OZONE

2014Brett Christopher MarksID -1551006412

[OZONE]This report seeks to outline the causes and effects of ozone depletion, the natural ozone VS commercial ozone and safety concerns of ozone in relation to human beings.

Commercial ozone

The first ozone generator was manufactured in Berlin by Von Siemens. It was originally created to aid in the sterilization of water, but today ozone generators can be found in all shapes and sizes. They are believed to be beneficial in purifying air and improving the sterilization of bacteria and unwanted odors.

Ozone generation works by converting oxygen molecules into Ozone particles. In nature lighting is what is able to convert these oxygen molecules into ozone molecules. An ozone generator works to imitate these conditions and the result is ozone molecules being emitted from the generator.Ozone generators can be used for the sterilization of water, but can also be used in medical facilities to purify the air and aid patient recovery.Although this commercially manufactured ozone can be beneficial to humans in many ways, people must be careful to not overexpose themselves to ozone. Overexposure to ozone can be detrimental to human health.

Natural Ozone

Ozone is natures way of purifying the air that we breathe. When oxygen (O2) rises up into the atmosphere, it becomes exposed to the ultraviolet rays from the sun. This Oxygen is then naturally turned into ozone (O3).Because ozone is heavier than air is it able to naturally fall back down towards earth. This ozone then purifies our air and water. Ozone is sometimes referred to as Activated Oxygen, this is because ozone is completely made up of oxygen. Ozone is the one of the most powerful sterilants known to man and its main function is to destroy bacteria, viruses and odors.Natural ozone occurs in nature as a result mainly of lightning strikes but also from water falls. The fresh clean rain smell that we can sometimes smell after a storm is a result of natures creation of ozone.

Safe exposure level to ozone for humanOzone and humansOzone is a toxic gas, after inhalation it can cause sickness if inhaled in sufficient quantity.Humans can stand a limited exposure of ozone, symptoms like dryness in the mouth and throat, coughing, headache and chest restriction can occur and nearby the lethal limits, more acute problems will follow in a higher concentration.Limits

0.06 PPM for 8 hours a day - 5 days a week (PPM = Parts Per Million) 0.3 PPM for a maximum of 15 minutes

The following diagram gives information about exposure times at different concentrations and their influences on humans.

Health effects of overexposure to ozone

If humans are to inhale Ozone from the air that we breathe, it can cause harm and be detrimental to our health. Even low levels of ozone can be considered to be unhealthy. Children, adults, people suffering from lung disease as well as active people can be susceptible to ozone levels. Breathing ozone can manifest into many health problems. These can include, coughing, chest pains, throat conditions and in severe cases bronchitis, asthma and emphysema. Repeated exposure to unsafe ozone levels can cause poor lung function and even permanent scaring of lung tissue.

Health effects caused by Ozone can include: Making it more difficult to breathe deeply Causing shortness of breath and pain when taking a deep breath. Coughing and sore or scratchy throat. Inflammation and damage of the airways. Aggravation of lung diseases such as asthma, emphysema, and chronic bronchitis. An Increase in the frequency of asthma attacks. Making the lungs more susceptible to infections. Continued damage to the lungs even after the symptoms have disappeared.

Ozone is particularly likely to reach unhealthy levels on hot sunny days in urban environments. It is a major part of urban smog. Ozone can also be transported long distances by wind. For this reason, even rural areas can experience high ozone levels. And, in some cases, ozone can occur throughout the year in some southern and mountain regions.

The relationship of ozone and photochemical smog

There are two requirements for the formation of photochemical smog; Bright sunny conditions and thermal inversion. Thermal inversion occurs when a layer of lighter warmer air forms on top of a layer of colder heavier air. This creates a barrier between the two layers. This in turn prevents the vertical mixing of the air and can trap pollutants. The relationship between photochemical smog and ozone is that photochemical smog is made up of ozone as well as lachrymators and other harmful chemicals.

A large contributor to this smog is pollutants from cars and other internal combustion engines. In ideal conditions combustion involves the reaction between a fuel, like petrol or diesel, with oxygen to produce carbon dioxide, heat and water. Unfortunately conditions are not always ideal, when for example a vehicle idols in traffic, far less oxygen enters the engine and incomplete combustion occurs. This further results in the production of carbon monoxide, unburned hydrocarbons as well as nitrogen and sulphur oxides. All these pollutants alongside ozone contribute to the formation of photochemical smog.

At higher levels in the atmosphere ozone is a beneficial molecule, however at lower levels, trapped below smog or within photochemical smog, this is when ozone can become dangerous to human health.

Benefits of ozone in the medical field

From a time as early as the First World War, humans were using ozone in medical fields. Due to Ozones bactericidal properties, they were used to treat infected wounds, fistulas and mustard gas burns. Since this time, we have refined ozone generation to cater to medical fields as oppose to only industrial ones. Nowadays many benefits can be derived from ozone therapies. Not only can they help purify the air that we breathe, they are also a powerful agent in sterilization from bacteria. Although some websites claim over 100 health benefits of ozone, some of the more commonly known benefits are ozones ability to combat viruses and bacterial infections, purification of blood, help in treating cancer symptoms and purifying the air that we breathe.In medical centers and hospitals they are obviously beneficial because these areas need to be sterile and free from any bacteria or airborne pollutants which could do further harm to patients in these facilities.

Causes of ozone depletionScientists have identified that manufactured chemicals, which contain bromine or chlorine, are destroying the stratospheric ozone of earths atmosphere. This chemicals are known as ozone-depleting substances or ODSs. Ozone depleting substances are considered environmentally safe in the lower atmosphere; this is in part why they became so popular in industry and other man made products. The main problem is, due to the stable nature of ODSs, they are able to float up into the stratosphere, and this is where they begin to cause damage to our earths natural ozone layer. At this level in our atmosphere, ultraviolet light emitted from the sun is able to break these molecules down into smaller parts, this releases chlorine and bromine. The rate at which chlorine and bromine can destroy ozone is quite staggering. To put it into perspective, a thousand molecules of ozone can be broken down by a single molecule of chlorine. Another disturbing factor is that these ODSs have a very long lifetime in our atmosphere, which can be up to several hundreds of years. This means that whatever man made ODSs released in the past century or so will continue to float up into our stratosphere and destroy our ozone for many centuries to come.

The main sources of ODSs are chlorofluorocarbons (CFCs), hydrochlorofluorcarbons (HCFCs), carbon tetrachloride, methyl chloroform and Halons (brominated fluorocarbons).

Ozone depleting chemicalCommonly used in;

Chlorofluorocarbons (CFCs)

Coolants for refrigerators, freezers, air conditioners and cars. Industrial solvents, dry cleaning agents and hospital sterilants. Foam products (cushions and mattresses)

Hydrofluorocarbons (HCFCs)

Major substitute for CFCs (less harmful)

Carbon Tetrachloride

Solvents and some fire extinguishers

Methyl Chloroform

Used mainly in industry, vapor degreasing, aerosols, cold cleaning, adhesives and chemical processing.

Halons

Fire extinguishers

Effects of Ozone DepletionAt the highest level, ozone depletion affects the earths climate and radiation levels reaching the earths surface. It contributes to climate changes and increased levels of radiation. Changes in climate can lead to an accumulation of tropospheric ozone and acid aerosois, this in turn creates air pollution and acid rain. From increases in air pollution and acid rain this effects both human beings, and our environment, forests and crops can be damaged and human respiratory illnesses can emerge as well as heart problems.Increases in radiation can directly effect humans in the following ways; suppression of immunity, increases in infectious diseases, proneness to skin cancer and eye damage. Alongside effects on humans, radiation also effects photochemical formation of tropospheric ozone, damage to materials such as paint, plastic and rubber, and can also effect biological links in the human food chain.

Referenceshttp://www.epa.gov/ozone/science/http://en.wikipedia.org/wiki/Ozone_depletionhttps://www.boundless.com/chemistry/chemistry-and-the-real-world/pollution-and-environmental-issues/photochemical-smog/http://www.in5d.com/100-benefits-of-ozone-therapy.htmlhttp://www.atm.damtp.cam.ac.uk/people/efs20/ozone/node3.htmlhttp://en.wikipedia.org/wiki/Ozone_holehttp://en.wikipedia.org/wiki/Ozone