Hear from Pippa Clemett, who recently completed work experience with us, on how she used OS OpenData and QGIS to carry out a project on radon potential and lung cancer incidences in England and Wales.
I’m Pippa and I am currently studying geography, geology, biology and chemistry at A-Level, and want to study geography at university. Whilst at Ordnance Survey for an amazing week of work experience, I spent time in the Products department where I used a Geographical Information System called QGIS to produce a small project on radon potential and lung cancer incidences in England and Wales. After using Ordnance Survey’s walk through guides for beginners, ‘Simple Guide’ and ‘Masterclass’, I quickly got the hang of the basics and then was able to apply my own interests to the powerful technology available at OS, to produce my own project.
After learning about how radon emmisions are used to predict earthquakes in geology lessons, and studying a health issues topic for my AS in geography, I thought this would be the perfect project to bring the two together.
Whilst reading the OS website, I came across a post about John Snow. He was an English physician who is most famously known for his work on the cholera outbreak in London in 1854. He was the first person to look at the relationship between disease and the physical environment. He created dot maps to locate the cluster of cholera outbreaks in order to identify the source of the outbreak, which he concluded was a contaminated water pump. Snow’s study is to this day recognised as a breakthrough in both public health and geography.
I wanted to use some of my newly aquired skills in QGIS to see whether there was any relationship between lung cancer incidences and radon potential.
I used open data from the British Geological Survey’s website and the MiniScale Map from the OS website to create a chloropleth map, on QGIS, on radon potential in areas across the UK.
Radon is a radioactive gas which is the decay product of radium, a solid. Both radon and radium are products in the Uranium-238 decay chain known as the ‘radium series’ or ‘uranium series’. Uranium is present in small amounts in all rocks – around 1 to 3 parts per million (ppm), however some rock types contain higher than average levels – up to 100 ppm. Therefore, we would expect the areas with rocks that contain more uranium to have higher levels of radon potential.
You can see very clearly from the chloropleth map that there are areas with very low radon potential such as the South and the East of England. You can also see areas with very high radon potential such as in the South West of England, the North of England and the majority of Wales.
After reading that granites, light coloured volcanic rocks and dark shales often contain high amounts of uranium, I wanted to map the underlying bedrock to see whether the geology related to the high levels of radon potential. I used GeoIndex on the British Geological Survey’s website to map the geology.
After mapping some areas, I found that when granite was the underlying geology, there were high levels of radon potential. In areas with the lowest radon potential, the geology was more varied and composed of rocks which contained low levels of uranium.
As radon is a gas, it enters pore spaces in the rock and can perpcolate upwards. Therefore more porous, unconsolidated and fractured rocks are likely to increase the radon potential of an area. This is because the radon will be able to travel up and escape the rock more easily. However, in the geology maps we were not able to take into account some of these factors for example, how fractured the rocks are.
Radon is a radioactive gas therefore exposure to it can be very damaging to health. After breathing it in, it gets trapped in our lungs and airways and decays, emmitting radiation. This can then lead to an increased risk of lung cancer.
People who live in zones with the highest potential levels, are at risk from radon entering their homes through water systems or through foundations and getting trapped. It is only when radon gets trapped in houses that it is an issue, as radon would normally, without harm, diffuse into the atmosphere.
If houses have poorly sealed foundations, then a large percentage of air will be drawn up from the ground. If these houses are in the high radon potential areas then this can leave a small amount, but very dangerous levels of radon inside the house. As it is a colourless, odourless gas, people are unaware that they are being exposed to it at very dangererous levels. Radon in homes is thought to cause over 20,000 lung cancer deaths in Europe every year and around 1,000 of these are in the UK.
I wanted to see whether lung cancer risk in the UK relate to the radon potential chloropleth map.
However when comparing the two maps, the relative risk of lung cancer and radon potential does not correlate. In fact, most of the areas with the radon potential, have the lowest lung cancer risk.
The health issues topic I studied for my AS geography covered the areas of regional variations of health and morbidity in the UK. We looked at factors which affected these patterns such as eductaion, income and environment which all relates to levels of deprivation. So despite not finding a connection between radon potential and lung cancer risk, I wanted use my knowledge in human geography to investigate the lung cancer risk cholorpleth map further using indices of deprivation.
When comparing the two maps of deprivation and lung cancer risk, you can see that areas such as the North West of England and the North East have the highest levels of lung cancer risk, and also have a large proportion of the most deprived 10% areas in England. The areas shown that are least deprived, tend to have the lowest risks. Therefore the general trend is that with an increase in deprivation, there is an increase in lung cancer risk.
All of the conclusions I have drawn in this project are in no way reliable or scientific, this was simply an exercise to enable me to use the mapping systems available here at OS and apply it to my own interests. Due to my short stay in the department, my project was nothing more than superficial; however, it gave me a fascinating insight into the potential of GIS. I hope that it has shown the way in which GIS and OS data is able to be tailored to the Ordnance Survey customer, to perform geospatial analysis for a variety of different purposes using different datasets.
I have had a brilliant week’s work experience here and had an insightful glimpse into the inner workings of the company. I would like to thank everyone for being so welcoming and friendly throughout the week and ensuring my time here was the most interesting and informative as it could be.