Occupational Exposure to Benzene and Chromosomal Structural Aberrations in the Sperm of Chinese Men

By Marchetti, Francesco; Eskenazi, Brenda et al. | Environmental Health Perspectives, February 2012 | Go to article overview

Occupational Exposure to Benzene and Chromosomal Structural Aberrations in the Sperm of Chinese Men


Marchetti, Francesco, Eskenazi, Brenda, Weldon, Rosana H., Li, Guilan, Zhang, Luoping, Rappaport, Stephen M., Schmid, Thomas E., Xing, Caihong, Kurtovich, Elaine, Wyrobek, Andrew J., Environmental Health Perspectives


BACKGROUND: Benzene is an industrial chemical that causes blood disorders, including acute myeloid leukemia. We previously reported that occupational exposures near the U.S. Occupational Safety and Health Administration permissible exposure limit (8 hr) of 1 ppm was associated with sperm aneuploidy

OBJECTIVE: We investigated whether occupational exposures near 1 ppm increase the incidence of sperm carrying structural chromosomal aberrations.

METHODS: We applied a sperm fluorescence in situ hybridization assay to measure frequencies of sperm carrying partial chromosomal duplications or deletions of Icen or lp36.3 or breaks within lcen-1q12 among 30 benzene-exposed and 11 unexposed workers in Tianjin, China, as part of the China Benzene and Sperm Study (C-BASS). Exposed workers were categorized into low-, moderate-, and high-exposure groups based on urinary benzene (medians: 2.9, 11.0, and 110.6[micro]g/L, respectively). Median air benzene concentrations in the three exposure groups were 1.2, 3.7, and 8.4 ppm, respectively.

RESULTS: Adjusted incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for all structural aberrations combined were 1.42 (95% CI: 1.10, 1.83), 1.44 (95% CI: 1.12, 1.85), and 1.75 (95% CI: 1.36, 2.24) and for deletion of lp36.3 alone were 4.31 (95% CI: 1.18, 15.78), 6.02 (95% CI: 1.69, 21.39), and 7.88 (95% CI: 2.21, 28.05) for men with low, moderate, and high exposures respectively, compared with unexposed men. Chromosome breaks were significantly increased in the high-exposure group [IRR 1.49 (95% CI: 1.10, 2.02)].

CONCLUSIONS: Occupational exposures to benzene were associated with increased incidence of chromosomally defective sperm, raising concerns for worker infertility and spontaneous abortions as well as mental retardation and inherited defects in their children. Our sperm findings point to benzene as a possible risk factor for de novo lp36 deletion syndrome. Because chromosomal aberrations in sperm can arise from defective stem cells/spermatogonia, our findings raise concerns that occupational exposure to benzene may have persistent reproductive effects in formerly exposed workers.

KEY WORDS: benzene, chromosome 1, germ cells, sperm fluorescence in situ hybridization, structural aberrations. Environ Health Perspect 120:229-234 (2012). http://dx.doi.org/10.1289/ehp.1103921 [Online 15 November 2011]

Benzene is an important industrial chemical with Greater than 2 billion pounds produced every year in the United States. Low-level exposures (Less than 5 ppb) to benzene, widespread in the U.S. population, are primarily due to smoking, gasoline fumes, and vehicle emissions (Hricko 1994). Early epidemiological cohort studies found that benzene is associated with an increased risk of leukemia at high levels (around 10 ppm average or 40 ppm-years) (Hayes et aI. 1997; Yin et al. 1996, l987a, 1987b), whereas more recent studies found excess leukemia risk associated with levels of exposure as low as 0.8-1.6 ppm or 2-4 ppm-years of cumulative exposure (Glass et al. 2003, 2004; Hayes et al. 2001). Benzene is hematotoxic, and in a large study of more than 400 workers, almost all blood cell counts were significantly decreased, even in individuals exposed to Less than 1 ppm benzene [mean [+ or -] SD of exposed individuals 0.57 [+ or -] 0.24 ppm, and mean of unexposed individuals [less than or equal to] 0.04 ppm (Lan et al. 2004)]. Therefore, benzene is highly regulated with the U.S. permissible exposure limit (PEL; 8-hr time-weighted average) set at 1 ppm by the Occupational Safety and Health Administration (OSHA 1987). Although significant international progress has been seen in reducing occupational exposure to benzene, workers in some countries still experience levels of benzene well above the U.S. PEL (Liang et al. 2005).

Specific chromosomal aneuploidies and aberrations implicated in leukemia have been detected in the blood cells of benzene-related leukemia patients as well as in healthy benzene-exposed workers, suggesting that these abnormalities precede and may he a potential mechanism underlying benzene-induced leukemia (Zhang et al.

The rest of this article is only available to active members of Questia

Sign up now for a free, 1-day trial and receive full access to:

  • Questia's entire collection
  • Automatic bibliography creation
  • More helpful research tools like notes, citations, and highlights
  • Ad-free environment

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Project items

Items saved from this article

This article has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this article

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited article

Occupational Exposure to Benzene and Chromosomal Structural Aberrations in the Sperm of Chinese Men
Settings

Settings

Typeface
Text size Smaller Larger
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Full screen

matching results for page

Cited passage

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited passage

Welcome to the new Questia Reader

The Questia Reader has been updated to provide you with an even better online reading experience.  It is now 100% Responsive, which means you can read our books and articles on any sized device you wish.  All of your favorite tools like notes, highlights, and citations are still here, but the way you select text has been updated to be easier to use, especially on touchscreen devices.  Here's how:

1. Click or tap the first word you want to select.
2. Click or tap the last word you want to select.

OK, got it!

Thanks for trying Questia!

Please continue trying out our research tools, but please note, full functionality is available only to our active members.

Your work will be lost once you leave this Web page.

For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

Already a member? Log in now.