Sunday, April 26, 2015

Blog #12: Opinion Piece

Opinion Piece: Blogging as a learning tool

I’ve personally have never taken a class like this, having to blog about the topics discussed in class and most cases go a step farther and learn more on the given topic. In my experience it led to some interesting finds. W topics are as general as Botox, I found myself learning a lot more than I would have thought on the subject. This is really more of an evaluation of my experiences with blogging as a learning tool. 
For me, almost every topic we were given to blog about was interesting, the information I found was usually varied applying to different fields that may or may not have been related to industry. A lot of times I had to condense information, usually limiting my posts to 300 words. Personally I found it hard to write on the topics at times, because while I'd research the topics picking and choosing what to put in my blog was hard. Other times I found the topic was very broad and spectrum of information I found even broader.
I can really only speak for myself and students like me, but blogging as a way to reinforce topics learned in class or just increase general knowledge on a subject, I think is very effective. My main reasons being, for students like who genuinely enjoy learning new things at their own pace, will probably like blogging as a learning tool. I liked it because I got to really learn more about the topic from varying and diverse sources, and usually going off topic to learn about other relating subjects
The only limitations I can really mention is the resources students use when researching topics, limiting viable sources to certain trusted and verified databases, sites and or online libraries will probably be necessary in the future for widespread and effective use of blogging as a learning tool. 

Sunday, April 19, 2015

Post #10 : WBGT

Because i'm a procrastinator who procrastinates:
I have no idea what happened but i don't have Tuesdays blogging topic. I was there but somehow i didn't write it down i don't know how that happened, could you please tell me it? I just realized i didn't have last Tuesdays (blog 10 topic) so sorry its so close to the deadline. I have Thursdays (penetration vs permeation) though.
- Sent Sun 4/19/2015 8:48 PM to Samuel Moss

-Update:

Blog #10 = WBGT


“Wet Bulb Globe Temperature (WBGT) is a measure of the heat stress in direct sunlight, which takes into account: temperature, humidity, wind speed, sun angle and cloud cover (solar radiation). This differs from the heat index, which takes into consideration temperature and humidity and is calculated for shady areas. If you work or exercise in direct sunlight, this is a good element to monitor. Military agencies, OSHA and many nations use the WBGT as a guide to managing workload in direct sunlight.”
- http://www.srh.noaa.gov/tsa/?n=wbgt

“Body temperature increases not only when the temperature is high, but also when there is high humidity, which makes it difficult for sweat to evaporate. Also, the temperature felt by the body changes just by avoiding direct and reflected sunlight. -- Since it is easy to develop heat disorders when the WBGT is high, this index is used to prevent heat disorders at work sites, sporting activities, and in everyday life.”
- https://www.otsuka.co.jp/en/health_illness/heatdisorder/care_12/

In the late 1950s, at the US Marine Corps Recruit Depot on Parris Island in South Carolina, there was a significant number of casualties due to heat stroke from the high heat and humidity of the training locations. Consequentially the Department of the Navy commissioned a series of studies on the effects of heat on work and exercise performance. The result was a heat index called the “Wet Bulb Globe Temperature” (WBGT). Later it was used by researchers as an easily measured general heat-stress index, and over time has become used in workplaces and sporting situations.

The WBGT is measured by a three-temperature element device:

The natural wet-bulb temperature abbreviated, ‘Tw’ includes a thermometer with a bulb covered by a wet cotton wick, and the distilled water is supplied from a reservoir. The cotton wick will always be wet, allowing for continuous cooling of the thermometer's bulb due to evaporation, simulating the process of human sweat. The natural wet-bulb thermometer is not protected from wind or radiation. Representing the effects of radiation, wind and humidity.

The black globe temperature abbreviated, ‘Tg’ usually consists of a six inch black globe with a thermometer located at the center. The black globe temperature represents the effects of radiation and wind.

The (shade) air temperature abbreviated, ‘Ta’ which is mainly a thermometer which is shielded from radiation - usually by being placed in a weather screen. This the standard temperature that is generally quoted in weather observations and forecasts.

When calculating the three elements Tw, Tg, and Ta are combined into a weighted average to produce the WBGT.

Two different methods are used to calculate WBGT in the workplace: one for workplaces with direct sunlight, and the other for workplaces without direct sunlight. When conditions of an area fluctuate widely, a time-weighted WBGT is often used.

WBGT = (0.7 × Tw) + (0.2 × Tg) + (0.1 × Ta)
Indoors, or when solar radiation is negligible:
WBGT = (0.7 x Tw) + (0.3 x Tg)

Post #11 Permeation vs. Penetration Protective Gear

Blog #11 - Permeation vs. Penetration Protective Gear

"The selection of any protective garment is complicated and carries the potential for serious consequences should the decision prove to be incorrect or the selection in any way inadequate. For this reason, standards bodies, vendors, customers, and workers are engaged -- often in the pages of this very magazine -- in ongoing conversations to determine the appropriate levels of protection for a given task.

In the area of liquid chemical protection these conversations often center around two alternate methods for testing garments—permeation and penetration. Often these approaches to evaluating chemical barrier protection are treated as being equally appropriate. This approach, however, is overly simplistic and rarely considers the strengths and deficiencies of each test.

Fundamentally, there is much that is not known regarding how a wide variety of chemicals react against skin to accept a compromised testing approach. At their core, all safety personnel know that what is unknown is, by definition, unsafe. With that principle in mind, a thorough investigation of what penetration and permeation tests are, and what they can achieve, should prompt safety managers to re-evaluate how they source chemical protection garments.
In the science of chemical protective clothing, the terms permeation and penetration represent very different mechanisms of chemical protection."
- http://ohsonline.com/Articles/2008/07/Permeation-vs-Penetration.aspx

"Penetration - is the flow of chemicals and micro-organisms through the porous material, seams, small holes or other small defects in a material.
Permeation - is the process where a chemical passes through material on a molecular level. Permeation means the following: a chemical’s molecules penetration through the outer material. Diffusion is the movement of molecules through the material. Desorption is the outward flow of molecules from the inside."
- http://www.guide.eu/en/info/EN/en374.html

When we talk about chemical protective clothing, penetration is the how a chemical passes through a pore or opening in the barrier material. Permeation is the how absorption and diffusion of a chemical occurs through the barrier material at the molecular level.
Factors that affect penetration:
The size of the particle
The size of the pores/openings in the fabric
How open the fabric structure is, this makes it more likely a particle will be able to penetrate a given fabric.
Permeation tests, usually test for hazardous liquids and or vapors. Critical factors that influence permeation:
The challenging chemical e.g. the concentration, the temperature, the surface tension, the size of the molecules.
The makeup of the barrier material
The exposure time
Physical factors like the 'ambient' temperature as well as pressure
The Permeation rate is the rate which the chemical will move through the material. It is measured in a laboratory and is expressed in units like milligrams per square meter per second (or some other [weight of chemical] per [unit area of material] per [unit of time]). The higher the permeation rate, the faster the chemical will move through the material.

Permeation testing usually deals in very small quantities; the measured “Normalized Breakthrough” which is the time it takes to achieve a PERMEATION RATE (through a given fabric) of 0.1 or 1,0 * µg / minute / cm2. (1 µg or 1 Microgram is 1 millionth of a gram).

Penetration testing deals in larger amounts, the breakthrough being measured at the point at which a “visible” breakthrough of the chemical is seen.

The 'Breakthrough' time is time it takes a chemical to permeate completely through the material. This is determined by applying the chemical on the glove exterior then measuring the time it takes to identify the chemical on the inside surface. The sensitivity of the instruments used in these measurements determine when a chemical is first detected. The breakthrough time gives an estimate of how long a glove can be used before the chemical will permeate through the material.

'Degradation' is a measure of the physical deterioration of the material due to contact with a chemical. The material may get harder, stiffer, more brittle, softer, weaker or swell. Worst case scenario the material dissolves in the chemical.



Sunday, April 12, 2015

Blog #9 Units of Exposure and Biological Effects

Blog 9: Units of Exposure and Biological Effects

“Ionizing radiation is emitted when radioactive substances decay. Radioactive decay occurs when the nucleus of an atom spontaneously decays by emitting a particle (an alpha particle, an electron, or one or more neutrons).

The four forms of ionizing radiation are alpha particles, beta particles, gamma rays, and, indirectly, neutrons. All have enough energy to ionize atoms, in other words, remove one or more of the atom’s electrons.”
-    http://ieer.org/resource/classroom/measuring-radiation-terminology/

“Beyond certain thresholds, radiation can impair the functioning of tissues and/or organs and can produce acute effects such as skin redness, hair loss, radiation burns, or acute radiation syndrome. These effects are more severe at higher doses and higher dose rates.”
-    http://www.who.int/mediacentre/factsheets/fs371/en/

There are four measures of radiation commonly encountered when dealing with the biological effects of Ionizing Radiation. Exposure, Dose, Dose Equivalent, and Dose Rate.

Exposure:  measures the strength of a radiation field, the roentgen aka ‘R’ indicates the degree of ionization a particle is capable of producing.

Dose or Absorbed Dose:  The dose is the amount of radiation absorbed by an object. Measured in ‘Gy’ (gray), however the ‘rad’ (Radiation Absorbed Dose) is more commonly used. 1 rad is equal to 0.01 Gy. Different materials can absorb the same amount of radiation differently. In the case of human tissue, one Roentgen of gamma radiation results in one rad of absorbed dose.

Dose Equivalent:  The dose equivalent draws a comparison to the absorbed dose and the resulting biological effects. The absorbed dose of specific types of radiation is then multiplied by a "quality factor" to get the dose equivalent. Measured in SV (sievert), but the rem ‘roentgen equivalent in man’ is more commonly used. One rem is equivalent to 0.01 SV. When exposed to X- or Gamma radiation, the quality factor is 1.

Dose Rate: Measure the rate radiation dose is received. Dose rate is usually depicted in terms of R/hour, mR/hour, rem/hour, mrem/hour, etc.


People are exposed to natural sources of ionizing radiation, such as in soil, water, vegetation, and in human-made sources, such as x-rays and medical devices. Ionizing radiation has many beneficial applications, including uses in medicine, industry, agriculture and research. Low doses of ionizing radiation can increase the risk of longer term effects such as cancer.

Biological effects of RAD:
0-25 No observable effect.
25-50       Minor temporary blood changes.
50-150 Nausea and vomiting and reduced WBC.
150-300 Increased reaction of above as well as diarrhea, malaise, loss of appetite even death.
300-500 Increased reaction of above and hemorrhaging.
500+
Cancer, leukemia, cataracts, and miscarriage. Genetic effects to children of exposed persons will occur and almost always harmful. Organs like lymphocytes, bone marrow, gastro-intestinal, gonads, and other fast-growing cells will be damaged by the exposure.

Blog #8 Radon Testing

Blog 8: Radon testing

“Radon is estimated to cause about 21,000 lung cancer deaths per year, according to EPA's 2003 Assessment of Risks from Radon in Homes (EPA 402-R-03-003). The numbers of deaths from other causes are taken from the Centers for Disease Control and Prevention's 2005-2006 National Center for Injury Prevention and Control Report and 2006 National Safety Council Reports.”
-                        http://www.epa.gov/radon/pubs/citguide.html#overview

“The average national indoor radon level is 1.3 pCi/L. The average indoor radon levels of Athens County, as determined by radon test results from Air Chek, Inc, is 5 pCi/L”
-                       http://county-radon.info/OH/Athens.html  

Radon is a radioactive gas. It is colorless, odorless and tasteless. Unless you test for it, there is no way of telling how much is present. Formed by the radioactive decay of uranium in rock, soil, and water. Once emitted, radon moves through the ground to the earth’s surface and air. Some remains below the surface and dissolves in water under the ground's surface. Radon has a half-life of four days.

Typically moving up through the ground to the air above and into one’s home the radon is then trapped inside, where it may build. The only sure way to know if radon is present is get tested. One important factor leading to Radon exposure in the home are homes with basements that are used as living spaces.

Radon gets into living spaces through:
Water supply like wells
Gaps around service pipes
Cracks in solid floors
Cavities inside walls
Construction joints
Cracks in walls
Gaps in suspended floors

There are two general ways to test for radon, ‘Short-term testing & Long term testing’:

“The quickest way to test is with short-term tests. Short-term tests remain in your home for two days to 90 days, depending on the device. "Charcoal canisters," "alpha track," "electret ion chamber," "continuous monitors," and "charcoal liquid scintillation" detectors are most commonly used for short-term testing. Because radon levels tend to vary from day to day and season to season, a short-term test is less likely than a long-term test to tell you your year-round average radon level.  Long-term tests remain in your home for more than 90 days. "Alpha track" and "electret" detectors are commonly used for this type of testing. A long-term test will give you a reading that is more likely to tell you your home's year-round average radon level than a short-term test.”
-                         http://www.epa.gov/radon/pubs/citguide.html#overview

A picocurie (pCi) is a measurement used to show the rate of radioactive decay of radon. One pCi is one trillionth of a Curie, 0.037 disintegrations per second, or 2.22 disintegrations per minute. The average indoor radon level is about 1.3 pCi/L, and around 0.4 pCi/L of radon is normally found in the outside air. Most homes can have their indoor radon levels reduced to 2 pCi/L or below.

A primarily used system to mitigate radon levels is a soil suction radon reduction system. Consisting of a vent pipe system and fan, which pulls radon from beneath the home and then vents it outside. This usually does not require any major changes to your home. Sealing foundation cracks and other openings makes this system more effective and cost-efficient. Other systems exist that may work better in your home. The right system depends on the design of the home and other factors.


Sunday, April 5, 2015

Blog #7 Preventing noise induced hearing loss with hearing protection

Blog 7: Preventing noise induced hearing loss with hearing protection 

The ear has three main parts: the outer, middle, and inner ear. The outer ear which is the part you can see leads into the ear canal. The eardrum separates the ear canal from the middle ear. Small bones in the middle ear help carry sound vibrations to the inner ear. The vibrations become nerve impulses, which the brain then translates to the sounds we hear like music, voices, and so forth.

Loud noises kill the nerve endings in the inner ear. Constant exposure to loud noise destroys nerve endings giving them no time to recover and a result, the number of nerve endings decrease along with your hearing. There is no known way to bring back dead nerve endings; this damage is permanent, along with the hearing loss.

“Noise is one of the most common causes of hearing loss, and one of the most common occupational illnesses in the United States. A single shot from a large caliber firearm, experienced at close range, may permanently damage your hearing in an instant. Repeated exposures to loud machinery may, over an extended period of time, present serious risks to human hearing.”

Sound is measured in decibels. Sounds of less than 75 decibels, even after long exposure, usually don’t to cause hearing loss. However, long or repeated exposure to sounds at or above 85 decibels can cause hearing loss. The louder the sound, the shorter the amount of time it takes for NIHL to happen.

Some average decibel ratings of everyday sounds:
-    Firecrackers and firearms - 150 decibels
-    Sirens - 120 decibels
-    An MP3 player at maximum volume - 105 decibels
-    Motorcycles - 95 decibels
-    Noise from heavy traffic - 85 decibels
-    Normal conversation - 60 decibels
-    The hum of a refrigerator - 45 decibels

“Habitual exposure to noise above 85 dB will cause a gradual hearing loss in a significant number of individuals, and louder noises will accelerate this damage. For unprotected ears, the allowed exposure time decreases by one half for each 5 dB increase in the average noise level. For instance, exposure is limited to 8 hours per day at 90 dB, 4 hours per day at 95 dB, and 2 hours per day at 100 dB. The highest permissible noise exposure for the unprotected ear is 115 dB for 15 minutes per day. Any noise above 140 dB is not permitted.”

Hearing protectors like earmuffs or earplugs decrease the intensity of sound. Earplugs are small inserts that fit into the outer ear canal. Effective earplugs totally block the ear canal with an air-tight seal. Earmuffs fit over the entire outer ear forming an air seal. Effective earmuffs must be snugly sealed covering the entire circumference of the ear canal.

Earplugs or muffs can reduce noise by 15 to 30 dB of sound. However, earplugs are better protection against low frequency noise like a jackhammer, and earmuffs are better protection against high frequency noise like the sound of an airplane taking off. Simultaneously using earplugs and muffs can add 10 to 15 dB more protection than using either alone. Combined use should be considered when noise exceeds 105 dB. 

Blog #6 Preventing occupational skin damage/injury

Blog 6: Preventing occupational skin damage/injury

The skin is the largest organ in the human body, with an average length of 2 square meters when stretched out, accounting for 15 percent of the human bodyweight. The skin has three layers epidermis, dermis and subcutis.

 “Your skin performs a range of different functions which include physically protecting your bones, muscles and internal organs, protecting your body from outside diseases, allowing you to feel and react to heat and cold and using blood to regulate your body heat.”

Occupational skin diseases are some of the most common occupational diseases reported. Occupational skin disease are separated into three groups. Irritant contact dermatitis, allergic contact dermatitis, and other occupational skin diseases.

“The following occupations account for 80% of reported occupational skin disease in developed countries in Europe; most involve wet working conditions, which commonly results in contact dermatitis.

-    Hairdressing/ beauty therapy
-    Food industry
-    Health care including dental and veterinary workers
-    Agriculture including gardeners and florists
-    Cleaning
-    Painting and decorating
-    Motor vehicle repair
-    Construction
-    Printing
The sites affected by occupational skin disease depend on exposure. About 80% of patients with occupational skin disease present with hand dermatitis.”

Irritant contact dermatitis develops because of constant and prolonged exposure to ‘weak’ irritants like water or soap. When exposed to more severe skin irritants such as heavy metals while rare, the reactions are usually more serious.

Allergic contact dermatitis develops when one is exposed even minimally to antigenic substances, these are substances that evoke an immune response. This includes plants like poison ivy, nickel, and acrylics. If a rash appears at the point of contact, is likely to be very red, blistering, and a case severe swelling.

Other occupational skin diseases include, oil acne and folliculitis. Which develops when one is constantly exposed to solvents and lubricants. Occupational skin neoplasm aka skin cancer develops when one is exposed to polycyclic hydrocarbons, inorganic metals, and arsenicals. Symptoms may not be visible until two or three decades after the exposure.

Occupational skin diseases can be prevented by,

-        Educating employees, Employers should make sure employees are aware of the hazards of the substances which they are exposed to and how to use them safely.

-        Making washing facilities like showers and bathrooms with hot water, disposable towels and mild soap more accessible to all employees.

-       The use of local exhaust ventilation systems and enclosures to separate employees from the harmful substances that they use or come in contact with.

-        Protective gear and clothing, like gloves, aprons, barrier creams and skin cleansers. Not all protective gear resists all substances. Employers should pay attention to the manufacturers' specifications.


Finally, Employers and employees should continually make sure to identify possible work hazards and the risks of exposure. When a hazard cannot be eliminated, it should be minimized. When possible choosing less harmful chemicals to do the same job, and rotate tasks to reduce individual exposure. This should be an on-going process that responds to changes in the workplace.