Documented Cases and Studies of Lung Health Risks Associated with Nanotechnology
When dealing with a new technology such as the manipulation of nanomaterials, the first and most important question should be whether or not there is a potential for human and environmental health risks. Nanoparticles are some of the least studied and most misunderstood substances capable of entering the human body. Whether by application of a common household product such as sunscreen or cosmetics or by inhalation of airborne particles, nanomaterials are truly unavoidable. When discussing the risks of nanotechnology in Advanced Science Communications, there were no documented, proven reports of nanoparticles causing adverse health effects mentioned. However, in the article, “Nanotechnology: Piecing Together the Puzzle of Risk,” Kuzma does remark on a case involving workers at a Chinese factory who were reported to have fallen ill with respiratory and lung disease due to inhalation of aerosol nanoparticles. This made me wonder if there are more cases out there where people have gotten sick due to what they or others believe was exposure to nanoparticles. After all, just because there don’t seem to be any proven health risks in nanotechnology so far, that doesn’t mean that they don’t exist, especially when, according to Kuzma, “As of now, producers of nanomaterials are primarily responsible for deciding what safety studies to conduct and whether to submit them through voluntary programs and release them publicly.” As she goes on to say, results are less reliable when the studies are conducted by “the hands of those who have vested interests.” (Source: “Nanotechnology: Piecing Together the Puzzle of Risk,” Jennifer Kuzma)
After conducting an extensive search on documented cases of nanomaterials causing illness in humans, there was one type of ailment that stood out frequently: respiratory diseases thought to be caused by airborne, and most commonly, aerosol sprayed nanoparticles. Not only were there two unrelated cases of nanomaterial exposure apparently causing lung damage and even death, but there were also several studies conducted on this issue. The first case was described in an article of the European Respiratory Journal titled, “New Study Seeks to Link Seven Cases of Occupational Lung Disease with Nanoparticles and Nanotechnology.” Seven female workers in a Chinese industrial facility whose jobs entailed spraying polyacrylic ester paste onto a polystyrene substrate fell ill with “serious and progressive lung disease” resulting in two deaths. According to the study, the generation of smoke at the workplace when the polystyrene boards were heated and dried “may indicate the formation of a condensation containing nanoparticles.” Nanoparticles about 30 nanometers in diameter were found in fluid surrounding the patients’ lungs as well as in the in the paste being sprayed, and in the ventilation system of the building. (Source: “New Study Seeks to Link Seven Cases of Occupational Lung Disease with Nanoparticles and Nanotechnology.” Oxford University Press. 2009. www.physorg.com/news). While this study presents some compelling evidence, it remains inconclusive as to the dangers of nanotechnology. This was a clinical trial on patients exposed to far more than just nanoparticles without using recommended occupational safety measures. Please see the following video for the news report.
A second case of nanoparticles causing respiratory illness was reported in Germany. According to the article, “Nano Safety Recall,” an aerosol form of a protective sealant for glass and ceramics was recalled after only two days on the shelf when 79 reports of breathing problems and coughing were reported. There were also six hospitalizations for pulmonary adema. According to Germany’s Federal Institute for Risk Assessment, “there were no problems with the product for the four years it was sold as a pump spray.” Apparently the new aerosol spray created a much finer mist of droplets which were able to stay airborne for longer and penetrate deeper into the lung tissues. (Source: “Nano Safety Recall.” Kevin Bullis. Technology Review, Published by MIT. 2006)
Both cases mentioned allude to the idea that nanoparticles can be much more dangerous if allowed to penetrate further into the lungs. In the Chinese factory cases, the patients were exposed for hours on end to a heated and sprayed material containing nanoparticles, and in the German recall, consumers were affected by an aerosol form of nanoparticles. A recent study at Rice University showed that when particles were crushed to less than 100 nanometers, they caused high inflammation in the lungs of lab rats, and some particles were even able to travel to the brain. According to the study, nanoparticles have invaluable benefits in technological applications due to their size and biological activity; however it also gives them unprecedented toxicity with the ability to “penetrate the body’s natural barriers.” (Source: “Societal Dynamics of Nanotechnology.” www.web2.clarkson.edu/projects/nanobird/2.3.php)
At this point, it is understandable how nanoparticles manage to enter the lungs, but the mode in which they cause damage and illness is another question. A study in the Journal of Molecular Cell Biology begins with the statement that “scientists have identified for the first time a mechanism by which nanoparticles cause lung damage.” This study looks at a class of nanoparticles called polyamidoamine dendrimers (PAMAMs). It was found that PAMAMs cause lung damage by triggering autophagic cell death. This type of cell death, called autophagy, is a natural process that degrades damaged materials in the body. The study showed that nanoparticles in the lungs appear to cause overactivity in this process leading to wide scale death of human lung cells. Testing on mice showed that introducing the nanoparticles “significantly increased lung inflammation and death rates.” The research also showed that therapeutic medicines to prevent cell death could protect against health risks of nanotechnology and could be beneficial in fighting other causes of lung damage. (Source: “Health Risks of Nanotechnology: How Nanoparticles Can Cause Lung Damage and How the Damage Can be Blocked,” Science Daily. 2009)
Two final studies which exposed rodents to Single-Wall Carbon Nanotubes (nanoparticles made from carbon with a broad commercial application due to superior mechanical, electrical, and magnetic properties) by intratracheal installation further validate the idea that nanoparticles entering into the lungs can cause major health effects in the respiratory system. The first study, “Pulmonary Toxicity of Single-Wall Carbon Nanotubes in Mice and 90 Days after Intratracheal Installation,” found “dose-dependent lung lesions characterized by granulomas.” The second study, “Comparative Pulmonary Toxicity Assessment of Single-Wall Carbon Nanotubes in Rats,” had similar results and went further to conclude that the formation of pulmonary lesions seem to occur as a “result of the lungs’ immune response to removal of foreign substances that are not easily degraded.” This study, like the one mentioned earlier, found that the mechanism for lung damage was due to autophagic cell death triggered by the nanoparticles. (Source: “Health and Environmental Impact of Nanotechnology: Toxicological Assessment of Manufactured Nanoparticles,” Kevin L. Dreher. www.toxsci.oxfordjournals.org)
The question of whether or not there are any cases out there of nanotechnology being linked to death or illness has been answered. However, many questions remain. If several studies and specific cases have linked nanoparticles of being dangerous when able to make their way into the lungs, then why are there no bans on aerosol forms of nanotechnology products until more conclusive research can be performed? Think of the spray sunscreens and cosmetics used commonly in the home. Why did the spray in the German recall cause problems but no reports of respiratory illness have been reported with these other aerosol products? As Kuzma said, most of the research on nanoparticles is conducted by those profiting from them, so even if there was some more conclusive research than what we have now, would it be published?
One concept highlighted here is the fact that companies such as those who sell aerosol sunscreens may have done some research on their products but have done so with motivated reasoning, either by slanting their studies to their own benefit or by not revealing some of their results. On the other hand, the two cases mentioned in this blog could have had nothing at all to do with nanoparticles. After all, the German spray and the Chinese factory obviously contained many more airborne agents besides nanomaterials. Especially in the case of the Chinese workers, there is an extreme and dangerous example of the deficit model concept. Surely had the employees been informed that the air they were breathing in (without any ventilation or even masks) could be dangerous to their health, they would have thought about protective gear. But, since they were neither provided with safety measures or information, they are now either sick or deceased. While their superiors may not have known about the threats of nanoparticles, they did know that they were not following recommended safety regulations and were therefore willingly putting their employees at risk. This brings about the concept of a cycle of mistrust. Are any results truly trustworthy especially when there is money at stake? It could be that the studies showing mice being affected by nanoparticles were conducted purely to slant society’s view against the nano industry much in the same way that cigarette companies performed studies to “prove” the benefits and safety of their product. There are many people with a preconceived notion that nanoparticles could end in a science fiction type of disaster and would do anything to stop their production, including fabricating the results of a study or assuming the cause of an illness. As people become more distrusting of nanoparticles because of these studies, scientists may become more distrusting of people with respiratory illnesses claiming to have been exposed to nanoparticles. The cycle may only be broken as more impartial studies and conclusive evidence of the effects of nanoparticles begin to circulate.
These findings not only show that the threat of nanoparticles may be bigger than previously believed, but that nanomaterials are completely unavoidable. Many people don’t even know that their cosmetics and sunscreens, along with many other household items contain nanotechnology, and if they did it wouldn’t even matter anyway. With molecules so small, there is no way to see them coming. If nanoparticles are airborne near you, there is no way to avoid breathing them in. They can also travel undetected in water systems and soil where food is grown for consumption. The societal implications are numerous. While we don’t yet fully understand the nature of nanoparticles and their risks, they have indeed entered our lives forever. Whatever the long-term consequences are, society will have to deal with them.
Despite the troubling results of these cases and studies, there is one positive outcome. In the previously mentioned study on PAMAMs, it was found that through therapeutic medicines, the autophagy caused by the nanoparticles could be prevented. This technology could also be used to prevent and cure other disease where overactive programmed cell death causes organ damage. In the future, continual study of nanoparticles and their effects on humans and animals could further eliminate health risks of nanotechnology as well as lead to new ways to cure previously incurable diseases. These results show once again, that even though the risks of nanotechnology are still uncertain, the benefits could be great. No matter what great future path nanotechnology could take, it is important to continue trying to understand the risks and the benefits as much as humanly possible.
Sources
1. “Nanotechnology: Piecing Together the Puzzle of Risk,” Jennifer Kuzma
2. “New Study Seeks to Link Seven Cases of Occupational Lung Disease with Nanoparticles and Nanotechnology.” Oxford University Press. 2009. www.physorg.com/news
3. “Nano Safety Recall.” Kevin Bullis. Technology Review, Published by MIT. 2006
4. “Societal Dynamics of Nanotechnology.” www.web2.clarkson.edu/projects/nanobird/2.3.php
5. “Health Risks of Nanotechnology: How Nanoparticles Can Cause Lung Damage and How the Damage Can be Blocked,” Science Daily. 2009
6. “Health and Environmental Impact of Nanotechnology: Toxicological Assessment of Manufactured Nanoparticles,” Kevin L. Dreher. www.toxsci.oxfordjournals.org
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