The Large Questions About Health Impacts from Tiny Nanoparticles

The Large Questions About Health Impacts from Tiny Nanoparticles

A new study examines the first reported case of worker sensitivity related to exposure to nanoparticles and raises nearly as many questions as it answers.

With little industry-specific regulation, some occupational health specialists and researchers are concerned that nanomaterial manufacturers and downstream users have been operating like the Wild West, with many of them unaware or choosing to ignore the potential dangers to workers handing particles so small that 100 million nanoparticles could fit on the head of a pin.

A new study, which examines the case of a chemist who formulated polymers and coatings and developed symptoms related to the use of nickel nanoparticle powder, provides new insight into the use of nanomaterials and the impact the lack of personal protective equipment (PPE) or engineering controls could have for many nano workers.

The 26-year-old, non-smoking, female chemist worked as a formulation chemist for 3 years in an industry involved with making metallic inks for various applications. She had no symptoms when doing work that involved formulating polymers and making coatings, nor when working in the same laboratory with metal -plating baths.

100 million nanoparticles fit on the head of a pin, but employers working with them don't monitor for airborne nanoparticle samples.

She usually used silver ink particles, but within one week of starting to work with nickel nanoparticle powder weighed out and handled on a lab bench with no protective measures, she began to develop throat irritation, nasal congestion, post-nasal drip, facial flushing and new skin reactions to her earrings and belt buckle. 

Airborne nanoparticle sampling was not performed at the company, and therefore was not available to determine the exposures of workers to nanomaterials.

After returning to work following some time off, the chemist experienced a return of the symptoms – even when working in other parts of the building – so she went to see an occupational physician. The occupational physician spoke with the company doctor about the need for further assessment and a change in how the nanoparticles were being handled. 

Eventually, the chemist had to move to another lab that had no metal chemistry work and her symptoms improved dramatically.

First Case Study of Nano Health Impacts

W. Shane Journeay, Ph.D., M.D. and Rose H. Goldman, M.D., MPH, examined the case of the chemist in a study published in the American Journal of Industrial Medicine, "Occupational Handling of Nickel Nanoparticles: A Case Report." 

As Journey and Goldman point out in the study, "Nanotechnology applications continue to be used in an increasingly diverse manner in the workplace, resulting in engineered nanoparticles with unique properties. The science of nanotoxicology is also developing as the unique physicochemical properties of nanoscale materials are discovered."

Few people realize there are over 1,600 consumer products on the market that use nanomaterials, and nanotechnology is a $20 billion industry. In fact, total sales of nanotechnology are expected to reach $48.9 billion by 2017, after increasing at a five-year compound annual growth rate (CAGR) of 18.7 percent.

 

While nanotechnology has some amazing properties that dramatically will change many products, the study by Journeay and Goldman reveals those same amazing, game-changing properties can be harmful to unprotected workers. They also raise a lot of questions about potential health impacts.

Currently, there are thousands of U.S. workers handing nanoparticles, according to Journeay, and by 2020 there will be an estimated 6 million workers handling nanoparticles worldwide with 2 million of them in the United States.

"The implementation of nanotechnology into the workplace poses a challenge for occupational risk assessment because of difficulty isolating exposures to specific types of nanoparticles and determining the presence or absence of nanoparticle toxicity," Journeay and Goldman noted in their study.

Explosive Growth of Nano Development

In an interview with EHS Today, Journeay confirmed there is a wide range of potential health effects for workers who are exposed to nanoparticles and a lack of scientific research about the health impacts nanomaterials have on humans. 

"I have been involved in research on the human health impacts of nanomaterials for many years and I have watched the research evolve," said Journeay, a toxicologist with specialization in respiratory toxicology and the potential human and environmental health risks associated with nanotechnology. "However, given explosive rate of development of nanotechnology, it does not surprise me that there are not more studies. Efforts are being made to study nanomaterial toxicity but the pace of industrial development is much faster, which means not all materials have been tested or will be tested prior to entering the workplace or the market."

That is one of the reasons that the case documented in the study from Journey and Goldman is so important; it provides confirmation of a human handling nanoparticles in the workplace and developing health effects, specifically allergic sensitization, breathing problems and rash. The concern among toxicologists is that these particles may cause unknown effects at even tiny doses and therefore lead to longer-term health problems like cancer.

"[This] case highlights the growing need to appreciate the differences between bulk and engineered nanoparticle materials, and to institute the proper exposure controls," wrote Journeay and Goldman. "This case also illustrates the need for more research to better define the nanotoxicological mechanisms by which nanoparticles can cause adverse health effects and the best ways to protect workers."

Workers may not know they are or were exposed to nanomaterials until they suffer an adverse reaction, said Journeay. "The major difficulty is lack of awareness of the differences in handling nanomaterials," he noted. "Many of the nanomaterials will be benign where others will be a problem and … we are finding that many companies do not have a full understanding of the nuances of nanoscale EHS. This ranges from management to the workers and therefore, if they treat nanomaterials like traditional chemicals, they may not realize the need for PPE."

Acute exposures can lead to symptoms such as congestion, headache, dermatitis, occupational asthma, cough, fatigue and allergic reactions. Few doctors in the world are trained in nanotoxicology. The chemist who was the subject of the study by Journay and Goldman originally was diagnosed with a sinus infection by a regular physician. There are some traditional occupational health effects that can be diagnosed by existing methods, however, it is deciphering the exposure that the worker has had to true nanoparticles that few physicians adequately are trained to assess.

"We feel that increasing awareness through training and education about nanomaterials EHS is crucial," Journeay told EHS Today. "Nanotechnology in the workplace is becoming more widespread and advanced and companies should get assistance in tackling these problems. If companies want to lead in the area of nano EHS, they should find specialized help to determine that good practices are in place or whether there is a need for new measures to protect workers."

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