Table 1.
Radon levels in homes throughout the world
| Country | Period[ref] | Area | No. of dwellings | 222Rn (Bq/m3) | ||||
|---|---|---|---|---|---|---|---|---|
| AM(SD) | GM(SD) | Median (Min, Max) | Excessive rate (%) | Recommended level | ||||
| USA | 1989–1990 [12, 42] | Nationwide (sample size) | 5,694 | 1.25(0.12) | 0.68(0.08) | - | 6.0 | 4pCi/L (USA unit is pCi/L) |
| 1991 [43] | Texas | 2,890 | 1.0 | 0.5 | 0.6 | 3.6 | ||
| 2003–2004 [44] | Illinois | 22,082 | - | 5.16(3.47) | 3.6 (0.4, 178.9) | 46.0 | ||
| 2010 [45] | Ohio | 159,340 | - | 3.99 | -(-, 927.6) | 32.64 | ||
| −2014 [46] | Kansas | 73,959 | 5.1 | - | -(-, 1,121.6) | 42.6 | ||
| −2014 [47] | New York | 73,519 | 6.24 | 2.72(3.52) | -(-, 522.1) | - | ||
| −2015.6 [48] | Nevada | 17,255 | 3.68 | - | - | 26.4 | ||
| Canada | 2007 [49] | Ottawa | 93 | 110(168) | 74(2.26) | -(8,1525) | 12.0 | 200 |
| 2008 [50] | Winnipeg | 116 | 143(101) | 112(2.07) | -(20, 483) | 20.0 | ||
| 2010 [51] | Fredericton | 45 | 138(213) | 82(2.56) | -(16, 1374) | 18.0 | ||
| 2010 [51] | Halifax | 64 | 259(475) | 107(3.67) | -(4, 2341) | 32.0 | ||
| UK | 1986–1987 [52] | Nationwide (sample size) | 2,093 | 20.5 | 15(2.2) | - | 0.5 | 200 |
| −2009 [52] | England | 465,000 | 99 | 53 | - | 11.3 | ||
| −2009 [52] | Wales | 16,800 | 91 | 51 | - | 10.7 | ||
| −2008 [54] | Scotland | 19,100 | 37 | 20 | -(-, 4,600) | 1.9 | ||
| −2009 [55] | Northern Ireland | 24,000 | 70 | 46 | -(-, 4,900) | 5.0 | ||
| Denmark | 1985–1986 [56] | Nationwide | 496 | 47 | 29(2.2) | - | 2.2 | 200 |
| 1995–1996 [57] | Nationwide | 3,019 | - | - | -(2, 590) | |||
| -[58] | Newly constructed | 200 | - | - | 36.8 (9.0, 118) | 7.0 | 100 (New homes) | |
| Finland | 1990–1991 [56] | Nationwide | 3,074 | 123 | 84(2.1) | - | 3.6 (Above 200 12.3) | 400 |
| −1996 [59, 60] | Nationwide | 51,443 | 248 | - | -(-, 32,700) | 13.0 (Above 200 33.0) | ||
| Germany | 1978–1984 | Nationwide | 7,500 | 50 | 40 | - | 1.5-2.5 (Above 200) | 100 |
| 1991–1993 [56] | ||||||||
| Hungary | 1994–2006 [61] | Nationwide | 6,154 | 174(139) | - | -(-, 1,841) | 29.0 | 200 |
| Ireland | 1992–1999 [62] | Nationwide | 11,319 | 89 | 57(2.40) | -(10, 1,924) | 8.8 | 200 |
| Japan | 1993–1996 [63] | Nationwide | 899 | 15.5(13.5) | 12.7(1.78) | 11.7 (-, 208) | - | - |
| -[64] | Hokkaido, Hiroshima, Kochi | 6,645 | 21.3(18.8) | 17.3(1.83) | 16.4 (-) | 0.4 (Above 148) | ||
| China | 1984–1990 [65] | Nationwide | 10,811 | 22.5 | 19.6 | - | - | |
| 1994–1998 [66] | Shenyang | 608 | 115.7 | 91.2(1.93) | 122.4 (-) | 17.4 (Above 148) | ||
| Gansu | 2,394 | 222.9 | 176.2(2.08) | 227.8 | 65.7 (Above 148) | |||
AM arithmetic mean, SD standard deviation, GM geometric mean, Min minimum, Max maximum