Nuclear fallout, low birthweight, and immune deficiency

Perinatal mortality after Chornobyl in contaminated regions of Ukraine

BACKGROUND

Belarus and Ukraine were the countries most affected by the consequences of the Chornobyl nuclear power plant in 1986. A study of perinatal mortality in Belarus found a highly statistically significant increase in the 1990s in the most contaminated oblast Gomel but no increase during this period in the rest of Belarus. As a possible mechanism to interpret this increase as a late Chornobyl effect, it has been suggested that strontium-90 contained in Chornobyl fallout, incorporated during menarche, impairs the immune system of pregnant women which in turn increases perinatal mortality. In the present study, this hypothesis is tested using data from Ukraine.

METHODS

Annual data on perinatal mortality, in the period 1981-2006 were provided by the Ministry of Public Health of Ukraine. Trends in perinatal mortality rates in the most contaminated regions of Ukraine (Kyiv and Zhytomyr oblasts and the city of Kyiv; study region) were compared with rates in the rest of Ukraine (control region). To identify any differences in perinatal mortality trends between the study and control regions, the ratios of perinatal mortality rates in the study region to the rates in the control region were analyzed using the calculated strontium concentration as a predictor.

RESULTS

A trend analysis of perinatal mortality rates in Ukraine revealed two bell-shaped deviations from a long-term exponential trend with maxima at the beginning and end of the 1990s. The same pattern was found in the data from the study and control regions, but the deviations were almost three times higher in the study region than in the control region. An analysis of the ratios of perinatal mortality rates in the study region to the rates in the control region (odds ratios) showed an increase and decrease during the 1990s which was approximated by a lognormal density distribution. The calculated strontium concentration, when used as a predictor, also fitted the data well. Thus, the data from Ukraine confirms the results from Belarus. The analysis of the odds ratios revealed about 1000 excess perinatal deaths in the study region in the period 1990-2004. The corresponding figure for Ukraine as a whole was estimated at 3500 perinatal deaths.

CONCLUSION

It is hypothesized that the observed increase in perinatal mortality in the 1990s may be a late effect of incorporated strontium-90 on the immune system of pregnant women. The analysis is based on a theoretical model, as no data on strontium concentrations were available; the results should therefore be interpreted with caution. An updated study for Belarus would be desirable to corroborate the results.

Statistical modeling of trends in infant mortality after atmospheric nuclear weapons testing

The global fallout from atmospheric nuclear weapons testing in the 1950s and 1960s caused by far the greatest exposure of mankind to ionizing radiation. Surprisingly few epidemiological studies of the possible health effects of atmospheric testing have been conducted. Here, long-term trends in infant mortality rates in the United States (U.S.) and five major European countries (EU5) were examined: The United Kingdom, Germany, France, Italy, and Spain. Bell-shaped deviations from a uniformly decreasing secular trend were found beginning in 1950, with maxima around 1965 in the U.S. and 1970 in EU5. From the difference between observed and predicted infant mortality rates, in the period 1950-2000, the overall increase in infant mortality rates was estimated to be 20.6 (90% CI: 18.6 to 22.9) percent in the U.S. and 14.2 (90% CI: 11.7 to 18.3) percent in EU5 which translates to 568,624 (90% CI: 522,359 to 619,705) excess infant deaths in the U.S. and 559,370 (90% CI: 469,308 to 694,589) in the combined five European countries. The results should be interpreted with caution because they rely on the assumption of a uniformly decreasing secular trend if there had been no nuclear tests, but this cannot be verified. It is concluded that atmospheric nuclear weapons testing may be responsible for the deaths of several million babies in the Northern Hemisphere.

Perinatal Mortality in West Germany Following Atmospheric Nuclear Weapons Tests

Using trend analysis, the author sought a possible association between perinatal mortality rates in West Germany, 1955-1993, and the fallout from atmospheric nuclear weapons testing in the years 1952-1993. The regression model used a continuously falling trend and a superimposed extra term that reflects the average strontium content in pregnant women. Mortality rates show an upward deviation that peaked in 1970. The model attributes more than 100,000 excess perinatal deaths to strontium in the fallout. The dose-response curve is curvilinear with a power of dose of 1.81 +/- 0.23. In addition, using a combined regression model, the author analyzed the two data subsets of perinatal mortality (i.e., stillbirth rate and early neonatal mortality). The strontium effect is 3.4 times greater on early infant deaths than on stillbirths. According to the prevailing wisdom, the fetus is protected against damage from ionizing radiation by a threshold dose of 50-200 mSv, but the doses from strontium in the fallout were well below 1 mSv/yr in Germany. The results reported here seem to contradict the existence of a threshold dose for perinatal mortality at low doses.

The Viral Model for AIDS: Paradigmatic Dominance, Politics, or Best Approximation of Reality?

In 1981, a non-infectious disease hypothesis was offered by the Centers for Disease Control to explain the cluster of atypical pneumonias which had appeared among gay men in the United States. Although quickly supplanted by the now widely held viral hypothesis and largely ignored by professional and media sources, that view has persisted. This article raises the question of why one explanation for the epidemic of immune system suppression has dominated the discourse on AIDS, despite the anomalies attributed to it by the proponents of other viewpoints. Alternative responses to the question are set forth drawing upon literatures in the philosophy of science and public policy formulation. Some discussion is provided of what the consequences may be if one of the contrarian hypotheses proves to be the closer approximation to the truth about AIDS etiology.