Difficulties in interpretation when assessing prolonged and subacute exposure to the toxic effects of chlorine

[The role of the pulmonologist in an armed conflict]

INTRODUCTION

Recent news points to the eventuality of an armed conflict on the national territory.

STATE OF THE ART

In this situation, pulmonologists will in all likelihood have a major role to assume in caring for the injured, especially insofar as chest damage is a major cause of patient death.

PERSPECTIVES

The main injuries that pulmonologists may be called upon to treat stem not only from explosions, but also from chemical, biological and nuclear hazards. In this article, relevant organizational and pedagogical aspects are addressed. Since exhaustiveness on this subject is unattainable, we are proposing training on specific subjects for interested practitioners.

CONCLUSION

The resilience of the French health system in a situation of armed conflict depends on the active participation of all concerned parties. With this in mind, it is of prime importance that the pneumological community be sensitized to the potential predictable severity of war-related injuries.

Enhanced Visible-Light Absorption of Fe2O3 Covered by Activated Carbon for Multifunctional Purposes: Tuning the Structural, Electronic, Optical, and Magnetic Properties

Visible-light absorption is a critical factor for photocatalyst activity and absorption of electromagnetic (EM) interference application. The band gap of Fe2O3 is 2 eV, which can be increased by doping with a high-band-gap material such as carbon from activated carbon (AC) with a band gap of 4.5 eV for increased visible-light absorption. The porosity decreases from 88 to 81.6%, and the band gap increases from 2.14 to 2.64 eV by increasing the AC from 10 to 25%, respectively. The photocatalytic activity takes 120 min to produce a harmless product for 10-20% AC, but 25% AC shows 89.5% degradation in only 90 min and the potential to attenuate the EM wave up to 99% due to the RL being below -20 dB. The second- and third-cycle degradation achieved by the composite Fe2O3-AC having 25% AC is 88.2 and 86.5% in 90 min, respectively. The pore of the surface state of AC contains a trapped charge, and interaction occurs between the charge (electron/hole) and O2 or H2O to produce OH and superoxide (O2 -) radicals. These radicals move inside the molecule of the pollutant (methylene blue (MB)) to break up the bond, with the final products being H2O and CO2. The X-ray photoelectron (XPS) spectra show that oxygen plays a key role in the interatomic bonding with Fe, C, and MB atoms. The best absorption of EM interference is -21.43 dB, with degradation reaching 89.51% in only 90 min for 25% AC due to its higher band gap and anisotropy constant. Fe2O3-carbon is a multifunctional material for the green environment because of its electromagnetic interference absorption and photodegradation of wastewater.

Dynamic characteristics of chlorine dispersion process and quantitative risk assessment of pollution hazard

The aim of this study was to analyze dispersion behavior characteristics and pollution hazard risk after a release of liquid chlorine. A full-scale model of liquid chlorine tanks in an area with a radius range of 3 km was established using FLACS (Flame Acceleration Simulator) code, and the chlorine dispersion characteristics of six leakage scenarios were calculated according to the POOL model, and the individual risk and social risk under different conditions as calculated quantitatively. The results show that leakage occurs in three stages: dynamic dispersion, gravity dispersion, and atmospheric dispersion. Variations in dispersion processes were expressed as "outward expansion" and "inward contraction." At the same time, dispersion was accompanied by the phenomenon of "cloud separation." In the six leakage scenarios, the total distance of chlorine dispersion was 84-1000 m for a concentration of 225 ppm, and 27.5-401.3 m for a concentration of 900 ppm. The corresponding times (duration) to the farthest dispersion distance were 235-1345 s and 185-680 s, respectively. Chlorine concentration and dispersion distance are consistent in trend; however, the farthest dispersion distance shows a "delay effect" in time. At 225 ppm and 900 ppm, the delay time was 125-1145 s and 75-480 s indifferent leakage scenarios. The installation of a safety instrument system (SIS) can effectively reduce the risk of chlorine dispersion.

Development of an LC-MS/MS method for quantification of 3-chloro-L-tyrosine as a candidate marker of chlorine poisoning

A simple and sensitive liquid chromatography coupled with electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) method for the determination of 3-chloro-L-tyrosine (Cl-Tyr) was developed and validated. For sample preparation, 50 μL of the body fluids or tissue extracts were processed by protein precipitation followed by the derivatization with dansyl chloride. The calibration curve was linear over the concentration range of 2.0-200 ng/mL blood or 4.0-400 ng/g tissue. Our method allowed the reproducible and accurate quantification. That is, the intra- and inter-assay coefficients of variation were below 7.73 and 6.94%, respectively in both the blood and lung. We applied the developed method to the analysis of Cl-Tyr in the human autopsy samples, which were suspected of chlorine poisoning, and detected 55.2 ng/mL and 206.6 ng/g Cl-Tyr in left heart blood and lung, respectively. Furthermore, in more than 20 autopsy samples, which were obtained from other causes of death including burn, drowning, hanging, internal disease, trauma and drug poisoning, Cl-Tyr was almost not detected in their both body fluids and organ tissues. In conclusion, the data here reported demonstrate that the LC/ESI-MS/MS method allows the Cl-Tyr in the autopsy samples and that chlorine exposure strongly affects its level, providing a basis for novel identification tool of chlorine poisoning.

Determination of 3-chloro-l-tyrosine as a novel indicator of chlorine poisoning utilizing gas chromatography-mass spectrometric analysis

Chlorine gas exposure occurs in chemical warfare, industrial and household accidents. In forensic science, the generation of chlorine gas by mixing sodium hypochlorite detergent and strong acid detergent cannot be overlooked because of the possibility of suicide method (NaClO + 2HCl → NaCl + H₂O + Cl₂). Though typical autopsy findings are obtained in chlorine exposure, such as pulmonary edema, useful biomarkers don't exist. In this research, we developed an analytical method of 3-chloro-l-tyrosine (Cl-Tyr) in blood as a novel marker of chlorine poisoning utilizing gas chromatography-mass spectrometry (GC-MS). Cl-Tyr was purified using protein precipitation and cation-exchange solid phase extraction, derivatized by the silylation agent and subjected to GC-MS. The quantification range was 10-200 ng/mL and good reproducibility was obtained. We applied the developed method to analyze Cl-Tyr in autopsy sample, which is suspected of chlorine poisoning, and detected 59.7 ng/mL Cl-Tyr in left heart blood. To our knowledge, this is the first report of determination of the chlorinated biomolecule in the human autopsy sample from chlorine poisoning.

Respiratory effects of occupational exposure to low concentration of hydrochloric acid among exposed workers: a case study in steel industry

Occupational exposure to hydrochloric acid in pickling of steel for remove rust or iron oxide scale from iron processing occurs at low concentration. This study aimed to investigate the respiratory symptoms and pulmonary dysfunction caused by exposure to low concentration of hydrochloric acid in acid washing unit in one of the steel industries. A case control study was carried out in the acid washing unit of the cold rolling of the steel industry in 2017. The exposed group included 45 male workers, and another 41 unexposed employees from official employees were enrolled as control group. A questionnaire was used to collect personal and occupational data and pulmonary function tests, including forced vital capacity (FVC), forced expiratory volume in the first second and peak expiratory flow rate followed guidelines given by the American Thoracic Society and measured with a portable calibrated vitalograph spirometer. For determination of acid concentration, 21 breathing zone air samples were collected in accordance with Method 7903 NIOSH. The findings showed that nose sensitivity, throat irritation and shortness of breath were the highest prevalence symptoms among exposed persons (30.4% to 32.6%). Also, the results showed that FVC and forced expiratory volume in the first second had highest and direct or positive correlation with height (0.965 and 0.927, respectively). Age and weight put in the next priorities (P < 0.01). On the other hand, based on the results of multivariate linear regression, exposing to the acid and job history are two main predictor factors for FVC. So that, the exposing to acid, by itself can reduce FVC as 4.386 units. This value is equal to 1.117 for the job history. Exposure to low concentrations of hydrochloric acid alone could increase the risk of respiratory tract damage and pulmonary function disorders. But the extent to which it can cause respiratory complications for occupational exposure is still unknown and requires further study. This study was approved by Ethical Committee of Qom University of Medical Sciences (approval No. IR.MUQ.REC.1397.118) on November 6, 2018.