Mixture Effects of Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX) on Lung Carcinoma Cells via a Hanging Drop Air Exposure System

Abstract

A recently developed hanging drop air exposure system for toxicity studies of volatile chemicals was applied to evaluate the cell viability of lung carcinoma A549 cells after 1 and 24 h of exposure to benzene, toluene, ethylbenzene, and xylenes (BTEX) as individual compounds and as mixtures of four or six components. The cellular chemical concentrations causing 50% reduction of cell viability (EC50) were calculated using a mass balance model and came to 17, 12, 11, 9, 4, and 4 mmol/kg cell dry weight for benzene, toluene, ethylbenzene, m-xylene, o-xylene, and p-xylene, respectively, after 1 h of exposure. The EC50 decreased by a factor of 4 after 24 h of exposure. All mixture effects were best described by the mixture toxicity model of concentration addition, which is valid for chemicals with the same mode of action. Good agreement with the model predictions was found for benzene, toluene, ethylbenzene, and m-xylene at four different representative fixed concentration ratios after 1 h of exposure, but lower agreement with mixture prediction was obtained after 24 h of exposure. A recreated car exhaust mixture, which involved the contribution of the more toxic p-xylene and o-xylene, yielded an acceptable, but lower quality, prediction as well.

Structure of a Luminescent MOF-2 Derivative with a Core of Zn(II)-Terephthalate-Isoquinoline and Its Application in Sensing of Xylenes

“…They are carcinogenic species and considered as some of the most hazardous pollutants among VOCs [29]. Acute exposure to xylene isomers and toluene, typically found in gasoline, has been associated with skin, eye irritation, and effects on the respiratory system [30]. The constant and chronic exposure to small amounts of these solvents (200 ppm or greater) in the ambient or at home with common products such as adhesives and solvents for paints is associated with various adverse health effects [27,31].…”

Time-Resolved Freely Dissolved Concentrations of Semivolatile and Hydrophobic Test Chemicals in In Vitro Assays—Measuring High Losses and Crossover by Headspace Solid-Phase Microextraction

“…The test results are normally based on the nominal concentration of a test chemical added to the culture medium at the start of the test. However, several studies have found that volatile and/or hydrophobic chemicals evaporate from wells, [1][2][3][4] cross over to adjacent wells, 5 sorb to microtiter plates, 1,2,6,7 and sorb to medium constituents. 1,2,6,8 Therefore, the actual exposure of the cells to the test substances is often not known and decreases with time, which can lead to reduced toxicity and assay sensitivity.…”

Impact of oil-related environmental pollutants on the ovary structure in the freshwater leech Erpobdella johanssoni (Johansson, 1927) (Clitellata: Hirudinea)

“…BTEX has been identified as potential groundwater pollutants, which cause deleterious effects on organisms, including humans (Chen et al 2008;Li et al 2013;Lim et al 2014;Liu et al 2014). Our histological findings demonstrated obvious alterations in the progression of oogenesis in E. johanssoni with BTEX treatment of 25 µg L −1 for 26 days.…”