Monday, July 10, 2017

Particulate Matter Metrics, Adverse Health Outcomes and Ultrafine Particles

Particulate Matter Metrics, Adverse Health Outcomes and Ultrafine Particles

Historically, mass concentrations of airborne particulate matter have been the most widely used metric for assessing exposure levels.  Part of the reason for this grew out of studies in the mid 1900’s that showed correlations between mass concentrations of coal dust and the debilitating lung disease of pneumoconiosis (“black lung”) in underground coal miners. Because mass was one of the easiest properties to measure scientists initially used this metric to study and quantify the levels of dusts and aerosols that are present in the air we breathe and it is still used today. But particulate matter poses a particularly complex hazard where dose and toxicity are not always correlated well with mass concentrations but are associated with other physical parameters such as number, surface area and shape, as well as composition. Particulate matter exposure assessment therefore needs to reflect the roles of these parameters, as well as chemistry and particle size and shape, relative to the broad range of adverse health problems that particulate matter creates.
Mass concentrations may have correlated well with the incidence rates of pulmonary pneumoconiosis and there may be other respiratory illnesses that show similar correlations today, but mass concentrations alone do not appear to explain many additional adverse health problems.  While respiratory disease and cancer have been shown to be related to particulates for decades, additional diseases of the circulatory system and neurological disorders are now also being correlated with exposures to particulates.  In some of these studies negative health outcomes still persist at very low mass concentrations that are generally deemed safe and there is little, if any, evidence of correlations with these low mass concentrations.  For both respiratory and circulatory illnesses, the most convincing correlations appear to be with particulate matter surface areas, and, in many instances, a parameter called lung deposited surface area, or LDSA.
In addition, other recent studies that link particulate matter exposure to neurological disorders, such as dementia, show that number concentrations of nanometer size particles provide the best correlation.  It is also worth noting that LDSA is also dominated by the presence of particles typically in the 20 nm to 400 nm particle size range and that high number and surface concentrations can occur at quite low mass concentrations.  It is not unreasonable to expect such correlations since it is these very small particles that penetrate most deeply into the lung where they are retained with high efficiency. As more studies and more data accumulate that address the relationships between particulate matter exposure and adverse health outcomes, the scientific community needs to remain vigilant and cognizant of the importance of metrics other than mass that may be necessary to unravel these complex dependencies and interactions.
Measurement of ultrafine particulate matter, either as a component of PM2.5 or as particulate matter that exists as the only component of PM2.5, is more difficult because of the small size of the particles.  Techniques that have been shown to work the best for measurement of these particles usually involve some sort of particle charging scheme where the particles flow through a region of molecular ions or where particles are charged directly, such as via irradiation by ultraviolet light or some combination of the different charging schemes.  But these techniques are generally more expensive or involve radionuclides that render the technique difficult to implement.
Recently, Airviz Inc. has embarked upon a pioneering research effort to use simple and well-known optical techniques to measure ultrafine particle surface and mass concentrations that can result in small and inexpensive devices that will usher in a new era of particulate measurement capability currently unavailable to the general populace.  In the envisaged end-unit device, which is expected to be smaller and more compact than the current Speck sensor, monitoring of mass and surface concentrations of ultrafine particles that exist by themselves or as a major/minor component of PM2.5 will become routine.  This capability will allow us to expand our knowledge of the role(s) that ultrafine particles play in producing negative health consequences and premature morbidity.  Just recently, for instance, a new study (see Ref. 5 below) indicated that for every increment in PM2.5 of 10 µg/m3 life expectancies can be reduced by as much as ten years.  This is a remarkable number but questions still remain as to how much of this increase could be ultrafine particles and/or do ultrafine particles dominate these statistics.  With improved measurement capabilities available to a wider spectrum of the population and a potentially much finer mesh for correlation of exposures, these questions may be finally answered. Stay tuned……

Article by Dave Litton, Senior Scientist at Airviz Inc.

Wednesday, May 31, 2017

Improve Indoor Air Quality by Avoiding Asbestos, Particulate Matter & Dust


Basic needs -- food, water, shelter, family, and good health are common essentials for survival and well-being. While expanding those necessities a bit this Clean Air and Breathe Easy month, we’re raising asbestos, particulate matter, dust and other air pollutant awareness to detail how and why air quality matters. Affecting billions of people globally every single day, air quality can often be the key to living your highest quality of life for the most number of years possible.

On average, people living in developed countries spend roughly 90% of their time indoors, either at home or in the workplace. Being aware and able to improve the quality of the air you breathe from the comfort of your own home or workplace can significantly benefit your health and quality of life. 

Asbestos Awareness

Have you ever even heard of asbestos? Very resistant to chemicals, electricity and water, asbestos is a naturally occurring fibrous silicate mineral. Due to its malleability and other desirable physical properties, it has been used in building materials including roofs, tiles, wall boards, cables, even paints and much more, for many years. It was not until the 1960s that researchers identified asbestos-related illnesses and cancer such as mesothelioma - affecting the lungs, abdomen, heart or testes. In fact, exposure to asbestos is the only scientifically proven cause of mesothelioma, taking the lives of 3,000 people each year in the United States alone.

But what does a mineral have to do with air quality and my health? Because asbestos is fibrous in nature and used in products likely to crumble or flake such as insulation, roofing and more, there are a number of ways to become exposed to asbestos. Generally speaking if asbestos is undisturbed, it is not harmful. However, when asbestos fibers are disturbed, they can become airborne and when inhaled or ingested, the fibers can lodge in the lining of the heart, abdomen, lungs and other areas of the body, causing health effects up to 10-50 years later.

Although asbestos is not used in new construction, it has yet to be banned in the United States today and if your home was built prior to 1980, it is possible that some building materials used to construct your home may contain asbestos. If you suspect asbestos in your home, do not sweep, use a fan or disturb the asbestos or the area you suspect that may contain asbestos. Have your home tested for asbestos and consider a Speck air quality sensor to stay informed of the changes and trends in your home’s air concentration.

Dust & Particulate Matter Awareness

When it comes to the day to day, is particulate matter harmful? Yes. Mixtures of microscopic solids and liquid droplets suspended in the air make up harmful fine particle pollution. Those with heart or lung disease, especially older adults and children are considered at greater risk. Particulate matter can specifically aggravate diseases including coronary artery disease, congestive heart failure, asthma or chronic obstructive pulmonary disease (COPD).

Any particles of matter, suspended in the are that are 2.5 micrometers in diameter, or smaller, (thirty times smaller than the diameter of a single human hair) are classified as fine particles, which can cause or worsen heart and lung diseases. Due to their small size they can penetrate deep into the lungs, blocking air sacs where oxygen enters the bloodstream or attaching to lung tissue where their reactive surfaces can adversely affect lung tissue. Airborne chemicals that are toxic and reactive can attach to PM2.5 and enter your bloodstream.

Where does particulate matter come from and how can I stay safe at home? Fine particles and particulate matter are produced by many sources including household activities such as cooking and cleaning. For example, gas and oil heating can release particulates. Pay attention to where furnace vents are or if you have an oil heater. Forced-air heating and air conditioning systems can be major sources of air pollution if the ductwork is dirty or if there are no filters in the system to filter out particles as they move throughout the house. Use HEPA filters with forced-air systems to improve indoor air quality.

If you’ve caged up, cleaned or thrown away your dust bunnies this Spring, give yourself a pat on the back, but don’t stop there. Learn more about air quality monitoring and fine particulate matter in indoor environments, to truly breathe easy this Clean Air month and stay up to date on the latest news and air quality announcements, year-round by following our Speck Sensor Facebook page.

Written by MAA Center

Questions on how to dispose of asbestos? can help!

Tuesday, January 31, 2017

Focus on COPD

Focus on Chronic Obstructive Pulmonary Disease (COPD):

Chronic Obstructive Pulmonary Disease (COPD) is a debilitating and potentially fatal condition affecting over 15 million Americans.  In 2008, chronic lower respiratory disease, of which COPD is the largest primary condition, became the third leading cause of death. This condition is found to be increasing globally with increased numbers of emergency room visits and hospitalizations due to exacerbations of the condition brought on by exposures to irritating gases and particulate matter.  In France alone, the national medical costs in 2012 attributable to COPD amounted to over 670 million euros, an increase of almost 11% since 2007.  In the U.S., the medical costs for COPD in 2010 were over $36 billion dollars.  And these numbers, as well as the number of persons afflicted with this condition, continue to rise.  Eighty percent of the deaths from COPD are attributable to smoking and approximately 60% of persons with COPD are former smokers or live in homes where someone is a smoker.  Clearly, smoking is a major factor in acquiring this disease but for almost 40% of sufferers, smoking was not the primary cause.  Persons living in areas highly polluted by industry or near major traffic areas experience higher than average affliction rates.
There is no cure for COPD and once the condition is diagnosed, the best that can be hoped for is that it can be managed in a manner that minimally affects everyday lives.  But knowing what might be the triggers for episodes, i.e., exacerbations, has been difficult to quantify.  Data that is available is very general.  For instance, persons living in areas that have higher than average pollution levels tend to be affected more readily than persons living in lower pollution areas. But these are very general observations.  What pollutant is responsible? Or is one pollutant more responsible than another and why?  Ozone is known to have an effect and there is a growing body of evidence indicating that fine particles, PM2.5, or their even smaller constituent, ultrafine particles with diameters less than 300 nm, may also play a major role.  Studies in the UK, as well as some studies being proposed for the U.S., hope to shed more light on this problem by tracking individual exposure levels on a daily basis in order to correlate exacerbations with pollutant exposures.
Knowing this type of information can have significant impact not only on reducing the number of emergency room visits and hospitalizations but also on improving the quality of life of persons that are affected.  Using inexpensive pollutant monitors in homes can alert persons to perform simple actions, like closing windows, increasing ventilation, turning on air cleaners, or even replacing furnace and AC filters that can reduce pollutant level and decrease exposures that could have led to exacerbations and the subsequent consequences.  Even though there is still much work to be done to pinpoint and quantify those factors that produce adverse COPD reactions, the outlook is hopeful that these studies can have a major impact on reducing the devastating consequences associated with this condition.

A wealth of additional information can be found on the COPD Foundation website,  One of the more comprehensive COPD health care systems is operated by National Jewish Health located in Denver, CO,, and locally in the Pittsburgh, PA area UPMC maintains a Center for COPD and Emphysema,, and Allegheny Health Network (AHN) has recently established a Breathing Disorders Center,   
Additionally, links to some current and relevant research on this problem can be found below, as well as a link to a peer review journal dedicated to COPD….