Pharmacology, Toxicology and Environmental Health Commons^™

Replenishment Of Essential Natural Resources: An Assessment Of The Ability Of Freshwater Algae To Enhance Crop Quality And Soil Health, Lala Christina Ek

Theses and Dissertations

Disregard for soil, an essential natural resource, hinders global food production. Food insecurity is a major concern for both public health officials and environmental scientists due to soil quality decline, pollution, and climate change. Alternatives or targeted additions to chemical fertilizers can bolster soil quality, improve crop yields, lengthen crop shelf life, and mitigate environmental pollution. One potential alternative to chemical fertilizers is replacement of them with biological soil amendments, including algae, to enhance crop growth and improve soil health. Research was conducted at the University of South Carolina-Columbia campus garden to determine impacts of non-toxic freshwater algae on crop …

Integrated Wastewater Surveillance For Sars-Cov-2 And Antibiotic Resistant Bacteria: Implications For Public Health And Environmental Management, Mirza Isanovic

Theses and Dissertations

While current technologies have inadvertently resulted in wastewater treatment plants (WWTPs) becoming major sources of global antibiotic resistance gene (ARG) dissemination, wastewater can be leveraged to provide vital community-level health information. This project examined both of these aspects through wastewater-based surveillance of SARS-CoV-2 and metagenomic analysis of specific ARGs collected from both activated sludge and bioaerosols. In this study, we investigated treatment steps between the influent and final treated effluent to identify the point at which viral RNA is below detection. Additionally, we examined air surrounding high turbulence treatment steps to test for the presence of SARS-CoV-2 RNA in WWTP-generated …

Infection Intensity And Prevalence From Perkinsus Marinus In The Eastern Oyster, Crassostrea Virginica (Gmelin 1791) And Their Association With Salinity, Temperature, And Sex In South Carolina Estuaries, Deja E. Best

Theses and Dissertations

This project aimed to identify the associations between the infection intensity and prevalence of Perkinsus marinus infection (i.e., Dermo ) in the Eastern oyster, Crassostrea virginica (Gmelin), with extrinsic environmental factors such as changes in salinity and temperature along with oyster host factors such as sex ratio. The objectives of the study were to: (1) identify significant associations between the dependent variables, P. marinus prevalence and infection intensity, in relation to salinity and water temperature which may be affected by climate change; and (2) identify any intrinsic factors related to sex (i.e., male, female, intersex, and indeterminant) that may affect …

From Oceans To Public Health: Impact Of Climate Change And Socioecological Factors On Non-Cholera Vibrio Spp., Karlen Enid Correa Vélez

Theses and Dissertations

Climate change-induced stressors, such as temperature, salinity, pH, and wildfire, are contributing factors to the increase in frequency of Vibrio infections, altering Vibrio geographical constraints. At the same time, the expansion of the coastal population is resulting in increased input of treated municipal wastewater into areas that are also experiencing Vibrio proliferation. Given that increases in ocean temperature and sea level coupled with increases in human activity in coastal waters support greater Vibrio-human interactions, it is important to examine factors and mechanisms within this socio-ecological coupled system that may further strengthen this interaction. This study aimed to better understand the …

Quantification Of The Internalization Of A Commercially Available Silver Nanoparticle To The Bacterium Escherichia Coli, Samantha Mcneal Case

Theses and Dissertations

Nanoparticles (NPs), materials with dimensions ranging from 1 to 100 nanometers, are widely used in various consumer products, with silver nanoparticles (AgNPs) being the most prominent. Exposure to AgNPs occurs through multiple sources, including food packaging, supplements, and disinfectants, owing to their antimicrobial properties. Prior research has identified adverse health effects, such as cytotoxicity, toxicity, and Ag bioaccumulation resulting from AgNP exposure to bacteria in biological systems and the environment. However, most studies employ pristine, highly concentrated NPs, which may not accurately represent realistic exposure scenarios at environmentally relevant concentrations. This project investigates the fate and internalization of AgNPs, found …

Transdisciplinary Approaches To Community Engagement, Research Translation And Science Communication Through Application Of The Socio-Environmental Report Card Process And Product In Murrells Inlet, South Carolina, Ekaterina Negodyaeva Altman

Theses and Dissertations

Public health and environmental sustainability are interlinked. Three pillars of sustainable development are society, environment, and economy are supported and reinforced by healthy populations. Balancing these values in a long-term vision and application requires active involvement of communities and stakeholders in decision-making process of management of environmental resources and personal health choices. Transdisciplinary sustainability science provides a framework for addressing complex issues in sustainability and generates actionable knowledge to link science and policy and involved stakeholders in the scientific process. Transdisciplinary research processes use co-design, co-production, and co-implementation framework to create and re-integrate useful knowledge into practice on a local …

Ethnobotanical Survey On The Knowledge And Use Of Medicinal Plants For Malaria Management Among University Students, Felista W. Mwingira, Deokary J. Matiya, Neema G. Mogha

Tanzania Journal of Science

Malaria remains a public health problem in Tanzania, escalated by the emergence of both parasite and vector resistance. Plant-based traditional medicines have been widely utilized as alternatives to malaria management. However, proper documentation is minimal, especially among the younger generation. This study assessed the knowledge of medicinal plants for malaria management among 532 Dar es Salaam University College of Education students. Overall, twenty-four plant species, most belonging to the family Asteraceae, were identified with Azaradichta indica being the most dominant species. These results reveal a substantial knowledge of medicinal plants for malaria management among university students.

Microplastics In Water, Their Effects On The Aquatic Ecosystem And Human Public Health, And The Proposed Solutions, Mohanad Abouserie

The Undergraduate Research Journal

We could be swallowing a credit card's weight in plastic every week. Microplastic water pollution is becoming a threat to both humans and aquatic creatures. In this research, microplastic water contamination is discussed, and divergent solutions are proposed. This paper attempts to investigate the causes and effects of such pollution and analyze the current solutions for this issue. The adopted research method is secondary research, where several studies are explored and analyzed. This study explains numerous causes for this issue like cosmetics, cleaning products, factories, and sewage. Consequently, this contamination can negatively impact the organs and metabolisms of the living …

Factors Associated With Per- And Polyfluoroalkyl Substance (Pfas) Concentrations: Implications For Exposure Assessment And Highly Exposed Communities, Jordan Mcadam

Legacy Theses & Dissertations (2009 - 2024)

Background: Per- and polyfluoroalkyl substance exposure has been implicated as a factor contributing to the development of many adverse health outcomes across populations of all ages. Despite this, the factors associated with PFAS concentrations in humans are not well understood. Most studies evaluating factors associated with PFAS concentrations consider a small number of variables. Differences in the factors associated with PFAS levels in populations of high exposure versus low or background exposure (i.e., the general population) have not been considered. Advancing our understanding on this topic is necessary to better understand the serum elimination half-lives and toxicokinetics of PFAS. Additionally, …

Low-Cost Pm2.5 Sensors Can Help Identify Driving Factors Of Poor Air Quality And Benefit Communities, Tim Keyes, Rea Domingo, Samantha Dynowski, Royal Graves, Martha Klein, Melissa Leonard, John Pilgrim, Alison Sanchirico, Kate Trinkaus

WCBT Faculty Publications

Air quality is critical for public health. Residents rely chiefly on government agencies such as the Environmental Protection Agency (EPA) in the United States to establish standards for the measurement of harmful contaminants including ozone, sulfur dioxide, carbon monoxide, volatile organic chemicals (VOCs), and fine particulate matter at or below 2.5 μm. According to the California Air Resources Board [1], “short-term PM2.5 exposure (up to 24-h duration) has been associated with premature mortality, increased hospital admissions for heart or lung causes, acute and chronic bronchitis, asthma attacks, emergency room visits, respiratory symptoms, and restricted activity days”. While public agency resources …

Self-Reported Consumption Of Bottled Water V. Tap Water In Appalachian And Non-Appalachian Kentucky, Jason W. Marion

Journal of Appalachian Health

Introduction: Quantitative studies on drinking water perceptions in Appalachia are limited. High-profile water infrastructure failures in the U.S. and Eastern Kentucky, coupled with human-made and natural disasters in the Appalachian Region, have likely impacted opinions regarding tap water.

Purpose: To use existing unexplored data to describe baseline tap water v. bottled water consumption in Kentucky.

Methods: Telephone-based cross-sectional data were obtained from the 2013 Kentucky Health Issues Poll (KHIP) directed by the Foundation for a Healthy Kentucky. Among many items in KHIP, self-reported consumption of bottled water over tap water, reasons for bottled water use, and demographic data were obtained. …

Relationship Between Plasma Fluoride Levels, Glutathione Peroxidase Activity, Hemoglobin, And Abortion In Rural And Urban Pregnant Women From Settat (Morocco), Lalla Asmaa Katir Masnaoui, Abdellatif Rahim, Habiba Bouchab, Bouchra El Amiri, Boubker Nasser, Essamadi Abdel Khalid

Makara Journal of Health Research

Background: This study aimed to investigate the relationship between plasma fluoride and hemoglobin levels, glutathione peroxidase (GPx) activity, and abortion among rural and urban pregnant women from Settat province (Morocco).

Methods: Blood samples were collected from rural pregnant women who had not undergone abortion (N = 224), rural pregnant women who had an abortion (N = 38), urban pregnant women who had not undergone abortion (N = 163), and urban pregnant women who had an abortion (N = 14).

Results: The highest (p < 0.01) plasma fluoride levels and the lowest (p < 0.01) GPx activity were observed in rural pregnant women. In all participants, plasma fluoride levels were significantly higher (p < 0.001), and the GPx activity was significantly (p < 0.001) lower in pregnant women who had an abortion compared with those who did not undergo such process. No significant difference was observed between the hemoglobin levels of all participants. Furthermore, abortion was positively correlated with plasma fluoride levels (p < 0.001) and negatively correlated with GPx activity (p < 0.001) in rural participants.

Conclusions: Rural pregnant women had higher plasma …

Evaluation Of Organic And Synthetic Herbicides Applications On Indicators Of Soil Health And Weed Suppression In A Conventional Cropping System In Louisiana, Caitlin Denux

LSU Doctoral Dissertations

Synthetic herbicides, with their varying modes of action, are well known for their efficiency in the suppression and control of weed species in U.S. agriculture. However, the consequences of using synthetic herbicides without attention to the surrounding environment can produce chemical run-off, changes in soil health and soil health conditions, and create herbicide-resistant weeds. These consequences have encouraged growers to find alternatives in their weed management programs. In this study, organic and synthetic herbicides were assessed on how well they performed in weed suppression surveys, and their potential effects on soil health indicators. Commonly used indicators include soil pH, β-glucosidase …

Human Health Risk Assessment Of Some Heavy Metals In Eme River, Umuahia, Abia State, Nigeria, Emeka Donald Anyanwu, Onyinyechi Gladys Adetunji, Paschal Emeka Etusim, Solomon Nnanna Umeham

Journal of Bioresource Management

This study evaluated the health risk of some heavy metals in Eme River, Umuahia. The study conducted in 6 stations was between December 2017 and November 2018. The non-carcinogenic method that involves determination of chronic daily intake (CDI), hazard quotient (HQ) and hazard index (HI) was applied in the assessment of ingestion, dermal and incidental ingestion exposures. Iron, lead and cadmium exceeded their limits and warranted risk assessment. The heavy metals’ CDI values for the three routes were lower than their respective reference doses except for cadmium (ingestion route). Except for cadmium (ingestion), the hazard quotients also recorded values lower …

Molecular Mechanisms Of Novel Brain-Penetrating Oxime Acetylcholinesterase Reactivators On Sarin Surrogate-Induced Toxicities, Darby Caroline Stanford

Theses and Dissertations

Organophosphorus compounds (OPs), both nerve agents and insecticides, may induce damage leading to long-term neurological deficits. Oxime 20, the lead compound from a platform of substituted phenoxyalkyl pyridinium oximes (US Patent 9,227,937), is an oxime that reactivates OP-inhibited acetylcholinesterase (AChE) and has displayed neuroprotection within the brain of rats in in vivo tests where the currently approved treatment, pralidoxime (2-PAM), has not. This research investigated the neuroprotective effect of novel oxime therapy. Gene expression in rat piriform cortex was analyzed to determine if neurotoxicity, stress, and synaptic plasticity-associated genes were down-regulated by Oxime 20 following a sublethal dose of sarin …

The Role Of E-Liquid Constituents In E-Cigarette-Induced Cardiac Arrhythmia And Autonomic Imbalance., Cory Kucera

Electronic Theses and Dissertations

Introduction. Accumulating evidence indicates that exposure to electronic cigarettes (e-cigs) promotes sympathetic dominance and electrophysiologic instability in the heart, potentially culminating in arrhythmogenesis. E-liquids contain various formulations of nicotine and flavorings, but the effects of specific e-liquid constituents and their concentrations on e-cig-induced autonomic imbalance and electrical dysfunction are unresolved. To that end, we tested the hypothesis that e-cigs modify cardiac autonomic balance and ventricular arrhythmogenesis in mice dependent on e-liquid constituent type and concentration. Methods. Using a crossover design and a serial exposure regimen, ECG-telemetered male C57BL/6J mice underwent whole-body exposure to e-cig aerosols generated from e-liquids containing different …

Effects Of Environmental Pollutants On Liver Disease: Role Of The Gut-Liver Axis., Ngozi Victoria Adiele

Electronic Theses and Dissertations

Polychlorinated biphenyls (PCBs) and polystyrene (PS) microplastics are environmental pollutants associated with various diseases including toxicant associated fatty liver disease (TAFLD). Previously, exposure to Aroclor 1260 (a PCB mixture) has been shown to exacerbate TAFLD, partly through Aroclor 1260 induced gut dysbiosis. Studies has also demonstrated that PS exposure alters gut microbiome composition and induced obesity. However, the effects of Aroclor 1260 on the gut and the effects of PS on the liver are still understudied. Therefore, we hypothesize that environmental pollutants will disrupt the gut-liver axis through changes in gut and its microbiome as well as changes in liver …

Coal Ash Dumps In The Mountain West, Julia Salangsang, Nicole Diaz Del Valle, Zachary Billot, Caitlin J. Saladino, William E. Brown Jr.

Environment

This fact sheet presents data on coal ash dumps, their management, and the pollutants that exist at each site in the Mountain West states of Arizona, Colorado, Nevada, New Mexico, and Utah. The original report includes data on coal ash dumping sites for all 50 states.

An Observed Increase In Cardiovascular And Respiratory-Disease Related Hospitalizations And Mortality In An Area Surrounding A Hazardous Waste Thermal Treatment Plant, Liana Isabelle Dela Torre Baconguis

LSU Master's Theses

Particulate matter (PM) pollution is highly correlated with respiratory and cardiovascular disease incidence. The generation of oxidative stress is a major way by which PM can damage the body. Environmentally persistent free radical-containing PM are generated by combustion processes and are capable of exerting increased damage on the respiratory and cardiovascular systems due to their ability to remain stable and regenerate reactive oxygen species for up to five years. Clean Harbors, LLC operates a thermal treatment plant near the city of Colfax, LA in Central Louisiana. Its regular open burning of explosives causes disturbances to the community, such as loud …

Developing A National-Scale Exposure Index For Combined Environmental Hazards And Social Stressors And Applications To The Environmental Influences On Child Health Outcomes (Echo) Cohort., Sheena E. Martenies, Mingyu Zhang, Anne E. Corrigan, Anton Kvit, Timothy Shields, William Wheaton, Deana Around Him, Judy Aschner, Maria M. Talavera-Barber, Emily S. Barrett, Theresa M. Bastain, Casper Bendixsen, Carrie V. Breton, Nicole R. Bush, Ferdinand Cacho, Carlos A. Camargo, Kecia N. Carroll, Brian S. Carter, Andrea E. Cassidy-Bushrow, Whitney Cowell, Lisa A. Croen, Dana Dabelea, Cristiane S. Duarte, Anne L. Dunlop, Todd M. Everson, Rima Habre, Tina V. Hartert, Jennifer B. Helderman, Alison E. Hipwell, Margaret R. Karagas, Barry M. Lester, Kaja Z. Lewinn, Sheryl Magzamen, Rachel Morello-Frosch, Thomas G. O'Connor, Amy M. Padula, Michael Petriello, Sheela Sathyanarayana, Joseph B. Stanford, Tracey J. Woodruff, Rosalind J. Wright, Amii M. Kress, Program Collaborators For Environmental Influences On Child Health Outcomes

Manuscripts, Articles, Book Chapters and Other Papers

Tools for assessing multiple exposures across several domains (e.g., physical, chemical, and social) are of growing importance in social and environmental epidemiology because of their value in uncovering disparities and their impact on health outcomes. Here we describe work done within the Environmental influences on Child Health Outcomes (ECHO)-wide Cohort Study to build a combined exposure index. Our index considered both environmental hazards and social stressors simultaneously with national coverage for a 10-year period. Our goal was to build this index and demonstrate its utility for assessing differences in exposure for pregnancies enrolled in the ECHO-wide Cohort Study. Our unitless …

Lung And Colorectal Cancer Disparities In Appalachian Kentucky: Spatial Analysis On The Influence Of Education And Literacy, Nicole Robertson Mph, Todd Burus, Lauren Hudson, Pamela C. Hull, Lee Park, Nathan L. Vanderford

Markey Cancer Center Faculty Publications

Low educational attainment and high cancer incidence and mortality rates have long been a challenge in Appalachian Kentucky. Prior studies have reported disparities in cancer incidence and mortality between Appalachian and non-Appalachian populations, but the influence of education on this disparity has not been extensively studied. Herein, all cancers and two cancer sites with available screenings (colorectal and lung) were joined with education indicators (educational attainment and literacy) and one geographic indicator across all 120 Kentucky counties. This dataset was used to build choropleth maps and perform simple linear and spatial regression to assess statistical significance and to measure the …

Linking The Metabolic And Ecological Fate Of Caribbean Ciguatoxins And Related Neurotoxins In Reef Herbivores, Jessica K. Gwinn

Graduate Theses and Dissertations (2019 - present)

Ciguatera poisoning (CP) is one of the most prominent seafood-borne illnesses worldwide, affecting between 25,000–500,000 people annually. Ciguatera is caused by the ingestion of seafood contaminated with algal-derived ciguatoxins (CTX), the precursors of which are produced by benthic and toxigenic dinoflagellates in the genera Gambierdiscus and Fukuyoa. These compounds enter marine food webs through herbivory and are subsequently transferred to higher trophic levels, undergoing complex metabolic biotransformations, which produce structurally related CTX derivatives. Consumption of CTX induces a variety of severe neurological, gastrointestinal, and/or cardiovascular symptoms beginning within hours and lasting for weeks to months following exposure. Despite the impact …

Investigation Of Antidiabetic Activities Of Cu(Ii) Complex Of Anacardium Occidentale Leaves Crude Extract, Mary Adelaide Oladipo, Folasade Omobolanle Ajao, Adewusi John Adepoju, Kayode Taiwo Ishola, Deborah Omowumi Afolabi

Tanzania Journal of Science

Many synthetic chemical drugs have been widely used for the treatment of diabetes. However, many of these drugs are not locally available, are less effective, and are unaffordable for many diabetic patients in developing and underdeveloped countries. Therefore, in order to search for a locally available, effective, and cost-effective antidiabetic agent, this study synthesized the Cu(II) complex of crude leaf extract of Anacardium occidentale and investigated its antidiabetic activity in alloxan induced albino rats. The leaf crude extract and its metal complex were characterized using atomic absorption spectroscopy (AAS) and infrared (IR) spectroscopy. Experimental diabetic animals were induced by a …

Ameliorative Effects Of Vitamins C And E On Haematotoxicity And Spleen Histopathology Induced By Dichlorvos Insecticide In Female Wistar Rats, Halima Mfaume, Harishchandra Pratap, Claudius Luziga, Felister Urasa

Tanzania Journal of Science

This research aimed to assess the toxicological effects of dichlorvos insecticide (2,2-dichlorovinyl dimethyl phosphate or DDVP) on haematological indices of female Wistar rats and to investigate the antioxidant properties of vitamins C and E in ameliorating haematotoxicity. The rats were divided into 6 groups; control-water, control-oil, dichlorvos group, dichlorvos + vitamin C group, dichlorvos + vitamin E group and dichlorvos + vitamin C + E group. Dichlorvos and vitamins were orally administered to rats with an interval of half an hour between treatments. The control-oil group was given 2 ml corn oil and the control-water group was given water adlib. …

Reintroducing Hemp (Rongony) In The Material Palette Of Madagascar: A Study On The Potential Of Hemp Clay Components And Its Impact On Social And Ecological Communities., Henintsoa Thierry Andrianambinina

Masters Theses

When mentioning the word hemp, especially in the local language of Madagascar, the literal translation does not set it apart from marijuana, as they are both called “rongony” - creating the stigma around hemp as the negative stereotype of marijuana. However, the material has been used by the ancestors of Madagascar, as well as across cultures, in its fibrous form to produce fabrication like textile goods and packaging. During colonization, the prohibition of hemp intensified, and since then, any activity related to either of these plants is prohibited and will end in severe punitive measures. This thesis explores the strengths …

Data To Action: Community-Based Participatory Research To Address Concerns About Metal Air Pollution In Overburdened Neighborhoods Near Metal Recycling Facilities In Houston, Elaine Symanski, Heyreoun An Han, Sheryl Mccurdy, Loren Hopkins, Juan Flores, Inkyu Han, Mary Ann Smith, James Caldwell, Cecelia Fontenot, Bobbie Wyatt, Christine Markham

Faculty, Staff and Student Publications

BACKGROUND: Exposures to environmental contaminants can be influenced by social determinants of health. As a result, persons living in socially disadvantaged communities may experience disproportionate health risks from environmental exposures. Mixed methods research can be used to understand community-level and individual-level exposures to chemical and nonchemical stressors contributing to environmental health disparities. Furthermore, community-based participatory research (CBPR) approaches can lead to more effective interventions.

OBJECTIVES: We applied mixed methods to identify environmental health perceptions and needs among metal recyclers and residents living in disadvantaged neighborhoods near metal recycling facilities in Houston, Texas, in a CBPR study, Metal Air Pollution Partnership …

Climate Change Imperils Pediatric Health: Child Advocacy Through Fossil Fuel Divestment., Sandra H. Jee, Elizabeth Friedman, Ruth A. Etzel, Vi T. Nguyen, Todd L. Sack, Kathi J. Kemper

Manuscripts, Articles, Book Chapters and Other Papers

Climate change poses an existential threat to children's health. Divestment of ownership stakes in fossil fuel companies is one tool available to pediatricians to address climate change. Pediatricians are trusted messengers regarding children's health and therefore bear a unique responsibility to advocate for climate and health policies that affect children. Among the impacts of climate change on pediatric patients are allergic rhinitis and asthma; heat-related illnesses; premature birth; injuries from severe storms and fires; vector-borne diseases; and mental illnesses. Children are disproportionately affected as well by climate-related displacement of populations, drought, water shortages, and famine. The human-generated burning of fossil …

Migratory Material: Epigenetics & Weaving At The Us-Mexico Border, Valerie Navarrete

Masters Theses

Discourse often sutures the body shut, disallowing representations of identity to outgrow sociopolitical interests. This issue may originate from borders, but also from the unnamable pathology that generational colonial trauma transmits to the mind, body, and environment. Without a direct form of translatability, this thesis proposes a new materialism that deviates from any object-oriented ontology. Untethered and intra-active, epigenetics and weaving represent objects that transform typical ways of knowing and seeing. Their sensitivity to the environment, in addition to their mobility across generations of time, broaden the spatiotemporal loci of the body and its embodiment. Proposing new materials that expand …

Nursing Education In Complementary Alternative Modalities: A Case Study, Deborah Bird

Dissertations

Purpose: The purpose of this embedded case study was to describe the preparation for and utilization of complimentary alternative modality (CAM) interventions by an experienced Doctor of Nursing Practice (DNP) prepared nurse practitioner (NP) working in an outpatient setting.

Background: Given the widespread use of CAM by the American public and the potential complications involved in combining CAM and standard medical care, a lack of educational preparation in CAM interventions by NPs delivering primary care in outpatient health care settings represents both a potential risk and a missed opportunity to provide holistic patient care. Such a lack of knowledge also …

Neuroinflammatory And Metabolomic Temporal Dynamics From Inhaled Wildfire Smoke With Attenuation Via Pharmacological Intervention, David Scieszka

Biomedical Sciences ETDs

Wildfire smoke is a global issue affecting nearly all humans on the surface of this Earth. Smoke dispersion from wildfires can span continents and cross oceans with amazing ease. Furthermore, total acres of land burned per year in the United States has roughly doubled since 1980, meaning this issue will persist for an indeterminate amount of time. Exposure to wildfire smoke is hazardous and promotes aging-associated events in the cardiopulmonary systems. Yet long- and short-term effects on the brain remain relatively unknown. From these, it is critically important to understand the neurological impacts from wildfire smoke exposure; to compare these …