Local Exhaust Ventilation

What is Local Exhaust Ventilation? Why do we use it?

   Local exhaust ventilation is a way to remove any contaminates in the air away from an individual's breathing zone.  These machines take away a large part of the hazardous particles so that the workers can do their job safely.  Without this equipment, the employees are being exposed to harmful materials that can cause major health problems.  What's different about this type of ventilation is that the contaminates are being removed directly from the source.  They are being contained or stored and then discarded properly.  Local exhaust ventilation is one of the many ways to remove vapors, mists, dusts, and other hazardous particles from one's breathing zone. Although these are very effective, they have to be used properly to work the way that they are designed to work.  Failure to correctly use these machines, can lead to damage of the worker's health.  The most important thing is to make sure that the workers have proper training and understand how to effectively use these machines.

How does it work?

   There are five main parts on local exhaust ventilation systems: hood, duct, air cleaner, fan, and stack.  Initially, there has to be a contaminate that the ventilation system will interact with.  The contaminate first travels through the hood.  The hood is where the contaminate is first captured from the source.  The next location for the contaminate is the duct.  The duct is where the air travels through the system to the step.  The duct is then connected to the air cleaner.  The air cleaner, as it sounds, is where the air is cleaned of contaminates. After it flows through the air cleaner, the fan propels the air through the next step, the stack.  The final step of ventilation is where the cleaned air is now ready to be put back into a safe environment through the stack pipe.  This process is the way that air is removed, cleaned, and then reintroduced into the environment.  The local exhaust ventilation system is a very effective way to remove hazardous air from a specific emission location.  

Sources:

  Center for Occupational Health and Safety

     http://www.ccohs.ca/oshanswers/prevention/ventilation/introduction.html

  Health and Safety Authority 

 http://www.hsa.ie/eng/Publications_and_Forms/Publications/Occupational_Health/Local_Exhaust_Ventilation_LEV_Guidance.pdf

Particulate Matter

What is particulate matter?

   Particulate matter is a combination of solid and liquid pieces found in the air.  These tiny pollutants can range in size, shape, origin, and effects.  The sizes can range from 10 micrometers down to 2.5 micrometers.  These are particles that can be inhaled into the respiratory system.  Depending on the size of the particle, determines how far into the respiratory system the particles travel.  These particles can come from many different places.  They all have different origins, ranging from forest fires and smokestacks to construction and car emissions.  No matter where you are, there are bound to be particles in the air that you are inhaling.  Every time you breathe, you are adding more pollution and particles into your respiratory system.  Over exposure to the inhalation of these particles poses seriously health risks for the community.  Not only does it affect society now, but it affects future generations as well.

How does it affect my health?

   Due to the constant inhalation of these particles, they start to have an adverse affect on the human health.  The different sizes of the particles change how far they can lodge into the respiratory system, which in turn results in different health effects.  The smaller the particle, the more damage it can have on an individual's health.  Some particles can cause irritation to the airways, which results in coughing, sneezing, and difficulty breathing.  This can lead to their lungs slowing down and not functioning properly.  The list continues with bronchitis, asthma, irregular heartbeat, mild heart attacks, and even cancer.  Not only does the particulate matter affect you, but it can also affect mortality rate of children.  Air pollution due to particulate matter causes about 800,000 premature deaths each year.  The young children don't have a strong respiratory system yet, which increases the hazard of any particulate matter entering their airways.  Not only does it severely affect young children, but also the elderly have a higher risk as well due to a low respiratory system.  Overall, particulate matter is a very serious topic that affects everyone.  We are so use to breathing because it's automatic, that we don't even think about what particles we are breathing in and how they affect our bodies.  

Sources:

  United States Environmental Protection Agency

     http://www.epa.gov/airscience/air-particulatematter.htm

  National Library of Medicine

     http://www.ncbi.nlm.nih.gov/pubmed/22194192

  Spare the Air

     http://www.sparetheair.org/Stay-Informed/Air-Quality-and-Your-Health/PM-Health-Effects.aspx

Wheatstone Bridge

What is a Wheatstone Bridge?

  The Wheatstone Bridge is a tool used to measure the resistance through the use of an electrical circuit.  It was first invented in 1833 by Samuel Christie, but was later improved by Charles Wheatstone.  The device was named after Wheatstone later in 1834.  The original purpose of this device was to compare and analyze soil, while today it is used for many other purposes than soil analysis.

How does it work?

  The Wheatstone Bridge is powered by a battery.  The whole premise of the device is through comparison.  A comparison of the change in the amount of conductivity between that of a known substance to that of an unknown sample of air.  There are sensors in the device that are coated with a catalyst.  The catalyst then reacts with the combustible gas to generate heat. This change in temperature causes a difference in the circuit conductivity. This difference in conductivity is then proportional to the amount of gas present.

How is it used in air sampling?

  Even though the methods were explained above, a more specific use for this tool is for air sampling. One specific situation is for the measurement of oxygen present in the air.  The device is not limited to only measuring oxygen, but this is one of the many common uses.  A magnet surrounds the filament, with the air sample in the device.  Due to the nature of oxygen, it is attracted to the magnetic field in the apparatus.  The air sample is then heated which makes oxygen loose its charge.  This forces the oxygen out of the previous magnetic field.  After that filament is cooled down, there is a voltage that is the output of the Wheatstone Bridge.  This voltage is proportional to the level of oxygen that was in the measured sample.  Oxygen is just one of the many gases that can be detected in a sample through the use of a Wheatstone Bridge.  Other gases that can be identified are mercury vapor, NO2, NO, carbon monoxide, and other combustable gases. Overall, this is a very effective way to measure levels of gases in the air. 

Sources:

  Basics of Industrial Hygiene 

     page 132-133

  Bright Hub Engineering 

     http://www.brighthubengineering.com/commercial-electrical-applications/53492-how-to-find-unknown-resistance-using-wheatstone-circuit/

  Indoor Air Quality Engineering: Environmental Health and Control of Indoor Pollutants 

     page 190-191

  

Respiratory Diseases

What is a Respiratory Disease?

   The respiratory system is divided into two parts: the upper airway passage and the lower airway passage.  The upper passage includes the nose, mouth, and larynx.  The lower passage includes the area from the vocal cords down to the alveoli in the bronchial tree.  There are many different types of respiratory diseases that effect different levels of the respiratory system.  Common diseases include cancer, bronchitis, pneumonia, emphysema, asthma, cystic fibrosis, etc.  These diseases are all caused by the inhalation of some form of toxin.  Although some of the particles may not be dangerous in small amounts, overexposure could lead to detrimental health affects. 

How do particles get into the lungs? Why does size matter?

  The top way that particles from the environment get into the respiratory system is through inhalation.  This is something that humans rely on to survive, even though it's the transport of many diseases.  The overall idea is that the smaller the particle, the higher the chance it has to get deeper into respiratory tract.  The larger particles tend to camp out in the nose and mouth due to size and the fact that they are too large to travel farther.  These large particles range from about 2.5 to 10 microns.  The reason that we cough or sneeze is to get these particles out of our system and keep them from adventuring further.  The tiny particles have the ability to get further into the lung and have a more harmful affect.  The deeper these particles get within the respiratory system, the harder they are to get out of the system.  These small particles range from about 2.5 to 0.1 microns.  Those particles that are smaller than 0.1 microns have the ability to enter the blood stream which affects the whole body, not just the respiratory system.  

How do I avoid respiratory diseases?

   There are many ways to avoid these horrible diseases.  Many of the precautions that can be taken include avoiding places with large amounts of dust or wearing protective gear.  Avoiding the places with large amount of airborne toxins is the best way to ensure that the contact you have with the particles is minimal.  If the particles are present on a job site where you can't avoid them, the next best thing to do is to wear protective gear such as masks or ventilators.  The main thing that you can do to protect your health is to stay informed and educated.  Be aware of your surroundings and know what is or could be harmful to your health.  

Sources:

  Canadian Centre for Occupational Health and Safety

     http://www.ccohs.ca/oshanswers/chemicals/how_do.html

  American Lung Association

     http://www.stateoftheair.org/2013/health-risks/health-risks-particle.html

  Minnesota Department of Health 

     http://www.health.state.mn.us/divs/eh/air/pm.htm

  Occupational and Environmental Lung Disease

     http://www.agius.com/hew/resource/lung.htm

Botox

What is it? 

   Botulinum Toxin, also known as Botox, is a protein that is produced by Clostridium botulinum bacteria.  It is one of the most powerful neurotoxins discovered so far.  Clostridium botulinum is a bacteria that does not need oxygen to grow, which means in can grow in more places than we think.  Even boiling the bacteria does not get rid of all of the toxic cells.  In large doses, it is lethal to humans.  Yet, 6 million Americans each year choose to inject this toxin into their skin to get rid of wrinkles.

What is it used for?

   Not only is Botox used for reduction of wrinkles, it is also used to treat muscle spasms and migraines.  The Botulinum Toxin is injected into the muscles, which impacts the nerves and paralyzes them.  The injections tend to last 4-6 months, and then more injections are necessary to keep the desired effects.  Although Botox is injected into a certain area, it does have the capability of spreading to nearby regions.  Many patients tend to love the cosmetic affect of this toxin, while others, such as those with migraines, rely on it to function.  The repeated injections of this toxin may cause harm to the body due to the fact that it is foreign and unnatural in the human body.

How does it work?

   After Botox is injected into the muscle, it blocks the nerve signals to other muscles that tell them to contract.  This in turn paralyzes the muscles and inhibits communication. Therefore, if the muscles don't tense up, wrinkles are not formed.  The solution that is injected into the muscles consists of a mixture of Botulinum Toxin and a saline solution.  The concentration of the Botox is around .75 nano-grams per 100 units.  The amount that is injected in each area stays the same and is constant through all of the visits.  In each visit, one tends to get between 5 and 10 injections at a time.  It make take up to a week to notice the effects of the injections.  Overall, Botox is a toxin, so it is very important to make sure that all precautions are taken to ensure health and safety.

Sources:
  LabSpaces
     http://www.labspaces.net/blog/1566/The_deadly_neurotoxin_that_is_Botox
  WebMD
     http://www.webmd.com/beauty/botox/botulinum-toxin-botox
  Family Doctor
     http://familydoctor.org/familydoctor/en/drugs-procedures-devices/procedures-devices/botulinum-toxin-injections-a-treatment-for-muscle-spasms.html
  All About Vision
     http://www.allaboutvision.com/cosmetic/botox.htm