorus-poor granitic bedrock, the Sierra Nevada is considered a phosphorus-limited ecosystem, but the researchers believe their findings will hold true for other mountainous ecosystems around the world and have implications for predicting forest response to changes in climate and land use.
Nutrients are generally supplied to plants as bedrock is converted to soil. Nutrients, to a large degree, regulate the distribution of life across Earth’s surface, so understanding the relative importance of different nutrient sources—including bedrock and dust—is a fundamental question in ecology, biogeochemistry and geobiology.
But the researchers were surprised to find that the dust is important even in actively eroding, relatively young mountain ecosystems like the Sierra Nevada. “Dust provides important inputs of the plant-growth limiting nutrient phosphorus to western Sierra Nevada ecosystems,” Hart said. “These dust inputs may be critical for maintaining plant productivity in these geologically young montane environments, and dust inputs may increase as land use in the Central Valley intensifies and as the climate warms in the future.”
An interdisciplinary and inter-institutional collaboration involving isotope geochemists, a geomorphologist, ecosystem ecologists and microbial ecologists from UC Merced, the University of Michigan, the University of Wyoming and UC Riverside sought to quantify the importance of transoceanic and regional dust as a nutrient source to Sierra Nevada ecosystems.
The researchers examined samples from four sites in the Southern Sierra Critical Zone Observatory (SSCZO) in the Sierra National Forest, from about 1,300 feet to 8,800 feet elevations, and compared dust nutrient inputs to rates of soil formation based on modern and millennial rates of soil loss.
The research team is also studying microbial “hitchhikers” that are riding on the dust particles.
“I think we’ll also be able to use the microbial DNA to pinpoint where the dust comes from with a similar or higher fidelity than using radiogenic isotopes in the dust,” said Hart, who’s with the School of Natural Sciences and the Sierra Nevada Research Institute.
UC Merced graduate student Nicholas Dove, who volunteered to be part of the project for the experience of working with this diverse group, said he was tasked with collecting dust and helping write the paper by offering comments and critiques.
“Harvesting dust for scientific purposes is surprisingly rudimentary. We use many household supplies: Wooden posts hold up bundt pans filled with marbles, and the dust settles in the marble matrix,” he explained. “We collect this dust by ‘washing’ the marbles with sterile water. The water is filtered and, voila, you have your dust.”
Dove’s dissertation is focused on the effects of fire suppression and altered wildfire regimes on microbial communities and biogeochemical processes in mixed-conifer forests of the Sierra Nevada, but he jumped at the chance for more work in the SSCZO.
“Working in the SSCZO has allowed me to meet and work with other researchers outside from around the country,” he said.
The SSCZO, led by UC Merced Professor Roger Bales, is part of a network of 10 critical zone observatories established by the National Science Foundation, and is a collaborative effort with the Pacific Southwest Research Station of the Forest Service.
“The CZO network was set up to carry out research such as this, which integrates physical, geochemical and biological measurements from the subsurface through the land surface, giving us an unprecedented predictive ability to improve management of these rapidly changing forested landscapes,” Bales said.
“This research reveals that the transport of dust in the atmosphere is important for the ecological health of many parts of our planet,” said Richard Yuretich, program director for the NSF’s Critical Zone Observatory Network. “Complex cycles and feedbacks regulate conditions at the surface of the Earth. This study adds a significant piece to our knowledge of how the Earth works and what we can do to keep it functioning properly.”
The Nature Communications paper is called “Dust outpaces bedrock in nutrient supply to montane forest ecosystems.”

Trust you enjoyed this article. Regards, Chris.

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

Training Course

Please note that the training course for Pretoria is scheduled for  30, 31 May, 1 June 2017.

Avenues Guesthouse
881 Wekker Road
Moreleta Park
Pretoria East, South Africa

Contact Person for accommodation bookings: (Optional – Any accommodation can be used but this is the venue for the training)

Michelle Botha

Mobile no:082 826 9889



Please book accommodation if required independently at this venue or an alternative venue.  The training will take place at this venue.

Please diarise those dates if you can make it, and RSVP by  25th of May 2017.

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

The costs for the training – R2800 per person per day, and the course runs for three days.  You can also select which days to attend.

Below is a brief outline of the course, although the course will be customised to meet the specific needs of those attending.

The course has three main topics that will be covered over the three days.

  1. Fallout dust monitoring theory (Day 1)
  2. Fallout dust monitoring practical (Day 2)
  3. Fallout Dust Monitoring Reporting (Day 3)

The fallout dust monitoring section of the course aims to train the trainees so that they are able to do the following.

  1. Understand what fallout dust monitoring achieves and what is collected.  This will include discussion around the legislative requirements and will also address the possible influences of dust sensitive areas like communities, hospitals, farms, and recreational areas.
  2. Prepare buckets, transport buckets and change buckets in the Fallout Dust Monitoring units.
  3. Filter the bucket contents using a filter bench and using the related equipment used in the filtering process.  This includes advice on how to minimise the filtering time and what can be done when samples are taking very long to filter.
  4. Understand how to calculate the fallout dust monitoring results in mg/m2/day and how to interpret these results.
  5. Report writing and presentation options for the results will also be discussed.
  6. Some computer training may also be included in the course if required.
  7. Access to our software for processing of the fallout dust data will also be included after the course.  This can be used to simplify the data collection and report writing and will also provide a database of the fallout dust levels over the years.

The course will be presented by Christopher Loans who is a Professional Chemical Engineer with a Masters in Occupational Hygiene focused on the Mining Industry.

Please do not hesitate to contact me regarding any queries.

Chris Loans
DustWatch CC – Precipitant Dust Monitoring

082 875 0209 or 021 789 0847 (Chris)
083 308 4764 (Gerry)
0866 181 421 (Fax)


Training course

Studying interstellar dust from a balloon

In just a few days, the Pilot astrophysics experiment will be launched under a stratospheric balloon from Alice Springs in central Australia. Its aim is to observe the polarized emission of dust particles found in the interstellar medium of our galaxy and nearby galaxies.

With a mass approaching one metric ton, Pilot uses the largest balloons ever launched by CNES, the French national space agency. The experiment was developed by the Research Institute in Astrophysics and Planetology (CNRS/CNES/Paul Sabatier University), the Institute of Space Astrophysics (CNRS/Paris-Sud University), and the Institute of Research into the Fundamental Laws of the Universe (CEA-Irfu).

The first Pilot flight was launched from Canada in September 2015; the forthcoming flight will thus be its first flight in the southern hemisphere sky, which contains more features of interest for Pilot than the northern hemisphere.

Studying interstellar dust from a balloon

The emission of dust particles in the interstellar medium of our galaxy and nearby galaxies is slightly polarized, as the particles are elongated and aligned with the magnetic field that prevails in the interstellar medium. The measurements obtained by Pilot will help scientists understand the nature of dust particles and why they are aligned in this way. The measurements will also be used to map the geometry of the magnetic field, which plays an important part in contracting the gas in the interstellar medium, a phenomenon that leads to the formation of new stars.
This emission is also an obstacle for experiments that seek to accurately measure the polarization of the cosmic microwave background, and Pilot’s measurements will shed more light on it, and thus improve the interpretation of the results obtained with this type of experiment.
The Pilot experiment will observe this emission in the far infrared region. It is equipped with 2,048 individual detectors, cooled to a temperature of 300 millikelvin, i.e. close to absolute zero. Polarization is measured using a rotating blade and a polarizer that separates two orthogonal polarizations on the two focal planes of the experiment. Apart from the primary mirror of the telescope, all the optics is maintained at a cryogenic temperature (2 kelvins or -271°C) inside a cryostat, cooled with liquid helium, to limit the instrument’s own emission.
The experiment was conceived and built by CNRS scientists and engineers at the Research Institute in Astrophysics and Planetology (CNRS/CNES/Paul Sabatier University) and IAS (CNRS/Paris-Sud University), with major contributions from the CNES Balloon Division in Toulouse, the ESA, the CEA (Saclay), which developed the focal plane and its electronics, La Sapienza University in Rome (Italy), and Cardiff University (United Kingdom). The whole project is backed by CNRS laboratories and CNES funding.
In a few days, Pilot will be launched by CNES as part of a campaign comprising three flights with different gondolas from Alice Springs, in central Australia. Pilot weighs nearly one metric ton and will have to climb to an altitude of nearly 40 km. It therefore requires the use of an open stratospheric balloon, approximately 100 m in diameter (the largest open balloon ever launched by CNES), and a payload chain as tall as the Eiffel Tower.
The flight will take place during one of the two annual reversals of stratospheric winds, which is a prerequisite for any hope of performing observations for more than 30 hours at the ceiling altitude. Although Pilot has already been launched in the past – its first flight was from Canada in September 2015 – this new flight will be in the southern hemisphere, thus providing an opportunity to observe outstanding astrophysical sources, such as the Magellanic Clouds, satellite galaxies of our own galaxy, or inner regions of the Milky Way, that cannot be observed from the northern hemisphere.

Thanks to Phys Org for this article on studying interstellar dust from a balloon.

Another great article I found is also from Phys Org……….

NASA team explores using LISA Pathfinder as ‘comet crumb’ detector

LISA Pathfinder, a mission led by ESA (the European Space Agency) with contributions from NASA, has successfully demonstrated critical technologies needed to build a space-based observatory for detecting ripples in space-time called gravitational waves. Now a team of NASA scientists hopes to take advantage of the spacecraft’s record-breaking sensitivity to map out the distribution of tiny dust particles shed by asteroids and comets far from Earth.

Most of these particles have masses measured in micrograms, similar to a small grain of sand. But with speeds greater than 22,000 mph (36,000 kph), even micrometeoroids pack a punch. The new measurements could help refine dust models used by researchers in a variety of studies, from understanding the physics of planet formation to estimating impact risks for current and future spacecraft.
“We’ve shown we have a novel technique and that it works,” said Ira Thorpe, who leads the team at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “The next step is to carefully apply this technique to our whole data set and interpret the results.”
The mission’s primary goal was to test how well the spacecraft could fly in formation with an identical pair of 1.8-inch (46 millimeter) gold-platinum cubes floating inside it. The cubes are test masses intended to be in free fall and responding only to gravity.
The spacecraft serves as a shield to protect the test masses from external forces. When LISA Pathfinder responds to pressure from sunlight and microscopic dust impacts, the spacecraft automatically compensates by firing tiny bursts from its micronewton thrusters to prevent the test masses from being disturbed.
Scientists call this drag-free flight. In its first two months of operations in early 2016, LISA Pathfinder demonstrated the process with a precision some five times better than its mission requirements, making it the most sensitive instrument for measuring acceleration yet flown. It has now reached the sensitivity level needed to build a full multi-spacecraft gravitational wave observatory.
“Every time microscopic dust strikes LISA Pathfinder, its thrusters null out the small amount of momentum transferred to the spacecraft,” said Goddard co-investigator Diego Janches. “We can turn that around and use the thruster firings to learn more about the impacting particles. One team’s noise becomes another team’s data.”
Much of what we know about interplanetary dust is limited to Earth’s neighborhood, thanks in large part to NASA’s Long Duration Exposure Facility (LDEF). Launched into Earth orbit by the space shuttle Challenger in April 1984 and retrieved by the space shuttle Columbia in January 1990, LDEF hosted dozens of experiments, many of which were designed to better understand the meteoroid and orbital debris environment.
The different compositions, orbits and histories of different asteroids and comets naturally produce dust with a range of masses and velocities. Scientists suspect the smallest and slowest particles are enhanced in Earth’s neighborhood, so the LDEF results are not representative of the wider solar system.

“Small, slow particles near a planet are most susceptible to the planet’s gravitational pull, which we call gravitational focusing,” Janches said. This means the micrometeoroid flux near Earth should be much higher than that experienced by LISA Pathfinder, located about 930,000 miles (1.5 million kilometers) closer to the sun.
To find the impacts, Tyson Littenberg at NASA’s Marshall Space Flight Center in Huntsville, Alabama, adapted an algorithm he originally developed to search for gravitational waves in data from the ground-based detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO), located in Livingston, Louisiana, and Hanford, Washington. In fact, it was one of many algorithms that played a role in the discovery of gravitational waves by LIGO, announced in February 2016.
“The way it works is that we come up with a guess of what the signal might look like, then study how LIGO or LISA Pathfinder would react if this guess were true,” Littenberg explained. “For LIGO, we’re guessing about the waveform, the peaks and valleys of the gravitational wave. For LISA Pathfinder, we’re guessing about an impact.”
To map out the probability of likely sources, the team generates millions of different scenarios describing what the source might be and compares them to what the spacecraft actually detects.
In response to an impact, LISA Pathfinder fires its thrusters to counteract both the minute “push” from the strike and any change in the spacecraft’s spin. Together, these quantities allow the researchers to determine the impact’s location on the spacecraft and reconstruct the micrometeoroid’s original trajectory. This may allow the team to identify individual debris streams and perhaps relate them to known asteroids and comets.
“This is a very nice collaboration,” said Paul McNamara, the LISA Pathfinder project scientist at ESA’s Directorate of Science in Noordwijk, the Netherlands. “This is data we use for doing our science measurements, and as an offshoot of that, Ira and his team can tell us about microparticles hitting the spacecraft.”
Its distant location, sensitivity to low-mass particles, and ability to measure the size and direction of impacting particles make LISA Pathfinder a unique instrument for studying the population of micrometeoroids in the inner solar system. But it’s only the beginning.
“This is a proof of concept, but we’d hope to repeat this technique with a full gravitational wave observatory that ESA and NASA are currently studying for the future,” said Thorpe. “With multiple spacecraft in different orbits and a much longer observing time, the quality of the data should really improve.”
LISA Pathfinder is managed by ESA and includes contributions from NASA Goddard and NASA’s Jet Propulsion Laboratory in Pasadena, California. The mission launched on Dec. 3, 2015, and began orbiting a point called Earth-sun L1, roughly 930,000 miles (1.5 million km) from Earth in the sun’s direction, in late January 2016.
LISA stands for Laser Interferometer Space Antenna, a space-based gravitational wave observatory concept that has been studied in great detail by both NASA and ESA. It is a concept being explored for the third large mission of ESA’s Cosmic Vision Plan, which seeks to launch a gravitational wave observatory in 2034.

Hope you enjoyed the read.  Have a great day further!

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