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Following the 1984 Bhopal methyl isocyanate (MIC) gas disaster, genetic alterations were sporadically reported on small cohorts. However, the outcome of the multi-center cytogenetic screening conducted at that time remains unknown and no follow-up studies on the long-term effects of MIC exposure have been published. The present work examines genetic changes in the exposed population,with the aim of identifying any long-term effects of MIC. G-Banded metaphases were studied in lymphocytes of 130 individuals. Chromosomal aberrations (CA) were broadly grouped as abnormal cells (Abc), aberrations (Abn), and aberration/abnormal cell (Abn/Abc). From the previous multi-center screening, 946 records were retrieved, from which CA, sister chromatid exchanges (SCE), and cell-cycle kinetics (RI) were computed. In our analysis of the previous study, Abc and Abn were higher in the moderately and severely exposed groups than in the unexposed population. Abc appeared uniform in all groups of the present study, although Abn and Abn/Abc were higher in the exposed groups. Aberrations were now significantly higher in the unexposed and moderately exposed groups than in the previous screening. Although Abn and Abc now appeared lower in severely exposed subjects, the Abn/Abc ratio was higher, perhaps due to more rearrangements and damage in a smaller number of Abc. This result may be attributed to differences between the methods used in the studies, then and now. Elevated SCEs and reduced RI were seen in the severely exposed population shortly after exposure, and stable/clonal rearrangements were seen 30 y later. Follow-up of index cases and their progenies is needed.

There is a vital need to understand details of the methylisocyanate (MIC) release that occurred at the 1984 Union Carbide Ltd. pesticide plant in Bhopal, India in order to avoid or respond to such releases in the future. However, we believe there are serious deficiencies in currently available dispersion predictions of the impact of toxic materials on humans and animals downwind of the plant. Specifically, cloud densities have been underestimated due to failure to account for the presence of a liquid/solid aerosol that would have been produced by the chemical reactions that caused the problem. Using data reported in Union Carbide's own investigation of the accident, which included chemical reaction data, we estimated aerosol compositions and cloud densities, then modeled the Bhopal release, simulating potential exposure levels at various locations under a number of wind-condition scenarios. For the worst-case (low wind speed and high aerosol densities), our predicted MIC concentrations at ground level are at least one order of magnitude greater than any previously published estimates. The centerline elevation of the jetting plume released at 33 m elevation is predicted to rise to about 41 m before falling, resulting in a 40 ppm (Immediately Dangerous to Life or Health, IDLH) concentration contour that reaches the ground at about 410 m downwind of the release location. This is consistent with observations that the plant environs were not hard-hit while the public immediately downwind of the plant perimeter was severely exposed. Concentrations on the order of 1000 ppm are predicted at some ground-level locations, which are more consistent than previous estimates with the reported large numbers of deaths and injuries of humans and animals.

Disasters come in all shapes and forms, and in varying magnitudes and intensities. Nevertheless, they offer many of the same lessons for critical care practitioners and responders. Among these, the most important is that well thought out risk assessment and focused planning are vital. Such assessment and planning require proper training for providers to recognize and treat injury from disaster, while maintaining safety for themselves and others. This article discusses risk assessment and planning in the context of disasters. The article also elaborates on the progress toward the creation of portable, credible, sustainable, and sophisticated critical care outside the walls of an intensive care unit. Finally, the article summarizes yields from military-civilian collaboration in disaster planning and response.

Nearly three decades on, tragedy continues to unfold in Bhopal, which witnessed the world’s worst chemical and environmental disaster on Dec 3, 1984. The leakage of methyl isocyanate (MIC) and other toxic gases from the pesticide factory of Union Carbide Corporation killed thousands and caused illness in several thousand others. Over the years, survivors of the disaster have been fighting for damages, environmental remediation of the site, and medical rehabilitation. Bhopal presented an opportunity to help survivors and study the longterm eff ects of MIC toxicity in human beings. Now it seems this prospect has been lost forever. The latest report by the Indian Council of Medical Research (ICMR) has revealed that a large percentage of the cohort of the epidemiological study, which includes the only health-monitoring project for gas victims, has been lost. In 1985, ICMR established the Bhopal Gas Disaster Research Centre at the Gandhi Medical College in Madhya Pradesh to initiate a number of studies. Researchers registered a cohort of 80 021 people exposed to MIC in Bhopal, while another cohort of 15 931 people from areas not exposed to MIC served as the control group. However, by the time data collection began in 1986, only 62 706 from the exposed group and 13 526 from the control group, could be contacted. Of them, just 16 860 exposed and 5741 from control areas were actually available in 2010, according to the Technical Report on Population-based Long-term Epidemiological Studies part II (1996–2010) published by ICMR recently. This translates into a cohort loss of 79% in aff ected, and 64% in control, areas over the 25-year period. The report concluded that mortality rates among those exposed to MIC are higher than those in the control group, with respiratory diseases being the most common cause in both the groups. General morbidities among those exposed to MIC continue to be higher than in the control population. Abortion rates have declined in aff ected areas, but no clear pattern has emerged on stillbirths due to scarcity of data. The fi ndings for 1996–2010 are in line with those reported in the fi rst population-based epidemiological study covering the period 1985–94 but released in 2004.