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Traditional occupational hygiene assessment of occupational exposures to organic gases and vapours rely on low flow (<200 ml/min) NIOSH sorbent tubes. This work investigates 3M charcoal filter media (JK50 and JK40, 3M, Inc.) for collection and analysis of organic vapours across 0.1-5 l/min. To enable this work, a custom exposure facility was constructed and validated within which organic analyte gas/vapour concentrations could be introduced at known concentrations while controlling environmental variables such as temperature and humidity and other variables. This facility enabled experiments designed to investigate collection and desorption efficiencies across a range of sample flow rates, temperature and humidity conditions for both NIOSH sorbent tubes (e.g. SKC tube) and 3M charcoal filter media. As a result of the investigations described in this thesis, the following conclusions are drawn. Performance of the 3M charcoal filter media for collection and desorption efficiencies for loading, storage time, humidity and breakthrough at low flow rates (<0.5 l/min) were found comparable to the SKC sorbent tube. It is concluded that 3M charcoal media (JK50 and JK40) are suitable for sampling and analyses of hydrocarbons at flow rates <0.5 l/min. The collection efficiencies of the 3M charcoal filter media were investigated at high flow rates (>0.5l/min) for the same parameters, i.e., loading, temperature and humidity. It is concluded that 3M charcoal filter media can be used with confidence in sampling and analysis of airborne hydrocarbons up to 5 l/min. The Wheeler-Jonas model was found to satisfactorily predict the adsorption kinetics of the 3M charcoal filter media at different loading values of hydrocarbons. It was therefore concluded that the model can be applied to determine the suitable amount of 3M charcoal filter media prior to sampling for a given loading.

Traditional occupational hygiene assessment of occupational exposures to organic gases and vapours rely on low flow (<200 ml/min) NIOSH sorbent tubes. This work investigates 3M charcoal filter media (JK50 and JK40, 3M, Inc.) for collection and analysis of organic vapours across 0.1 ¿ 5 l/min. To enable this work, a custom exposure facility was constructed and validated within which organic analyte gas/vapour concentrations could be introduced at known concentrations while controlling environmental variables such as temperature and humidity and other variables. This facility enabled experiments designed to investigate collection and desorption efficiencies across a range of sample flow rates, temperature and humidity conditions for both NIOSH sorbent tubes (e.g. SKC tube) and 3M charcoal filter media. As a result of the investigations described in this thesis, the following conclusions are drawn. Performance of the 3M charcoal filter media for collection and desorption efficiencies for loading, storage time, humidity and breakthrough at low flow rates (<0.5 l/min) were found comparable to the SKC sorbent tube. It is concluded that 3M charcoal media (JK50 and JK40) are suitable for sampling and analyses of hydrocarbons at flow rates <0.5 l/min. The collection efficiencies of the 3M charcoal filter media were investigated at high flow rates (>0.5l/min) for the same parameters, i.e., loading, temperature and humidity. It is concluded that 3M charcoal filter media can be used with confidence in sampling and analysis of airborne hydrocarbons up to 5 l/min. The Wheeler-Jonas model was found to satisfactorily predict the adsorption kinetics of the 3M charcoal filter media at different loading values of hydrocarbons. It was therefore concluded that the model can be applied to determine the suitable amount of 3M charcoal filter media prior to sampling for a given loading.

Objectives: The aim of this study was to determine if exposure to volatile organic compounds can lead to DNA damage and impaired DNA repair capacity. Nail cosmetics is a fast growing industry around the world where employees and clients are subjected to various chemical substances which may be harmful to their health: such as formaldehyde, toluene, acetone, xylene, ethylmethacrylate, methylmethacrylate and n–buthyl acetate. These chemicals have the potential to be harmful to their health and exposure to these chemicals should be actively controlled. Formaldehyde is classified as a human carcinogen by the IARC, whereas, toluene and xylene are group three carcinogens, classified in 1999 (not classified as carcinogenic to humans), and various studies have linked DNA damage and impaired DNA repair to the above mentioned substances. Methods: Fifteen nail technicians were monitored by means of personal air sampling, measuring formaldehyde, toluene, xylene, acetone and ethylmethacrylate exposure. Fifteen unexposed subjects were chosen and matched for age and smoking habits with the exposed group. Heparinised blood samples were obtained from each test subject with which the Comet Assay was performed on lymphocytes to determine DNA damage and repair ability. Results: Exposure to ethylmethacrylates and methylmethacrylates leads to DNA damage. Methylmethacrylate causes DNA damage by specifically targeting pyrimidine (fpg) bases. N–buthyl acetate, xylene and acetone exposure impaired DNA repair capacity. The exposed group showed signs of Class III and Class IV DNA damage, whereas the control group had little Class III damage and no indication of Class IV damage. The overall DNA repair ability of the nail technicians was slightly impaired when compared to that of the control group, which is in concurrence with previous studies. Smoking habits and age did not show significant influences on the level of DNA damage and repair when compared with the control group. Conclusion: Exposure to volatile organic compounds such as ethylmethacryale and methylmethacrylate may lead to DNA damage and altered DNA repair in some individuals, although further studies are recommended. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011.

Objectives: The aim of this study was to determine if exposure to volatile organic compounds can lead to DNA damage and impaired DNA repair capacity. Nail cosmetics is a fast growing industry around the world where employees and clients are subjected to various chemical substances which may be harmful to their health: such as formaldehyde, toluene, acetone, xylene, ethylmethacrylate, methylmethacrylate and n–buthyl acetate. These chemicals have the potential to be harmful to their health and exposure to these chemicals should be actively controlled. Formaldehyde is classified as a human carcinogen by the IARC, whereas, toluene and xylene are group three carcinogens, classified in 1999 (not classified as carcinogenic to humans), and various studies have linked DNA damage and impaired DNA repair to the above mentioned substances. Methods: Fifteen nail technicians were monitored by means of personal air sampling, measuring formaldehyde, toluene, xylene, acetone and ethylmethacrylate exposure. Fifteen unexposed subjects were chosen and matched for age and smoking habits with the exposed group. Heparinised blood samples were obtained from each test subject with which the Comet Assay was performed on lymphocytes to determine DNA damage and repair ability. Results: Exposure to ethylmethacrylates and methylmethacrylates leads to DNA damage. Methylmethacrylate causes DNA damage by specifically targeting pyrimidine (fpg) bases. N–buthyl acetate, xylene and acetone exposure impaired DNA repair capacity. The exposed group showed signs of Class III and Class IV DNA damage, whereas the control group had little Class III damage and no indication of Class IV damage. The overall DNA repair ability of the nail technicians was slightly impaired when compared to that of the control group, which is in concurrence with previous studies. Smoking habits and age did not show significant influences on the level of DNA damage and repair when compared with the control group. Conclusion: Exposure to volatile organic compounds such as ethylmethacryale and methylmethacrylate may lead to DNA damage and altered DNA repair in some individuals, although further studies are recommended. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011.