The Bhopal disaster and its aftermath: a review

Rapid Non-Contact Detection of Chemical Warfare Agents by Laser Photoacoustic Spectroscopy

Nerve agents have recently been used in battlefield operations, espionage wars, and terrorist attacks. These compounds, like some pesticides, cause organophosphate poisoning. The rapid, noncontact detection of a sarin simulant in the liquid phase has been demonstrated at the Diagnostics and Metrology Laboratory of the Italian National Agency for New Technologies, Energy and Sustainable Economic Development using laser photoacoustic spectroscopy, an infrared absorption technology. The first measurements, carried out with an experimental system based on a quantum cascade laser and developed for the assessment of food authenticity in the "fingerprint region", show that a detection limit of one nanolitre is within the reach of the instrument when chemometric analysis is applied.

Long-term health and human capital effects of in utero exposure to an industrial disaster: a spatial difference-in-differences analysis of the Bhopal gas tragedy

OBJECTIVES

Globalisation and industrialisation can increase economic opportunity for low/middle-income nations, but these processes may also increase industrial accidents and harm workers. This paper examines the long-term, cohort-based health effects of the Bhopal gas disaster (BGD), one of the most serious industrial accidents in history.

DESIGN

This retrospective analysis uses geolocated data on health and education from India's National Family Health Survey-4 (NFHS-4) and the 1999 Indian Socio-Economic Survey by the National Sample Survey Organization (NSSO-1999) to examine the health effects of exposure to the BGD among men and women aged 15-49 years living in Madhya Pradesh in 2015-2016 (women n=40 786; men n=7031 (NFHS-4) and n=13 369 (NSSO-1999)), as well as their children (n=1260). A spatial difference-in-differences strategy estimated the relative effect of being in utero near Bhopal relative to other cohorts and to those further from Bhopal separately for each dataset.

RESULTS

We document long-term, intergenerational impacts of the BGD, showing that men who were in utero at the time were more likely to have a disability that affected their employment 15 years later, and had higher rates of cancer and lower educational attainment over 30 years later. Changes in the sex ratio among children born in 1985 suggest an effect of the BGD up to 100 km from the accident.

CONCLUSIONS

These results indicate social costs stemming from the BGD that extend far beyond the mortality and morbidity experienced in the immediate aftermath. Quantifying these multigenerational impacts is important for policy consideration. Moreover, our results suggest that the BGD affected people across a substantially more widespread area than has previously been demonstrated.

The Impacts and Analysis of Individual and Social Risks of the Stochastic Emission of Benzene from Floating-Roof Tanks Using Response Surface Analysis and MPACT Model

In the present study, the researchers used an integrated approach composed of response surface analysis (RSM) and MPACT model to predict fatality rates caused by benzene emitted from floating-roof tanks. RSM scenarios were configured in Expert Design (version 7.0) software using the central composite design (CCD) method and five variables of wind speed, relative humidity, atmospheric temperature, failure diameter, and emission height were considered. Continuous Pasquill-Gifford Gaussian model was used to estimate the results of the RSM scenarios. The response values were considered for exposure concentrations above 50 ppm (slight damages), 150 ppm (moderate damage), and 1000 ppm (high damage). The analysis of individual and social risks for each scenario was done using the MPACT model in SAFETI program (version 8.22) by providing two variables of population characteristics and the frequency of tank wall failure. The results showed that atmospheric temperature, wind speed, failure diameter, and emission height have positive effects on the dispersion of the cloud of toxic benzene vapor with a concentration of 1000 ppm. Intolerable individual risk distances were estimated to be lower for indoor environments than for outdoor. Maximum distances of intolerable individual risks for the worst-case scenarios were estimated up to 2500 m from the emission point, which resulted from exposure to a concentration of 1000-ppm benzene. Results regarding the estimation of social risks showed that over 1600 fatalities should be expected under the worst-case scenarios. The three factors of high temperature, low wind speed, and low emission height play a major role in the occurrence of scenarios with the highest fatalities. High wind speed and high emission height were the most important factors in most scenarios with zero fatalities rate. Generally, the findings of this study show the necessity to provide an emergency response plan in the studied industry in both autumn and winter due to low wind speed. However, the coupling of the developed statistical models based on regional meteorological conditions with the MPACT model can help researchers to design an emergency response plan to deal with leakage incidents in petrochemical industries.

Study on the potential risks under a hazardous gas leakage accident: effects of source characteristics and ambient wind velocities

In this study, a full-scale storage tank was established to investigate the potential risks of leakage accident. We have developed a series of leak scenarios that close to real accidents and have divided the ambient areas according to relevant regulations. Considering the variety and complexity of real-life accident scenarios, the presented work revealed the combined effect of source release intensity and ambient wind speed on dispersion features by classifying leakage scenarios into active or passive release. The environmental hazards in each area is evaluated under various leak scenarios. The results show that when the approaching wind speed is low, the leakage on the windward side is the most dangerous release pattern. With the increase of the wind speed, the case with jet angle perpendicular to the incoming wind produces the largest cloud volume. Top release is the least dangerous way among the studied leak scenarios. However, the results illustrate that under some release angles, the cloud volume near the tank is not sensitive to wind speed. In leak accidents, quantitatively analysis reveals that the commonly used dimensionless concentrations ([Formula: see text]) cannot be used as a suitable parameter to discuss the concentration field except under top/leeward passive release conditions. This study will be beneficial to on-site rescue and decision-making when leakage accidents occur and provide reasonable suggestions for subsequent research on the environmental impact of container leakage and the diffusion of pollutants.

Review on rewiring of microalgal strategies for the heavy metal remediation - A metal specific logistics and tactics

Phycoremediation of heavy metals are gaining much attention and becoming an emerging practice for the metal removal in diverse environmental matrices. Still, the physicochemical state of metal polluted sites is often found to be complex and haphazard in nature due to the irregular discharge of wastes, that leads to the lack of conjecture on the application of microalgae for the metal bioremediation. Besides, the foresaid issues might be eventually ended up with futile effect to the polluted site. Therefore, this review is mainly focusing on interpretative assessment on pre-existing microalgal strategies and their merits and demerits for selected metal removal by microalgae through various process such as natural attenuation, nutritional amendment, chemical pretreatment, metal specific modification, immobilization and amalgamation, customization of genetic elements and integrative remediation approaches. Thus, this review provides the ideal knowledge for choosing an efficient metal remediation tactics based on the state of polluted environment. Also, this in-depth description would provide the speculative knowledge of counteractive action required for pass-over the barriers and obstacles during implementation. In addition, the most common metal removal mechanism of microalgae by adsorption was comparatively investigated with different metals through the principal component analysis by grouping various factor such as pH, temperature, initial metal concentration, adsorption capacity, removal efficiency, contact time in different microalgae. Conclusively, the suitable strategies for different heavy metals removal and addressing the complications along with their solution is comprehensively deliberated for metal removal mechanism in microalgae.

A complete, evidence-based review on novichok poisoning based on epidemiological aspects and clinical management

Background: The whole world has learned about the existence of a highly toxic neuro-paralytic substance called Novichok. A wide range of neuro-paralytic toxins were used during the wars of decades ago, which also had harmful and irreversible effects. Fortunately, the establishment of conventions prohibiting the use of these weapons prevented the adverse clinical consequences of these compounds. What we did in the present study was to evaluate the clinical features of Novichok, how to manage exposure to it, and to evaluate the prognostic aspects associated with this poisoning agent. Methods: The manuscript especial databases including Medline, Web of knowledge, Google scholar, and Scopus were deeply searched by the two blinded investigators for all eligible studies based on the considered keywords. Initially 98 articles were initially collected by database searching that considering eligibility criteria, 83 articles were finally eligible for the final assessment. There is a lack of clinical trials and case-cohort studies on general population about treatment and side effects when it comes to human nerve agents and most of the data in our search is based on animal studies. Results: In evaluating various clinical, auto physiological and prognostic aspects of exposure to these substances, special attention was necessary to the following points. First, Novichok agents are considered more potent than other toxic agents. Pathophysiologically, these agents irreversibly bind acetylcholinesterase and produce a rapid cholinergic toxidrome which is responsible for the clinical manifestations as well as the potential dangerous and life threatening side effects caused by these agents. Uniquely, these agents are thought to also target every neuron in the central and peripheral nervous system. As a managerial and therapeutic approach, early and timely treatment of its related complication along with prevents massive exposure and decontamination in addition to rapid resuscitation can prohibit debilitating neuropathy and death due to facing it. Conclusion: The present review highlights the importance of recognizing the potential acute toxic effects of Novichok agents, diagnostic and therapeutic approaches (life-saving antidotal therapy) to complications and ultimately the application of guidelines to improve the prognosis of exposure to these agents for both victims and medical community.

Numerical Investigation of Overtopping Prevention for Optimal Safety Dike Design

Leakage accidents at chemical facilities have a negative impact on both the environment and human life, and the government has established and implemented regulations on dikes in order to minimize such accidents. However, the overtopping phenomenon in which chemicals overflow the dike due to catastrophic leakage requires additional safeguards. In this study, the mitigation effect was confirmed by simulating tanks and dikes using various deflector plates to minimize the effect of spilled chemicals. ANSYS Fluent 19.1, a computational fluid dynamics program, was used, and the overtopping effect was compared with a dike design that satisfies the safety regulations using a volume of fluid (VOF) model that analyzes multiphase flow through a surface tracking technique. Nitric acid and sulfuric acid were used in the study; they were selected because they are frequently involved in leakage accidents. In the event of a leak in a liquid tank, a dike with a deflector plate was very effective in reducing overtopping, and a deflector at a 45° angle was more effective than a 30° deflector. However, it is necessary to install additional safeguards at the joint between the dike and the deflection plate to withstand the force of the liquid.

Identification and determination of phenyl methyl carbamate released from adducted hemoglobin for methyl isocyanate exposure verification

Methyl isocyanate (MIC), an intermediate in the synthesis of carbamate pesticides, is a toxic industrial chemical that causes irritation and damage to the eyes, respiratory tract, and skin. Due to the high reactivity of MIC, it binds to proteins to form protein adducts. While these adducts can be used as biomarkers to verify exposure to MIC, methods to detect MIC adducts are cumbersome, typically involving enzymatic (pronase) or strong acid (Edman degradation) hydrolysis of hemoglobin. Hence, in this study, a simple method was developed which utilizes base hydrolysis of MIC-tyrosine adducts from isolated hemoglobin to form phenyl methyl carbamate (PMC), followed by rapid liquid-liquid extraction, and liquid chromatography tandem mass spectrometry analysis. The hydrolysis chemistry is the first report of base hydrolysis of a tyrosine-β-C-hydroxo phenol bond in aqueous solution. The method produced excellent sensitivity (detection limit of 0.02 mg/kg), linearity (R² = 0.998, percent residual accuracies > 96), and dynamic range (0.06‒15 mg/kg). The accuracy and precision (100 ± 9% and < 10% relative standard deviation, respectively) of the method were outstanding compared to existing techniques. The validated method was able to detect significantly elevated levels of PMC from hemoglobin isolated from MIC-exposed rats.

Pesticides and environmental injustice in the USA: root causes, current regulatory reinforcement and a path forward

Many environmental pollutants are known to have disproportionate effects on Black, Indigenous and People of Color (BIPOC) as well as communities of low-income and wealth. The reasons for these disproportionate effects are complex and involve hundreds of years of systematic oppression kept in place through structural racism and classism in the USA. Here we analyze the available literature and existing datasets to determine the extent to which disparities in exposure and harm exist for one of the most widespread pollutants in the world – pesticides. Our objective was to identify and discuss not only the historical injustices that have led to these disparities, but also the current laws, policies and regulatory practices that perpetuate them to this day with the ultimate goal of proposing achievable solutions. Disparities in exposures and harms from pesticides are widespread, impacting BIPOC and low-income communities in both rural and urban settings and occurring throughout the entire lifecycle of the pesticide from production to end-use. These disparities are being perpetuated by current laws and regulations through 1) a pesticide safety double standard, 2) inadequate worker protections, and 3) export of dangerous pesticides to developing countries. Racial, ethnic and income disparities are also maintained through policies and regulatory practices that 4) fail to implement environmental justice Executive Orders, 5) fail to account for unintended pesticide use or provide adequate training and support, 6) fail to effectively monitor and follow-up with vulnerable communities post-approval, and 7) fail to implement essential protections for children. Here we’ve identified federal laws, regulations, policies, and practices that allow for disparities in pesticide exposure and harm to remain entrenched in everyday life for environmental justice communities. This is not simply a pesticides issue, but a broader public health and civil rights issue. The true fix is to shift the USA to a more just system based on the Precautionary Principle to prevent harmful pollution exposure to everyone, regardless of skin tone or income. However, there are actions that can be taken within our existing framework in the short term to make our unjust regulatory system work better for everyone.

Impact of Weak Signals on the Digitalization of Risk Analysis in Process Safety Operational Environments

Weak signals in risk analysis digitalization are of great importance for preventing major accidents in risk analysis in the process industry, especially for process operations and production. However, some of the negative impacts are incorrect operational risk identification, significant inventory carrying costs, disruption of risk frequency, and risk consequence analysis, all of which will signal inaccurate information about unforeseen and current dangers in process facilities and operational environments. While the positive impacts are viewed as an early warning system that provides information on operational risk system status, the identification of potential risk weaknesses in process facilities, indicators of a transition or an emerging problem that may become significant in the future, highlighting future assumptions, challenge our views of the future and expand the selection of a processing facility. Lastly, weak signal identification in the digitalization of risk analysis can provide relevant information in supporting, assessing and analyzing the risks associated with the operation, in order to design a technical system and estimate the industry’s level of accident risk, as well as the possible control of a system. The present research will provide valuable information to the process industry on how to protect their operational facilities and increase process safety by providing information on weak safety risk monitoring systems in operations, strengthening the processes of the operational area.

Organic Isocyanates and Isothiocyanates: Versatile Intermediates in Agrochemistry

In recent decades, organic isocyanates and isothiocyanates have been often applied as reactive intermediates in research syntheses or manufacturing routes of many agrochemicals. These heterocumulenes allowed the installation of crucial carboxylic functions, such as carbamates, ureas, and semicarbazones, but have also been used for the construction of five- and six-membered heterocycles, such as tetrazolones, thiazoles, and uracils.

1 Introduction

2 Preparation of Carboxylic Acid Functions

3 Preparation of Heterocyclic Rings

4 Conclusion

Methodology for the Determination of a Process Safety Culture Index and Safety Culture Maturity Level in Industries

A mature of safety culture is crucial to preventing and mitigating accidents, incidents, and unsafe behaviors in the process industry, so as to make it more sustainable and economically responsible. Measurement, investigation, and assessment of the safety culture using interviews, questionnaires, behavior observation, reviewing documentation, and its impact on the safety performances of an organization is complicated, challenging, and requires a commitment to all employees. The aim of this study was to propose a novel, unique semi-quantitative methodology for the determination of a total process safety culture index and parametric model of process safety culture maturity in an organization based on the Bradley model. The methodology includes a questionnaire concerning different process safety culture factors, calculation procedures, and a graphical tool. In addition, three quantitative survey indicators were proposed: indicators of direct communication, average communication time, and the applicability rate of the proposed changes by employees. A fully-developed total process safety culture index allows for identifying, hierarchizing, and benchmarking different factors of the safety culture among companies and sectors. Moreover, it will enable identifying the area of actions required to improve safety practices and elements applied to the organization analyzed. The proposed methodology was verified in a case study of one energy company with three locations in Poland and can be easily applied to different industrial fields, including logistics and warehousing, the food industry, the paper industry, security services, fire services, and environmental and other agencies.

Taking the Green Road Towards Pharmaceutical Manufacturing

The introduction of the Green Chemistry Principles in the late 1990s formed the basis for a transition to a greener environment. These Principles have become an integral part in the work on designing chemical processes, especially for large-scale manufacture. The ultimate target is the achievement of a sustainable production method allowing hundreds of tons of valuable materials to be prepared. For this purpose, a holistic view must be applied to the elements constituting a fully-fledged process encompassing layout of the synthetic route, defining starting materials and their origin, output of product and quality features, quantity of effluent streams and waste, recovery and recycling of chemicals involved, and energy consumption. These parameters form a complex matrix where the individual components are in a complicated relationship with each other. This short review addresses these issues and the benefits of life-cycle assessment and metrics commonly used to measure the performance of chemical manufacturing – all from a pharmaceutical industry perspective as experienced by the author.

1 Introduction: Facing Severe Challenges

2 The Historical Context: Addressing an Image Problem

3 Prospects, Drivers and Roadmap for the Green Future

4 Living by the Principles: Industrial Perspectives

5 Taking the Green Route – Catalysis Leading the Way: Case Stories

6 State of the Art: How Green Are We?

7 Sending Signals, Creating Impressions: Focus on Communication

8 Conclusions

Morphology-driven gas sensing by fabricated fractals: A review

Fractals are intriguing structures that repeat themselves at various length scales. Interestingly, fractals can also be fabricated artificially in labs under controlled growth environments and be explored for various applications. Such fractals have a repeating unit that spans in length from nano- to millimeter range. Fractals thus can be regarded as connectors that structurally bridge the gap between the nano- and the macroscopic worlds and have a hybrid structure of pores and repeating units. This article presents a comprehensive review on inorganic fabricated fractals (fab-fracs) synthesized in labs and employed as gas sensors across materials, morphologies, and gas analytes. The focus is to investigate the morphology-driven gas response of these fab-fracs and identify key parameters of fractal geometry in influencing gas response. Fab-fracs with roughened microstructure, pore-network connectivity, and fractal dimension (D) less than 2 are projected to be possessing better gas sensing capabilities. Fab-fracs with these salient features will help in designing the commercial gas sensors with better performance.

The Impacts of Illegal Toxic Waste Dumping on Children's Health: A Review and Case Study from Pasir Gudang, Malaysia

Poor management of hazardous waste can lead to environmental pollution, injuries, and adverse health risks. Children’s exposure to hazardous waste may cause serious acute and chronic health problems due to their higher vulnerability to the toxic effects of chemicals. This study examines an incident of illegal chemical dumping in Pasir Gudang, Malaysia and its potential health impacts on children. The study introduced a risk assessment of possible health-related effects due to chemical contamination based on a real case scenario where quantification of the contamination was not feasible. A literature review and spatial analysis were used as research methods. On 6th March 2019, tons of hazardous waste were illegally disposed into Kim Kim River, Pasir Gudang, Malaysia. They were identified as benzene, acrolein, acrylonitrile, hydrogen chloride, methane, toluene, xylene, ethylbenzene, and d-limonene. As a result, 975 students in the vicinity developed signs and symptoms of respiratory disease due to the chemical poisoning. The findings of this study indicate that more effective policies and preventive actions are urgently needed to protect human health, especially children from improper hazardous waste management.

Dynamic of a stochastic delayed one-predator two-prey model with Lévy jumps in polluted environments

This paper is concerned with a stochastic delayed one-predator two-prey model with Lévy jumps in polluted environments. First, under some simple assumptions, we prove that there exists a unique global nonnegative solution which is permanent in time average. Moreover, sufficient criteria for the extinction of each species are obtained. Finally, we carry out some numerical simulations to verify the theoretical results.

Learnings from conducting mental health research during 2004 tsunami in Tamil Nadu, India

Background

The Indian Ocean tsunami experience in 2004 caused a major loss of life and subsequent emotional trauma for survivors. Psychosocial needs in the aftermath of this disaster were extensive, yet the cohesion and effectiveness of response were limited due to lack of preparedness and relevant policy. The Schizophrenia Research Foundation (SCARF) was one of the organizations that quickly responded to provide psychosocial assistance to people in the tsunami affected areas and recognized a need for relevant research on disaster response. Therefore, we undertook research on the challenges, success and limitations of psychosocial interventions in alleviating post-traumatic symptomology.

Discussion

Both community-level workers and researchers were limited in their preparedness to carry out tasks related to response. Language barriers, cultural differences, and a gap in long-term services limited the breadth and scope of research that was able to be completed. Lack of policy, poor co-ordination of services, lack of trained researchers and limited resources were challenges that emerged during this period and various strategies were adopted to meet these challenges.

Conclusions

Continued research and evaluation of data has brought crucial considerations to light, including the variance in symptomology, effective tools of measurement, and the nuanced response of survivors. Future research should take relevant factors into consideration including barriers to care. Understanding of the local language and religious beliefs are significant resources in understanding the nature of survivors’ trauma response and effective means of coping. Lastly, limitations regarding time frame and scope of research should be evaluated to provide more effective, comprehensive methods in future studies.

Coupling of the AQUATOX and EFDC Models for Ecological Impact Assessment of Chemical Spill Scenarios in the Jeonju River, Korea

In this study, an ecological impact was assessed for the short-term leak scenario through the AQUATOX-EFDC model, which combines the proven ecological model AQUATOX with the hydrodynamic model EFDC. A case study of the coupled AQUATOX-EFDC model was conducted for 30-30,000 kg toluene leak scenarios in the Jeonju River in South Korea. A 21-day scenario simulation was conducted, and the impact of the toluene spill accident was evaluated by comparing the biomass between the control simulation and the perturbed simulation. As a result of the simulation, it was found that in the scenario in which 3000 kg of toluene was leaked for a day, a substantial change was expected in the range of 0-640 m from the accident site. Additionally, for a 30,000 kg leak, a substantial change was expected in the range of 0-2300 m from the accident site, and the greatest damage was observed for the fish species group, the top predators. As a result, the AQUATOX-EFDC simulation showed a significant ecological impact, and the proposed model will be helpful to understand the ecological impact and establish the management strategy for the ecological risk of the chemical spill.

Decentralized Multi-agent information-theoretic control for target estimation and localization: finding gas leaks

This article presents a new decentralized multi-agent information-theoretic (DeMAIT) control algorithm for mobile sensors (agents). The algorithm leverages Bayesian estimation and information-theoretic motion planning for efficient and effective estimation and localization of a target, such as a chemical gas leak. The algorithm consists of: (1) a non-parametric Bayesian estimator, (2) an information-theoretic trajectory planner that generates “informative trajectories” for agents to follow, and (3) a controller and collision avoidance algorithm to ensure that each agent follows its trajectory as closely as possible in a safe manner. Advances include the use of a new information-gain metric and its analytical gradient, which do not depend on an infinite series like prior information metrics. Dynamic programming and multi-threading techniques are applied to efficiently compute the mutual information to minimize measurement uncertainty. The estimation and motion planning processes also take into account the dynamics of the sensors and agents. Extensive simulations are conducted to compare the performance between the DeMAIT algorithm to a traditional raster-scanning method and a clustering method with coordination. The main hypothesis that the DeMAIT algorithm outperforms the other two methods is validated, specifically where the average localization success rate for the DeMAIT algorithm is (a) higher and (b) more robust to changes in the source location, robot team size, and search area size than the raster-scanning and clustering methods. Finally, outdoor field experiments are conducted using a team of custom-built aerial robots equipped with gas concentration sensors to demonstrate efficacy of the DeMAIT algorithm to estimate and find the source of a propane gas leak.

Initial impacts of global risk mitigation measures taken during the combatting of the COVID-19 pandemic

This paper presents an analysis of risk mitigation measures taken by countries around the world facing the current COVID-19 outbreak. In light of the current pandemic the authors collated and clustered (using harmonised terminology) the risk mitigation measures taken around the globe in the combat to contain, and since March 11, 2020, to limit the spread of the SARS-CoV-2 virus known to cause the Coronavirus disease 2019 (COVID-19). This overview gathers lessons learnt, providing an update on the current knowledge for authorities, sectors and first responders on the effectiveness of said measures, and may allow enhanced prevention, preparedness and response for future outbreaks. Various measures such as mobility restrictions, physical distancing, hygienic measures, socio-economic restrictions, communication and international support mechanisms have been clustered and are reviewed in terms of the nature of the actions taken and their qualitative early-perceived impact. At the time of writing, it is still too premature to express the quantitative effectiveness of each risk mitigation cluster, but it seems that the best mitigation results are reported when applying a combination of voluntary and enforceable measures.

Initial impacts of global risk mitigation measures taken during the combatting of the COVID-19 pandemic

This paper presents an analysis of risk mitigation measures taken by countries around the world facing the current COVID-19 outbreak. In light of the current pandemic the authors collated and clustered (using harmonised terminology) the risk mitigation measures taken around the globe in the combat to contain, and since March 11, 2020, to limit the spread of the SARS-CoV-2 virus known to cause the Coronavirus disease 2019 (COVID-19). This overview gathers lessons learnt, providing an update on the current knowledge for authorities, sectors and first responders on the effectiveness of said measures, and may allow enhanced prevention, preparedness and response for future outbreaks. Various measures such as mobility restrictions, physical distancing, hygienic measures, socio-economic restrictions, communication and international support mechanisms have been clustered and are reviewed in terms of the nature of the actions taken and their qualitative early-perceived impact. At the time of writing, it is still too premature to express the quantitative effectiveness of each risk mitigation cluster, but it seems that the best mitigation results are reported when applying a combination of voluntary and enforceable measures.

Alleviation of methyl isocyanate-induced airway obstruction and mortality by tissue plasminogen activator

Methyl isocyanate (MIC, "Bhopal agent") is a highly reactive, toxic industrial chemical. Inhalation of high levels (500-1000 ppm) of MIC vapor is almost uniformly fatal. No therapeutic interventions other than supportive care have been described that can delay the onset of illness or death due to MIC. Recently, we found that inhalation of MIC caused the appearance of activated tissue factor in circulation with subsequent activation of the coagulation cascade. Herein, we report that MIC exposure (500 ppm for 30 min, nose-only) caused deposition of fibrin-rich casts in the conducting airways resulting in respiratory failure and death within 24 h in a rat model (LC_90-100 ). We thus investigated the effect of airway delivery of the fibrinolytic agent tissue plasminogen activator (tPA) on mortality and morbidity in this model. Intratracheal administration of tPA was initiated 11 h post MIC exposure and repeated every 4 h for the duration of the study. Treatment with tPA afforded nearly 60% survival at 24 h post MIC exposure and was associated with decreased airway fibrin casts, stabilization of hypoxemia and respiratory distress, and improved acidosis. This work supports the potential of airway-delivered tPA therapy as a useful countermeasure in stabilizing victims of high-level MIC exposure.

A Comparative Study to Explore the Effect of Different Compounds in Immune Proteins of Human Beings Against Tuberculosis: An In-silico Approach

Background:

The lungs are directly exposed to pollutants, pathogens, allergens, and chemicals, which might lead to physiological disorders. During the Bhopal gas disaster, the lungs of the victims were exposed to various chemicals. Here, using molecular modelling studies, we describe the effects of these chemicals (Dimethyl urea, Trimethyl urea, Trimethyl isocyanurate, Alphanaphthol, Butylated hydroxytoluene and Carbaryl) on pulmonary immune proteins.

Objective:

In the current study, we performed molecular modelling methods like molecular docking and molecular dynamics simulation studies to identify the effects of hydrolytic products of MIC and dumped residues on the pulmonary immune proteins.

Methods:

Molecular docking studies of (Dimethyl urea, Trimethyl urea, Trimethyl isocyanurate, Alphanaphthol, Butylated hydroxytoluene and Carbaryl) on pulmonary immune proteins was performed using the Autodock 4.0 tool, and gromacs was used for the molecular dynamics simulation studies to get an insight into the possible mode of protein-ligand interactions. Further, in silico ADMET studies was performed using the TOPKAT protocol of discovery studio.

Results:

From docking studies, we found that surfactant protein-D is inhibited most by the chemicals alphanaphthol (dock score, -5.41Kcal/mole), butylated hydroxytoluene (dock score,-6.86 Kcal/mole), and carbaryl (dock score,-6.1 Kcal/mole). To test their stability, the obtained dock poses were placed in a lipid bilayer model system mimicking the pulmonary surface. Molecular dynamics simulations suggest a stable interaction between surfactant protein-D and carbaryl.

Conclusion:

This, study concludes that functioning of surfactant protein-D is directly or indirectly affected by the carbaryl chemical, which might account for the increased susceptibility of Bhopal gas disaster survivors to pulmonary tuberculosis.

Formamides as Isocyanate Surrogates: A Mechanistically Driven Approach to the Development of Atom-Efficient, Selective Catalytic Syntheses of Ureas, Carbamates, and Heterocycles

Despite the hazardous nature of isocyanates, they remain key building blocks in bulk and fine chemical synthesis. By surrogating them with less potent and readily available formamide precursors, we herein demonstrate an alternative, mechanistic approach to selectively access a broad range of ureas, carbamates, and heterocycles via ruthenium-based pincer complex catalyzed acceptorless dehydrogenative coupling reactions. The design of these highly atom-efficient procedures was driven by the identification and characterization of the relevant organometallic complexes, uniquely exhibiting the trapping of an isocyanate intermediate. Density functional theory (DFT) calculations further contributed to shed light on the remarkably orchestrated chain of catalytic events, involving metal-ligand cooperation.

Decontamination and management of contaminated hair following a CBRN incident

This in vitro study evaluated the "triple protocol" of dry decontamination, the ladder pipe system, a method for gross decontamination, and technical decontamination in the decontamination of hair following chemical contamination. First, we assessed the efficacy of the three protocols, alone or in combination, on excised porcine skin and human hair contaminated with either methyl salicylate (MS), phorate (PHR), sodium fluoroacetate (SFA) or potassium cyanide (KCN). A second experiment investigated the residual hair contamination following decontamination with the triple protocol at different intervals post exposure. In a third experiment, hair decontaminated after exposure to MS or PHR was evaluated for off-gassing. Though skin decontamination was highly effective, a substantial proportion (20-40%) of the lipophilic compounds (MS and PHR) remained within the hair. The more water-soluble contaminants (SFA and KCN) tended to form much smaller reservoirs within the hair. Interestingly, substantial off-gassing of MS, a medium volatility chemical, was detectable from triple-decontaminated hair up to five days post exposure. Overall, the decontamination strategies investigated were effective for the decontamination of skin, but less so for hair. These findings highlight the importance of contaminated hair serving as a source of potential secondary contamination by contact or inhalation. Therefore, consideration should be given to the management of contaminated hair following exposure to toxic chemicals.

Exposure index of methyl isocyanate (MIC) gas disaster and a comprehensive spectrum of cytogenetic analysis after 30 years

Severity of clinical expression and high mortality could not facilitate establishing exposure index/association following MIC disaster in Bhopal. Mortality-based exposure stratification was critiqued by the International Medical Commission on Bhopal (IMCB). IMCB stratified exposure considering distance as surrogate at 2 km intervals after 10 years. The first follow-up cytogenetic screening of the pre-screened survivors after 30 years has demonstrated chromosome abnormalities (CA). Exposure stratification was attempted considering cytogenetic screening conducted during 1986-1988. Elevation of CA appeared proportional to exposure status and authenticated the initial mortality-based stratification. The one-on-one comparison of the previous and present cytogenetics has described the individual response to MIC exposure over 30 years. Chi-square test has been carried out for checking the cytogenetic changes at the individual level statistically, which revealed that differences of chromosomal aberrations collected immediately post-disaster and 30 years later are nonsignificant. The prominence of interindividual variation was noticed in general. The impact of overall exposure was higher in males. Constitutional abnormalities in 8.5% of the study population, including translocation, inversion, deletion, fragile sites, etc., necessitate screening of blood-linked members. The incidence of acrocentric association was prominent in the study population. Normal karyotype in children born to severely exposed parents with congenital anomalies indicates necessity of molecular karyotyping and/or screening of mutations. The study highlights follow-up of the health of the index cases at shorter (3-6 months) intervals. This comprehensive spectrum of cytogenetic report highlights immediate post-disaster chromosomal aberrations, the changes that occurred over 30 years in conjunction with other environmental factors at the individual level, constitutive genomic aberrations, polymorphic variations, and chromosomal patterns in congenitally malformed children of the survivors, which collectively indicate the possibility of acquisition/persistence of stable aberrations in MIC-exposed lymphocytes through interaction with environmental/biological confounders.

Endoscopic Optical Coherence Tomography for Assessing Inhalation Airway Injury: A Technical Review

Diagnosis of inhalation injury has been clinically challenging. Currently, assessment of inhalation injury relies on subjective clinical exams and bronchoscopy, which provides little understanding of tissue conditions and results in limited prognostics. Endoscopic Optical coherence tomography (OCT) technology has been recently utilized in the airway for direct assessment of respiratory tract disorders and injuries. Endoscopic OCT is capable of capturing high-resolution images of tissue morphology 1-3 mm beneath the surface as well as the complex 3D anatomical shape. Previous studies indicate that changes in airway histopathology can be found in the OCT image almost immediately after inhalation of smoke and other toxic chemicals, which correlates well with histology and pulmonary function tests. This review summarizes the recent development of endoscopic OCT technology for airway imaging, current uses of OCT for inhalation injury, and possible future directions.

Multivariate analysis of short time series in terms of ensembles of correlation matrices

When dealing with non-stationary systems, for which many time series are available, it is common to divide time in epochs, i.e. smaller time intervals and deal with short time series in the hope to have some form of approximate stationarity on that time scale. We can then study time evolution by looking at properties as a function of the epochs. This leads to singular correlation matrices and thus poor statistics. In the present paper, we propose an ensemble technique to deal with a large set of short time series without any consideration of non-stationarity. Given a singular data matrix, we randomly select subsets of time series and thus create an ensemble of non-singular correlation matrices. As the selection possibilities are binomially large, we will obtain good statistics for eigenvalues of correlation matrices, which are typically not independent. Once we defined the ensemble, we analyze its behavior for constant and block-diagonal correlations and compare numerics with analytic results for the corresponding correlated Wishart ensembles. We discuss differences resulting from spurious correlations due to repetitive use of time-series. The usefulness of this technique should extend beyond the stationary case if, on the time scale of the epochs, we have quasi-stationarity at least for most epochs.

Determination of methyl isopropyl hydantoin from rat erythrocytes by gas-chromatography mass-spectrometry to determine methyl isocyanate dose following inhalation exposure

Methyl isocyanate (MIC) is an important precursor for industrial synthesis, but it is highly toxic. MIC causes irritation and damage to the eyes, respiratory tract, and skin. While current treatment is limited to supportive care and counteracting symptoms, promising countermeasures are being evaluated. Our work focuses on understanding the inhalation toxicity of MIC to develop effective therapeutic interventions. However, in-vivo inhalation exposure studies are limited by challenges in estimating the actual respiratory dose, due to animal-to-animal variability in breathing rate, depth, etc. Therefore, a method was developed to estimate the inhaled MIC dose based on analysis of an N-terminal valine hemoglobin adduct. The method features a simple sample preparation scheme, including rapid isolation of hemoglobin, hydrolysis of the hemoglobin adduct with immediate conversion to methyl isopropyl hydantoin (MIH), rapid liquid-liquid extraction, and gas-chromatography mass-spectrometry analysis. The method produced a limit of detection of 0.05 mg MIH/kg RBC precipitate with a dynamic range from 0.05-25 mg MIH/kg. The precision, as measured by percent relative standard deviation, was <8.5%, and the accuracy was within 8% of the nominal concentration. The method was used to evaluate a potential correlation between MIH and MIC internal dose and proved promising. If successful, this method may be used to quantify the true internal dose of MIC from inhalation studies to help determine the effectiveness of MIC therapeutics.

Geologic and anthropogenic sources of contamination in settled dust of a historic mining port city in northern Chile: health risk implications

Chile is the leading producer of copper worldwide and its richest mineral deposits are found in the Antofagasta Region of northern Chile. Mining activities have significantly increased income and employment in the region; however, there has been little assessment of the resulting environmental impacts to residents. The port of Antofagasta, located 1,430 km north of Santiago, the capital of Chile, functioned as mineral stockpile until 1998 and has served as a copper concentrate stockpile since 2014. Samples were collected in 2014 and 2016 that show elevated concentrations of As, Cu, Pb, and Zn in street dust and in residents' blood (Pb) and urine (As) samples. To interpret and analyze the spatial variability and likely sources of contamination, existent data of basement rocks and soil geochemistry in the city as well as public-domain airborne dust were studied. Additionally, a bioaccessibility assay of airborne dust was conducted and the chemical daily intake and hazard index were calculated to provide a preliminary health risk assessment in the vicinity of the port. The main conclusions indicate that the concentrations of Ba, Co, Cr, Mn, Ni, and V recorded from Antofagasta dust likely originate from intrusive, volcanic, metamorphic rocks, dikes, or soil within the city. However, the elevated concentrations of As, Cd, Cu, Mo, Pb, and Zn do not originate from these geologic outcrops, and are thus considered anthropogenic contaminants. The average concentrations of As, Cu, and Zn are possibly the highest in recorded street dust worldwide at 239, 10,821, and 11,869 mg kg^-1, respectively. Furthermore, the contaminants As, Pb, and Cu exhibit the highest bioaccessibilities and preliminary health risk indices show that As and Cu contribute to elevated health risks in exposed children and adults chronically exposed to dust in Antofagasta, whereas Pb is considered harmful at any concentration. Therefore, an increased environmental awareness and greater protective measures are necessary in Antofagasta and possibly other similar mining port cities in developing countries.

Spectrum of health condition in methyl isocyanate (MIC)-exposed survivors measured after 30 years of disaster

Health effects of methyl isocyanate (MIC) exposure were mostly reported on the one-time acute exposure in Bhopal population. Epidemiological survey conducted by the Indian apex body of health research has been reported as Technical Reports, which were lacking in peer review by the expert epidemiologic scientists. The present pilot survey was aimed to measure the health effects 30 years post disaster in MIC-exposed survivors. Questionnaire-based survey has captured every health complaint in 168 individuals and grouped as systemic functions for interpreting the long-term effects of MIC. Key health parameters, including reproductive outcome and respiratory/orthopedic/general morbidity, were prevalent among the severely exposed population compared to control and moderately exposed groups. The collective incidence of diabetes, hypertension, and cancer also was prevalent in the severely exposed group. Ophthalmic morbidity was almost similar in the three groups, rather with higher incidence in the control group, though not statistically significant. Among all health parameters, reproductive, ophthalmic, and respiratory effects were prevalent over others. Although the incidence of health problems has been declined among the survivors, long-term effect is apparent as scars of one-time acute exposure might trigger sequel of long-term effects. Additionally, acquisition of genetic rearrangements, survival of T cell sub-populations, variable latency of chemical effect on DNA nucleosides, nutritional status, occupational exposure, living environment, lifestyle, and overall gene-environment interaction might perturb individual immunity and favor onset of long-term illness in a scenario of background exposure to MIC. However, the exercise should be continued on a larger sample size for drawing a conclusive result on long-term MIC effect on survivors' health.

Combining uretdione and disulfide reversibly degradable polyurethanes: route to alternating block copolymers

Uretdione (temperature and catalyst controlled) and disulphide (REDOX controlled) functionalised polyurethanes have been described and the reversibility of these bonds tested.