The Element Radon is a colorless, radioactive, inert gaseous element formed by the radioactive decay of radium, and it is a radioactive gas that forms naturally when uranium, thorium, or radium, which are radioactive metals break down in rocks, soil and groundwater. People can be exposed to radon primarily from breathing radon in air that comes through cracks and gaps in buildings and homes, since radon comes naturally from the earth, people are always exposed to it. It is used as a radiation source in radiotherapy and to produce neutrons for research.

Nature of Radon: Radon diffuses as it flows along the path of least resistance to the surface of the ground before reaching the atmosphere. Radon becomes diluted in the outdoor air and concentrations are so low and it is of less concern, has it enters the atmosphere, . Since it is a gas, radon can also move into any air space, such as basements, crawl spaces, or caves. Once inside an enclosed space, such as a home, radon can accumulate. For this reason, indoor concentrations are usually higher than those found outdoors. Houses with little air exchange because of improvements to prevent heat loss will generally have higher indoor radon levels than draftier houses.

Lagos State Radon Concentration

Lagos State is a metropolitan state in the southwestern geopolitical zone of Nigeria, smallest state of the 36 states of Nigeria. Lagos State is arguably the most economically important state of the country, the nation's largest urban area, which is bounded on the north and east by Ogun State. In the west it shares boundaries with the Republic of Benin. Behind its southern borders lies the Atlantic Ocean. 22% of its 3,577 km2 are lagoons and creeks. It largest city, inland from the Gulf of Guinea across Lagos Lagoon, and with and approximate area of 1,171 km² Urban area: 907 km² and Elevation of 41 m, and has a geology of mainly sedimentary of tertiary and quaternary sediments. Tertiary sediments are unconsolidated sandstones, grits with mudstone band and sand with layers of clay. Quaternary sediments are recent deltaic sands, mangrove swamps and alluvium near the coast.

The radon concentration of the Lagos shown in the resulted image of the research performed presents that the concentration of radon in Local Governments like

• Alimosho : 0.326030672 - 0.583342685 pCi/L
• Amowo Odofin 0.326030672 - 1.097966711 pCi/L
• Ikeja 0.326030672 - 0.840654698 pCi/L
• Kosofe 0.583342685 - 1.097966711 pCi/L
• Eti-Osa 1.097966712 - 1.355278724 pCi/L
• Apapa 1.097966712 - 1.355278724 pCi/L
• Ojo 0.326030672 - 0.583342685 pCi/L
• Mushin 0.583342685 -1.097966711 pCi/L
• Ibeju - Lekki 0.840654698 - 1.86990275 pCi/L
• Oshodi/isolo 0.326030672 - 0.840654698 pCi/L
• Agege 0.326030672 - 0.583342685 pCi/L
• Ikorodu 0.840654698 - 2.641838789 pCi/L
• Ifako ijaye 0.326030672 - 0.583342685 pCi/L
• Epe 0.840654698 - 1.86990275 pCi/L
• Badagry 0.583342685 - 0.840654698 pCi/L
• Surulere 0.840654698 - 1.097966712 pCi/L
• Shomolu 0.840654698 - 1.097966711 pCi/L
• Ajeromi/ ifelodun 0.840654698 - 1.097966711 pCi/L
• Lagos mainland 0.840654698 - 1.097966711 pCi/L
• Lagos island 0.840654698 - 1.355278724 pCi/L

According to Marie Bannister (November 8, 2019) the best radon level measurement would be zero, but that's not an ideal level. The average global outdoor radon level varies between 0.135-0.405 pCi/L. what to know is that the lower the level, the lower the risk. As radon gas can be accumulated indoors, it is important to have a daily monitor. Ikorodu local governmnet has the Highest radon concentration amidst all other local government in lagos state with radon value ranging from 0.840654698 - 2.641838789 pCi/L, while Alimoso and Agege has the least concentration of radon in Lagos state ranging from 0.326030672 - 0.583342685 pCi/L.

Hazard of Radon: When you breathe in radon, radioactive particles from radon gas can get trapped in your lungs. Over time, these radioactive particles increase the risk of lung cancer. It may take years before health problems appear, and smokers who are exposed to radon are at a greater risk of lung cancer.

Recommendation

Radon Value (pCi/L ) AIRTHINGS Recommendation

• 0 - 1.3 pCi/L:No action needed
• 1.4 - 2.6 pCi/L: Experiment with ventilation and sealing cracks to reduce radon level
• 2.7 - 4 pCi/L: Keep measuring, if level is maintained for more than 3 month a professional radon mitigator is needed.
• 4.1 And above pCi/L: Keep measuring, if level are maintained for more than 1 month a professional radon mitigator is needed.

Epe, Ibeju-Lekki, and Ikorodu are in need of natural ventilations, and sealing cracks to reduce radon level.