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Are you coming up to speed on dust monitoring and associated occupational health risks? Here are some of Dr Winnie Chu’s  favorite articles!

History of Wearable Personal Particle Sampling

The wearable personal particle sampling device has been evolving since the first dust sampling devices were developed in the 1930s. Much research and development was undertaken in the 1960s and the 1970s to understand the health outcomes and develop effective devices to monitor worker conditions.

The following articles provide a background on the understanding and development of personal sampling devices leading up to today’s wearable personal particle sampler.

Accurate Personal Particle Samplers – Historical perspective of personal dust sampling in coal mines​

Accurate, lightweight, real-time personal particle dust sampling devices have been the objective of Occupational Health and Safety since the 1930s. It has been known since the 1960s that dust particles under 7 µm in size pose the most danger because they are small enough to penetrate deeply into the lungs. By the 1970s, it was recognized that personal samplers are vastly superior to area samplers. Real-time sampling is especially crucial in situations where dynamic, dangerous concentrations of small particles occur.

Quoting Kissell et al ” Over the last 20 years many dust-measuring technologies have been evaluated as candidates to replace the personal gravimetric sampler. Most have been found inadequate because of low accuracy, excessive size and weight and/or high cost.”

Particle Counting History – In defense of the dust count technique
For over 50 years, dust counting methods have been used by industrial hygienists to evaluate airborne industrial health hazards. This method was extremely labour consuming and hence expensive to use. In the 1970s, the industry shifted to mass concentration techniques for several reasons: new technology, lower cost and a direct and provable health relationship with lung cancer and other cardiovascular related diseases. However, recent studies are showing that smaller particles can pass through the lungs into the bloodstream and settle in the organs of the body, including the brain. Mass concentration techniques are unable to distinguish the extra danger posed by smaller particles. We need to revisit particle counting and add it to our arsenal of sampling techniques to determine the true risks to workers.

Quoting Horowitz: “one 10 µm particle, for instance, contributes as much to the weight of a sample as 1,000 or more particles 1 µm in size, but does not contribute as much to the hazard.”

As technology evolves so does the techniques and methods available to detect and measure aerosol particles. It is important to review the various methods to understand their advantages and limitations in the workplace in order to select the products and methods that best suit the Occupational Health application.

Techniques and Methods

Comparison of Real-Time Instruments Used to Monitor Airborne Particulate Matter

Five real-time continuous airborne particle monitors were compared to measurements using reference filter-based samples to evaluate the suitability of each instrument for use in a real-time continuous network in central California in winter conditions.

Theoretical Investigation of the Interrelationship Between Stationary and Personal Sampling in Exposure Estimation

In exposure estimation, personal sampling is the method of choice as it is representative of the contaminant concentration in the breathing zone. However, it may also be an attractive sampling method for many other circumstances due to its adaptability to telemetering observations, and the versatility of the stationary sampling in obtaining much higher sensitivity.

Health Outcomes

In order to devise effective methods and products to detect harmful aerosols it is necessary to understand the complex correlation between the concentration of particles in the air and the health effects on the human body.

The human body has evolved to tolerate most naturally occurring particles in the air. The larger particles are either prevented from entering or exhaled or coughed up. The smaller particles are captured and removed or destroyed by the bodies natural defenses. Once the particles get below 10 um in diameter they are deposited in either the nose, throat, larynx, bronchia or alveolar regions of the air system. Studies have shown that deposition in the upper respiratory system can cause cancer in the respiratory system but deposition in the alveolar region can get into the bloodstream and end up in the organs of the body, including the brain where they can cause cancer and disrupt the bodies cell structures.

About Aerosols – Dusts, Fumes, and Mists

This document provides a correlation between inhaled aerosols and health effects. It shows the difference in deposition percentages as the particles get smaller and the area of the respiratory system that is affected. Especially instructive are the figures at the end of the document.

Fine Particle Components and Health

Short-term exposure to fine particle mass (PM) has been associated with adverse health effects, but little is known about the relative toxicity of particle components. We conducted a systematic review to quantify the associations between particle components and daily mortality and hospital admissions. The available evidence suggests that both EC and secondary inorganic aerosols are associated with adverse health effects.

Standards are crucial in the Occupational Health industry to ensure accuracy and repeatability of results in order to ensure effective protection of workers in the market.


NIOSH 0600 Respirable Dust Sampling

The present standard for Respirable dust sampling as Outlined in the NIOSH Manual of Analytical Methods