Perinatal mortality after the Fukushima nuclear accident: An ecological study

Area of Science:

• Environmental Health
• Epidemiology
• Nuclear Safety

Background:

• The Fukushima Daiichi nuclear power plant (FDNPP) accident in March 2011 raised concerns about potential long-term health effects.
• Previous studies have investigated perinatal mortality trends in Japan post-accident, necessitating continued monitoring and expanded analysis.

Purpose of the Study:

• To analyze perinatal mortality rates in a broader region of Japan and extend the study period up to 2019.
• To identify temporal trends and geographical variations in perinatal mortality following the FDNPP accident.
• To assess the relationship between proximity to the FDNPP and observed changes in perinatal mortality.

Main Methods:

• Utilized Japanese government-provided monthly perinatal mortality data at the prefecture level.
• Defined a study region encompassing 12 prefectures around the FDNPP, with the rest of Japan serving as the control.
• Employed non-linear regression to model perinatal mortality, accounting for seasonal variations, common asymptotic limits, and periodic peaks.

Main Results:

• A significant 6.4% overall increase in perinatal mortality was observed in the study region between 2012-2019.
• This increase corresponds to an estimated 590 excess perinatal deaths, with higher rates in prefectures closer to the FDNPP.
• Annual peaks in perinatal mortality were noted, particularly in the spring, with substantial increases recorded in 2018 and 2019 in core prefectures.

Conclusions:

• Periodic increases in perinatal mortality were identified in the 12 prefectures surrounding the FDNPP between 2012 and 2019.
• The significant rise in mortality rates, especially in 2018-2019, warrants ongoing surveillance of perinatal health in Fukushima's contaminated areas.
• Further research is recommended to understand the long-term impact of the FDNPP accident on reproductive health outcomes.