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Health Risks of Ionizing Radiation: - Clark University

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38 Medical Exposures<br />

<br />

<br />

Mean total body dose 2.6 Gy Increased risk <strong>of</strong> cancer (RR 1.30, 1.24-<br />

1.35) with a significant dose-response<br />

relationship 7 and time-dependent risks<br />

<strong>of</strong> various sites 8<br />

Cohort study <strong>of</strong> cancer mortality in 15,577 ankylosing<br />

spondylitis patients treated in the UK, 1935-1957<br />

Weiss<br />

et al. 1994<br />

Non-CLL leukemia RR 3.11 (2.37-4.07)<br />

with a strong trend over time 9 ; ERR<br />

during the first 25 years after exposure<br />

12.37/Gy (2.25-52.07) 10<br />

Mean bone marrow dose 4.4<br />

Gy<br />

Cohort study <strong>of</strong> leukemia mortality in 14,767<br />

ankylosing spondylitis patients treated in the UK,<br />

1935-1957<br />

Weiss<br />

et al. 1995<br />

Brain tumor RR 15 (0.8-286); thyroid<br />

cancer RR 4.2 (0.4-47)<br />

Typical doses <strong>of</strong> 0.78 Gy<br />

(lower brain) and 0.09 Gy<br />

(thyroid)<br />

Cohort study <strong>of</strong> cancer incidence in 2,925 people who<br />

had been exposed to nasopharyngeal radium treatment<br />

in childhood (Maryland, 1943-1960)<br />

Yeh<br />

et al. 2001<br />

The ERR for non-leukemia cancer mortality was estimated to be 0.1/Gy (0.04-0.18) in a simple linear model. A more accurate estimate for the low-dose<br />

region, however, may be 0.28/Gy (0.07-0.48), the linear coefficient in a linear-quadratic model. This compares to an ERR <strong>of</strong> 0.47/Gy in the atomic bomb<br />

7<br />

survivors (Preston et al. 2003).<br />

8<br />

In addition to leukemia (see next reference), there were significantly positive risks <strong>of</strong> non-Hodgkin’s lymphoma, multiple myeloma, and cancers <strong>of</strong> the<br />

esophagus, colon, pancreas, larynx, lung, bones, connective tissue, prostate, bladder, and kidney. For colon and lung cancers, non-Hodgkin’s lymphoma, and<br />

cancer generally the risk declined over time. For all non-leukemia cancers the RR was 1.38 over the 5-25 years after exposure, declining to 1.16 for the<br />

period more than 25 years after exposure.<br />

9<br />

The RR was 11.01 over the first five years after exposure and declined to 1.87 for the period 25 or more years after exposure<br />

10<br />

The estimated ERR <strong>of</strong> 12.37/Gy is the linear term <strong>of</strong> a compartmental linear-exponential model. The estimated ERR for 25-40 years after exposure was<br />

5.18/Gy (0.81-23.63)

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