Related Experiment Video
Updated: Jul 9, 2026
09:50
Impact Assessment of Repeated Exposure of Organotypic 3D Bronchial and Nasal Tissue Culture Models to Whole Cigarette Smoke
Published on: February 12, 2015
Issues when modeling benzene, toluene, and xylene exposures using a literature database
Misty J Hein1, Martha A Waters, Edwin van Wijngaarden
1National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, Ohio 45226, USA. MHein@cdc.gov
Journal of Occupational and Environmental Hygiene
|November 29, 2007
Summary
This study created models to predict benzene, toluene, and xylene exposure using workplace factors. These models aid in estimating chemical exposure for community health studies.
Area of Science:
- Occupational and Environmental Hygiene
- Toxicology
- Industrial Hygiene
Background:
- Benzene, toluene, and xylene (BTEX) are common industrial chemicals with known health risks.
- Accurate exposure assessment is crucial for understanding occupational and environmental health impacts.
- Existing data on BTEX exposure determinants is fragmented.
Purpose of the Study:
- To develop statistical models for predicting benzene, toluene, and xylene exposure.
- To identify key workplace determinants influencing BTEX exposure levels.
- To provide a tool for estimating exposure in community-based case-control studies.
Main Methods:
- Compiled a comprehensive database of BTEX measurements from literature.
- Included exposure determinants such as job type, operation, ventilation, and location.
- Developed statistical models linking exposure to workplace determinants.
Main Results:
- Statistical models were successfully developed for benzene, toluene, and xylene exposure.
- Parameter estimates for specific operations and determinants were derived.
- Identified key factors influencing BTEX exposure levels in various work settings.
Conclusions:
- The developed models can effectively predict BTEX exposure levels.
- These models are valuable for exposure assessment in epidemiological studies.
- Acknowledged statistical and data limitations inherent in historical data modeling.
![Chemical-Induced Skin Carcinogenesis Model Using Dimethylbenz[a]Anthracene and 12-O-Tetradecanoyl Phorbol-13-Acetate (DMBA-TPA)](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60445.jpg&w=3840&q=50)
Related Concept Videos
01:07Structure of Benzene: Kekulé Model
In 1865, August Kekule suggested the structure of benzene according to the structural theory of organic chemistry based on the three assertions—formula of benzene is C6H6, all the hydrogens of benzene are equivalent, and each carbon must have four bonds due to its tetravalency.
He proposed that benzene has a cyclic structure of six carbon atoms attached to one hydrogen atom each, with three alternating pi bonds.
He proposed that benzene has a cyclic structure of six carbon atoms attached to one hydrogen atom each, with three alternating pi bonds.
01:18Structure of Benzene: Molecular Orbital Model
According to the molecular orbital (MO) model, benzene has a planar structure with a regular hexagon of six sp2 hybridized carbons. As shown in Figure 1, each carbon is bonded to three other atoms with C–C–C and H–C–C bond angles of 120°. The C–H bond length is 109 pm, and the C–C bond length is 139 pm which is midway between the single bond length of sp3 hybridized carbons (154 pm) and sp2 hybridized carbons (133 pm).
01:18Benzene to 1,4-Cyclohexadiene: Birch Reduction Mechanism
Birch reduction uses solvated electrons as reducing agents. The reaction converts benzene to 1,4-cyclohexadiene. The reaction proceeds by the transfer of a single electron to the ring to form a benzene radical anion. This anion is highly basic—it abstracts a proton from the alcohol to form a cyclohexadienyl radical. Another single electron transfer gives the cyclohexadienyl anion. A proton transfer from the alcohol forms 1,4-cyclohexadiene. Since this reduction occurs via radical anion...
01:25Aromatic Compounds: Overview
In general, the term ‘aromatic’ indicates a pleasant smell or fragrance from fresh flowers, freshly prepared coffee, etc. In the early history of organic chemistry, many benzene derivatives were isolated from the pleasant odor oils of the plants. For example, vanillin was isolated from the oil of vanilla, methyl salicylate from the oil of wintergreen, and cinnamaldehyde from the oil of cinnamon. They all had a pleasant odor; hence the name aromatic was given.
In 1825, Faraday isolated benzene...
In 1825, Faraday isolated benzene...
01:37NMR Spectroscopy of Benzene Derivatives
Simple unsubstituted benzene has six aromatic protons, all chemically equivalent. Therefore, benzene exhibits only a singlet peak at δ 7.3 ppm in the 1H NMR spectrum. The observed shift is far downfield because the aromatic ring current strongly deshields the protons. Any substitution on the benzene ring makes the aromatic protons nonequivalent, and the protons split each other. The peak is, therefore, no longer a singlet and the splitting pattern and their associated coupling constants depend...
01:36Types of Toxins
Humans continually engage with an environment rich in potentially harmful chemicals. These are introduced to our bodies through inhalation, ingestion, or skin contact. These chemicals exist in various forms, such as air and environmental pollutants, agricultural chemicals, organic solvents, and heavy metals.
Air pollutants, primarily gases, pose significant threats to respiratory health, leading to conditions like hypoxia, lung cancer, and in extreme cases, death.
Environmental pollutants like...
Air pollutants, primarily gases, pose significant threats to respiratory health, leading to conditions like hypoxia, lung cancer, and in extreme cases, death.
Environmental pollutants like...