Engineered Nanomaterial Term Paper Samples
Background and industry overview of engineered nanomaterials
Although there are some naturally occurring nanomateials, engineered nanomaterials are deliberately designed and manufactured with a goal of achieving certain premeditated properties. That is why nanomaterials exhibit superior properties than their corresponding bulk components. Materials can be engineered to achieve properties such as improved optical characteristics, enhanced magnetic properties, superior strength to weight ratios, and increased thermal/electric conductivities. One characteristic of a nanomaterial is that at least one of its primary dimension is not more than 100 nanometers. Proponents of nanotechnology believed that the introduction of the technology would result in tremendous changes in the fields of agriculture, health, communications, energy, industry, energy, consumer products, and so forth. Being a promising, the technology is expected to play a key role in the future economies. Typical materials used in the manufacture of nanomaterial include metals, ceramics, metal oxides, carbon, and carbon compounds (Sellers et al, 2009). Recent surveys show nanomaterials products has reached 1, 317 with 24 nations actively engaged in the manufacture. Health and fitness account for 56% of these products while specific material analysis show silver lead with 23% of the products, followed by carbon with 7 % and thirdly titanium dioxide at 4%. Expenditure in nanotechnology has been increased with time and the sector was expected to employ up to 2 million workers by 2015.
Exposure control strategies
Although nanotechnology is a new field with many things yet to be understood, there are emerging health concerns about occupational exposure. For example, the amount of minimum acceptable exposure or risks of exposure still remain unknown. Nonetheless, manufacturers are warned to ensure their employees operate in a safe and healthy environment. Such warnings are backed by recent toxicological studies by various scientists which showed exposure to nanoparticles can pose health risks. To avoid health consequences of exposure, a number of strategies has been proposed include elimination, substitution, engineering controls, administrative controls, and personal protective equipment (NIOSH, 2013). Elimination and substitution processes are viewed as cost-effective alternatives but have to be implemented during the design stage. While elimination is the total removal of a hazard, substitution involves replacement of high level hazards with low level hazards. Engineering controls involve placing a barrier between a worker and hazardous material (guards, barricades) or removal of hazardous materials using technologies such as ventilation and air filtration. Administrative controls are applied where engineering control measures fail to minimize hazards to acceptable levels and involve work scheduling, job rotation, training, and other feasible strategies. Personal protective equipment (PPE) are also used where the engineering controls have failed to minimize hazards to the acceptable minimum levels. PPE can be employed to protect critical parts of the body such as the skin and respiratory tract.
Nanotechnology processes and engineering controls
The nature of an engineering control adopted to minimize exposure to nanoparticles depends on the stage of nanotechnology process. For example, there is production of nanotechnology at the primary level where downstream processes take place. One approach has been to use the shapes, sizes, and chemical composition to design appropriate engineering controls. In a typical pharmaceutical industry where hazardous liquids and powders with no occupational exposure limits are used, the idea is to use a performance based strategy using exposure control limits. Given that many of the products manufactured in the pharmaceutical industry are the same as those used in the nanotechnology industry, the general concepts for handling hazardous materials apply and include medical surveillance, general ventilation, cleaning and disposal, maintenance, PPE, local exhaust ventilation, and monitoring of industrial hygiene (Naumann et al. 1996). Studies have also shown that source containment is one of the best strategies applicable in the pharmaceutical industry and include equipment modifications, process modifications, elimination, product modification, and substitution.
Hazard control evaluations
Evaluations for hazard control to determine if the engineering controls are as effective as they are supposed to be. Following this, an evaluation procedure have been proposed. The first task in this is to identify the sources of emissions. This involves a walk-through survey meant to identify likely sources of emissions before an in-depth evaluation is carried out. Second is conducting a background and area monitoring where a background sampling of concentrations in areas adjacent to the workplace is carried out. Third involves air monitoring and filter sampling. This can be achieved by reading the measurements from the instruments directly. Fourth is the assessment of air velocities and patterns. A hot wire anemometer and a pitot tube are useful for assessment of velocities when establishing sampling locations, assessment of existing control measures, and evaluation of outdoor contaminant penetration. Finally is about filling of a facility sampling and evaluation checklist (NIOSH, 2013). Evaluating sources of emissions and exposure to nanomaterials can be achieved by direct-reading monitoring, off-line analysis, and video exposure monitoring. Evaluating ventilation control systems can be achieved by using standard containment test methods for ventilated enclosures.
Health hazards associated with nanomaterial exposures
Clear evidence of health hazards associated with nanomaterials are not yet documented. However, there is a big concern that nanoparticles might be potentially harmful to skin, heart, and lungs. There effects of reproductive performance and its likelihood of causing cancer has been hypothesized (EPA, 2012). Toxicological studies being currently studied suggest certain nanoparticles like titanium dioxide and carbon nanotubes have impacts on animals (Warheit et al, 2008).
Conclusions and recommendations
Although the health hazards of exposure to nanoparticles is not yet known, the recent findings of impacts on animals is cause for great worry and it is advisable to take precautionary measures where nanomaterial exposure is likely. One of the best precautionary measures is to use a combination of methods such as preliminary health assessment of facilities and prevention through design. Control banding and observation of occupational exposure limits is also a desirable practice. Other effective strategies that has been proposed include hierarchy of controls involving elimination, substitution, engineering controls, administrative control, and personal protective equipment are also some of the methods that can be effectively applied to minimize health hazards. Current strategies such as those used in the pharmaceutical industry can apply for nanomaterial manufacturing to a large extent where particle size handled in both cases is the same.
Environmental Protection Agency (EPA). (2012). Research Investigates Human Health Effects of Nanomaterials. Retrieved from: http://www.epa.gov/nanoscience/quickfinder/hh_effects.htm
Naumann, B. D., Sargent, E. V., Starkman, B. S., Fraser, W. J., Becker, G. T., & Kirk, G. D. (1996). Performance-based exposure control limits for pharmaceutical active ingredients. American Industrial Hygiene Association Journal, 57(1), 33-42.
National Institute for Occupational Safety and Health (NIOSH). (2013). Current strategies for engineering controls in nanomaterial production and downstream handling processes. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2014–102
Sellers K., Mackay C., Bergeson, L.L., Clough, S.R., Hoyt, M., Chen, J., Henry, K., Hamblen, J. (2009). Nanotechnology and the Environment. Boca Raton, FL: CRC Press
Warheit, D. B., Sayes, C. M., Reed, K. L., & Swain, K. A. (2008). Health effects related to nanoparticle exposures: environmental, health and safety considerations for assessing hazards and risks. Pharmacology & therapeutics, 120(1), 35-42.