Caracterização da qualidade do ar atmosférico na Cidade de São Paulo para compostos do grupo BTEX (benzeno, tolueno, etilbenzeno e xilenos), utilizando amostradores passivos / Characterization of atmospheric air quality in the City of São Paulo for compounds of the BTEX group (benzene, toluene, ethylbenzene and xylenes), using passive samplers

A presença de compostos do grupo BTEX, no ar atmosférico de grandes centros urbanos como a cidade de São Paulo é proveniente principalmente de emissões veiculares e demais fontes como as industriais. A exposição a estes compostos, principalmente quando inalados, podem causar sérios efeitos adversos a saúde humana, especialmente o composto benzeno que possui propriedades cancerígenas. Desta forma, a presente pesquisa teve objetivo realizar uma caracterização da qualidade do ar atmosférico na cidade de São Paulo utilizando amostradores passivos para quantificação de compostos do grupo BTEX. Foram selecionadas 5 áreas na cidade conforme dados de tráfego destas regiões e de acordo com o perfil de uso e ocupação do solo. Adicionalmente, foi selecionada uma área como background, com interferência mínima de emissões veiculares ou industriais. Ao todo foram realizadas 3 campanhas de amostragem no entre os anos de 2020 e 2021. O período de coleta de cada campanha foi de 21 dias e na sequência as amostras foram enviadas para análise química em laboratório através do método USEPA-TO17, de 1999 com a utilização de dessorvedor térmico acoplado à um cromatógrafo de gás e um espectrômetro de massas. Foram quantificadas concentrações de BTEX em todas as áreas selecionadas, com destaque para as concentrações de benzeno cuja variação foi de 1,2µg/m3 a 13,5µg/m3, e média de 4,6µg/m3, considerando as 3 campanhas e todas as áreas. Dentro as áreas avaliadas, os pontos localizados no bairro de Santo Amaro apresentaram as maiores concentrações de BTEX, seguido dos pontos no Jaguaré, Mooca, Pinheiros e Paraíso. A campanha realizada no inverno de 2021 apresentou as maiores concentrações tendo influência das condições meteorológicas características desta estação como também influência do aumento do número de veículos circulando na cidade decorrente da diminuição do distanciamento social necessário por conta da pandemia da COVID-19. Os tratamentos estatísticos utilizados nesta pesquisa, especialmente as ferramentas PCA e PMF, concluíram que a principal contribuição para a presença dos BTEX no ar atmosférico são as emissões veiculares, principalmente para os veículos movidos a gasolina.

The presence of compounds from the BTEX group in the atmospheric air of large urban centers such as the city of São Paulo comes mainly from vehicular emissions and other sources such as industrial ones. Exposure to these compounds, especially when inhaled, can cause serious adverse effects on human health, especially the compound benzene, which has carcinogenic properties. Thus, the present research aimed to carry out a characterization of the atmospheric air quality in the city of São Paulo using passive samplers to quantify compounds of the BTEX group. Five areas were selected in the city according to traffic data from these regions and according to the profile of land use and occupation. Additionally, an area was selected as a background, with minimal interference from vehicular or industrial emissions. In all, 3 sampling campaigns were carried out between the years 2020 and 2021. The collection period of each campaign was 21 days and then the samples were sent for chemical analysis in the laboratory using the USEPA-TO17 method, from 1999 with the use of a thermal desorber coupled to a gas chromatograph and a mass spectrometer. BTEX concentrations were quantified in all selected areas, especially benzene concentrations which ranged from 1.2µg/m3 to 13.5µg/m3, and an average of 4.6µg/m3, considering the 3 campaigns and all areas. Within the evaluated areas, the points located in the Santo Amaro neighborhood had the highest concentrations of BTEX, followed by the points in Jaguaré, Mooca, Pinheiros and Paraíso. The campaign carried out in the winter of 2021 showed the highest concentrations influenced by the meteorological conditions characteristic of this season as well as the influence of the increase in the number of vehicles circulating in the city due to the decrease in the social distance necessary due to the COVID-19 pandemic. The statistical treatments used in this research, especially the PCA and PMF tools, concluded that the main contribution to the presence of BTEX in the atmospheric air are vehicular emissions, especially for gasoline-powered vehicles.

Comparative Bioaccumulation of PAH and BTEX in Malapterurus electricus (Siluriformes: Malapteruridae) and its Enteric Parasite, Electrotaenia malopteruri Sampled from Lekki Lagoon, Lagos, Nigeria / Bioacumulação comparativa de HAP e BTEX em Malapterurus electricus (Siluriformes: Malapteruridae) e seu parasita entérico, Electrotaenia malopteruri, coletado na lagoa Lekki, Lagos, Nigéria

Abstract Contamination of Lekki lagoon by petrogenic chemicals such as polycyclic aromatic hydrocarbons (PAH) and benzene, toluene, ethylbenzene, and xylene (BTEX) has been widely reported. The study was aimed at investigating the bioaccumulation of PAH and BTEX in Malapterurus electricus collected from Lekki lagoon in Lagos, Nigeria. BTEX was analyzed in the intestine, water, and sediment samples using 8260B Agilent 7890B gas chromatograph coupled to a mass spectrometer (GC-MS). While PAHs were tested in the same media using a gas chromatograph coupled to a flame ionization detector (GC-FID). Histopathological analysis of the fish intestine was conducted using haematoxylin and eosin (H&E) stains. Parasite intensity, antioxidant enzymes, and lipid peroxidation activities were investigated in the fish. The parasitic infection detected in Malapterurus electricus was Electrotaenia malopteruri. The parasite showed weak and no depurative capacities for BTEX and PAH respectively. The decrease in superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) in conjunction with an increase in Malondialdehyde (MDA) characterized relatively higher susceptibility among the male fish. Varieties of tissue injuries increased with the standard length of the fish groups. Results suggest that lengthier and uninfected M. electricus were more susceptible to PAH in Lekki lagoon than the shorter and infected ones. The study demonstrated a promising tendency of the enteric parasite, E. malopteruri to depurate chlorobenzene, ethylbenzene, o-xylene, m+p-xylene, and 1,4-dichlorobenzene from the intestine of its host fish, M. electricus, while PAHs were poorly mediated by the parasite.

Resumo A contaminação da lagoa Lekki por produtos químicos petrogênicos, como hidrocarbonetos aromáticos policíclicos (HAP) e benzeno, tolueno, etilbenzeno e xileno (BTEX), foi amplamente relatada. O estudo teve como objetivo investigar a bioacumulação de HAP e BTEX em Malapterurus electricus, coletados na lagoa Lekki, em Lagos, Nigéria. O BTEX foi analisado no intestino, na água e nas amostras de sedimento usando o cromatógrafo de gás Agilent 7890B 8260B acoplado a um espectrômetro de massa (GC-MS). Já os HAP foram testados no mesmo meio utilizando cromatógrafo gasoso acoplado a detector de ionização de chama (GC-FID). A análise histopatológica do intestino do peixe foi conduzida usando colorações de hematoxilina e eosina (H&E). Intensidade de parasitas, enzimas antioxidantes e atividades de peroxidação lipídica foram investigadas nos peixes. A infecção parasitária detectada em Malapterurus electricus foi Electrotaenia malopteruri. O parasita mostrou fraca e nenhuma capacidade depurativa para BTEX e HAP, respectivamente. A diminuição da superóxido dismutase (SOD), catalase (CAT) e glutationa reduzida (GSH), em conjunto com o aumento do Malondialdeído (MDA), caracterizou a suscetibilidade relativamente maior entre os peixes machos. Variedades de lesões nos tecidos aumentaram com o comprimento padrão dos grupos de peixes. Os resultados sugerem que os M. electricus maiores e não infectados foram mais suscetíveis aos HAP na lagoa Lekki do que os menores e infectados. O estudo demonstrou uma tendência promissora do parasita entérico E. malopteruri de depurar clorobenzeno, etilbenzeno, o-xileno, m + p-xileno e 1,4-diclorobenzeno do intestino de seu peixe hospedeiro, M. electricus, enquanto os HAP foram mal mediados pelo parasita.

Occupational Health Risk Assessment of Benzene, Toluene, and Xylene in Shanghai / 生物医学与环境科学（英文）

Objective@#This study was designed to conduct a retrospective and systematic occupational health risk assessment (OHRA) of enterprises that used benzene, toluene, and xylene (BTX) in Shanghai, China.@*Methods@#All data for the study were obtained from 1,705 occupational health examination and evaluation reports from 2013 to 2017, and a semiquantitative model following Chinese OHRA guidelines (GBZ/T 298-2017) was applied for the assessment.@*Results@#The selected enterprises using BTX were mainly involved in manufacturing of products. Using the exposure level method, health risk levels associated with exposure to BTX were classified as medium, negligible, or low. However, the risk levels associated with benzene and toluene were significantly different according to job types, with gluers and inkers exhibiting greater health risks. For the same job type, the health risk levels assessed using the comprehensive index method were higher than those using the exposure level method.@*Conclusion@#Our OHRA reveals that workers who are exposed to BTX still face excessive health risk. Additionally, the risk level varied depending on job categories and exposure to specific chemicals. Therefore, additional control measures recommended by OHRA guidelines are essential to reduce worker exposure levels.

Effects of Toluene on the Development of the Inner Ear and Lateral Line Sensory System of Zebrafish / 生物医学与环境科学（英文）

Objective@#The aim of this study was to explore the ototoxicity of toluene in the early development of zebrafish embryos/larvae.@*Methods@#Zebrafish were utilized to explore the ototoxicity of toluene. Locomotion analysis, immunofluorescence, and qPCR were used to understand the phenotypes and molecular mechanisms of toluene ototoxicity.@*Results@#The results demonstrated that at 2 mmol/L, toluene induced zebrafish larvae death at 120 hours post fertilization (hpf) at a rate of 25.79% and inhibited the rate of hatching at 72 hpf. Furthermore, toluene exposure inhibited the distance travelled and average swimming velocity of zebrafish larvae while increasing the frequency of movements. As shown by fluorescence staining of hair cells, toluene inhibited the formation of lateral line neuromasts and middle line 1 (Ml @*Conclusion@#This study indicated that toluene may affect the development of both the inner ear and lateral line systems in zebrafish, while the lateral line system may be more sensitive to toluene than the inner ear.

Avaliação da exposição a BTEX em postos de revenda de combustíveis no Rio de Janeiro, Brasil, e os riscos à saúde do trabalhador / Assessment of exposure to BTEX in vehicle filling stations in Rio de Janeiro, Brazil, and risks to workers' health / Evaluación de la exposición a BTEX en puestos de reventa de combustibles, en Río de Janeiro, Brasil, y riesgos para la salud del trabajador

A gasolina é uma mistura complexa de substâncias, dentre elas estão hidrocarbonetos como o benzeno, tolueno, etilbenzeno e xilenos (BTEX), sendo esses compostos emitidos para a atmosfera, com destaque ao benzeno, por ser comprovadamente carcinogênico. Objetivamos avaliar as concentrações de BTEX no ar de postos de revenda de combustíveis no Município do Rio de Janeiro, Brasil, e calcular o risco de câncer associado a estas exposições. Foram realizados dois tipos de amostragem (fixa e móvel) adaptadas da metodologia nº 1.501 do Instituto Nacional de Segurança e Saúde Ocupacional (Estados Unidos), em seis postos de revenda de combustíveis na Zona Oeste da cidade. A amostragem fixa foi feita próxima às bombas de combustível, enquanto a móvel foi realizada através da coleta do ar na zona respiratória dos trabalhadores (frentistas), conforme estes se deslocavam pelo posto. As amostras foram analisadas por cromatografia gasosa com detecção por ionização em chama. Com os resultados das amostragens foram feitos os cálculos de risco à saúde, usando os indicadores Quociente de perigo (HQ) e Risco de câncer (CR), para avaliar os possíveis efeitos não-carcinogênicos e carcinogênicos, respectivamente, nos trabalhadores dos postos de revenda de combustíveis. As concentrações ambientais para a maioria dos compostos BTEX foram abaixo dos limites preconizados, menos para o benzeno, um composto carcinogênico, que apresentou concentrações muito acima dos limites, levando a altos valores de risco de câncer. Os resultados demonstraram que há riscos à saúde dos trabalhadores de postos de revenda de combustíveis, principalmente o risco de desenvolver câncer, devido à exposição excessiva ao benzeno.

Gasoline is a complex mixture of substances, including aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylenes (BTEX). These compounds are emitted into the air, with the special relevance of benzene since it is provenly carcinogenic. The study aimed to assess BTEX concentrations in filling stations in the city of Rio de Janeiro, Brazil, and to calculate the cancer risk associated with such exposures. Two types of sampling were performed (stationary and mobile), adapted from methodology n. 1,501 (U.S. National Institute for Occupational Safety and Health) for aromatic hydrocarbons, in six filling stations in the West Zone of Rio de Janeiro. Stationary sampling was done near the fuel pumps, while mobile sampling was done in the breathing zone of the workers (station attendants) as they moved around the station. The samples were analyzed with gas chromatography flame ionization detector. The sampling results were used to calculate the health risk, using the indicators Hazard quotient (HQ) and Cancer risk (CR) to assess the possible non-carcinogenic and carcinogenic effects, respectively, in filling station workers. Environmental concentrations for the most of the BTEX compounds were below the recommended limits, except for benzene, a carcinogenic compound, which displayed concentrations far above the limits, leading to high cancer risk values. The results showed that there are health risks for filling station attendants, especially the risk of developing cancer from excessive exposure to benzene.

La gasolina es una mezcla compleja de sustancias, entre ellas existen hidrocarburos como el benceno, tolueno, etilbenceno y xilenos (BTEX), emitiéndose estos compuestos a la atmósfera, donde se destaca el benceno, al tratarse de un carcinogénico comprobado. Los objetivos fueron evaluar las concentraciones de BTEX en el aire de puestos de reventa de combustibles, en el municipio de Río de Janeiro, Brasil, así como calcular el riesgo de cáncer asociado a estas exposiciones. Se realizaron dos tipos de muestra (fija y movible), adaptadas de la metodología nº 1.501 del Instituto Nacional de Seguridad y Salud Laboral (EE.UU.), en seis puestos de reventa de combustibles de la zona oeste de la ciudad. La muestra fija se realizó cerca de las bombas de combustible, mientras que la móvil se hizo mediante tomas de aire en la zona respiratoria de los trabajadores (de la gasolinera), a medida que estos se desplazaban por el lugar de trabajo. Las muestras se analizaron por cromatografía gaseosa con detección por ionización en llama. Junto a los resultados de las muestras, se realizaron cálculos de riesgo para la salud, usando los indicadores Cociente de peligro (HQ) y Riesgo de cáncer (CR), con el fin de evaluar los posibles efectos no-carcinogénicos y carcinogénicos, respectivamente, en los trabajadores de los puestos de reventa de combustibles. Las concentraciones ambientales para la mayoría de los compuestos BTEX estuvieron por debajo de los limites preconizados, menos en el caso del benceno, un compuesto carcinogénico, que presentó concentraciones muy por encima de los límites, llevando a altos valores de riesgo de cáncer. Los resultados demostraron que existen riesgos para la salud de los trabajadores de puestos de reventa de combustibles, principalmente, riesgo de desarrollar cáncer, debido a la exposición excesiva al benceno.

Intoxicación por tolueno / Toluene poisoning

Resumen El ser humano está inmerso en un entorno donde inhala, ingiere o absorbe muchas sustancias químicas, de las cuales toman relevancia las exposiciones en los lugares de trabajo y las que causan la muerte en la práctica médico forense. El tolueno es un inhibidor neuronal asociado con daño progresivo del sistema nervioso central y periférico, su toxicidad puede ocurrir por inhalación involuntaria o deliberada y puede llevar incluso a la muerte. Se realizó una revisión bibliográfica en diferentes bases de datos, de los artículos publicados referentes al tema de los últimos ocho años, con el objetivo de revisar las características del químico, el metabolismo, las intoxicaciones agudas y las crónicas, así como sus implicaciones letales. Se concluye que para mejorar la pericia médico legal, al valorar casos de intoxicacion por tolueno se deben de contemplar los criterios de causalidad en los casos de enfermedad laboral y en sospecha de causa de muerte es fundamentantal el resultado toxicológico ante la ausencia de hallazgos específicos en la autopsia.

Abstract The human being is immersed in an environment where he inhales, ingests or absorbs many chemical substances, in forensic medical practice the exposures in the workplace and those that cause death take on relevance. Toluene is a neuronal inhibitor associated with progressive damage of the central and peripheral nervous system, its toxicity can occur by involuntary or deliberate inhalation and can even lead to death. A bibliographic review was carried out in different databases, of the published articles referring to the subject of the last eight years, with the objective of reviewing the characteristics of the chemical, the metabolism, both acute and chronic poisoning and its lethal implications. It is concluded that to improve the legal medical expertise when assessing cases of toluene poisoning, causality criteria must be considered in cases of occupational disease and in suspected cases of death the toxicology result is fundamental in the absence of specific findings in the autopsy.

Maternal exposure to benzene and toluene and preterm birth. A longitudinal study

ABSTRACT BACKGROUND: Exposure to air pollutants has several effects on human health, including during pregnancy. OBJECTIVE: To identify whether exposure to benzene and toluene among pregnant women contributes to preterm delivery. DESIGN AND SETTING: Longitudinal study using data on newborns from mothers living in São José dos Campos (SP) in 2016, who had been exposed to benzene and toluene. METHODS: A logistic regression model with three hierarchical levels was constructed using maternal variables relating to newborns, and using benzene and toluene concentrations in quartiles. Occurrences of cesarean births, twins or malformations were excluded. Maternal exposure windows of 5, 10, 15, 30, 60 and 90 days prior to delivery were considered. RESULTS: Out of the 9,562 live births, 3,671 newborns were included and 343 newborns were born at less than 37 weeks of gestation (9.3%). The average birth weight was 3,167.2 g. Exposure to benzene and toluene was significantly associated (P = 0.04) with preterm delivery in the five-day window. There was no association in any of the other exposure windows. CONCLUSIONS: It was possible to identify that maternal exposure to benzene and toluene has an acute effect on preterm delivery.

Neuropsychological effects among workers exposed to organic solvents / Efectos neuropsicológicos en trabajadores expuestos a disolventes orgánicos

Abstract: Objective: To assess neuropsychological performance among workers at a paint factory in Mexico City. Materials and methods: During 2004 and 2005 we assessed the neuropsychological performance of 208 workers who were exposed to organic solvents at a paint factory, mainly toluene and xylene. We categorized workers into low and high exposure groups using a cumulative index for toluene, based on times spent in different tasks. We evaluated cognitive and motor functions with 13 neuropsychological tests. Results: We found lower attention, longer time to complete the test β=5.5 (R2=12.3%), and a lower score in the motor-cognitive test β=-15.7 (R2=19.5%) in the high exposure group through multiple linear regression model analysis, with adjustment for age and education. Conclusion: Our results are similar to the ones reported in the literature, but the effects are less severe, probably due to lower exposure to organic solvents.

Resumen: Objetivo: Evaluar el desempeño neuropsicológico de los trabajadores de una fábrica de pintura en la Ciudad de México. Material y métodos: Se evaluó el desempeño neuropsicológico de 208 trabajadores expuestos a disolventes orgánicos, principalmente tolueno y xileno, en una fábrica de pintura en la Ciudad de México durante 2004 y 2005. Se categorizaron en grupos de baja y alta exposición con un índice acumulado de tolueno con base en el tiempo empleado por actividad. Se evaluaron funciones motoras y cognitivas con 13 pruebas neuropsicológicas. Resultados: Se registró un tiempo más largo para completar la prueba β=5.5 (R2=12.3%) y una puntuación baja en la prueba motor-cognitiva de β=-15.7 (R2=19.5%) en el grupo de alta exposición en los modelos de regresión lineal múltiple, ajustados por confusores. Conclusión: Los presentes resultados son similares a los reportados en la literatura, aunque los efectos son menos graves, probablemente debido a la baja exposición.

A case of acute organic solvent poisoning during epoxy coating

BACKGROUND: In the construction industry, maintaining health and safety of workers often challenging. Among the workers at construction sites, painters are at particular risk of respiratory diseases and neurotoxicity. However, in Korea there is weak enforcement of workers' health and safety practices in the construction industry in Korea. Poisonings frequently occur at (semi)closed construction sites. In this study, we report a case of acute organic solvent poisoning during construction site painting. CASE PRESENTATION: A 71-year-old man was found unconscious at a construction site and immediately transferred to the emergency room. The consciousness level was 'stupor state' and the body temperature was hypothermic, at 32 degrees (Celsius). There were no acute brain or cardiac lesions that would have accounted for the faintness. In addition, blood and urine tests did not indicate a cause of loss of consciousness. He had been painting epoxy to waterproof the basement floor before fainting. According to exposure simulation, the patient was overexposed to various organic solvents, such as approximately 316–624 ppm toluene during the work before fainting. Considering the ventilation status of the workplace and the status of no protection, it is considered that exposure through the respiratory tract was considerable. CONCLUSIONS: The patient in this case lost consciousness during the epoxy coating in a semi-enclosed space. It can be judged as a result of acute poisoning caused by organic solvent exposure and considered to be highly related to work environment.

Controlling Painters' Exposure to Volatile Organic Solvents in the Automotive Sector of Southern Colombia

BACKGROUND: Painters in the automotive sector are routinely exposed to volatile organic solvents, and the levels vary depending on the occupational health and safety controls enforced at the companies. This study investigates the levels of exposure to organic vapors and the existence of controls in the formal economy sector in southern Colombia. METHODS: This is an exploratory study of an observational and descriptive character. An analysis of solvents is conducted via the personal sampling of painters and the analysis of samples using the National Institute for Occupational Safety and Health 1501 method. The amount of solvents analyzed varied according to the budget allocated by the companies. The person in charge of the occupational safety and health management system was interviewed to learn about the exposure controls implemented at the companies. RESULTS: A medium exposure risk for toluene was found in one company. Another presented medium risk for carbon tetrachloride, xylene, ethylbenzene, and n-butanol. The others showed low risk of exposure and that the controls implemented were not sufficient or efficient. CONCLUSION: These results shed light on the working conditions of these tradespeople. The permissible limits established by Colombian regulations for the evaluated chemical contaminants were not exceeded. However, there were contaminants that exceeded the limits of action. The analysis of findings made it possible to propose improvements in occupational safety and health management systems to allow the optimization of working conditions for painters, prevent the occurrence of occupational diseases, and reduce costs to the country's health system.

Insights Into Emissions and Exposures From Use of Industrial-Scale Additive Manufacturing Machines

BACKGROUND: Emerging reports suggest the potential for adverse health effects from exposure to emissions from some additive manufacturing (AM) processes. There is a paucity of real-world data on emissions from AM machines in industrial workplaces and personal exposures among AM operators. METHODS: Airborne particle and organic chemical emissions and personal exposures were characterized using real-time and time-integrated sampling techniques in four manufacturing facilities using industrial-scale material extrusion and material jetting AM processes. RESULTS: Using a condensation nuclei counter, number-based particle emission rates (ERs) (number/min) from material extrusion AM machines ranged from 4.1×1010 (Ultem filament) to 2.2×1011 [acrylonitrile butadiene styrene and polycarbonate filaments). For these same machines, total volatile organic compound ERs (mg/min) ranged from 1.9×104 (acrylonitrile butadiene styrene and polycarbonate) to 9.4×104 (Ultem). For the material jetting machines, the number-based particle ER was higher when the lid was open (2.3×1010 number/min) than when the lid was closed (1.5–5.5×109 number/min); total volatile organic compound ERs were similar regardless of the lid position. Low levels of acetone, benzene, toluene, and m,p-xylene were common to both AM processes. Carbonyl compounds were detected; however, none were specifically attributed to the AM processes. Personal exposures to metals (aluminum and iron) and eight volatile organic compounds were all below National Institute for Occupational Safety and Health (NIOSH)-recommended exposure levels. CONCLUSION: Industrial-scale AM machines using thermoplastics and resins released particles and organic vapors into workplace air. More research is needed to understand factors influencing real-world industrial-scale AM process emissions and exposures.

Niveles urinarios de ácido trans, trans mucónico y orto cresol en una población infanto-juvenil residente en Ciudad Autónoma de Buenos Aires y Conurbano Bonaerense / Urinary levels of trans, trans muconic and ortho cresol in an infant-juvenile population resident in the Autonomous City of Buenos Aires and the Conurbano of Buenos Aires

Introducción: la exposición crónica al benceno y tolueno produce alteraciones sobre la médula ósea y el sistema nervioso central, entre otros. En orina, el ácido trans, trans mucónico (t, t-MA) es uno de los biomarcadores de exposición al benceno y el o-cresol (oCre) al tolueno. Objetivo: analizar los resultados de los niveles de t, t-MA y oCre urinarios en una población infanto-juvenil residente en Ciudad Autónoma de Buenos Aires y Conurbano Bonaerense potencialmente expuesta a benceno y tolueno ambiental. Materiales y métodos: se realizó un estudio retrospectivo de los resultados de t, t-MA y oCre urinarios. Las muestras de orina ingresaron al laboratorio con solicitud de t, t-MA (n=1519) y oCre (n=1447) durante el período 2011-2017 (rango etario entre 0 a 19 años). El t, t-MA se cuantificó por UFLC con detector de arreglo de diodos y el oCre por CG con detector de ionización por llama. Resultados: la edad promedio de los pacientes fue de 4,8 años y la mediana 4,6 años.Las concentraciones de t, t-MA urinario fueron: menor de 50 μg/l (44,8%); entre 50-500 μg/l (52,1%) y mayores de 500 μg/l (3,1%). Expresadas por gramo de creatinina: entre 15-163 μg/g creatinina (60,4%) y mayores de 163 μg/g creatinina (39,6%). El límite de cuantificación de t, t-MA fue de 50 μg/l. Las concentraciones de oCre urinario fueron: menor de 0,20 mg/l (97,7%) y entre 0,20-0,50 mg/l (2,3%) y mayor de 0,50 mg/l (0%). Expresadas por gramo de creatinina: menor de 0,30 mg/g creatinina en el 0,8% y mayores de 0,30 mg/g creatinina en el 1,5%. El límite de cuantificación de oCre fue de 0,20 mg/l. Conclusiones: los resultados del trabajo podrían indicar una contaminación ambiental persistente, en especial en el Conurbano Bonaerense, donde debería continuarse el monitoreo de algunas zonas. Pero, por otro lado, es de vital importancia tener en cuenta los factores de confusión, tales como la dieta, la exposición al humo de tabaco ambiental (fumador pasivo) y la tasa de excreción renal que llevarían a una sobre-estimación de los resultados y a una incorrecta toma de decisiones.

Introduction: Chronic exposure to benzene and toluene produces alterations in the bone marrow and the central nervous system, among other effects. In urine, trans, trans muconic acid (t, t-MA) is one of the biomarkers of exposure to benzene and o-cresol (oCre), to toluene. Objective: To analyze the results of urinary t, t-MA and oCre levels in an infant-juvenile population resident in the Autonomous City of Buenos Aires and the Conurbano Bonaerense, potentially exposed to environmental benzene and toluene. Materials and methods: A retrospective study of urinary t, t-MA and oCre results was performed. The urine samples entered the laboratory with the request of t, t-MA (n = 1519) and oCre (n = 1447) during the period 2011- 2017. The age range of the population was between 0 and 19 years. The t, t-MA was quantified by UFLC with diode array detector and the oCre by GC with flame ionization detector. Results: The average age of the patients was 4.8 years and the median age was 4.6 years. The urinary concentrations of t, t-MA were: below 50 μg/l (44.8%); between 50-500 μg/l (52.1%) and above 500 μg/l (3.1%). Expressed per gram of creatinine: between 15-163 μg/g creatinine (60.4%) and greater 163 μg/g creatinine (39.6%). The limit of quantification of t, t-MA was 50 μg/l. The urinary oCre concentrations were: less than 0.20 mg/l (97.7%) and between 0.20-0.50 mg/l (2.3%). Expressed per gram of creatinine: less than 0.30 mg/g creatinine in 0.8% and greater than 0.30 mg/g creatinine in 1.5%. The limit of quantification of oCre was 0.20mg/l. Conclusions: The results of the study could indicate persistent environmental contamination, especially in the Conurbano Bonaerense, where monitoring of some areas should be continued. However, it is of vital importance to take into account the confounding factors, such as diet, exposure to environmental tobacco smoke (passive smoking) and the rate of renal excretion, which would lead to an over-estimation of the results and to incorrect decision-making.

An aggravated return-to-work case of organic solvent induced chronic toxic encephalopathy

BACKGROUND: Organic solvent-induced chronic toxic encephalopathy (CTE) is known as a non-progressive disorder that does not progress after diagnosis. The authors present a case those symptoms worsened after continued exposure to organic solvent after returning to work. Because such a case has not been reported in South Korea to the best of our knowledge, we intend to report this case along with literature review. CASE PRESENTATION: A 59-year-old man, who performed painting job at a large shipyard for 20 years, was receiving hospital treatment mainly for depression. During the inpatient treatment, severe cognitive impairment was identified, and he visited the occupational and environmental medicine outpatient clinic for assessing work relatedness. In 1984, at the age of 27, he began performing touch-up and spray painting as a shipyard painter. Before that he had not been exposure to any neurotoxic substances. In 2001, at the age of 44, after 15 years of exposure to mixed solvents including toluene, xylene and others, he was diagnosed with CTE International Solvent Workshop (ISW) type 2A. After 7 years of sick leave, he returned to work in 2006. And he repeated return-to-work and sick leave in the same job due to worsening of depressive symptoms. He had worked four times (2006–2010, 2011–2011, 2011–2011, 2016–2017) for a total of 5 years as a shipyard painter after first compensation. During the return-to-work period, the mean values of the mixed solvent index ranged from 0.57 to 2.15, and except for a one semiannual period, all mean values were above the standard value of 1. We excluded other diseases that can cause cognitive impairment like central nervous system diseases, brain injury, psychological diseases and metabolic diseases with physical examinations, laboratory tests, and brain image analysis. And finally, throughout neuropsychological tests, an overall deterioration in cognitive function was identified compared to 2002, and the deterioration types was similar to that often shown in the case of CTE; thus a diagnosis of CTE (ISW) type 3 was made. CONCLUSION: This case is showing that CTE can go on with continued exposure to mixed solvents. Appropriate “fitness to work” should be taken to prevent disease deterioration especially for the sick leave workers.

Serum Periostin Levels: A Potential Serologic Marker for Toluene Diisocyanate-Induced Occupational Asthma

PURPOSE: Toluene diisocyanate (TDI) is a leading cause of occupational asthma (OA). Periostin is a matricellular protein implicated in type 2 immunity-driven asthma. Its pathogenic role in TDI-OA has not been completely elucidated. The present study was performed to investigate the role of periostin in TDI-OA. MATERIALS AND METHODS: Serum periostin levels were measured in subjects with TDI-OA, asymptomatic TDI-exposure controls (AECs), non-occupational asthmatics (NAs), and unexposed normal controls (NCs). To understand the mechanism by which TDI induces periostin production, primary small airway epithelial cells (SAECs) were cultured under stimulation of TDI and neutrophils from asthmatic patients. RESULTS: Fifty-three subjects with TDI-OA, 71 AECs, 67 NAs, and 83 NCs were enrolled. Serum periostin levels were significantly higher in TDI-OA subjects than in AECs (p=0.001), NAs (p < 0.001), and NCs (p < 0.001). In TDI-exposed subjects (TDI-OA and AEC), the PC20 methacholine levels were significantly lower in subjects with a higher periostin level than in those with a lower periostin level. TDI exposure did not increase periostin production directly by SAECs; however, periostin production increased significantly after co-culture with TDI and neutrophils, which was suppressed by an antioxidant. In addition, increased release of TGF-β1 was noted from SAECs when exposed to TDI and neutrophils, which was also suppressed by an antioxidant. CONCLUSION: These results suggest that an increased periostin level may contribute to the progression of airway inflammation to remodeling in TDI-exposed workers. A high serum periostin level is a potential serologic marker of the phenotype of TDI-OA.

Study of the removal difference in indoor particulate matter and volatile organic compounds through the application of plants

This study was conducted to evaluate the ability of plants to purify indoor air by observing the effective reduction rate among pollutant types of particulate matter (PM) and volatile organic compounds (VOCs). PM and four types of VOCs were measured in a new building that is less than three years old and under three different conditions: before applying the plant, after applying the plant, and a room without a plant. The removal rate of each pollutant type due to the plant was also compared and analyzed. In the case of indoor PM, the removal effect was negligible because of outdoor influence. However, 9% of benzene, 75% of ethylbenzene, 72% of xylene, 75% of styrene, 50% of formaldehyde, 36% of acetaldehyde, 35% of acrolein with acetone, and 85% of toluene were reduced. The purification of indoor air by natural ventilation is meaningless because the ambient PM concentration has recently been high. However, contamination by gaseous materials such as VOCs can effectively be removed through the application of plants.

Modeling the effects of pollutant emissions from large industrial complexes on benzene, toluene, and xylene concentrations in urban areas

This study utilized the Community Multiscale Air Quality model to simulate the spatial distribution of benzene, toluene, and xylene (BTX) concentrations from large national industrial complexes (IC) located in the Ulsan metropolitan region (UMR). Through controlling pollutant emissions from major IC, this study performed a quantitative analysis of the influence of pollutant emissions on BTX concentrations in surrounding urban areas. The results showed that approximately 40% of the annual average BTX concentrations in nearby urban grids were directly influenced by pollutant emissions from the IC. Seasonal modeling results indicated that average BTX concentrations were high around petrochemical complexes, with higher concentrations in the surrounding urban areas during the summer (July). All three of the BTX pollutants showed similar seasonal differences. Daily contributions differed significantly throughout the modeling period, with some values reaching a maximum of 80% during July. Overall, when urban areas were located downwind of the IC, contributions rose. Moreover, this study compared the differences in BTX contributions at each measurement point within the IC and urban areas, which showed that the influence of the IC emissions decreased significantly with distance. The spatial distribution and direct influence of the IC on BTX concentrations in the UMR identified through this study could be used to provide input data in environmental epidemiological studies.

Parkinson's Disease among Firefighters : A Focused Review on the Potential Effects of Exposure to Toxic Chemicals at the Fire Scene

Previous studies have found that firefighters have a tenfold higher prevalence of Parkinson's disease (PD) compare to the general population. Firefighters are constantly exposed to various occupational hazards including toxic chemicals of fire residue and the toxic chemicals can effects development and progression of PD. Nevertheless, there were no studies about the association between exposure to chemical byproducts of combustion and the development of PD among firefighters. Thus the aim of this study is to look into existing researches regarding the effect of chemical byproducts of combustion on the development of PD. An extensive literature search was conducted to identify harmful chemical components of smoke and fire residue, using the PubMed database during November of 2016. We searched for relevant articles by combining several keywords that contained “Parkinson's disease” and each of the different toxic chemicals, yielding a total of 1401 articles. After applying the selection criteria, 12 articles were chosen. Chemical substances reported to have a harmful effect on PD, in at least one article, were carbon monoxide, toluene, manganese and lead. Carbon monoxide and metal substances including manganese and lead were found to be associated with an increased PD risk in more than two articles. There was a heightened risk of PD in firefighters due to exposure of chemical byproducts of combustion including carbon monoxide, toluene, man-ganese and lead. However, to the best of our knowledge, to support this result we need more systematic epidemiological studies about these risk factors of PD among firefighters. In addition, further studies for the effects of prolonged exposure to toxic fire residue on the development and progression of PD in firefighters are needed.

Epithelial folliculin is involved in airway inflammation in workers exposed to toluene diisocyanate

Toluene diisocyanate (TDI) exposure can directly activate and damage airway epithelium. Folliculin (FLCN) is a protein expressed by human airway epithelial cells (HAECs) to maintain airway epithelial integrity and survival. This study investigated the involvement of FLCN in the pathogenesis of TDI-induced occupational asthma (OA). Enzyme-linked immunosorbent assay was used to measure serum levels of FLCN in TDI-exposed subjects (93 TDI-OA patients and 119 asymptomatic exposed controls (AEC)), 200 non-occupational asthma (NOA) patients and 71 unexposed healthy normal controls (NCs). Significantly more subjects in the TDI-OA and AEC groups had high serum levels of FLCN compared to those in the NOA group (P=0.002 and P=0.001, respectively), all of which were higher than the NC group (all P<0.001). The serum level of FLCN was positively correlated with TDI exposure duration (r=0.251, P=0.027), but was negatively correlated with asthma duration of TDI-OA patients (r=−0.329, P=0.029). TDI-exposed subjects with high FLCN levels had higher serum levels of total IgE than those with lower levels. The effects of TDI exposure on FLCN production was investigated by treating HAECs (A549 cells) with TDI-human serum albumin conjugate, which showed increased expression and release of FLCN and interleukin-8 from HAECs. Co-culture with peripheral blood neutrophils also induced FLCN expression and release from HAECs. In conclusion, TDI exposure and TDI-induced neutrophil recruitment into the airways can activate and stimulate HAECs to produce FLCN, which could be involved in airway inflammation in workers exposed to TDI.

Toluene diisocyanate exposure induces airway inflammation of bronchial epithelial cells via the activation of transient receptor potential melastatin 8

Toluene diisocyanate (TDI) is the most important cause of occupational asthma (OA), and various pathogenic mechanisms have been suggested. Of these mechanisms, neurogenic inflammation is an important inducer of airway inflammation. Transient receptor potential melastatin 8 (TRPM8) is a well-established cold-sensing cation channel that is expressed in both neuronal cells and bronchial epithelial cells. A recent genome-wide association study of TDI-exposed workers found a significant association between the phenotype of TDI-induced OA and the single-nucleotide polymorphism rs10803666, which has been mapped to the TRPM8 gene. We hypothesized that TRPM8 located in airway epithelial cells may be involved in the pathogenic mechanisms of TDI-induced OA and investigated its role. Bronchial epithelial cells were treated with TDI in a dose- and time-dependent manner. The expression levels of TRPM8 mRNA and protein were determined by quantitative real-time polymerase chain reaction and western blotting. TDI-induced morphological changes in the cells were evaluated by immunocytochemistry. Alterations in the transcripts of inflammatory cytokines were examined in accordance with TRPM8 activation by TDI. TRPM8 expression at both the mRNA and protein levels was enhanced by TDI in airway epithelial cells. TRPM8 activation by TDI led to significant increases in the mRNA of interleukin (IL)-4, IL-13, IL-25 and IL-33. The increased expression of the cytokine genes by TDI was partly attenuated after treatment with a TRPM8 antagonist. TDI exposure induces increased expression of TRPM8 mRNA in airway epithelial cells coupled with enhanced expression of inflammatory cytokines, suggesting a novel role of TRPM8 in the pathogenesis of TDI-induced OA.

Microwave Assisted Extraction, Optimization using Central Composite Design, Quantitative Estimation of Arjunic Acid and Arjunolic Acid using HPTLC and Evaluation of Radical Scavenging Potential of Stem Bark of Terminalia arjuna

The optimization and microwave assisted extraction of stem bark of Terminalia arjuna, quantitative estimation of the marker compounds arjunic acid and arjunolic acid using HPTLC and the evaluation of free radical scavenging activity has been performed in this study. The central composite design was used for optimization and the values of parameters for optimized batch of microwave assisted extraction were 1000W (Power), 3 minutes (Time) and 1/120 (Solid/solvent ratio). The solvent system to carry out the HPTLC was toluene: acetic acid: ethyl acetate (5: 5: 0.5) and quantitative estimation was done using standard equations obtained from the marker compounds. The in-vitro free radical scavenging activity was performed spectrophotometrically using ascorbic acid as standard. The value of estimated percentage yield of arjunic acid and arjunolic acid was 1.42% and 1.52% which upon experimentation was obtained as 1.38% and 1.51% respectively. The DPPH assay of the different batches of microwave assisted extraction and marker compounds taken suggested that the marker compounds arjunic acid and the arjunolic acid were responsible for the free radical scavenging activity as the batch having the maximum percentage yield of the marker compounds showed best free radical scavenging effect as compared to standard ascorbic acid. The IC₅₀ value of the optimized batch was found to be 24.72 while that of the standard ascorbic acid was 29.83. Hence, the yield of arjunic acid and arjunolic acid has direct correlation with the free radical scavenging activity of stem bark extract of Terminalia arjuna and have potential to serve as active lead compounds for free radical scavenging activity.