The "disease of the crazy hatman" and the effects of human exposure to mercury: A case report / A "doença do homem do chapéu maluco" e os efeitos da exposição humana ao mercúrio: Um relato de caso

INTRODUCTION: Mercury, in addition to being a heavy metal, is considered a neurotoxin, that is, a substance capable of negatively affecting the neurological functions of the human body. Nowadays, ““Mad Hatter's Disease”” is the name used to characterize these neurological disorders caused by mercury. PURPOSE: to report a clinical case of the manifestation of “Mad Hatter's Disease”, as well as to discuss about the effects of human exposure to mercury. METHODOLOGY: this is a clinical case report, in which the patient is essential. CASE REPORT: A 45-year-old male patient, gold miner, from a riverside community in the Amazon, was referred to the hospital with complaints of headache, extremities tremor, diarrhea, tiredness, discouragement, irritability, depression, unusual shyness and hallucinations. On physical examination, the patient was anxious, irritable, symmetrical small-amplitude tremors in the extremities, hyperreflexia ++/4+ in the upper limbs, +/4+ in the lower limbs, normal muscle strength, mild ataxia of the right hand, stained skin and mucous membranes, and acyanotic, with erythematous-scaly lesions, confluent on the trunk, palms and soles of the feet. Screening for mercury poisoning was performed, where it was found, both in blood and urine, the presence of mercury 20 times above the biological tolerance limit. A battery of specific neuropsychological tests was carried out in neurotoxicological assessments and these demonstrated impairment of the cognitive domains (deficit of memory, attention, concentration, reasoning and abstraction) and alterations in motor functions, showing reduced coordination and motor speed. The diagnosis of hydrargyrism or occupational chronic metallic mercuralism (MMCO) was given. DISCUSSION: Chronic occupational exposure to inorganic mercury can cause subclinical abnormalities, as well as long-term psychomotor and neuromuscular behavioral impairment. Neuropsychiatric abnormalities (inattention, memory, interpretation, and motor performance) appear to be dose-related. FINAL CONSIDERATIONS: chronic exposure to metallic mercury vapor characteristically compromises the nervous system, initially with nonspecific symptoms and, later, with characteristic motor disorders - small amplitude tremor, paresis, dysreflexia and difficulty in motor coordination, which gives rise to the "Disease of the Mad Hatter”, and inhaling large amounts of mercury vapor can be lethal.

Sphingidae (Lepidoptera: Bombycoidea) assemblage in the State Ecological Station of Wenceslau Guimarães, Bahia, Brazil

The diversity of hawkmoths (Lepidoptera: Sphingidae) is poorly known in the biomes of the Bahia state. However, studies were carried out in other states of the northeastern region with species inventories in the Atlantic Forest, Caatinga and Cerrado. In order to bro aden the knowledge on of the richness and diversity of hawkmoths in the Atlantic Forest of the state of Bahia, six monthly sampling sessions were carried out in the State Ecological Station of Wenceslau Guimarães. Hawkmoths were captured using a 250-watt mercury-vapor light trap set against a white cloth panel, for two nights a month, between 6:00 p.m. and 6:00 a.m. A total of 266 specimens were collected, distributed across 17 genera and 41 species. The most abundant and dominant species were Isognathus swainsoni C. Felder, 1862, with a relative abundance of 12.41%, and Xylophanes amadis (Cramer, 1782) and Xylophanes anubus (Cramer, 1777), both with 7.9%. Our study represents the second inventory of hawkmoths for the state, totaling 59 species known for the Atlantic Forest of Bahia. Isognathus excelsior (Boisduval, [1875]) and Manduca lucetius (Cramer, 1780) represented new records for the biome. The accumulated number of species indicates the need for further sampling in order to safely reach the curve asymptote.

STUDY OF METHODS FOR MEASURING THE OPTICAL CHARACTERISTICS OF LOW-PRESSURE MERCURY LAMPS

Obtaining experimental data on the electrical and photometric parameters of low-pressure tubular amalgam lamps with a discharge in a mixture of mercury vapor and inert gases at high current densities of 0.5-1.2 A/cm2 with frequencies of tens of kilohertz is one of the key problems of modern metrology. Since a full-fledged study of the properties of experimental samples of mercury lamps is impossible without a reliable method of photometric measurements, and for ozone lamps such a technique, taking into account the features of the object of study, has not yet been proposed, its development and testing is the main task of this work. Based on the analysis of existing techniques, a technique for measuring the fluxes of the 185 and 254 nm lines of a low-pressure mercury lamp is proposed, taking into account the change in the nature of the spatial distribution of radiation during operation, without directly measuring the RIC. The method proposed by the author for measuring the fluxes of ozonizing and bactericidal radiation can be used as the basis for the development of an automated system for measuring parameters and monitoring the quality of gas-discharge UV radiation sources.

Assembly of UV-Ozone Reactor to Combat of Coronavirus and Other Pathogenic Microorganisms

The contamination on the surface of objects caused by: fungi, microbes, bacteria and viruses (and also coronavirus) can be solved using UV rays and/or ozone gas. For this reason, a UV-Ozone reactor apparatus with low cost was mounted to test two different types of HID (high intensity discharge) lamps: high pressure mercury vapor lamp (HPMVL) and metal halide lamp (MHL), both with nominal power of 400 watts and E-40 (base, screw) were studied as possible method of disinfection. Each lamp used the respective electromagnetic ballasts and both were manufactured by Osram Company. These lamps have two bulb types: the outer bulb which was removed and it is responsible for filtering the ultraviolet wavelengths and the internal bulb (where there is mercury, argon or metal halide confined at high pressure) that is the main source of ultraviolet rays. The complete apparatus was assembled using: aluminum reflector (used as a chamber), two microcomputer fans and a wooden base covered by an aluminum foil. A rubber strip was placed at the edge of the reflector for better adhesion on the aluminum foil (for better confinement ozone gas). The ozone concentration inside the reactor was measured with a monitor, the temperatures were measured near lamps with a thermocouple and a spectroradiometer with optical fiber was used to obtain the wavelengths. The results revealed to the elapsed time of 2 minutes a maximum peak of ozone concentration of 23 ppm for LVMAP, while the MHL presented 4.5 ppm only. The temperature obtained by HPMVL was lower with 31.5 ºC, while the MHL presented 48.0 ºC. The HPMVL presented higher amount of wavelengths at the ranges: UV-A, UV-B and UV-C, while the MHL presented only UV-A. For these reasons, it is suggested to be most promissory the use of HPMVL to combat the coronavirus and other pathogenic microorganisms.

Long-term visual pathway alterations after elemental mercury poisoning: report of a series of 29 cases

Background There are few clinical data on retinal involvement after acute exposure to high concentrations mercury and the available reports are based on a small number of patients suffering chronic exposure. The purpose of this paper is to report findings in workers acutely exposed to very high concentrations of mercury vapor with the aim of providing data on a possible direct retinal involvement. Methods Twenty-nine patients and 16 controls were evaluated in a comparative case series. Mercury levels in blood and urine samples, visual acuity (VA), contrast sensitivity (CS), visual field (VF), color discrimination and optical coherence tomography (OCT) were recorded. The pattern reversal visual-evoked potentials (PRVEP), full-field and multifocal electroretinography (ffERG/mfERG), pattern electroretinography (PERG), systemic symptoms, presence of erethism, and electromyography (EMG) were also gathered. A descriptive analysis was performed. The correlations between variables also were studied. In addition, electrophysiological data from those patients with deeper VF defects (group 1) were compared with a normal control group. Results Twenty-six workers exhibited symptoms of erethism. The EMG showed sensorimotor polyneuropathy and multiple mononeuropathy. The VA was slightly affected in 48.27% (n = 14) of subjects. Loss of CS in at least one of four spatial frequencies and color vision alterations occurred in 96.5% (n = 28) and 44.8% (n = 13), respectively. VF alterations were identified in 72.4% (n = 21) patients. No morphologic changes were seen in the OCT scans. Latencies over 100 milliseconds and reduced amplitudes of P100 were found in the PRVEP (p < 0.05). The reduced amplitude of the b wave at the ffERG, of the P50 at the PERG and of the P1 wave at the mfERG results (p < 0.05) suggested that the outer retina was involved. Significant negative correlations among blood mercury levels, VA, and ffERG were observed. Conclusions In this case series, showed that acute exposure to mercury vapor had a hazardous effect on the visual system. Although neurologic and visual pathway involvement was clearly demonstrated, the differences found compared to control support the existence of a direct functional retinal damage and participation in impaired vision in mercury poisoning.

Effective Decontamination and Remediation After Elemental Mercury Exposure: A Case Report in the United States

Elemental mercury exposure can result in significant toxicity. Source decontamination and remediation are often required after larger elemental mercury exposures, but the details of these processes are infrequently reported. In the case described herein, a 64-year-old woman and her husband were exposed to elemental mercury in their home after the husband purchased it online for the purpose of recreational barometer calibration. After the mercury reportedly spilled during the calibration process, a vacuum cleaner was used to decontaminate the affected surface; this led to extensive mercury contamination of the home. The couple was relocated from the home while remediation occurred over the course of several weeks. Vacuum cleaning of an elemental mercury spill can lead to extensive volatilization and recirculation of mercury vapor. For smaller mercury spills, careful removal of visible mercury beads by using an eyedropper, cardboard, and masking tape is recommended. Larger spills require professional decontamination and remediation and may necessitate involvement of governmental resources. Vacuum cleaning should not be used as an initial method of decontamination after elemental mercury exposure. Careful attention to source decontamination can reduce the emotional and financial costs associated with extensive remediation after elemental mercury exposure.

Effects of Elemental Mercury Vapor Inhalation on Arterial Blood Gases, Lung Histology, and Interleukin-1 Expression in Pulmonary Tissues of Rats

We investigated the effects of elemental mercury vapor inhalation on arterial blood gases (ABGs), lung histology, and interleukin-1 (IL-1) expression in pulmonary tissues in rats. A total of 42 Sprague Dawley rats were divided randomly into three groups. Rats in the first group were used as the control (CG). A short-term group (STG) and a long-term group (LTG) were exposed to 500 μg/m3 of mercury vapor 2 hrs/day for 21 days and 65 days, respectively. After exposure periods were completed, arterial blood samples were obtained, and ABGs were measured. Lung tissue sections were prepared for histology evaluation and immune-stained to detect IL-1 expression. There was a significant decrease in body weight in both STG (15%) and LTG (22%) compared with the CG. In the LTG, six out of 14 (43%) rats died, including two males and four females, while none of the rats in the STG died during the experiment. In both STG and LTG, a significant acid-base imbalance was characterized by a significant decrease in blood pH values and a significant increase in PCO2 values. Both PO2 and SpO2 blood values were significantly decreased in the STG and LTG, while no changes were observed in HCO3 values in all groups. Histological evaluation of lung tissues revealed severe lesions characterized by pulmonary emphysema and inflammatory cellular infiltrate. IL-1 expression in lung tissues was not significantly different between exposed rats and control subjects. These results indicate significant alterations in blood acid-base status characterized by severe respiratory acidosis with hypoxemia and no evidence of compensatory alkalosis in rats after exposure to short- and long-term elementary mercury vapor.

BIOLOGICAL MONITORING OF WORKERS EXPOSED TO MERCURY AND ITS COMPOUNDS

Biological monitoring is used to assess the toxic effect of mercury on the human body and to identify risk groups for the development of mercury intoxication at various stages of clinical and laboratory examination of workers who have contact with mercury vapor. A comprehensive analysis of changes in the biomarkers of exposure and effect in the conditions of professional exposure to mercury on the body of workers allows us to identify groups at increased risk of developing health disorders and optimize therapeutic and preventive measures taking into account the individual characteristics of the body. Biological monitoring should be implemented at the stage of preliminary, periodic medical examinations and in-depth examination of workers in contact with mercury vapor. Correlation and regression analysis of the data obtained showed a significant positive relationship between the average concentration of mercury in the air of the working area and the average concentration of mercury in the urine of the main occupational groups of mercury production workers.

UV Inactivation of SARS-CoV-2 across the UVC spectrum: KrCl* excimer, mercury-vapor, and LED sources

Effective disinfection technology to combat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can help reduce viral transmissions during the on-going COVID-19 global pandemic and in the future. Ultraviolet (UV) devices emitting UVC irradiation (200-280 nm) have proven to be effective for virus disinfection, but limited information is available for SARS-CoV-2 due to the safety requirements of testing, which is limited to biosafety level (BSL) 3 laboratories. In this study, inactivation of SARS-CoV-2 in thin-film buffered aqueous solution (pH 7.4) was determined across UVC irradiation wavelengths (222 nm to 282 nm) from krypton chloride (KrCl*) excimers, a low-pressure mercury-vapor lamp, and two UVC light emitting diodes. Our results show that all tested UVC devices can effectively inactivate SARS-CoV-2, among which the KrCl* excimer had the best disinfection performance (i.e., highest inactivation rate). The inactivation rate constants of SARS-CoV-2 across wavelengths are similar to those for murine hepatitis virus (MHV) from our previous investigation, suggesting that MHV can serve as a reliable surrogate of SARS-CoV-2 with a lower BSL requirement (BSL-2) during UV disinfection tests. This study provides fundamental information for UVC action on SARS-CoV-2 and guidance for achieving reliable disinfection performance of UVC devices. IMPORTANCE UV light is an effective tool to help stem the spread of respiratory viruses and protect public health in commercial, transportation and healthcare settings. For effective use of UV, there is a need to determine the efficiency of different UV wavelengths in killing pathogens, specifically SARS-CoV-2, to support efforts to control the on-going COVID-19 global pandemic and future coronavirus-caused respiratory virus pandemics. We found that SARS-CoV-2 can be inactivated effectively using a broad range of UVC wavelengths, and 222nm provided the best disinfection performance. Interestingly, 222 nm irradiation has been found to be safe for human exposure up to thresholds that are beyond effective for inactivating viruses. Therefore, applying UV light from KrCl* excimers in public spaces can effectively help reduce viral aerosol or surface transmissions.