Category Archives: NIOSH

Hitting 'em where it hurts: BPA reduces sperm quantity and quality in male workers

By | Bio | Published: October 28, 2010

Richard Denison, Ph.D., is a Senior Scientist.

As reported by Rob Stein in the Washington Post this morning, a NIOSH-funded study of male Chinese workers conducted by researchers at Kaiser-Permanente in Oakland, California has found that exposure to the endocrine-disrupting chemical bisphenol A (BPA) significantly increases the incidence of low sperm counts and concentrations, as well as lowered sperm motility and higher mortality.

The 5-year study, published in the peer-reviewed journal Fertility and Sterility (that's a title only slightly more cheery than the CDC's publication Morbidity and Mortality!), shows that the same kinds of adverse effects of BPA on sperm already observed in animal studies also occur in humans with detectable levels of BPA in their urine.

And while the most pronounced effects were observed in highly exposed workers, the authors of the study note:

Similar dose-response associations were observed among participants with only environmental BPA exposure at levels comparable to men in the general United States population.

Despite a markedly reduced sample size in this group of men exposed only to low environmental BPA sources, the inverse correlation between increased urine BPA level and decreased sperm concentration and total sperm count remain statistically significant.

Read More »

Also posted in Bisphenol A, Endocrine disruption, Exposure, Health, Worker Safety | Comments closed

Won’t we ever stop playing whack-a-mole with “regrettable chemical substitutions”?

By | Bio | Published: January 12, 2010

Richard Denison, Ph.D., is a Senior Scientist.

In recent days, two compelling cases have surfaced of so-called “regrettable substitutions” – industry responding to concerns about the use of one dangerous chemical by replacing it with another that is less well-studied, or at least not currently in the crosshairs.

Case 1:  Chinese manufacturers of children’s jewelry, responding to concerns and restrictions on the use of lead in such products produced for export to the U.S., have replaced it with cadmium, a known human carcinogen and developmental toxicant that, if anything is even more toxic to kids than lead – but is not subject to any restrictions in such kids’ products. 

Case 2:  American food product manufacturers, responding to concerns about the devastating effects on the lungs of workers exposed to diacetyl – an artificial butter flavoring used in many products, most notably microwave popcorn – have begun to replace it with closely related chemicals likely to break down into diacetyl or otherwise have similar effects.

Are we destined forever to play this dangerous variant on the game of whack-a-mole, or can something be done? Read More »

Also posted in Consumer Products, Exposure, Hazard, Health, Industry, Inhalation, Regulation, Testing, TSCA, Uncategorized, Worker Safety | Comments closed

MWCNT toxicity: Another dot to asbestos is connected

By | Bio | Published: March 25, 2009

Richard Denison, Ph.D., is a Senior Scientist.

Some months ago, my colleague John Balbus posted here about studies finding that when multi-walled carbon nanotubes (MWCNTs) are injected into the abdominal cavities of mice, they induce inflammation and mesothelioma-like reactions similar to those caused by asbestos.  He appropriately cautioned that – among other critical questions – these studies had not demonstrated that inhaled MWCNTs could actually move out of the lung and into the tissues where asbestos gives rise to its effects.  Well, that particular dot now appears to have been connected. Read More »

Also posted in Carbon Nanotubes, Health, Inhalation, Research, Worker Safety | Comments closed