abstract: United States Environmental Protection Agency (USEPA) had identified and recommended air quality monitoring to take place at 63 schools throughout the country. Unfortunately, tribal schools were not considered during the time USEPA conducted the analysis. The importance of identifying any air toxic pollutants affecting school children needs to be analyzed. Conducting an air monitoring toxic analysis on the Navajo Nation at Church Rock Elementary School, Church Rock, New Mexico (CRNM) was carried out. The current school location posed a concern, in regards to the surrounding stationary, mobile, and natural emissions emitted all types of toxic pollutants. USEPA sponsors various air monitoring program, which Tribal Air Monitoring Support (TAMS) program undertook, and offered tribal programs, organizations or agencies to utilized air monitoring equipment's. The air monitoring setup was conducted with the contract Eastern Research Group, Inc. (ERG) laboratory, where collection of 24-hour ambient air samples for 60 days on a 6-day sampling interval were performed. The analysis for volatile organic compounds (VOCs)were collected from canister samples using USEPA Compendium Method TO-15, polycyclic aromatic hydrocarbons (PAHs) from polyurethane foam (PUF) and XAD-2 resin samples using USEPA Compendium Method TO-13A. Carbonyl compounds were collected by sorbent cartridge samples using USEPA Compendium Method TO-11A, and trace of metals from filters were sampled using USEPA Compendium Method IO-3.5 and FEM EQL-0512-202. A total of 53 VOC concentrations were greater than 1 μg/m3, where dichlorodifluoromethane, trichlorofluoromethane, chloromethane, dichloromethane, propylene, toluene, acrolein and acetylene were detected. A total of 23 carbonyl compound concentrations were greater than 1 μg/m3, where acetone and formaldehyde were measured. Naphthalene average with the highest average for PAHs, where phenanthrene and retene were the second and third highest averages. As for the metals the highest averages resulted from manganese, chromium and lead. Overall, the air toxic pollutants resulted from CRNM surrounding monitoring site were detected. Identifying the potential emitter source or sources cannot be assessed. / Dissertation/Thesis / Masters Thesis Engineering 2015

Benzene, toluene, ethylbenzene, and xylenes (BTEX) are hazardous air pollutants commonly found in outdoor air. Several studies have explored the potential of vegetation to mitigate BTEX in outdoor air, but they are limited to a northern temperate climate and present conflicting results. To investigate this issue in a subtropical climate, we deployed passive air samplers for two weeks in parks and nearby residences at four locations: three in an urban area and one in a rural area in Alabama, USA. All BTEX concentrations were below health-based guidelines and were comparable to those found in several other studies in populated settings. Concentrations of TEX, but not benzene, were 3-39% lower in parks than at nearby residences, and the differences were significant. In and around two of the parks, toluene:benzene ratios fell outside the range expected for vehicular emissions (p<0.01), suggesting that there are additional, industrial sources of benzene near these two locations. The ratio of m-,p-xylene:ethylbenzene was high at all locations except one residential area, indicating that BTEX were freshly emitted. Concentrations of individual BTEX compounds were highly correlated with each other in most cases, except for locations that may be impacted by nearby industrial sources of benzene. Results of this study suggest that parks can help reduce BTEX exposure by a modest amount, but future research is needed to ascertain this potential through more measurements at higher spatial and temporal resolution and analysis of vegetation for evidence of uptake of BTEX. / Master of Science / Benzene, toluene, ethylbenzene, and xylenes (BTEX) compose a significant fraction of anthropogenic non-methane organic gases in the atmosphere. These compounds are harmful to human health and are precursors to secondary organic aerosol and ozone. Several chamber studies have demonstrated that plants can reduce exposure to BTEX in indoor environments, but, to the best of our knowledge, no study has identified this effect in ambient air. To investigate this issue, we sampled for two weeks in parks and nearby residences at four locations; three were in the city of Birmingham, Alabama, and one was in the rural city of Camden, Alabama. All BTEX concentrations were below health-based guidelines and were comparable to those found in several other studies in urban and rural settings. TEX levels were lower in parks compared to residential areas, and the difference was significant. BTEX were attributable to vehicular emissions in the Camden site and one Birmingham site. In the other two Birmingham sites, there were likely additional, industrial sources of benzene. Future research should investigate the effect of different types of vegetation between parks and explore seasonal cycles in vegetation.

Hazardous air pollutants (HAP’s) are assumed to act without threshold meaning any level of exposure can theoretically initiate the carcinogenic process. With approximately 57,000 new cancer diagnoses and 25,900 deaths predicted in Ontario in 2006, the implications of lifetime low dose cumulative exposure to HAP’s in the etiology of cancer is unknown, yet may be significant. As such, this burden of disease (BoD) model was designed to provide a comprehensive assessment of the current and future BoD attributable to long term cumulative exposure to six carcinogenic HAP’s in two highly exposed regions of Ontario, using a summary measure of population health, disability-adjusted life years (DALY’s). Results indicated a total of 32,074 DALY’s were lost in Toronto and Southwestern Ontario (SWO) from six cancer sites in 2001, with the largest burden from cancers of the lung, followed by lymphomas, then leukemia. Approximately 0.58% of the burden (187 DALY’s) was attributable to current HAP exposures, with the largest health impacts associated with exposure to nickel refinery dusts in SWO (8.91 DALY’s) and benzene in Toronto (46.30 DALY’s). The model predicted 0.3% of the exposure attributable BoD (96 DALY’s) could be avoided in the future if ambient exposures were reduced to a feasible distribution. If ambient exposures were further reduced to levels expected if there were no anthropogenic releases, the model predicts 147 DALY’s could be avoided, such that only 0.12% of the total BoD would be attributable to natural sources of HAP’s. Results of the sensitivity analysis support the notion of the DALY as a robust measure to estimate exposure attributable health impacts, as the incorporation of alternative value choices had negligible impact on the relative importance of cancer sites, or exposures to the total BoD. Results of the model can be used by decision makers to inform public health policy regarding abatement priorities of HAP’s in Ontario, on the basis associated health impacts.

Hazardous air pollutants (HAP’s) are assumed to act without threshold meaning any level of exposure can theoretically initiate the carcinogenic process. With approximately 57,000 new cancer diagnoses and 25,900 deaths predicted in Ontario in 2006, the implications of lifetime low dose cumulative exposure to HAP’s in the etiology of cancer is unknown, yet may be significant. As such, this burden of disease (BoD) model was designed to provide a comprehensive assessment of the current and future BoD attributable to long term cumulative exposure to six carcinogenic HAP’s in two highly exposed regions of Ontario, using a summary measure of population health, disability-adjusted life years (DALY’s). Results indicated a total of 32,074 DALY’s were lost in Toronto and Southwestern Ontario (SWO) from six cancer sites in 2001, with the largest burden from cancers of the lung, followed by lymphomas, then leukemia. Approximately 0.58% of the burden (187 DALY’s) was attributable to current HAP exposures, with the largest health impacts associated with exposure to nickel refinery dusts in SWO (8.91 DALY’s) and benzene in Toronto (46.30 DALY’s). The model predicted 0.3% of the exposure attributable BoD (96 DALY’s) could be avoided in the future if ambient exposures were reduced to a feasible distribution. If ambient exposures were further reduced to levels expected if there were no anthropogenic releases, the model predicts 147 DALY’s could be avoided, such that only 0.12% of the total BoD would be attributable to natural sources of HAP’s. Results of the sensitivity analysis support the notion of the DALY as a robust measure to estimate exposure attributable health impacts, as the incorporation of alternative value choices had negligible impact on the relative importance of cancer sites, or exposures to the total BoD. Results of the model can be used by decision makers to inform public health policy regarding abatement priorities of HAP’s in Ontario, on the basis associated health impacts.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Matrizes inorgÃnicas tÃm sido utilizadas como materiais adsorventes para remoÃÃo de poluentes quÃmicos em sistemas aquÃticos, dada Ãs suas boas capacidades de adsorÃÃo e estabilidades fÃsicas e quÃmicas Neste trabalho, foi sintetizado esferas de sÃlica funcionalizadas com EDTA com a finalidade de remover Ãons metÃlicos em soluÃÃo aquosa. A cinÃtica de adsorÃÃo dos Ãons em estudo (Cu2+, Cd2+ e Zn2+) foi feita em pH 5,5 numa concentraÃÃo de 60 mg L-1, onde se observou que o equilÃbrio à atingido extremamente rÃpido, cerca de 10 minutos, o que indica que a etapa limitante do processo de adsorÃÃo pode ser a quimissorÃÃo, evidenciado pelos melhores ajustes para o modelo de pseudo-segunda ordem. As isotermas de adsorÃÃo foram submetidas ao modelo linear e nÃo linear para efeito de comparaÃÃo, utilizando o R2 e funÃÃo erro SSE como referencia. O estudo com sistema simples e multielementar dos Ãons foi realizado em pH 5,5, concentraÃÃes variando de 10-300 mg L-1, onde os dados foram submetidos aos modelos de Langmuir, Freundlich, Temkin e Redlich-Peterson. Os resultados evidenciaram um melhor ajuste para o modelo de Langmuir, o qual defende que os sÃtios de adsorÃÃo sÃo homogÃneos e adsorÃÃo à em monocamada. As capacidades mÃximas de adsorÃÃo observadas nos estudos de equilÃbrio para o sistema mono e multielementar seguem a ordem Cu2+> Zn2+> Cd2+. Para efeito de comparaÃÃo de modelos foi utilizado o mÃtodo de AKAIKEÂS onde comprovou que os resultados se ajustam melhor ao modelo de Langmuir. Com respeito ao estudo de adsorÃÃo em coluna, as curvas de ruptura indicaram que a saturaÃÃo da mesma ocorre num volume de 35 mL. O uso do eluente HCl 0,1 M, permitiu recuperar 100% dos Ãons adsorvidos. A coluna foi utilizada por trÃs ciclos para verificar seu potencial de uso, e foi comprovado que nos trÃs ciclos consegue-se recuperar 100% dos metais, o que significa uma Ãtima eficiÃncia das esferas de sÃlica-APTS-EDTA. / Inorganic matrices have been used as adsorbent mate rial for removal of chemical pollutants in aquatic systems, due to its good adsorption capacity for physical and chemical stabilities and this work was synthesized silica spheres functionalized with EDTA in order to remove metal i ons in aqueous solution . The kinetics of adsorption of the ions under study (Cu 2 + , Cd 2 + and Zn 2 + ) was performed at pH 5.5 at a concentration of 60 mg L -1 , where it was observed that equilibrium is reached very fast, about 10 minutes, indicating tha t limiting step of the adsorption process may be the chemisorption, as evidenced by t he best fitting model for the pseudo-second order. The adsorption isotherms were subjected to linear and nonlinear model for comparison, using the error fun ction SSE and R 2 as a reference. The study of simple and multielement ions was carri ed out at pH 5.5, concentrations ranging from 10-300 mg L -1 , where the data were submitted to the models of Langmuir, Freundlich, Temkin and Redlich-Peterson. The results showed a better fit to the Langmuir model, which argues that the adsorp tion sites are homogeneous and monolayer adsorption. The maximum sorption capaciti es observed in studies of equilibrium for the system mono and multielement fo llow the order Cu 2 + > Zn 2 + > Cd 2+. For comparison model method was used Akaike's whe re proved that the Langmuir model is the best. With respect to the stu dy of adsorption column, the breakthrough curves indicate that saturation occurs in the same volume of 35 mL. The use of the eluent 0.1 M HCl, allowed to recover 100% of the adsorbed ions. The column was used for three cycles to verify their po tential use, and it was proved that in the three-cycles can recover 100% of the metals, which means an optimum efficiency of the spheres of silica-APTS-EDTA.

Les produits cosmétiques sont des substances utilisées pour entretenir ou modifier l'aspect des parties superficielles du corps humain (telles que la peau, les ongles ou les cheveux). Dans de nombreux pays d’Afrique et d’Asie et dans certaines communautés africaines immigrantes, plusieurs femmes et parfois des hommes utilisent des produits contenant des agents actifs tels que le mercure, l’hydroquinone et le propionate de clobétasol pour éclaircir leur peau. Ces principaux agents sont toxiques et leur présence dans les cosmétiques est règlementée, voire interdite, dans plusieurs pays. Dans notre étude, nous avons déterminé les concentrations de ces ingrédients dans plusieurs produits utilisés en Afrique de l’Ouest et au Canada. Nous avons également exploré l’effet de ces produits sur le microbiome cutané. Nos résultats révèlent que 68 à 84% des crèmes et 7.5 à 65% des savons dépassent les normes lorsqu’on considère l’interdiction de mercure, d’hydroquinone et de propionate de clobétasol et les concentrations déclarées sur les étiquettes ne sont pas souvent fiables. Selon la diversité de Shannon, il semble y avoir plus d’équitabilité, et donc moins de dominance dans le groupe des femmes utilisant les crèmes éclaircissantes que dans le groupe des femmes qui ne les utilisent pas. Par ailleurs, nous n’avons pas trouvé de différences significatives au niveau du microbiome cutané du groupe avec crèmes et sans crèmes au niveau du phylum et du genre. Cependant, d’autres méthodes plus approfondies avec plus d’échantillonnage pourraient révéler à des échelles plus fines (espèces, souches, etc.) l’effet de ces produits sur le microbiome cutané. / Cosmetics are substances used to maintain or change the appearance of external parts of the human body (such as skin, nails or hair). In many countries of Africa and Asia and in some immigrant African communities, many women and sometimes men use products containing active agents such as mercury, hydroquinone and clobetasol propionate to lighten their skin. These main active agents are toxic and their presence in cosmetics is regulated or even banned in several countries. In our study, we determined the concentrations of these ingredients in many products used in West Africa and Canada. In addition, we also explored the effect of these products on the skin microbiome. Our results reveal that 68 to 84% of cream and 7.5 to 65% of soaps exceed the standards when considering mercury, hydroquinone and clobetasol propionate ban in lightening products and concentrations of the three compounds declared on labels of soaps and creams usually did not correspond to concentrations actually measured. According to Shannon diversity index, there seems to be more evenness, less dominance in group of African women with creams than in those without cream. Moreover, we have not found significant differences in the skin microbiome of the group with creams and the one without creams at the phylum and genus level. However, additional detailed studies with more sampling methods could reveal at finer scales (species, strains, etc.) the effect of these products on the human skin microbiome.

Environmental airborne benzene is a ubiquitous hazardous air pollutant whose emissions are generated from multiple sources, including industrial emissions, fuel station emissions, and automobile emissions. Chronic occupational exposures to elevated levels of benzene are known to be associated with leukemic cancers, in particular, acute myeloid leukemia (AML), though epidemiological evidence regarding environmental exposures and subsequent AML development is lacking. This investigation uses historical airborne monitoring data from six counties in the State of Florida to characterize the environmental cancer risk from airborne benzene concentrations using current Federal and State regulatory analysis methodology, and a comparative analysis based on occupational epidemiological evidence. Airborne benzene concentrations were collected from 24 air toxics monitoring stations in Broward, Duval, Orange, Miami-Dade, Hillsborough, and Pinellas counties. From the years 2003 - 2006, 3,794 air samples were collected using 8, 12, and 24 hr samples with sub-ambient pressure canister collectors consistent with EPA benzene methodological protocols 101 and 176. Mean benzene concentrations, by site, ranged from 0.18 - 3.58 ppb. Using risk analysis methodology consistent with the EPA and the Florida Department of Environmental Protection (FLDEP) the resulting cancer risk estimates ranged from 4.37 x 10-6 to 8.56 x 10-5, exceeding the FLDEP's acceptable cancer risk level, 1 x 10-6 for all monitoring sites. The cumulative lifetime exposures were calculated in ppm-years by site, ranging from 0.036 - 0.702 ppmyears. A comparative analysis with available epidemiological literature revealed that associations between benzene exposure and cancer outcomes were related to cumulative lifetime exposures in great excess of 1 ppm-years. The results of this investigation indicate that it is not reasonable to expect additional cancer outcomes in Florida residents as a result of airborne benzene exposures consistent with measured concentrations, despite the fact that all regulatory risk calculations exceed acceptable cancer risk levels in the State of Florida.

No description available.

There is a growing public concern that emissions of mobile source air toxics (MSATs) from motor vehicles may pose a threat to human health. At present, no state or federal agencies require dispersion modeling of these compounds, but many agencies are concerned about potential future requirements. Current air pollution professionals are familiar with Federal Highway Administration (FHWA) and U.S. Environmental Protection Agency (EPA) requirements for dispersion modeling to produce predicted concentrations for comparison with appropriate standards. This research examined a method in which the potential near-road concentrations of MSATs were calculated. It was believed that by assessing MSATs in much the same way that are used for other pollutants, the model and methods developed in this research could become a standard for those quantifying MSAT concentrations near-roadways. This dissertation reports on the results from short-term (1-hour) and long-term (annual average) MSATs dispersion modeling that has been conducted on seven intersections and seven freeway segments in the state of Florida. To accomplish the modeling, the CAL3QHC model was modified to handle individual MSAT emissions input data and to predict the concentrations of several MSATs around these roadway facilities. Additionally, since the CAL3MSAT model is DOS based and not user-friendly, time was invested to develop a Windows® graphical user interface (GUI). Real-world data (traffic volumes and site geometry) were gathered, worst-case meteorology was selected, mobile source emission factors (EFs) were obtained from MOVES2010a, and worst-case modeling was conducted. Based on a literature search, maximum acceptable concentrations (MACs) were proposed for comparison with the modeled results, for both a short-term (1-hour) averaging time and a long-term (1-year) averaging time. iv Results from this CAL3MSAT modeling study indicate that for all of the intersections and freeway segments, the worst-case 1-hour modeled concentrations of the MSATs were several orders of magnitude below the proposed short-term MACs. The worst-case 1-year modeled concentrations were of the same order of magnitude as the proposed long-term MACs. The 1-year concentrations were first developed by applying a persistence factor to the worst-case 1-hour concentrations. In the interest of comparing the predicted concentrations from the CAL3MSAT persistence factor approach to other dispersion models, two EPA regulatory models (CAL3QHCR and AERMOD) with the ability to account for yearly meteorology, traffic, and signal timing were used. Both hourly and annual MSAT concentrations were predicted at one large urban intersection and compared for the three different dispersion models. The shortterm 1-hour results from CAL3MSAT were higher than those predicted by the two other models due to the worst-case assumptions. Similarly, results indicate that the CAL3MSAT persistence factor approach predicted a worst-case annual average concentration on the same order of magnitude as the two other more refined models. This indicated that the CAL3MSAT model might be useful as a worst-case screening approach.

No description available.