Nanotech Occupational Exposures - A Look Back at 2015 Studies
Exposure to nanomaterials is a significant emerging issue facing the Property & Casualty insurance industry. The nanotechnology industry continues to grow with innovation and expansion into new fields on a regular basis; however, the health and safety implications of nanoparticles remain uncertain. We try to stay abreast of the field to determine how and where issues may emerge that will shape the exposures underwritten today and tomorrow.
While there is likely more exposure to consumers than many realize, occupational exposures are still perhaps the most concerning to insurers.
Determining if a substance is potentially harmful to humans can be a lengthy process, taking years. It may still be some time before science can find an association, and perhaps longer to confirm or refute causation. In the meantime, concerns about workplace and product exposures to nanomaterials remain.
A Look Back at 2015
Dozens of studies have been published the last few years by researchers from around the world who found that exposure to nanomaterials can cause harm. Listed below are a handful of studies published in 2015. Many are animal studies, while those performed on human cells are most likely Petri dish studies:
- Nanometer long carbon nanotubes caused sustained lung inflammation and fibrosis in the lungs (i.e., lung scarring similar to what is seen in asbestos exposure). Researchers found that the inflammatory and fibrotic responses induced by these nanotubes were more severe than those caused by crocidolite (a.k.a. blue asbestos) which is considered the most hazardous asbestos fiber.1
- Chinese researchers monitored workers exposed to nanoscale carbon black (CB) via inhalation and found “evidence of a link between human exposure to CB and long-term pulmonary effects.”2
Carbon black is a material produced by the incomplete combustion of heavy petroleum products. Subtypes are acetylene black, channel black, furnace black, lamp black and thermal black.
- Inhalation of silica nanoparticles damages the lungs. The study found that “the nanoparticles induced inflammation, lung injury and increased susceptibility to lethal pneumonia.”3
- “Chronic exposure to single-walled carbon nanotubes induced apoptosis [cell death] resistance of human lung epithelial cells.” While resistance to death may initially sound like a good thing, this resistance results in “a foundation of neoplastic transformation and cancer development” in lung cells.4
- Inhaled nanoparticles of silicon dioxide increase risk of atherosclerosis [plaque buildup inside arteries]. Researchers believe that laboratory, and high-tech manufacturing workers may be at greatest risk.5
- Metal oxide nanoparticles at low concentrations could damage cells.6
- Exposure to silver nanoparticles induced death in human neural stem cells.7
- In what is believed to be the first study of its kind, it was found that multi-walled carbon nanotubes can penetrate the blood-brain barrier.8
- Inhaled nanoparticles are deposited in all regions of the respiratory tract and are transported to the central nervous system.9
- Titanium dioxide nanoparticles in the bloodstream promote disregulation of the blood-brain barrier, affecting the central nervous system.10
As various industry sectors find more, and more varied, use of nanomaterials, the number of occupationally exposed workers continues to grow.
There may be additional concerns for those secondary users importing nanomaterials from other countries that may not have proper manufacturing controls in place. While often cheaper, there is a possibility that these imported nanomaterials may be contaminated by other substances - some of which may increase toxicity.
In 2009 seven young female workers in China (ages 18 to 47), who were exposed to nanoparticles in a paint factory for a period of 5 to 13 months, were reported to have suffered from nanoparticle-induced lung disease.11 To date, there has not been much in the way of alleged illnesses caused by nanomaterials among U.S. workers.
Just one case reported acute illness of a lab worker who had only been working with nickel nanoparticles for one week. It is the latency issue that remains the foremost concern. We welcome a conversation on nanotechnology and what it means to the risks in your book of business.
- Nanometer-long Ge-imogolite nanotubes cause sustained lunginflammation and fibrosis in rats.
- Reduced pulmonary function and increased pro-inflammatory cytokines in nanoscale carbon black-exposed workers.
- Acute exposure to silica nanoparticles enhances mortality and increases lung permeability in a mouse model of Pseudomonas aeruginosa pneumonia.
- Carbon Nanotubes Induce Apoptosis Resistance of Human Lung Epithelial Cells Through FLICE-Inhibitory Protein.
- American Technion Society, Citations Environmental Toxicology.
- Comparison of cellular toxicity caused by ambient ultrafine particles and engineered metal oxide nanoparticles.
- Effects of silver nanoparticles on human and rat embryonic neural stem cells.
- The interaction of carbon nanotubes with an in vitro blood-brain barrier model and mouse brain in vivo.
- The Effects of Inhaled Nanoscale Particles in the Central Nervous System.
- Tissue biodistribution of intravenously administered titanium dioxide nanoparticles revealed blood-brain barrier clearance and brain inflammation in rat.
- Exposure to nanoparticles is related to pleural effusion, pulmonary fibrosis and granuloma.