C-+precautions+with+nanoparticles

Raymond Chang/ November 5, 2010

**__What precautions are taken to protect the health and safety of people working with nanoparticles?__**

**1.What are Nanoparticles (NPs)?** Nanoparticles are particles that are 100 nanometers or less in size and behave as a whole unit in terms of its transport and properties. The properties of many conventional materials change when formed from nanoparticles. This is because nanoparticles have a greater surface area per weight than larger particles and thus are more reactive to certain other molecules. For example, (1) gold nanoparticles melt at much lower temperatures (~300 °C for 2.5 nm size) than the gold slabs (1064 °C); (2) absorption of solar radiation in photovoltaic cells is much higher in materials composed of nanoparticles than it is in materials composed of thin films of continuous sheets of material – the smaller the particles, the greater the solar absorption.

**2. How are NPs made? Two primary methods include:** ·  Mechanical: ‘top-down’ method that reduces the size of particles by attrition, e.g.,  ball milling or planetary grinding. ·  Wet Chemistry : ‘bottom-up’ technique that uses  light scattering techniques. They  start with ions or molecules and build these up into larger structures.

** 3. Where are NPs applied? **  ·  High performance and yet smaller components such as ‘ capacitors ’ for mobile phones. · ‘ Anti-reflection coatings ’ in optical lenses <span style="color: black; font-family: Gisha,sans-serif; font-size: 10pt;">. · ‘ <span style="color: black; font-family: Gisha,sans-serif; font-size: 10pt;">Nano M <span style="color: black; font-family: Gisha,sans-serif; font-size: 10pt;">agnetic particles ’ <span style="color: black; font-family: Gisha,sans-serif; font-size: 10pt;">to improve detail s <span style="color: black; font-family: Gisha,sans-serif; font-size: 10pt;"> and contrast in MRI images. · <span style="color: black; font-family: Gisha,sans-serif; font-size: 10pt;">Enhance d <span style="color: black; font-family: Gisha,sans-serif; font-size: 10pt;"> heat transfer from solar collectors to storage tanks. · <span style="color: black; font-family: Gisha,sans-serif; font-size: 10pt;">Electrocatalysts for high efficiency fuel cells. · Developing improved wear resistant construction materials and fabrics. · Quantum Dots (crystalline nanoparticles) identify the location of cancer cells in the body. · Nanoparticles that deliver chemotherapy drugs directly to cancer cells. · Silicon nanoparticle coatings increase battery power and reduce recharge time. · Zinc oxide nanoparticle coatings to protect wood, plastic and textiles from UV rays. · <span style="color: black; font-family: Gisha,sans-serif; font-size: 10pt;">New anti-corrosion properties. · <span style="color: black; font-family: Gisha,sans-serif; font-size: 10pt;">Antibacterial silver coatings on wound dressings. · <span style="color: black; font-family: Gisha,sans-serif; font-size: 10pt;">Clean up of soil contamination and pollution, especially oil. · <span style="color: black; font-family: Gisha,sans-serif; font-size: 10pt;">Treatment of industrial emissions. · <span style="color: black; font-family: Gisha,sans-serif; font-size: 10pt;">More efficient and effective water filtration. · Cosmetics · <span style="font-family: Gisha,sans-serif; line-height: 14px;">Pesticides

**4. Are NPs safe?** Nanoparticles present possible dangers, both medically and environmentally. Most of these are due to the high surface to volume ratio, which can make the particles very reactive or catalytic. With length less than 100nm compared to 8000nm of human cells and 130nm of HIV virus, they are also able to pass through cell membranes in organisms, and their interactions with biological systems are relatively unknown. According to the San Fransico Chronicles, "Animal studies have shown that some nanoparticles can penetrate cells and tissues, move through the body and brain and cause biochemical damage they also have shown to cause a risk factor in men for testicular cancer. According to a comprehensive study conducted by researchers at UCLA's Jonsson Comprehensive Cancer Center, Titanium dioxide (TiO2) nanoparticles, found in everything from cosmetics to sunscreen to paint to vitamins, caused systemic genetic damage in mice.(//ScienceDaily, Nov. 17, 2009)// Silver particles can kill liver ans brain cells. Carbon nanoparticles damage the DNA. Humans can absorb and/or inhale nanoparticles.

**5. What do/can workers do to prevent possible risks?** · Ventilate workplaces. · Clean machines regularly to prevent dust build-up and subsequent explosions. · Check equipment to prevent leaks and cracks in machines. · Receive education on transportation and storage lest the nanoparticles spill or leak · Maintain the temperature and humidity at a level that would not trigger nanoparticles to combust. · Treat all of its effluents (wastematters)-solid, liquid, and even emissions-before they return to environment. · Minimize the number of transport process of nanoparticles · Perform high-risk operation in a separate space that is properly ventilated. · Carry all forms of nanoparticles, even dry ones, in ‘closed’ containers. · Keep all work surfaces non-porous and easy to clean. · Separate work clothes from street-clothes, and also keep as hygienic as possible at work. · Wear respiratory protection, where necessary. · Put on protective outwear and gloves to guard against skin absorption. · Receive regular training and information program. · Assess each worker’s exposure to possible toxicity on a regular basis.

**__Bibliography__**

<span style="color: black; font-family: Calibri,sans-serif; font-size: 11pt;">Biello, D. (2008, March 13). Do Nanoparticles in Food Pose a Health Risk?: Scientific American. //<span style="color: black; font-family: Calibri,sans-serif; font-size: 11pt;">Science News, Articles and Information | Scientific American //<span style="color: black; font-family: Calibri,sans-serif; font-size: 11pt;">. Retrieved November 5, 2010, from http://www.scientificamerican.com/article.cfm?id=do-nanoparticles-in-food-pose-health-risk

Nanoparticle. (2010). In //Encyclopædia Britannica//. Retrieved November 05, 2010, from Encyclopædia Britannica Online: []

Nanoparticle. [Photograph]. Retrieved November 2, 2010, from Encyclopædia Britannica Online: <span style="color: windowtext; line-height: normal; margin-bottom: 0cm; margin-left: 0cm; margin-right: 0cm; margin-top: 0cm;"> []

=<span style="color: black; font-family: Calibri,sans-serif; font-weight: normal;">Nanoparticles and their Applications. (n.d.).//Nanotechnology Made Clear//. Retrieved November 5, 2010, from [] =

=<span style="color: black; font-family: Calibri,sans-serif; font-weight: normal;">Ostiguy, C., Roberge, B., Menard, L., & Endo, C. (2009, June 15). Best Practices Guide to Synthetic wbr Nanoparticle Risk Management. //Docstoc – Documents, Templates, Forms, Ebooks, Papers & Presentations//. Retrieved November 5, 2010, from [] =

<span style="color: black; font-family: Calibri,sans-serif; font-size: 11pt;">University of California - Los Angeles (2009, November 17). Nanoparticles used in common household items cause genetic damage in mice. //<span style="color: black; font-family: Calibri,sans-serif; font-size: 11pt;">ScienceDaily //<span style="color: black; font-family: Calibri,sans-serif; font-size: 11pt;">. Retrieved November 5, 2010, from []

<span style="color: black; font-family: Calibri,sans-serif; font-size: 11pt; line-height: 14pt; margin-bottom: 0cm; margin-left: 0cm; margin-right: 0cm; margin-top: 0cm;">What Are Nanoparticles? - A Definition.. (n.d.). //Particle Size Analysis, Zeta Potential, Rheology, SEC, Particle Shape//. Retrieved November 5, 2010, from []