Radioactivity In Ionisation Smoke Alarms Environmental Sciences Essay

In this coursework, I will be discussing the role of radioactivity in ionisation smoke alarms; I will focus primarily on the main radioactive substance used in smoke alarms, americium 241, and will analyse its effects as well as its half life. I will also analyse a variety of data based on smoke alarms, and finally, I will discuss the advantages and disadvantages of smoke alarms.

In smoke detectors, Alpha radiation is given out. Alpha particles are made of 2 protons and 2 neutrons. This means that they have a charge of +2, and a mass of 4. Alpha particles are relatively slow and heavy. Alpha emitters must be used for smoke detectors since alpha particles ionise air the most, are mostly likely to be absorbed by cells and are least penetrating. Gamma rays and beta particles easily pass through air without causing ionisation, Beta particles are absorbed by a thin sheet of Aluminium and Gamma is absorbed by either concrete or thick lead.

The radiation given out from the smoke detector is essentially zero and in any case very much less than that from natural background radiation. This is the radiation which all around us. The alpha particles are absorbed within the detector. The small amount of radioactive material that is used in these detectors is not a health hazard and individual units can be disposed of in normal household waste.

However, Alpha radiation is most dangerous inside the body because it is most likely to be absorbed by the organs whereas Beta and Gamma radiation is more dangerous outside the body because the skin cannot stop them. Americium-241 is dangerous if it is taken into the body in soluble form.

The data which I mainly used for my coursework was from www.communities.gov.uk. I think this website is reliable and valid because it is a government website. It has not been created for the purpose of sale so it isn’t biased. However there are a few problems with this website. The problem lies in the data which shows how the % of homes with smoke alarms has changed between 1988-2005. This data is unreliable and invalid. It is invalid because they change from smoke alarm ownership to working smoke alarm ownership in conclusion to that it also has data missing from some years. It is not as valid as it should be because it not the same as what was being looked at in the beginning. But as for the rest of the information, I think it is reliable and valid because it is a government website, not any website just put up on to the internet.

The way in which we could make sure that the data we have it valid and reliable is by comparing them with other results from other sources. By doing this we would be able to see if they are similar or they are different and we would be able to find out if they are correct or not.

The results which I got could be improved if they were collected in a number of different ways. For example data could be collected from the history of the emergency services, data could also be collected by handing out questionnaires and surveys or even collected via the phone.

Advantages and Disadvantages of Smoke Alarms

There are many benefits of a smoke alarm and many disadvantages. Below are some advantages of a smoke alarm.

Firstly the most important benefit of a smoke alarm is that it saves lives. Smoke alarms are a powerful and effective fire safety technology. The smoke detector also allows the emergency services to react quicker so they are able to get to the fire quicker and save lives.

The most important thing is the life of a person. Besides this, a smoke detector also saves money and property. Some people may have money stored at home. For these people it would be a great loss if they were to lose everything in a fire. With a smoke detector, a person is able to quickly put out the fire so a lot of the property does not get damaged.

Another advantage is that the americium-241 is very sensitive. Ionization smoke alarms respond first to fast flaming fires. A flaming fire consumes flammable extremely fast, spreads rapidly and generates considerable heat with little smoke. It responds very quickly to small amounts of smoke.

Americium-241 has a half life of 442 which is not too long or too short. It is just right. If it had a long half-life then it wouldn’t have to be replaced very often but it would stay dangerous for a long time. If it had a short half-life then it would fall to safe level quickly but it would have to be replaced very often. The Americium is just right, not too short or too long, in the middle.

One advantage is that to have a smoke detector reduces the insurance cost. This is because a house which has a smoke detector has less chance of burning down because the smoke alarm will detect the fire so the occupants are able to put it off. For this reason there is cheaper insurance for the house which has a smoke alarm.

Finally, smoke alarms are very cheap. They are even free for many houses but for some people who have to buy it, it is of a very low price.

With the advantages, there are also disadvantages of smoke detectors. Below are some disadvantages of smoke alarms.

The biggest disadvantage is that it contains a very small amount of radioactive material. These devices are probably not a problem unless they burn, in which case the Americium would be released in particulate form – an inhalation hazard.

Another big disadvantage is that it is a bit too sensitive. It can be vulnerable to nuisance alarms if placed too close to cooking. It goes off many times especially if it is kept near a kitchen. This can be very annoying especially if it happens repeatedly.

One disadvantage is that because there are many smoke alarms which give out radiation in this country, they will be radioactive for 1000 of years. The radioactivity in the environment will increase. The disposal of this type of smoke alarm is very harmful, when the building is demolished and new buildings are made, the smoke alarm still emits radioactivity which is not good for the environment.

Finally, another disadvantage is that it works on battery and after a long period, the battery runs out. Therefore, smoke detector stops working so the batteries have to be replaced.

Overall, I think that smoke detectors are beneficial because it could save a persons life if a fire was to occur and it’s also very cheap to buy but it has it drawbacks that it emits radioactive material, however the advantages outweigh the disadvantages.