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.

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.

Mixture of kerosene and xylene: a contribution to clearing agents / Mezcla de kerosene y xileno: una contribución a agentes de aclaramiento

The aim of this study was to substitute costly and hazardous compound- xylene, used as clearing agent, with less costly compounds (mixture of xylene and kerosene) having less toxicity and without compromising the cellular integrity and staining characteristics of the sections. Tissues (liver and kidney) obtained from a presumable healthy adult Wistar rat, were fixed in 10 percent formol saline, separated in to five groups (A, B, C, D and E) and processed for light microscopic study adopting H & E staining procedure. During the clearing section, groups A, B, C, D and E were respectively cleared in solvent 1 (xylene only), solvent 2 (70ml xylene : 30ml kerosene), solvent 3 (50ml xylene : 50ml kerosene), solvent 4 (30ml xylene : 70ml kerosene) and solvent 5 (kerosene only). Our result revealed that tissues in groups A, B and C were properly cleared without any morphological impairment. The staining characteristics were also observed to be very bright. Groups D and E however presented poor staining intensity with reduced cellular details. Semi-stained transparent patches were also noticed. It is inferred from the present investigation that a mixture of xylene and kerosene could be employed in the clearing of tissues only at the prescribed ratio i.e. solvent 2 and solvent 3 without posing any health risk or compromising the cellular integrity.

El objetivo de este estudio fue el de sustituir el costoso y peligroso compuesto xileno, utilizado como agente de aclaramiento, por un compuesto menos costoso (mezcla de kerosene y xileno), con menor toxicidad y sin comprometer la integridad celular ni las características de tinción de las secciones. Los tejidos (hígado y riñon) fueron obtenidos a partir de una rata Wistar adulta presumiblemente sana, los que fueron fijados en solución de formalina salina al 10 por ciento, y separadas en cinco grupos (A, B, C, D y E) y tratadas para estudio con microscópico de luz, con tinción H & E. Durante el aclaramiento de las secciones histológicas, los grupos A, B, C, D y E, fueron, respectivamente, aclarados con el disolvente 1 (sólo xileno), solvente 2 (70ml de xileno: 30ml Kerosene), solvente 3 (50ml de xileno: 50ml Kerosene), solvente 4 (30ml xileno: 70ml kerosene) y solvente 5 (sólo el kerosene). Los resultados revelaron que los tejidos de los grupos A, B y C fueron aclarados correctamente sin alteraciones morfológicas. En la tinción también se observó como característica, ser muy brillante. Los grupos D y E, sin embargo presentaron una tinción de pobre intensidad con la reducción de los detalles celulares. Zonas con manchas semitransparentes también fueron observadas. Se infiere que una mezcla de xileno y kerosene podría ser empleado en el aclaramiento de los tejidos, sólo prescrito en la proporción del solvente 2 y 3, sin suponer ningún riesgo para la salud o comprometer la integridad celular.

BTEX Exposure and its Health Effects in Pregnant Women Following the Hebei Spirit Oil Spill / 예방의학회지

OBJECTIVES: We evaluated the health effects of exposure to BTEX (Benzene, Toluene, Ethylbenzene, m,p-Xylene, o-Xylene) in the Taean area after the Hebei Spirit oil spill. METHODS: We used a questionnaire survey to look for health effects among 80 pregnant women 2 to 3 months following the Hebei Spirit oil spill. Their BTEX exposures were estimated using the CALPUFF method. We then used a multiple logistic regression analysis to evaluate the effects of BTEX exposure on the women's health effets. RESULTS: Pregnant women who lived near the accident site reported more symptoms of eye irritation and headache than those who lived farther from the site. There was a trend of decreasing symptoms with an increase in distance from the spill site. Pregnant women exposed to higher ambient cumulative levels of Xylene were significantly more likely to report symptoms of the skin (OR 8.01 95% CI=1.74-36.76) in the first day after the accident and significantly more likely to report abdominal pain (OR 3.86 95% CI=1.02-14.59 for Ethylbenzene, OR 6.70 95% CI=1.82-24.62 for Xylene) during the 1st through 4th days following the accident. CONCLUSIONS: This study suggests that exposure to BTEX from an oil spill is correlated with an increased risk of health effects among pregnant women. This implies the need to take proper measures, including the development of a national policy for environmental health emergencies and a plan for studying the short- and long-term chronic health effects associated with such spills.

new sampler and analysis method for BTEX in ambient air

Benzene, toluene, ethylbenzene and xylene [BTEX] compounds are components of motor vehicle fuel. BTEX are released from exhausts of vehicles and also evaporation from the fuel tank, carburetor and crank case of engines. BTEX are dangerous chemicals that participate in photochemical reactions and produce secondary air pollutants such as ozone, peroxyacethyl nitrate, free radicals and nitrogen oxides. BTEX in ambient air of metropolitan areas has been the subject of concern in many studies through elaborate "Environmental Protection Agency" [EPA] method. Level of BTEX in the ambient air of major Iranian cities, has not been measured in concentration range of part per billion [ppbv] due to the inadequate sensitivity of available gas chromatography systems. The aim of this study was to improve the sensitivity of gas chromatography by using a special sampler and thermal desorber [Micro-Packed Injector]. Our sampler consisted of a 5-centimeter stainless steel tube one millimeter in diameter packed with carbopacked B heat-conditioned samplers utilized for sampling atmospheric BTEX. It was subsequently injected to a custom-made thermal desorber [225C] which was assembled onto the injection port of a gas chromatography device for analysis. BTEX standard atmospheres were analyzed with a gas chromatograph flame ionization detector [GC-FID] with linear range detection of 27.5-275ppb, 23.1-223.6ppb, 20-320-ppb, and 20-320ppb respectively. The Micro-Packed Injector [MPI] installed on ordinary GC-FID improved linear range detection of BTEX from previous ppm detection to ppb range

Benzene, toluene and xylene (BTX) pollution in ambient air: a case study.

Volatile Organic Compounds (VOCs) in presence of sunlight and oxides of nitrogen in atmosphere are considered as precursors for ozone production at the ground level. Concentration of Benzene, Toluene and Xylene (BTX) in ambient air was measured near seven traffic junctions in the city of Nagpur. Air samples were collected using Organic Vapour Sampler and analyzed by Gas Chromatograph equipped with Flame Ionization Detector (FID). Benzene concentration was found to be in the range 9.3 to 28.7 microg/m3, Toluene 3.26 to 21.0 microg/m3 and Xylene 4.9 to 15.0 microg/m3. These values are lower than those found in Metropolitan cities like Mumbai.

Evaluación de la exposición laboral a solventes aromáticos en la fabricación de pinturas / Evaluation of occupational exposure to aromatic solvents in manufacturing paints

Se estudiaron 19 obreros directamente expuestos a varios solventes orgánicos en 4 áreas de trabajo de una fábrica de pinturas. Se determinaron las concentraciones de tolueno y xileno en aire mediante muestreo personal, evaluándose el riesgo de exposición. Se hallaron los niveles en orina de los metabolitos inherentes a tales sustancias y se analizó la correlación existente entre los indicadores de exposición correspondientes. Las concentraciones en aire no excedieron los niveles límites admisibles. Se obtuvo una buena correlación entre los indicadores de exposición de xileno, no así para los de tolueno