Systematic Review and Meta-Analysis of Circulatory Disease from Exposure to Low-Level Ionizing Radiation and Estimates of Potential Population Mortality Risks

LITTLE M., SCHNEIDER T. et al.

Although high doses of ionizing radiation have long been linked to circulatory disease, evidence for an association at lower exposures remains controversial. However, recent analyses suggest excess relative risks at occupational exposure levels.

Environmental Health Perspectives, Vol. 120, N° 11, 2012, pp. 1503-1511 + Suppl.

Abstract

Background:

Although high doses of ionizing radiation have long been linked to circulatory disease, evidence for an association at lower exposures remains controversial. However, recent analyses suggest excess relative risks at occupational exposure levels.

Objectives:

We performed a systematic review and meta-analysis to summarize information on circulatory disease risks associated with moderate- and low-level whole-body ionizing radiation exposures.

Methods:

We conducted Medline/ISI Thompson searches of peer-reviewed papers published since 1990 using the terms “radiation” AND “heart” AND “disease” or “radiation” AND “stroke” or “radiation” AND “circulatory” AND “disease”. Radiation exposures had to be whole-body, with cumulative mean dose

Results:

Estimated excess population risks for all circulatory diseases combined ranged from 2.5% per Sv (95% confidence interval (CI): 0.8 to 4.2) for France to 8.5% per Sv (95% CI: 4.0 to 13.2) for Russia.

Conclusions:

Our review supports an association between circulatory disease mortality and low and moderate doses of ionizing radiation. Our analysis was limited by heterogeneity among studies (particularly for non-cardiac endpoints), the possibility of uncontrolled confounding in some occupational groups by lifestyle factors, and higher dose groups (>0.5 Sv) generally driving the observed trends. If confirmed, our findings suggest that overall radiation-related mortality is about twice that currently estimated based on estimates for cancer endpoints alone (which range from 4.2% to 5.6% per Sv for these populations).

A1126