Adetunji H, Pinto L M M, Siddique A , Samuel S Potential Occupational health risk from exposure to nano-scale particles from Photocopiers- A Pilot Study1 Adetunji H, Pinto L M M, Siddique A , Samuel S

Contents Background Nano-scale particles Occupational Health risks Study aims and Objectives Nano-scale particles What are they? Why are they considered dangerous? Natural nano-particles Possible safety concern Occupational Health risks Photocopier and its components Nano-scale particle research The Results & Discussion Prevention of nano-particle exposure

Background Exposure assessment of nanoparticles is still in its infant stage compared to the exposure assessment of other airborne pollutants2,3,4. There is growing evidence that nanoparticles are produced when office equipment such as printers are in use5,6. He et al5 and Morawska et al6 studied particle emission characteristics of the office printers , focused on the emission characteristics of submicron particles emitted from the office printers. One of the main aims of their work was to classify the printers as high, low or zero emitters.

Background The results of He et al5 suggested that there is potential harm to human beings because of breathed in toner particles. Printers and photocopiers are capable of emitting ozone as well as volatile organic compounds (VOCs)7. Banerjee and Wimpenny7, suggested that the standard toner consists of the following components: polymer, colorant or carbon black, charge control agent, flow control additives such as fumed silica (titanium oxide, organometallic salts) and wax. Some have iron –oxide additives up to 30%. Examining some of these components reveals links with health hazards.

Background This work aimed to characterize and quantify the nanoscale particles emitted by a typical heavy duty industrial photocopier and printer to assess the long term effect of these particles on occupational health. Part of the work was presented at a Conference organised by Society of Engineering Industrial Hygiene in Canada (2009) We are discussing the pilot results today

Background In order to assess the risk related to manufactured nanoparticles on adverse human health, the knowledge of the effect induced by nanoparticles on respiratory organs and or dermal contact is essential. One of the most important aspects to be considered is the dose or exposure rate. This requires a comprehensive and quantitative assessment of nanoparticles emitted from photocopiers and printers including particle size, particle count, residence time of these particles in a suspended state and size distribution with respect to residence time

Potential safety issues in nano-particles2 The safety issues with nanoparticles are not very well known but their potential for danger is evident due to the high surface area to volume ratio, which can make the particles very reactive or catalytic. In addition, these are able to pass through cell membranes in organisms and may interact with biological systems.

Natural nanoparticles and possible safety concerns Nanoparticles in nature can agglomerate quickly and poses no danger to organisms. Nanoparticle penetrations into cells and tissues have been confirmed in studies in Animal. These can lead to biochemical damage or cancer. Organisms have formed immunity to some of the nanoparticles found in nature such as salt particulates found in ocean aerosols or terpens found in plants.

How do nanoparticles penetrate the body? Nanoparticles can be found in form of individual particles, agglomerates of nanoparticles or nanosctured types in form of aerosol that can get into the body through inhalation or skin contact Nanoparticles inhaled have been found deposited in the respiratory tract by both Human and animal studies. There are evidences from Animal studies that nano particles get into the bloodstream and be transported to other body organs.   These particles may be individual particles, agglomerates of nano particles, and particles from nanostructured materials that become airborne or come into contact with the skin.

Occupational hazards with nanoparticles Examples of workplaces that raise the risk of exposure to Nanoparticles: Workers dealing with nano particles in liquid media without adequate protection such as wearing appropriate gloves Workers who deal with Nanoparticles liquied media requiring vigorous agitation run the risk of inhalation of the particles. Works involving nano structured powders have potential risk of aerosolization. Those that have to clean nanoparticles dust collection systems have higher risk of exposure to both skin and inhalation

The Study

Background The effect of nano-particle on Occupational Health risk Size A room (approx 4 x 5 x 3 m) with an industrial heavy duty Photocopier was chosen for investigating nano particles emitted from the photocopier. Chemical composition

Photo-copier and Printers Time spent Normal working place Educational institutions Commercial photo-copying (Statistics) Typical Room and type of Ventilations

Pilot Study Site Equipment Measurement sequence Printer and Photocopier room Equipment DMS 500 fast particle spectrometer, measurement range 5-1000 nano-meter with 1 sec interval Measurement sequence Every 10 sec Peak and off-peak measurements (one full working week) Overnight measurement to assess the effect of no-activity

Equipments and study site Sampling point Site Fast Particulate Spectrometer DMS-500 Photocopier and Laser printer at the site

Nano-scale particle measurement Air toner Size spectral density at each situation

Number of particles in a cc of sampled air Cumulative concentration at each situation

Toner and reference air –spectral density Spectral density of toner particle Spectral density of room air

Settling time- over night measurement Settling time :approx 12 hours to reach the reference value

Mathematical model for settling time C: concentration at any time A : constant , related to initial concentration t: time in hour x: related to air–exchange rate at the site

Comparison Spectral density Cumulative count spectral density and cumulative particle count with and without activity

Amount of particle and breathing worst case maximum number of particles in air NC 90000 n/cc tidal volume TV 500 cc/breath number of breaths in a min NB 18 total amount of particles inhaled 810,000,000 Reference case RNC 16600 149,400,000

Chemical composition of toner Carbon black (0-5%) Iron oxide (15-20%) Binder resin (70-95%) , HDPE, LDPE and PP Charge control agents (0.2-0.5%) External flow charge agents (eg., fumed silica)

Key findings This pilot study highlighted the effect of photocopier on nano-scale particle count in the work environment. It showed that the nano-scale particle in the room increases significantly and takes approximately 12 hours to settle. These increased levels of manufactured nano-particles in the photocopier work environment warrant further investigation to evaluate potential occupational health risks.

Summary The nano-scale particle count in the room increased 11 times when the photocopier was in use as compared to when there was no activity in the room The size distribution showed a strong correlation with the size distribution of the photo copier toner, suggesting the photo copier as the main source for the increased nano-particle count in the room. This study also identified the settling time for the nano-scale aerosol in the work environment as 12 hours with the existing ventilation system.

Risk for nanomaterials in use Have not been fully known Further studies required urgently Especially the long-term adverse effects

Prevention of nanoparticle exposure-1 Lab protection and hygiene – regularly laundered lab coats must be worn.  Lab coats may not be taken to private homes and laundered. Arm sleeves are required where high levels of exposure or splashes of solutions containing nano particles are anticipated. Hand washing facilities must be provided in all labs.  Hand washing must be performed after handling nano materials. Standard Penn safety glasses are required when working in any lab. Gloves (disposable nitrile) must be worn when handling nano materials.  Clothing should include long pants and closed toed shoes Respirators and ventilators are needed to prevent inhalation Dry nanomaterials should be handled only within fume hood, biological safety cabinet, glove box or a vented filtered enclosure.

Prevention of nanoparticle exposure-2 Dry nanomaterials need to be transferred in closed containers Nanoparticle solutions need to be handled over disposable bench covers Aerosol producing activities (such as sonication, vortexing and centrifuging) may not be conducted on the open bench.  These can be performed in fume hood, biological safety cabinet, glove box or a vented filtered enclosure. Spills of dry nano particles must be cleaned with a HEPA vacuum.  Dry sweeping must not be used. Large spills must be cleaned by EHRS. Lab pressurization must be negative to the hallway. Ventilation should be adequately managed. All solutions and solid materials must be disposed of as hazardous waste following established guidelines.

Sources / further reading Adetunji, H., Macedo Pinto, L., Siddique, A., and Samuel, S (2009). Potential Occupational health risk from exposure to nano-scale particles from Photocopiers- A Pilot Study. The International journal on Industrial Risks Engineering (JI-IRI), Vol. 2, No. 1: 15-27. Borm, P J A., and David Robbins et al, 2006, The potential risks of nanomaterials: a review carried out for ECETOC, Particle and Fibre Toxicology, 3:11, doi:10.1186/1743-8977-3-11 EPA factsheet: nanotechnology, 2006, An EPA research perspective. Fact Sheet: http://es.epa.gov/ncer/nano/factsheet/nano_factsheet.pdf [accessed 23 Dec 08] Oberdörster, G., Oberdörster, E., and Oberdörster, J., 2005, Nanotoxicology: An Emerging Discipline Evolving from Studies of Ultrafine particles (UFPs). Review, Environmental Health Perspectives, 113, 823-839 He, C., Morawska, L., and Taplin, L., 2007, Particle Emission Characteristics of Office Printers, Environ. Sci. Technol., 2007, 41 (17), pp 6039–6045, DOI: 10.1021/es063049z Morawska, L., Moore, M.R., and Ristovski, Z.D., 2004, Impacts of ultrafine Particles: Desktop Literature Review & Analysis. Department of the environment & Heritage, Commonwealth of Australia Government. . Banerjee S., Wimpenny D.I., 2006, Laser printing of Polymetric materials, Solid Freeform Fabrication Proceedings, pp 366-374 http://www.news-medical.net/health/Safety-of-Nanoparticles.aspx