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Po) in 1 liter of air that releases 1.3 × 10 5 MeV of potential alpha energy; [5] one WL is equivalent to 2.08 × 10 −5 joules per cubic meter of air (J/m 3). [1] The SI unit of cumulative exposure is expressed in joule-hours per cubic meter (J·h/m 3). One WLM is equivalent to 3.6 × 10 −3 J·h/m 3. An exposure to 1 WL for 1 working month ...
Radon is measured in picocuries per liter of air (pCi/L) or becquerel per cubic meter (Bq m-3). Both are measurements of radioactivity. The World Health Organization (WHO) sets the ideal indoor radon levels at 100 Bq/m-3. [97] In the United States, it is recommend to fix homes with radon levels at or above 4 pCi/L.
Open-air stores also release radon at a level potentially hazardous to workers. [3] Radon is a noble gas that is heavier than air and thus tends to accumulate in poorly ventilated underground spaces like mines or cellars. Naturally occurring radon is considered the second most common cause of lung cancer after smoking. [15]
Radon is thus assumed to be the second leading cause of lung cancer after smoking, and accounts for 15,000 to 22,000 cancer deaths per year in the US alone. [9] [better source needed] However, the discussion about the opposite experimental results is still going on. [10] About 100,000 Bq/m 3 of radon was found in Stanley Watras's basement in 1984.
The NOAEL could be defined as "the highest experimental point that is without adverse effect," meaning that under laboratory conditions, it is the level where there are no side-effects. It either does not provide the effects of drug with respect to duration and dose, or it does not address the interpretation of risk based on toxicologically ...
Engine exhaust, diesel [5] Estrogen-progestogen menopausal therapy (combined) Estrogen-progestogen oral contraceptives (combined) [note 5] Estrogen therapy, postmenopausal NB There is "evidence suggesting lack of carcinogenicity" for estrogen-only menopausal therapy in humans and colorectal cancer. An inverse association has been observed ...
The definition was refined in 1950 as "that dose of any ionizing radiation which produces a relevant biological effect equal to that produced by one roentgen of high-voltage x-radiation." [ 19 ] Using data available at the time, the rem was variously evaluated as 83, 93, or 95 erg /gram. [ 20 ]
Radioactive contamination, also called radiological pollution, is the deposition of, or presence of radioactive substances on surfaces or within solids, liquids, or gases (including the human body), where their presence is unintended or undesirable (from the International Atomic Energy Agency (IAEA) definition). [3]