Benzene Exposure Near the US Permissible Limit...

Research studies on wood smoke and other air pollution.

Benzene Exposure Near the US Permissible Limit...

Postby Wilberforce » Tue Feb 16, 2010 8:43 pm

RESEARCH (open access)

Benzene Exposure Near the US Permissible Limit Is Associated With Sperm Aneuploidy
Caihong Xing, Francesco Marchetti, Guilan Li, Rosana H. Weldon, Elaine Kurtovich, Suzanne Young,
Thomas E. Schmid, Luoping Zhang, Stephen Rappaport, Suramya Waidyanatha, Andrew J. Wyrobek, Brenda Eskenazi ... hp.0901531

Background: Benzene is a common industrial chemical that is known to induce leukemia and other blood
disorders, as well as aneuploidy in both human blood cells and sperm at exposures above 10 ppm. Recent
reports have identified health effects at exposure levels below 1 ppm, the Permissible Exposure Limit (PEL;
8 hour) set by US OSHA.

Objective: To investigate whether occupational exposures to benzene near 1 ppm induce aneuploidy in sperm.

Methods: We used multi-color fluorescence in situ hybridization to measure the incidence of sperm with
numerical abnormalities of chromosomes X, Y and 21 among 33 benzene-exposed men and 33 unexposed
men from Chinese factories. Individual exposures were assessed using personal air monitoring, urinary
benzene and urinary trans,trans-muconic acid (E,E-MA). Air benzene concentrations were not detectable in
unexposed men and ranged from below the detection limit to 24 ppm in exposed men (median = 2.9 ppm)
with 27% of exposed men (n=9) at or below 1 ppm. Exposed men were categorized into low and high
groups based on urinary E,E-MA (median concentrations of 1.9 and 14.4 mg/L, respectively; median air
benzene of 1 and 7.7 ppm, respectively) and aneuploidy frequencies were compared to unexposed men.

Results: Sperm aneuploidy increased across low- and high-exposed groups for disomy X (IRR [95% CI]=
2.0 [1.1, 3.4] & 2.8 [1.5, 4.9]), and overall hyperhaploidy for the three chromosomes investigated (IRR
[95% CI]=1.6 [1.0, 2.4] & 2.3 [1.5, 3.6]). We also found elevated disomy X and hyperhaploidy in the
9 men exposed at or below 1ppm compared to unexposed men (IRR [95%CI]=1.8 [1.1, 3.0] & 2.0
[1.1, 3.9], respectively).

Conclusions: Benzene appeared to increase the frequencies of aneuploid sperm for chromosomes associated
with chromosomal abnormality syndromes in human offspring, even in men whose air benzene exposure
was at or below the US PEL.
• The Surgeon General has determined that there is no safe level of exposure to ambient smoke!

• If you smell even a subtle odor of smoke, you are being exposed to poisonous and carcinogenic chemical compounds!

• Even a brief exposure to smoke raises blood pressure, (no matter what your state of health) and can cause blood clotting, stroke, or heart attack in vulnerable people. Even children experience elevated blood pressure when exposed to smoke!

• Since smoke drastically weakens the lungs' immune system, avoiding smoke is one of the best ways to prevent colds, flu, bronchitis, or risk of an even more serious respiratory illness, such as pneumonia or tuberculosis! Does your child have the flu? Chances are they have been exposed to ambient smoke!
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