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Every second of the day you are subjected to radiation from compounds in soil, buildings and even your own body.

But for people who fly frequently, cosmic radiation can increase this exposure significantly.

Now there is an app that records your personal radiation to reveal how much you are exposed to from from medical examinations, changes in your location, and flights. 

The TrackYourDose app (pictured) was developed by Germany-based firm esooka and uses a mathematical model developed by scientists and meteorologists. The £1.49 ($1.99) iOS app keeps a record of a user's personal radiation including exposure from changes in a person's location and flights

The TrackYourDose app was developed by Germany-based esooka.

It uses a mathematical model developed by scientists and meteorologists from the Physikalisch-Technische Bundesanstalt (PTB) in Germany and the University Oulu, Finland.

Since 1997, PTB has studied the cosmic radiation at typical flight altitudes and used this to calculate radiation levels.

To to do this, PTB's scientists developed a carry-on 'flight case'.

Using the case, PTB's scientists measured more than 2,500 points at flight altitudes between 5 miles (8km) and 7.5 miles (12km) worldwide between 1997 and 2006.

This covered geographical location, the flight altitude and solar activity.  

It can measure all the relevant types of radiation, in particular neutron radiation produced in the atmosphere.

Using the TrackYourDose app, users enter the details of the airports they are flying from and to and the date they are travelling. 

The current solar activity for the flight is then inputted, using a neutron monitor of the University of Oulu in Finland.

In addition to tracking cosmic radiation from air travel, the app accounts for gamma radiation and cosmic radiation on the ground and medical examinations with ionizing radiation such as X-rays or CT scans lead to radiation exposure.

The measurement is called the 'ambient dose equivalent' and is recorded in microsieverts (µSv). 

In the US, this is often measured in a unit called rem and one sievert is equivalent to 100 rem. 

A ten-hour flight across the North Atlantic, for instance, results in a radiation exposure of between 50 µSv to 100 µSv. 

By comparison, an X-ray at a dentist exposes patients to 6 µSv, depending on the type of X-ray.

In 2012, the total annual radiation exposure of a typical person in Europe, through naturally occurring radiation, came to about 2,100 µSv.  

The same year a radiation monitor tracked 131µSv per hour at the site of the Fukushima power plant. 

While the average radiation of someone in the US is 3,600µSv.  

Experts studied the cosmic radiation at flight altitudes between 5 miles (8km) and 7.5 miles (12km) worldwide between 1997 and 2006. A TrackYourDose user enters their flights details and solar activity for the flight is inputted, using a neutron monitor from the University of Oulu in Finland

A 10-hour flight over the North Atlantic, for instance, results in a radiation exposure of between 50 µSv to 100 µSv. By comparison, an X-ray (stock image right) exposes patients to 6µSv - depending on the X-ray, while a mammogram (right) produces 3,000 μSv. A dosage of 2,000,000 μSv is considered severe and potentially fatal

Approximately half of this dose comes from X-rays, mammograms, CT scans and similar. The other, natural half occurs from radioactive compounds in soil and building materials like concrete and brick.

The small amount of mineral potassium in the human body is also radioactive.

Of this natural radiation, around nine per cent comes from cosmic radiation. 

Particles from space interact with the atmosphere and Earth's magnetic field to generate cosmic radiation. Sources are said to include gamma ray bursts, solar flares and supernovae. 

It is what's known as ionising, which means particles can alter charged particles from atoms that can potentially cause chemical changes in body tissue.  

Exposure to this kind of radiation is more significant at higher latitudes and near the magnetic poles, and many planes take polar routes to cut journey times. 

This exposure is so significant that in 1994 US pilots and cabin crew were classified as 'radiation workers' and the maximum allowable yearly occupational does is 50,000 μSv. 

Last year researchers from the University of California found that pilots flying for an hour at 30,000ft get the same amount of radiation as 20 minutes on a tanning bed.

And researchers believe the levels could be higher when pilots are flying over thick clouds and snow fields, which can reflect UV radiation

The lowest yearly dose that has been linked to an increase in cancer risk is 100,000 μSv, while a dosage of 2,000,000 μSv is considered severe and potentially fatal.