Half of the ‘exhaled’ radon decays to Lead and is deposited after about four days of becoming airborne. This might create a zone of high lead contamination in and around CSG fields as it slowly builds up over time in the soil and dust. A little more every day … it just keeps adding up. The same could be expected to happen at further distances with lesser concentrations of Pb 210.
The other half of the airborne radon decays and falls becoming radioactive lead over the next 20 days. This creates a wide area of lead contamination which is less concentrated for now, but it is building up just like in the gas fields … a little more radioactive lead is added every day the gas fields release ‘technologically enhanced’ levels of lead producing, radon gas.
The table below indicates that about 98% of minefield concentrations of radon will have deposited after 24 days of being exhaled from the earth. Air moving at 10km per hour covers 240 km per day. Theoretically every tank and back yard at Australia is already contaminated to some extent, by radioactive lead from Coal Seam Gas fracking.