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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A Literature Review of Wipe Sampling Methods for Pesticides in Published Exposure Measurement Studies in the United States

Low, Christopher Michael 19 October 2016 (has links)
Pesticides in the United States are frequently used to control pests in many settings from residential homes to agricultural crops. Most pesticides, when used in accordance with their manufacturer's label are relatively safe, and will naturally degrade once exposed to the environment, however, these natural degradative processes can be hindered when introduced indoors. Furthermore, it has been shown that pesticides can easily bond to surface dislodgeable residues (SDRs) commonly known as dust. There are various methods that can be used to characterize the presence and exposure of pesticides indoors. Wipe sampling is one of the important methods commonly used to measure pesticides on surfaces due to its simple and inexpensive nature, however, several methods exist for wipe sampling and each method has varying steps involving different wiping material, pre-treatment of wipes, wetting solvent, surface type, collection pattern, and storage. The purpose of this literature review is to summarize concisely the methods from eighteen recent studies that used surface wipes to sample for pesticides from indoor environments. This report details the methods applied to perform the literature review, provide general wipe sampling information from government agencies, discuss other related surface sampling methods, provide a brief summary of wipe sampling methods applied in each study, and compare the methods applied to provide considerations for those seeking to use surface wipes for sampling pesticides. Overall, it would seem that there are more variations than similarities between wipe sampling methods from the literature reviewed. Similarities included the use of isopropyl alcohol (IPA) as the wetting solvent and how wipe samples were stored after collection. The differences in wiping materials, pre-treatment of wipes, surface types, and collection patterns still demonstrate the need for a standardized method. Until a standardized method is established, poor comparisons of study results will continue and knowledge gaps will remain.
2

Evaluating Worker Exposure to Hexavalent Chromium in Refractory Materials During Demolition Activities

Brenneman, Chad 08 April 2010 (has links)
No description available.
3

Dermal exposure to platinum group metals at a precious metal refinery : a pilot study / Marilize Barnard

Barnard, Marilize January 2014 (has links)
Background: Workers in a platinum group metals (PGMs) refinery are potentially exposed to various precious metals (iridium, osmium, palladium, platinum, rhodium and ruthenium) and their metal-salt compounds which may cause rhinitis, asthma, contact urticaria and conjunctivitis. Some cases revealed that sensitisation occurred in employees where it was not possible to detect any airborne soluble platinum or where the respiratory soluble platinum exposure was below the occupational exposure limit. It is unclear whether respiratory exposure or a combination of respiratory and dermal exposure may be involved in sensitisation and the possible elicitation of skin symptoms. Objectives: To determine if dermal exposure to PGMs took place during the refining process and in the administration area by using a removal method and to compare dermal exposure on the different anatomical areas and in two different working areas, Areas A and B for each of the PGMs. Methods: Dermal exposure samples were collected with a removal method using GhostwipesTM. The samples were collected from the palm of the hands, the wrists and the necks of the workers, before the shift started, before tea time, before lunch time and after the shift ended. The skin wipes were analysed for the PGMs (iridium, osmium, palladium, platinum, ruthenium and rhodium) according to Methods for the Determination of Hazardous Substances (MDHS) method 46/2, using Inductively Coupled Plasma-Mass Spectrometry. Results: No published data is available on occupational dermal exposure to PGMs in a precious metals refinery. This study proved that dermal exposure to PGMs in the refinery took place and was quantified. The PGM dermal exposure results in general, were very low (measured in nano grams), with platinum having the overall highest exposure. Exposure also occurred the most frequently during the last two intervals of the day, before lunch time and at the end of the shift. Exposure on all three the anatomical areas that were tested in the study, varied much with the palm of the hands having the highest exposure levels. There were also variations in exposure between areas A and B due to the fact that the processes in these two areas differ. Conclusions: It was confirmed that dermal exposure to PGMs took place at the precious metals refinery. The highest exposure took place before lunch time and towards the end of the shift. The metal to which the workers were exposed the most was platinum and the production area where the workers had the highest exposure to most of the metals was Area B. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2015
4

Dermal exposure to platinum group metals at a precious metal refinery : a pilot study / Marilize Barnard

Barnard, Marilize January 2014 (has links)
Background: Workers in a platinum group metals (PGMs) refinery are potentially exposed to various precious metals (iridium, osmium, palladium, platinum, rhodium and ruthenium) and their metal-salt compounds which may cause rhinitis, asthma, contact urticaria and conjunctivitis. Some cases revealed that sensitisation occurred in employees where it was not possible to detect any airborne soluble platinum or where the respiratory soluble platinum exposure was below the occupational exposure limit. It is unclear whether respiratory exposure or a combination of respiratory and dermal exposure may be involved in sensitisation and the possible elicitation of skin symptoms. Objectives: To determine if dermal exposure to PGMs took place during the refining process and in the administration area by using a removal method and to compare dermal exposure on the different anatomical areas and in two different working areas, Areas A and B for each of the PGMs. Methods: Dermal exposure samples were collected with a removal method using GhostwipesTM. The samples were collected from the palm of the hands, the wrists and the necks of the workers, before the shift started, before tea time, before lunch time and after the shift ended. The skin wipes were analysed for the PGMs (iridium, osmium, palladium, platinum, ruthenium and rhodium) according to Methods for the Determination of Hazardous Substances (MDHS) method 46/2, using Inductively Coupled Plasma-Mass Spectrometry. Results: No published data is available on occupational dermal exposure to PGMs in a precious metals refinery. This study proved that dermal exposure to PGMs in the refinery took place and was quantified. The PGM dermal exposure results in general, were very low (measured in nano grams), with platinum having the overall highest exposure. Exposure also occurred the most frequently during the last two intervals of the day, before lunch time and at the end of the shift. Exposure on all three the anatomical areas that were tested in the study, varied much with the palm of the hands having the highest exposure levels. There were also variations in exposure between areas A and B due to the fact that the processes in these two areas differ. Conclusions: It was confirmed that dermal exposure to PGMs took place at the precious metals refinery. The highest exposure took place before lunch time and towards the end of the shift. The metal to which the workers were exposed the most was platinum and the production area where the workers had the highest exposure to most of the metals was Area B. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2015

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