What have we learned about health effects more than 40 years after the Three Mile Island nuclear accident? A scoping and process review

The worst commercial nuclear accident and the first large-scale voluntary evacuation due to a nuclear event in United States history took place at Three Mile Island (TMI) in 1979. Within a short time, there was a well-recognized impact of the TMI accident by public health officials and academicians upon mental health of nearby residents- particularly pregnant women. Despite long-term and detailed follow-up of this population for cancer outcomes, community concerns continue. Herein, we conduct a scoping and process review of fetal/maternal/child health (MCH) and cancer health outcomes, and consider the findings in light of subsequent accidents. The process evaluation is enhanced by unpublished transcripts of the Pennsylvania Department of Health's (PA DOH) TMI Advisory Panel on Health Research Studies (APHRS), comprised of experts from prominent US research institutions. Research and process strengths included a rapid initial house-to-house health census of over 35,000 individuals, intense medical record reviews, in-person interviews of pregnant women within a 10-mile radius, and coordination of multiple parallel studies by PA DOH with APHRS collaboration. Major limitations include (1) errors in causal inference, (2) limited radiation exposure assessment, (3) failure to include TMI never-exposed groups in risk estimates, (4) exclusion of vulnerable populations, (5) nonindexed/never published investigations, and (6) government-stated need for long-term MCH follow-up that was never conducted. Lingering unaddressed actual and perceived risks were identified as major common themes among TMI, Chernobyl and Fukushima accidents. These findings underscore the need for the establishment of mechanisms to ensure long-term follow-up and preaccident protocols designed to address major health issues with inclusion of vulnerable populations and perceived risks.