CHAPTER II
REVIEW OF RELATED LITERATURE AND STUDIES
Petrolatum (also known as petroleum jelly or paraffin jelly) can be defined as a
semisolid mixture of hydrocarbons obtained through the dewaxing of heavy mineral oils.
Petrolatum is a complex mixture of hydrocarbons derived from the distillation of
petroleum. Hydrocarbons are compounds that contain only carbon and hydrogen. The
hydrocarbons that make up petrolatum belong to the methane (saturated or alkane) family
of hydrocarbons with the general formula CnH2N+2. Petrolatum is also a product of the
fractional distillation of crude oil. (Gale T., 2008)
Petroleum jellies ranges in color from white to yellowish to amber. It is
practically odorless and tasteless, oily liquid. It melts over a wide range, from about 38°C
to
about
55°C
(100°F
to
131°F).
It
is
in dichloromethane, chloroform, benzene, diethyl
insoluble
ether,
in
carbon
water
but
soluble
disulfide and
oil
of turpentine (“Petroleum Jelly”; Wikipedia, 2011).
Petrolatum is an example of a colloid; a hydrocolloid. A hydrocolloid is defined
as a colloid system wherein the colloid particles are dispersed in water. A hydrocolloid
has colloid particles spread throughout water (H2O). Hydrocolloids can be either
reversible (when the physical condition of the hydrocolloid is changed by temperature) or
irreversible (when the physical condition of the hydrocolloid is not changed by
temperature). Other examples of hydrocolloids include xanthan gum, gum Arabic, guar
gum, locust bean gum, cellulose derivatives as carboxymethyl cellulose, alginate and
starch (“Colloid”; Wikipedia, 2011). They can be simply defined as a substance that
forms a gel in contact with water.
Hydrocolloids are a special type of colloids. Colloids are a type of mixture A
colloid is composed of two phases namely, dispersion medium and dispersed phase.
Colloids are the mixtures in which dispersion phase is evenly distributed in the dispersion
medium. Colloidal system can be solid, liquid or gaseous. Colloidal systems and their
study were introduced by a Scottish scientist Thomas Graham (TutorVista.com, 2010).
Colloids have the appearance of solutions. One property of colloid systems that
distinguishes them from true solutions is that colloidal particles scatter light. If a beam of
light, such as that from a flashlight, passes through a colloid, the light is reflected and
scattered by the colloidal particles and the path of the light can therefore be observed
(The Columbia Electronic Encyclopedia 6th ed., 2007).
When a beam of light passes through a true solution, there is little scattering of the
light that the path of the light cannot be seen and the small amount of scattered light
cannot be detected except by very sensitive instruments. The scattering of light by
colloids, known as the Tyndall effect, was first explained by the British physicist John
Tyndall in 1869. Some colloids are translucent because of the Tyndall effect, which is the
scattering of light by particles in the colloid. Other colloids may be opaque or have a
slight color (The Columbia Electronic Encyclopedia 6th ed., 2007).
When an ultra microscope is used to examine a colloid, the colloidal particles
appear as tiny points of light in constant motion. This motion, called Brownian
movement, helps keep the particles in suspension.
Absorption is another characteristic of colloids, since the finely divided colloidal
particles have a large surface area exposed. The presence of colloidal particles has little
effect on the colligative properties of a solution. (The Columbia Electronic Encyclopedia
6th ed., 2007)
Petrolatum occurs in a semi-solid or liquid form. The semi-solid form is also
called petroleum jelly or mineral jelly and is commercially available under a number
of trade names, including Kremoline, Pureline, Sherolatum, and Vaseline™. The liquid
form is also known as liquid paraffin, mineral oil, or white mineral oil; such products are
sold commercially under trade names such as Alboline, Drakeol, Frigol, Kremol, and
Paroleine (Chemical Compounds, 2008).
The beneficial properties of petroleum jellies for skin care and treatment have
been extensively reported (Morrison, 1996). Petrolatum has a wide variety of uses,
ranging from personal care and medical applications to industrial uses. The solid form,
such as Vaseline™ is used as a topical ointment for the treatment of dry, cracked skin and
to reduce the risk of infection. (Gale T., 2008). However, the use of petrolatum can cause
some adverse effects. The prolonged use of petroleum can block off the skin’s pores
resulting in a thick layer of jelly that covers the skin and also lead to the formation of
another layer that mostly comprises secreted toxins, and this second layer leads to the
complications like acne, skin irritation, dryness, and other diseases. It can also cause
diarrhea, shortness of breath, abdominal pains, and irritation in the eyes, skin, and nose.
Petrolatum is also noted as a possible cancer risk, breast cancer to be specific
(“Petroleum Jelly Possible Cancer Risk”; Green and Chic, 2008)
Air is a combination of many gases, each one having its own physical properties,
in which varying amounts of tiny solid and liquid particles are suspended. Air is made up
of 78.084% Nitrogen, 20.946% Oxygen, 0.934% Argon, 0.038% Carbon Dioxide, and
trace gases like Neon (0.00182%), Helium (0.000524%), Methane (0.00015%), Krypton
(0.000114%), and Hydrogen (0.00005%). Water vapor, ozone, and aerosols (tiny
suspended solid and liquid particles in the air) are variable components of air (Tarbuck &
Lutgens, 2009).
Air quality, as Wikipedia (2011) defines, is the “measure of the condition of air
relative to the requirements of one or more biotic species and/or to any human need or
purpose” (“Air Quality”; Wikipedia, 2011). The measure of air quality means the
measurement of the pollutants in the air (“Air Quality”; Dictionary.com, 2011). Bad air
quality means there are a lot of air pollutants in the air which include fine particles.
Dr. Sarath Guttikunda said in a blog published in 2007 that Air Quality Index
(AQI) is an ‘index’ determined by calculating the degree of pollution in the city or at the
monitoring point and includes five main pollutants - particulate matter, ground-level
ozone, sulfur dioxide, carbon monoxide and nitrogen dioxide. Each of these pollutants
have an air quality standard which is used to calculate the overall AQI for the city.
Simultaneously, one can also establish the limiting pollutant(s), resulting in the
estimating AQI. Government agencies use the AQI to characterize the quality of the air at
a given location.
In numbers, AQI is represented between 0 to 500 with 0 representing good air and
500 representing hazardous air. For better understanding and presentation, the AQI is
broken down into six categories, each color coded with the number scale.
Good (green) is for numbers 0 through 50 and means satisfactory air quality.
Moderate (yellow) is 51-100 and is for acceptable air quality. Unhealthy for Sensitive
Groups (tan) is 101-150 and means sensitive individuals with sensitive skin may be
affected. Unhealthy (red) is 151-200 and almost everyone may experience problems.
Very unhealthy (pink) 210-300 is a health alert, where everyone may have health
problems. Hazardous (purple) over 300 numbers may contribute to emergency health
problems and will affect most people.
There are units used to measure air quality. Parts per million (ppm), parts per
billion (ppb), micrograms per cubic meter (/m3), and soiling index (also known as
coefficient of haze, COH) are common means of reporting air quality measurement
(Environment Software and Services Austria, 2011).
When harmful substances are introduced to the air, the AQI increases (worsens),
meaning that the air is polluted. Air pollution occurs when the air contains gases, dust,
fumes or odor in excess and harmful amounts. These amounts could be harmful to the
health and could cause damage to plants and materials. According to EPA Victoria in an
article published in 2006, air pollution has now been one of theg major problems faced by
every country worldwide. Air pollution contains air pollutants that mainly occur as a
result of gaseous discharges from industry and motor vehicles. There are also natural
sources such as wind-blown dust and smoke from fires. Some forms of air pollution
create global problems, such as upper atmosphere ozone depletion and global warming.
These problems are very complex, and require international cooperative efforts to find
solutions (EPA Victoria, 2006).
In article published in 2010, Sevier states that the polluted air contains five main
pollutants that can cause health effects. They are carbon monoxide (CO), oxides of
nitrogen (NOx), VOCs (Volatile Organic Compounds) and ozone, sulphur dioxide, and
fine particles.
Carbon monoxide is a poisonous gas produced mainly by petrol engines; it
damages respiratory and circulatory body functions and reduces oxygen supply to major
organs including the heart. Oxides of nitrogen are found in vehicle and smokestack
exhaust; it compromise lung functions and can cause respiratory and viral illness, notably
in children (Sevier, 2010).
VOCs are emitted as gases from certain solids or liquids. It includes chemicals
that may have adverse health effects, either short or long term. VOC concentrations are
consistently higher indoors than outdoors, and are emitted by several products which
include paints and lacquers, paint strippers, pesticides, building materials and furnishings,
office equipment such as copiers and printers, correction fluids and carbonless copy
paper, graphics and craft materials including glues and adhesive permanent markers
(United States Environmental Protection Agency, 2011). VOCs react with sunlight and
nitrous oxide and form ground level ozone, which is capable of travelling thousands of
miles; although in the stratosphere, ozone provides vital protection against the sun's
ultraviolet radiation, at ground level it can exacerbate health conditions such as asthma
and lung disease. (Sevier, 2010)
Sulphur dioxide is created through the combustion of fossil fuels that contain
sulphur compounds; it can contribute to various lung conditions even at moderate levels
of concentration. Fine particles include dusts, sulphates and nitrates from road traffic and
other sources. These fine particles can be carcinogenic and are able to pass through the
lungs into the bloodstream, causing inflammation as well as more serious conditions
(Sevier, 2010).
This study focuses more about the particulates. Particles of concern include both
very small, "fine" particles (that can only be seen through an electron microscope) and
somewhat larger "coarse" dust particles. Fine particles have been more clearly linked to
the most serious health problems.
According to AirNow in August 2003, particles in the air are a mixture of solids
and liquid droplets that vary in size and are often referred to as "particulate matter." Some
particles - those less than 10 micrometers in diameter - pose the greatest health concern
because they can pass through the nose and throat and get deep into the lungs.
Ten micrometers in diameter is just a fraction of the diameter of a single human
hair. Particles larger than 10 micrometers do not usually reach the lungs, but they can
irritate the eyes, nose and throat (AirNow, August 2003).
Very small particles with diameters less than 2.5 micrometers are called "fine
particles." They are produced any time fuels such as coal, oil, diesel or wood are burned.
Fine particles come from fuel used in everything from power plants to wood stoves and
motor vehicles (e.g., cars, trucks, buses and marine engines). These particles are even
produced by construction equipment, agricultural burning and forest fires. "Coarse" dust
particles range in size from 2.5 to 10 micrometers in diameter. Particles of this size are
produced during crushing or grinding and from vehicles traveling on paved or unpaved
roads (AirNow, August 2003).
According to the Ministry for the Environment on an article published in 2008,
Total Suspended Particulate (TSP) comes from sources like dusty roads, soil tiling,
quarries and fuel combustion. Particles with a diameter less than 10 microns (PM10) and
Particles with a diameter less than 2.5 microns (PM2.5) come from sources such as
burning coal, oil, wood and light fuel oil in domestic fires, transportation and industrial
processes. Natural sources of particles include sea salt, dust, pollens and volcanic
activity. PM2.5 is also formed through chemical reactions in the atmosphere. (Ministry for
the Environment, January 2008)
AirNow also mentioned in an article published in August 2003 that particles can
aggravate heart diseases such as congestive heart failure and coronary artery disease. If a
person has a heart disease, particles may cause him to experience chest pain, palpitations,
shortness of breath and fatigue. Particles have also been associated with cardiac
arrhythmias and heart attacks. Particles can also aggravate lung diseases such as asthma
and bronchitis, causing increased medication use and doctor visits. If a person has lung
disease, and the person is exposed to particles, the person may not be able to breathe as
deeply or vigorously as normal. The person may have respiratory symptoms including
coughing, phlegm, chest discomfort, wheezing and shortness of breath. The person also
may experience these symptoms even if the person is healthy, although he is unlikely to
experience more serious effects. Particles can also increase the susceptibility to the
body’s respiratory infections.
Particles in the air causes so much damage. People’s health need to be protected
from those air particles but first one must know if there are any in the area. One device
called TSI P-Trak Ultrafine Particle Counter, records particulates in the air. It is a
particulate monitor that is used to measure specific sizes of material suspended in air. It
uses the same fundamental technology behind TSI's condensation particle counters
(CPCs), well-proven instruments that have been used in research and industrial
applications around the world for many years. In fact, CPCs have been used for decades
to track and record particle sources. The P-Trak UPC comes with everything you need to
start solving tough IAQ (indoor air quality problems). The device is also battery-operated
(Pine Environmental Services, Inc., 2009). This device costs much and it is to no avail in
our area. But an alternative method for determining the quality of air without the use of
such devices and without spending too much money, can be done. One way to determine
the quality of air is by using petrolatum as a trap for particulates found the air, according
to an article in eHOW published in 2011. The chances are great for the determination of
the quality of air because of the translucency of the petrolatum; the particulates stuck in
the petrolatum can be easily seen.
Fine particles in the air reduce visibility because they scatter or absorb light. This
is usually associated with small particles or certain gases in the atmosphere and can occur
at night or during the day.