An outbreak of Middle East Respiratory Syndrome (MERS) among healthcare workers in Saudi Arabia in 2012 led to an investigation of hand-hygiene behaviors among healthcare professionals. Direct contact with patients is a major pathway for MERS, a droplet virus, which refers to a virus that lays on surfaces. This study investigated factors associated with respiratory disease transmission (e.g., MERS) in hospital settings among healthcare workers (i.e., physicians and nurses). I developed a 16-item checklist based on three sources: the CDC standards, the WHO Five Moments for Hand Hygiene, and Boyce and Pittet's (2002) guidelines of hand hygiene. I used those 16 items in both direct-observation and self-reported questionnaire formats. The checklist addressed three time frames of contact: before, during, and after contact with patients, devices, and surrounding surfaces. Hand-hygiene behaviors surrounding these time frames were assessed. The study also explored healthcare workers' beliefs about hygiene practices by comparing personal reports of hand hygiene assessed by questionnaire to observed actual hand-hygiene practices. The study was a cross-sectional research design and was conducted in the outpatient examination rooms and emergency departments of three hospitals (public, private, and military) in the Eastern region of Saudi Arabia. The total sample size included 87 physicians and nurses who were recruited while on duty during the researcher's observation periods. To provide clear results, I used two independent sample t-tests to test each of the 8 hypotheses. I found that no statistically significant differences were found among health-care workers when observing their behaviors of hand-hygiene practices. However, when using the self-reported questionnaire data, I found statistically significant differences between physicians' and nurses' hand-hygiene practices before, during, and after interacting with patients. Also, I found statistically significant differences between male and female hand-hygiene practices during interacting with patients, and I found statistically significant differences between health-care workers in public and military hospitals hand-hygiene practices during interacting with patients. For the primary hypothesis, I used Pearson correlation to determine the relationship between healthcare workers' reports of hand-hygiene practices, and observed healthcare workers behaviors of hand-hygiene practices. I found that no statistically significant correlation between the two data collection instruments. To provide a further analysis, a multivariate analysis of covariance (MANCOVA) was used to examine whether healthcare workers' hand-hygiene practices before, during, and after were different while controlling for their gender, department, and hospital type. I found that no statistically significant differences were found when observing the healthcare workers behaviors of hand-hygiene practices. However, when using the self-reported questionnaire data, I found that nurses and females reported better hand-hygiene than physicians and males. From these data, I conclude healthcare workers understand the importance of hand-hygiene and fail to appropriately implement the practice.

Occupational exposures to hand-arm vibration and dust have been shown to have deleterious human health effects. Exposure to vibration from pneumatic tools can result in Hand-arm Vibration Syndrome (HAVS), which is a collection of vascular, sensorineural, and musculoskeletal disorders. Exposure to dust can result in a variety of adverse respiratory symptoms. The use of a low-frequency, high-magnitude sand rammer tool during mold-making processes at a foundry could result in significant exposure to these hazards, thus it is important to mitigate the associated risks in order to ensure worker safety. The goal of this study was to evaluate whether different pneumatic pressure levels and sand rammer types have an effect on reducing hand-arm vibration and dust exposures at a foundry. Vibration and dust measurements were obtained at three different pneumatic pressure levels (90 psi, 80 psi, 70 psi) and for three different sand rammer types (LM, SM, T). The primary concern of the study was reducing hand-arm vibration exposure. Measurements were taken in compliance with ISO 5349-1 resulting in frequency-weighted, root-mean-square (rms) acceleration values (m/s2). Significant differences in mean rms acceleration were observed across all pneumatic pressure levels and sand rammer types. At 90 psi the mean rms acceleration value was 25.53 m/s2, decreasing to 19.58 m/s2 at 80 psi, and further decreasing to 18.38 m/s2 at 70 psi. The mean rms acceleration values were 19.63 m/s2 for sand rammer LM, 21.46 m/s2 for SM, and 19.95 m/s2 for T. The results of this study indicate that reducing pneumatic pressure levels can reduce vibration exposure in the workplace when using low-frequency, high-magnitude tools. The results also indicate that the use of different sand rammer types produces differences in vibration exposure when tested across all pneumatic pressure levels. Dust measurements were taken concurrently with vibration measurements. The number of dust particles was counted for each pneumatic pressure level and sand rammer type. Overall, the mean particle count for the dust measurements was the highest at 90 psi (41,681) followed by 70 psi (33,514), and 80 psi (26,047). Sand rammer SM had the highest mean dust particle count at 35,732, followed by T at 34,460, and LM at 31, 382. The results indicate that lowering pneumatic pressure levels could potentially reduce dust exposure in the workplace when using a percussive tool such as a sand rammer. However, variability in the sampling conditions related to dust measurements weaken the association.

Gulf Coast communities face many environmental threats that disproportionately impact the health of pregnant women. While the perception of risk strategies often differ across cultural groups, little is known about the detail of these differences. The purpose of this study was to explore the cultural knowledge of environmental threats within an at-risk group (low-income, first-time mothers in Southeast Louisiana). This proposal was a part of a SAMHSA-supplemental-funded study, which was an extension of a National Institutes of Health (NIH) funded U19 consortium called the Transdisciplinary Research Consortium for Gulf Resilience on Women’s Health (GROWH). In the first of a two-phase ethnographic approach, interviews with mothers helped identify risk in the environment, important steps to manage these threats, and trustworthy sources to turn to for help. Next, a larger sample (n=112) of mothers indicated their level of agreement to these items. These ratings were analyzed through cultural consensus analysis which gave a quantitative estimate of cultural sharing and beliefs. Results revealed that mothers shared a common pattern of risk perception and behavior regarding the assessment of different environmental threats. Further analyses detailed these cultural models, and identified if cultural knowledge was associated with key socio-demographic factors. Additionally, subtle areas of intra-cultural variation within the general consensus showed that some mothers emphasized health behaviors that may increase household risk. The results of this study contribute to an understanding of how low-income households manage environmental health threats, how cultural knowledge is distributed, and what factors influence knowledge. Study results can help to identify greater awareness of cultural differences within an at-risk population, which can be used to create culturally-tailored risk messaging. Implications for environmental health research, and public health policy are also discussed. / 1 / Christopher Mundorf

acase@tulane.edu

In order to provide an improved in vitro model with which to investigate human diseases, such as cancer that may be promoted by toxicant exposure, we have characterized a newly developed cell line derived from the renal proximal tubule epithelial cells (RPTEC) of a healthy human male donor. The RPTEC/TERT1 cell line has been immortalized using the human telomerase reverse transcriptase (hTERT) catalytic subunit and does not exhibit chromosomal abnormalities (Evercyte Laboratories). We have conducted single-compound and binary mixture experiments with the common environmental carcinogens, cadmium (Cd) and benzo[a]pyrene (B[a]P). Cells exhibited cytotoxicity to concentrations of B[a]P and Cd as low as 1 nM and 3 μM, respectively. We examined a panel of eight genes relevant to the toxic responses of these two agents. RPTEC/TERT1 cells exhibit compound-specific gene expression responses to concentrations as low as 1 nM B[a]P and 1 μM Cd. A significant increase in the expression of genes coding for B[a]P metabolizing enzymes (CYP1A1, CYP1B1) occurred in a dose- and time-dependent manner. Activity of these enzymes was verified using the EROD activity assay. Gene expression changes after co-exposure were consistent with changes in gene expression seen after single-compound exposures. We detected BPDE-DNA adducts after exposure to B[a]P which confirms that the RPTEC/TERT1 cell line responds to B[a]P consistently with what is known regarding these cells in a normal, healthy kidney. Under co-exposure, adducts detected were significantly decreased in some groups. A significant increase in the expression of NRF2 antioxidant pathway genes after co-exposure was observed. Additionally, total glutathione levels were significantly increased in cells exposed to Cd alone and co-exposure groups. These results suggest that Cd may antagonize the formation of BPDE-DNA adducts in RPTEC/TERT1 cells under these conditions. Future studies will test mutagenesis under conditions of co-exposure to Cd and B[a]P. Our studies are the first to provide information regarding toxicological responses in this novel cell line that model those of the target tissue. We conclude that these cells can provide a useful tool for future toxicological studies. These studies will help scientists better understand the initiating events that may promote carcinogenesis in normal, healthy human cells. / acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

Farmworkers and their families may experience increased levels of agricultural pesticides in their homes due to both (1) take-home/soil track-in on shoes, clothes and skin, and (2) air infiltration from nearby agriculture fields via agricultural pesticide drift in the vapor phase or adhered to resuspended soil particles. This dissertation estimates the relative contributions o the take-home/soil track-in and air infiltration pathways of agricultural pesticides into homes, as well as identifies the risk factors for increased in-home agricultural pesticide levels for farmworkers and their families living near agriculture fields. Samples of outdoor air, yard soil, and house dust from 21 farmworkers' homes in Yuma County, Arizona were collected and analyzed for a suite of agricultural pesticides. To capture household information, such as behaviors, demographics, and housing structure, a participant questionnaire was administered at the time of the sampling. A pesticide transport model was developed, evaluated, and applied to quantify relative contributions of the air infiltration and the take-home/soil track-in pathways of agricultural pesticides into the house dust of the farmworkers' homes. To explore a wide-range of potential risk factors for increased agricultural pesticide levels in the homes, traditional statistical methods and Classification and Regression Tree (CART) analyses were used. The results of this study, found that the air infiltration pathway contributes to over 90% of some agricultural pesticides in the house dust found in the farmworkers' homes. In addition, among the influential risk factors for increased in-home agricultural pesticide levels was the home being a closer distance to an agricultural field, as well as the home having carpeted floors, more farmworkers per square footage of the home, and less months of heating and cooling the home. It is suggested that future intervention efforts to reduce in-home agricultural pesticide levels put more emphasis on targeting the air infiltration pathway, and take into consideration relevant risk factors for increased pesticide levels in the home.

In recent years exposure to endocrine-disrupting chemicals (EDCs) in humans and wildlife has become an increasing concern. These compounds have been found ubiquitously in the environment and are suspected to induce adverse effects on the health of aquatic organisms. The results of health effects due to EDCs are clearly presented in many aquatic organisms, such as the feminization of male fish and a near extinction of some species. No clear effects on human health have been documented at this time. The major sources of these contaminants in the environment are discharges from wastewater treatment plants (WWTP) and diffuse pollution. Conventional wastewater treatment processes are not designed to remove such emerging pollutants and removal efficiency depends on many factors, including treatment technology and pollutant species. Passage through WWTPs and changes due to treatment technologies lead to detection of minute concentrations of EDCs in water downstream from discharge points. In New Orleans, Louisiana, discharge from its East Bank WWTP is being considered for potential reuse for wetland restoration. Therefore, effluents must be treated adequately to prevent adverse effects on the natural biota. Since effluents from wastewater treatment plants using conventional technologies may prove potentially unsafe for the environment due to the presence of EDCs, improved and/or new treatment processes for removal of these contaminants are needed. Ferrate (Fe+6) is known as an alternative oxidant for the treatment of wastewater that can be used as an oxidizing, disinfectant, and/or coagulating agent. Because of its redox potential, ferrate has been used as a disinfection agent and has been reported as a tool for enhanced treatment to remove many micropollutants without producing undesirable disinfection byproducts in contrast to other disinfection processes. Recent research has noted the ability of ferrate to deactivate a wide range of EDCs present in wastewater effluents. The negative effect of effluent's soluble organic matter on ferrate has been reported and higher doses of ferrate may be needed to obtain desired effluent quality. This study found that aerobic biological treatment processes reduce more than half of EDCs in wastewater and that free chlorine disinfection increases estrogenic activity in discharged effluent. Higher organic content in wastewater results in increased ferrate demand. The optimum ferrate dosage to deactivate EDCs in lab scale is 6 ppm, and a dosage of 8 ppm is possibly the operational optimum dose. pH neutralization by concentrated sulfuric acid was not found to affect EDCs deactivation efficiency by ferrate when added at the end of designed contact time. Ferrate was observed to have a high oxidation rate in the first10 minutes after application into wastewater and then degraded to other iron states, such as iron III. Higher oxidation rates can be obtained when more organics are present in wastewater as TOC. Higher dosages required longer oxidation reaction times. Ferrate was observed to generate fewer disinfection byproducts as compared to chlorine. Haloacetic acids in ferrate-treated effluent are generated from organics in wastewater and reactions with residual hypochlorite from the incomplete ferrate synthesis process. The reduction of trihalomethanes may be related to EDCs deactivation by ferrate. Because this study was performed on a lab scale, assessment of onsite production and application of ferrate is required to determine the feasibility of the ferrate treatment process at a full-scale treatment plant and to optimize required dosage. / acase@tulane.edu

acase@tulane.edu