In utero exposure to radiation and haematological malignancies: pooled analysis of Southern Urals cohorts
A partir des données de deux cohortes conduites dans la région de l'Oural du sud incluant 19 536 enfants de salariées du secteur nucléaire ou de femmes vivant à proximité d'endroits contaminés par des accidents ou déchets nucléaires, cette étude évalue l'association entre une exposition in utero à des rayonnements ionisants et le risque de lymphome ou de leucémie
Background: It is scientifically uncertain whether in utero exposure to low-dose ionising radiation increases the lifetime risk of haematological malignancies. Methods: We pooled two cohorts from the Southern Urals comprising offspring of female workers of a large nuclear facility (the Mayak Production Association) and of women living in areas along the Techa River contaminated by nuclear accidents/waste from the same facility, with detailed dosimetry. Results: The combined cohort totalled 19 536 subjects with 700 504 person-years at risk over the period of incidence follow-up, and slightly more over the period of mortality follow-up, yielding 58 incident cases and 36 deaths up to age 61 years. Risk was increased in subjects who received in utero doses of greater than or equal to80 mGy (excess relative risk (ERR): 1.27; 95% confidence interval (CI): −0.20 to 4.71), and the risk increased consistently per 100 mGy of continuous exposure in utero (ERR: 0.77; CI: 0.02 to 2.56). No association was apparent in mortality-based analyses. Results for leukaemia and lymphoma were similar. A very weak positive association was observed between incidence and postnatal exposure. Conclusions: In summary, the results suggest a positive association between in utero exposure to ionising radiation and risk of haematological malignancies, but the small number of outcomes and inconsistent incidence and mortality findings preclude firm conclusions