Three physicians and researchers from the Capital University of Medical Sciences (Beijing, China) have published a case report in the European Respiratory Journal describing severe lung disease in seven female workers employed at a shop where they applied polyacrylic coatings to polystyrene boards.  The lung disease is just one part of the story—two of the women died (ages 19 and 29)—the other part is that pathology samples from the workers’ lungs identified 30 nm (nanometer) in diameter particles.  Further investigation found that the coatings used by the workers contained nano partcles, too.

I commend the authors for taking the time to write up their findings and sharing them in the peer-reviewed literature.  As our public health history has demonstrated time and again, we rely on alert clinicians to find time in their stretched-thin schedules to share compelling, puzzling, exceptional or intriguing medical findings.   Here are the basics of this case(s) report:

The seven women workers in Beijing China (aged 18-47) were identified between January 2007 through April 2008, after being admitted to a hospital with shortness of breath.  Clinical examinations found hypoxemia (low oxygen saturation in blood), pleural effusion (fluid in thoracic cavity) and pericardial effusion (fluid around heart).   They also had a severe skin rash from intense itching of their faces, hands and forearms.  The women underwent a slew of medical tests, including invasive procedures like thoracentesis, bronchoscopy, thorascoscopy, and video-assisted thoracic surgery. 

Epidemiologists from the Chinese Center of Disease Control and other local specialists visited the workplace and collected samples of the materials used by the workers and dust particles from the ventilation system.  The worker protection practices and industrial hygiene in the plant were poor.   The women were working with a toxic mix of solvents, with n-butyl ester, toluene, di-tert-butyl peroxide, butonoic acid among others in the coating compound.

Critics of the authors’ paper are already lining up:

“I think the paper should never have been published without characterising the exposure and the toxicological reactivity of the nanoparticles before blaming the effects on them.” (from here) (Ken Donaldson, PhD, U of Edinburgh)

I disagree.   

We don’t know, for example, all that we’d like to know about the butter-flavoring agent diacetyl.  But using this logic, NIOSH should not have published its preliminary findings on disease in microwave popcorn plant workers. 

Andrew Maynard, PhD at 2020Science.org, wrote earlier this week about the study and solicited reaction from “six highly regarded experts“, including Dr. Donaldson quoted above.  Dr. Kristen Kulinowski, Director of the International Council On Nanotechnology (ICON) at Rice University, chose to focus on all the issues not addressed in this one paper.  These include: “more analysis of the particles themselves,” “what are the particles made of?” “were the particles part of the paste or created by the spraying or dying process?”   These are all reasonable scientific questions, but I’d argue beyond the scope of this single paper.

She goes on:

“The real tragedy here is that these workers could have been protected if a conventional chemical hygiene plan had been implemented that included a working ventilation system and personal protective equipment.  Preventing inhalation of 30-nm nanoparticles can be as simple as the proper use of an inexpensive mask sold by your neighborhood home improvement store.”

Is that true?  Wearing an “inexpensive mask sold by your neighborhood” hardware store can prevent workers from inhaling nanoparticles?  I’ve not heard that from my industrial hygiene colleagues.  [NIOSH, OSHA, others, is Dr. Kulinowski correct?]

(Just in case you’re wondering, Dr. Kulinowski’s ICON is funded by DuPont, Intel, Loreal, Lockheed Martin, Proctor & Gamble, Unidym, National Science Foundation, among others.)

Another expert providing comment is Professor Vicki Stone of Napier University, who also thought the authors should have done more to confirm the source of the nanoparticles in the workers’ lungs:

“…they did not provide any evidence to show that these particles were derived from the working environment.   …Humans constantly inhale particles from a wide variety of sources, including traffic, domestic and industrial pollution.  It is therefore important to confirm that these particles were gained specifically from the working environment before the fumes associated with their employment can be blamed for the health effects observed.”

I’m troubled by this comment for a couple of reasons. 

First, she’s telling us that we’re already walking around with nanoparticles in our bodies.   I’d like to know why these have been allowed recklessly into our environment?   AND, before we’ve a clue about their health effects?  I’ve heard this story before and it’s ending is not a good one for public health.

Second, the suggestion that these young workers may have inhaled the nanoparticles from some other source, sounds just like employers who insist that Joe Worker’s asbestosis came from one of Joe’s other employers.  Those asbestos fibers nanoparticles aren’t from my plant, he inhaled them from the joint down the street.  

It makes me wonder whether the NHANES supplements on environmental chemicals should be expanded to include biological samples (tissue/fluid) biopsies to identify nanoparticles.  (Granted, a tricky undertaking.  Nano manufactuers could be compelled to foot the bill.)

Professor Vicki Stone suggests that its quite likely that nanos are residing quite comfortably in our body tissue.   Wouldn’t it be interesting to compare the relative quantity of nanoparticles in the general population compared to those who are exposed occupationally?  And then follow these individuals long-term?

Speaking of workers, I doubt the Chinese factory workers described in the article  had a clue about the health hazards of the toxic soup with which they were working, let alone any notion that the coating compound contained nano materials.  What about workers in our own country?  Are they better informed when they are manufacturing, applying or using nano?  What about a right-to-know label like:

“CONTAINS Nano Particles.  Research pending on Health Effects.”

or

“CONTAINS Nano Particles.  Not sure yet if it will harm you or your kids.”

One final question:  Why did the paste producer add the nanoparticles to the polyacrylic ester compound in the first place?   Is it really that much better with the nano?

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Citation for paper:  Song Y, Li X, Du X. Exposure to nanoparticles is related to pleural effusion, pulmonary fibrosis and granuloma. European Respiratory Journal, Aug 2009.