@article{burris_simmons_webb_moore_jaykus_zheng_reed_ferreira_brown_bell_2021, title={Salmonella enterica colonization and fitness in pre-harvest cantaloupe production}, volume={93}, ISSN={["1095-9998"]}, DOI={10.1016/j.fm.2020.103612}, abstractNote={Cantaloupes have emerged as significant vehicles of widespread foodborne illness outbreaks caused by bacterial pathogens, including Salmonella . The purpose of this study was to investigate the efficiency of Salmonella colonization and internalization in cantaloupes by relevant routes of contamination. Cantaloupe plants ( Cucumis melo ‘reticulatus’) from two cultivars ‘Athena’ (Eastern) and ‘Primo’ (Western) were grown from commercial seed. Plants were maintained in the NCSU BSL-3P phytotron greenhouse. Salmonella enterica (a cocktail of cantaloupe-associated outbreak serovars Javiana, Newport, Panama, Poona and Typhimurium) contamination was introduced via blossoms or soil at ca. 4.4 log 10 CFU/blossom or 8.4 log 10 CFU/root zone, respectively. Cantaloupes were analyzed for Salmonella by enrichment in accordance with modified FDA-BAM methods. Five randomly chosen colonies from each Salmonella -positive sample were typed using the Agilent 2100 bioanalyzer following multiplex PCR. Data were analyzed for prevalence of contamination and serovar predominance in fruit, stems and soil. Of the total cantaloupe fruit harvested from Salmonella -inoculated blossoms (n = 63), 89% (56/63) were externally contaminated and 73% (46/63) had Salmonella internalized into the fruit. Serovar Panama was the most commonly isolated from the surface of fruit while S. Panama and S. Poona were the most prevalent inside the fruit. When soil was inoculated with Salmonella at one day post-transplant, 13% (8/60) of the plants were shown to translocate the organism to the lower stem (ca. 4 cm) by 7 days post-inoculation (dpi). We observed Salmonella persistence in the soil up to 60 dpi with S. Newport being the predominant serovar at 10 and 20 dpi. These data demonstrate that contaminated soil and blossoms can lead to Salmonella internalization into the plant or fruit at a relatively high frequency. • Salmonella- contaminated soil and blossoms lead to plant or fruit internalization. • Blossom inoculations resulted in a high percentage of Salmonella internalization to fruit. • Serovar Panama was the most commonly isolated serovar from the surface of fruit. • S. Panama and S . Poona were the most prevalent serovars internalized to fruit. • Salmonella persisted in soils up to 60 days post inoculation.}, journal={FOOD MICROBIOLOGY}, author={Burris, Kellie P. and Simmons, Otto D., III and Webb, Hannah M. and Moore, Robin Grant and Jaykus, Lee-Ann and Zheng, Jie and Reed, Elizabeth and Ferreira, Christina M. and Brown, Eric and Bell, Rebecca L.}, year={2021}, month={Feb} }
 @article{burris_simmons_webb_deese_moore_jaykus_zheng_reed_ferreira_brown_et al._2020, title={Colonization and Internalization of Salmonella enterica and Its Prevalence in Cucumber Plants}, volume={11}, ISSN={1664-302X}, url={http://dx.doi.org/10.3389/fmicb.2020.01135}, DOI={10.3389/fmicb.2020.01135}, abstractNote={Consumption of cucumbers (Cucumis sativus var. sativus) has been linked to several foodborne outbreaks involving Salmonella enterica. The purpose of this work was to investigate the efficiency of colonization and internalization of S. enterica into cucumber plants by various routes of contamination. Produce-associated outbreak strains of Salmonella (a cocktail of serovars Javiana, Montevideo, Newport, Poona, and Typhimurium) were introduced to three cultivars of cucumber plants (two slicing cultivars and one pickling) via blossoms (ca. 6.4 log10 CFU/blossom, 4.5 log10 CFU/blossom, or 2.5 log10 CFU/blossom) or soil (ca. 8.3 log10 CFU/root zone) and were analyzed for prevalence of Salmonella contamination (internal and external) and serovar predominance in fruit and stems. Of the total slicing fruit harvested from Salmonella-inoculated blossoms (ca. 6.4, 4.5, or 2.5 log10 CFU/blossom), 83.9% (47/56), 81.4% (48/59) or 71.2% (84/118) were found colonized and 67.9% (38/56), 35.6% (21/59) or 22.0% (26/118) had Salmonella internalized into the fruit, respectively. S. Poona was the most prevalent serovar isolated on or in cucumber fruits at all inoculation levels. When soil was inoculated at 1 day post-transplant (dpt), 8% (10/120) of the plants were shown to translocate Salmonella to the lower stem 7 days post-inoculation (dpi). Results identified blossoms as an important route by which Salmonella internalized at a high percentage into cucumbers, and S. Poona, the same strain isolated from the 2015 outbreak of cucumbers imported from Mexico, was shown to be well-adapted to the blossom niche.}, journal={Frontiers in Microbiology}, publisher={Frontiers Media SA}, author={Burris, Kellie P. and Simmons, Otto D. and Webb, Hannah M. and Deese, Lauren M. and Moore, Robin Grant and Jaykus, Lee-Ann and Zheng, Jie and Reed, Elizabeth and Ferreira, Christina M. and Brown, Eric W. and et al.}, year={2020}, month={May} }
 @inproceedings{moore_ducharme_burris_simmons_jaykus_zheng_brown_bell_2019, title={Antimicrobial Resistance of Salmonella Recovered from Environmental Samples on Three North Carolina Tomato Farms}, author={Moore, R.G. and Ducharme, D.T. and Burris, K.P. and Simmons, O.D., III and Jaykus, L.A. and Zheng, J. and Brown, E. and Bell, R.L.}, year={2019} }
 @inproceedings{burris_simmons_webb_moore_jaykus_zheng_reed_brown_bell_2019, title={Prevalence and Fitness of Produce Outbreak Associated Salmonella enterica in Tomato Plants}, author={Burris, K.P. and Simmons, O.D., III and Webb, H.M. and Moore, R.G. and Jaykus, L.A. and Zheng, J. and Reed, E. and Brown, E. and Bell, R.L.}, year={2019} }
 @inproceedings{burris_webb_simmons_moore_jaykus_zheng_reed_brown_bell_2018, title={Colonization and Internalization of Salmonella enterica in Cantaloupe Plants}, author={Burris, K.P. and Webb, H.M. and Simmons, O.D., III and Moore, R.G. and Jaykus, L.A. and Zheng, J. and Reed, E. and Brown, E. and Bell, R.L.}, year={2018} }
 @misc{simmons_2018, place={Wilson, NC}, title={FSMA Update Presentation}, author={Simmons, O.D., III}, year={2018} }
 @inproceedings{simmons_2018, place={Fayetteville, NC}, title={FSMA Update Presentation}, author={Simmons, O.D., III}, year={2018} }
 @inproceedings{simmons_2018, title={FSMA Update Presentation to the Natural Environment Committee}, author={Simmons, O.D., III}, year={2018} }
 @misc{simmons_2018, title={FSMA for Small Farms Workshop}, author={Simmons, O.D., III}, year={2018} }
 @misc{simmons_2018, title={FSMA for Small Farms Workshops}, author={Simmons, O.D., III}, year={2018} }
 @misc{simmons_2018, title={Pasquotank County Cabbage Growers Meeting}, author={Simmons, O.D., III}, year={2018} }
 @misc{simmons_2018, title={Southeast Fruit & Vegetable EXPO}, author={Simmons, O.D., III}, year={2018} }
 @article{bailey_casanova_simmons_sobsey_2018, title={Tertiary treatment and dual disinfection to improve microbial quality of reclaimed water for potable and non-potable reuse: A case study of facilities in North Carolina}, volume={630}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2018.02.239}, abstractNote={Treated wastewater is increasingly of interest for either nonpotable purposes, such as agriculture and industrial use, or as source water for drinking water supplies; however, this type of advanced treatment for water supply is not always possible for many low resource settings. As an alternative, multiple barriers of physical, chemical and biological treatment with lower cost and simpler operation and maintenance have been proposed as more globally applicable. One such water reclamation system for both non-potable and potable reuse, is that approved by the State of North Carolina "for Type 2" reclaimed water (NCT2RW). NC Type 2 potable reuse systems consist of a sequence of tertiary treatment to produce well oxidized reclaimed water that is then then further treated by two steps of disinfection, typically UV radiation and chlorination. In this case study, the log10 microbial reduction performance of NCT2RW producing water reclamation facilities is evaluated. Based on the results presented here, NCT2RW consistently achieved high (6 for bacteria, 4 for virus and 4 for protozoan parasite surrogates) log10 reductions using the NC proposed treatment methods. Additionally, lower but significant log10 reduction performance was also documented for protozoan parasites and human enteric viruses.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Bailey, Emily S. and Casanova, Lisa M. and Simmons, Otto D., III and Sobsey, Mark D.}, year={2018}, month={Jul}, pages={379–388} }
 @inproceedings{burris_simmons_jaykus_zheng_reed_brown_bell_webb_2017, title={Colonization and internalization of Salmonella enterica in cucumber plants}, author={Burris, K.P. and Simmons, O.D., III and Jaykus, L.A. and Zheng, J. and Reed, E. and Brown, E. and Bell, R.L. and Webb, H.M.}, year={2017}, month={Jul} }
 @misc{simmons_johnston_nobles_2017, title={FSMA Preparedness in North Carolina: Where do we stand today?}, author={Simmons, O.D., III and Johnston, L. and Nobles, C.}, year={2017}, month={Jan} }
 @inproceedings{rogers_simmons_2017, title={FSMA’s Produce Safety Rule: Its impact on Small Farms}, author={Rogers, E.T. and Simmons, O.D., III}, year={2017}, month={Jun} }
 @misc{simmons_2017, title={The FSMA Fresh Produce Rule: Provisions that Apple Growers Should Understand!}, author={Simmons, O.D., III}, year={2017}, month={Jan} }
 @article{bradshaw_simmons_jaykus_2017, title={Updates from the NoroCORE Project: Progress toward Reducing the Burden of Foodborne Viruses}, journal={Food Safety Magazine}, author={Bradshaw, E. and Simmons, O.D., III and Jaykus, L.A.}, year={2017}, month={Apr} }
 @misc{rogers_simmons_2017, title={What do you need to know about FSMA’s Produce Safety Rule?}, author={Rogers, E.T. and Simmons, O.D., III}, year={2017}, month={Jan} }
 @misc{simmons_macmullan_mcreynolds_2016, title={Coordinated Efforts for FSMA Preparedness in North Carolina}, author={Simmons, O.D., III and MacMullan, A. and McReynolds, R.}, year={2016}, month={May} }
 @inproceedings{arnold_cope_simmons_chapman_2016, title={Knowledge and Risk Communication for Undercooked Oyster Preparation in Restaurants}, author={Arnold, N. and Cope, S. and Simmons, O.D., III and Chapman, B.}, year={2016}, month={Aug} }
 @article{lu_yuan_cheng_rose_classen_simmons_2016, title={Modeling the Growth of Archaeon Halobacterium halobium Affected by Temperature and Light}, volume={181}, ISSN={0273-2289 1559-0291}, url={http://dx.doi.org/10.1007/s12010-016-2270-x}, DOI={10.1007/s12010-016-2270-x}, abstractNote={The objective of this study was to develop sigmoidal models, including three-parameter (Quadratic, Logistic, and Gompertz) and four-parameter models (Schnute and Richards) to simulate the growth of archaeon Halobacterium halobium affected by temperature and light. The models were statistically compared by using t test and F test. In the t test, confidence bounds for parameters were used to distinguish among models. For the F test, the lack of fit of the models was compared with the prediction error. The Gompertz model was 100 % accepted by the t test and 97 % accepted by the F test when the temperature effects were considered. Results also indicated that the Gompertz model was 94 % accepted by the F test when the growth of H. halobium was studied under varying light intensities. Thus, the Gompertz model was considered the best among the models studied to describe the growth of H. halobium affected by temperature or light. In addition, the biological growth parameters, including specific growth rate, lag time, and asymptote changes under Gompertz modeling, were evaluated.}, number={3}, journal={Applied Biochemistry and Biotechnology}, publisher={Springer Science and Business Media LLC}, author={Lu, Hao and Yuan, Wenqiao and Cheng, Jay and Rose, Robert B. and Classen, John J. and Simmons, Otto D.}, year={2016}, month={Oct}, pages={1080–1095} }
 @inproceedings{ducharme_gunter_simmons_rogers_johnston_nobles_2016, title={Reinforcing Key Learning Concepts of Food Safety & The FSMA Through Customizable Interactive Practices}, author={Ducharme, D.T. and Gunter, C. and Simmons, O.D., III and Rogers, E.T. and Johnston, L. and Nobles, C.}, year={2016}, month={Nov} }
 @article{hu_wang-li_simmons_classen_osborne_2016, title={Size Distributions of Bioaerosols in an Egg Production Facility and Its Vicinity}, volume={33}, ISSN={["1557-9018"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84964715430&partnerID=MN8TOARS}, DOI={10.1089/ees.2015.0220}, abstractNote={Abstract Air emissions from animal feeding operations may cause elevated concentrations of bioaerosols in surrounding areas, posing adverse health effects to the people working on or living near the farm. Concentrations of nonselective airborne bacteria and fungi in various size ranges were measured by the Andersen six-stage viable samplers in an egg production house and at four ambient stations surrounding the farm in winter, spring, and summer. It was discovered that in-house bacterial particle size distributions (PSDs) were different among seasons. Under higher temperature and lower relative humidity conditions, more bacteria were associated with the small size ranges. Seasonal variations of in-house fungal PSDs were not significant. On average, 60–80% of in-house bacteria were in respirable size range (≤4.7 μm), whereas 60–70% of in-house fungi were in respirable size range. Bacterial PSDs at ambient locations were different among stations in winter but not in spring and summer. There were significant...}, number={4}, journal={ENVIRONMENTAL ENGINEERING SCIENCE}, author={Hu, Di and Wang-Li, Lingjuan and Simmons, Otto D. and Classen, John J. and Osborne, Jason A.}, year={2016}, month={Apr}, pages={215–223} }
 @inproceedings{simmons_gunter_ducharme_rogers_nobles_johnston_2016, title={What Does the Reality of the Food Safety Modernization Act (FSMA) Look Like for our Stakeholders?}, author={Simmons, O.D., III and Gunter, C. and Ducharme, D.T. and Rogers, E.T. and Nobles, C. and Johnston, L.}, year={2016}, month={Nov} }
 @misc{simmons_gunter_ducharme_2015, title={A Fresh Produce Update}, author={Simmons, O.D., III and Gunter, C. and Ducharme, D.T.}, year={2015} }
 @inproceedings{ducharme_gunter_perkins-veazie_simmons_zheng_son_brown_bell_jaykus_2015, title={Agricultural Biodiversity within North Carolina Tomato Production Systems Associated with Serotypes and Environmental Reservoirs of Salmonella spp}, author={Ducharme, D.D. and Gunter, C.C. and Perkins-Veazie, P. and Simmons, O.D., III and Zheng, J. and Son, I. and Brown, E.W. and Bell, R.L. and Jaykus, L.A.}, year={2015}, month={Jul} }
 @inproceedings{ducharme_zheng_reed_ferreira_burrows_wang_son_muruvanda_keys_melka_et al._2015, title={Ecology, distribution, persistence and diversity of salmonellae isolated from the Coastal Plains, Piedmont and Mountain regions of North Carolina}, author={Ducharme, D. and Zheng, J. and Reed, E. and Ferreira, C.M. and Burrows, E.W. and Wang, C.Y. and Son, I. and Muruvanda, T. and Keys, C.E. and Melka, D. and et al.}, year={2015}, month={May} }
 @misc{simmons_2015, title={Food Safety Modernization Act (FSMA) Water Testing Requirements}, author={Simmons, O.D., III}, year={2015} }
 @article{jenny_jasper_simmons_shatalov_ducoste_2015, title={Heuristic optimization of a continuous flow point-of-use UV-LED disinfection reactor using computational fluid dynamics}, volume={83}, ISSN={0043-1354}, url={http://dx.doi.org/10.1016/j.watres.2015.06.031}, DOI={10.1016/j.watres.2015.06.031}, abstractNote={Alternative disinfection sources such as ultraviolet light (UV) are being pursued to inactivate pathogenic microorganisms such as Cryptosporidium and Giardia, while simultaneously reducing the risk of exposure to carcinogenic disinfection by-products (DBPs) in drinking water. UV-LEDs offer a UV disinfecting source that do not contain mercury, have the potential for long lifetimes, are robust, and have a high degree of design flexibility. However, the increased flexibility in design options will add a substantial level of complexity when developing a UV-LED reactor, particularly with regards to reactor shape, size, spatial orientation of light, and germicidal emission wavelength. Anticipating that LEDs are the future of UV disinfection, new methods are needed for designing such reactors. In this research study, the evaluation of a new design paradigm using a point-of-use UV-LED disinfection reactor has been performed. ModeFrontier, a numerical optimization platform, was coupled with COMSOL Multi-physics, a computational fluid dynamics (CFD) software package, to generate an optimized UV-LED continuous flow reactor. Three optimality conditions were considered: 1) single objective analysis minimizing input supply power while achieving at least (2.0) log10 inactivation of Escherichia coli ATCC 11229; and 2) two multi-objective analyses (one of which maximized the log10 inactivation of E. coli ATCC 11229 and minimized the supply power). All tests were completed at a flow rate of 109 mL/min and 92% UVT (measured at 254 nm). The numerical solution for the first objective was validated experimentally using biodosimetry. The optimal design predictions displayed good agreement with the experimental data and contained several non-intuitive features, particularly with the UV-LED spatial arrangement, where the lights were unevenly populated throughout the reactor. The optimal designs may not have been developed from experienced designers due to the increased degrees of freedom offered by using UV-LEDs. The results of this study revealed that the coupled optimization routine with CFD was effective at significantly decreasing the engineer's design decision space and finding a potentially near-optimal UV-LED reactor solution.}, journal={Water Research}, publisher={Elsevier BV}, author={Jenny, Richard M. and Jasper, Micah N. and Simmons, Otto D., III and Shatalov, Max and Ducoste, Joel J.}, year={2015}, month={Oct}, pages={310–318} }
 @misc{simmons_2015, title={High Pathogenic Avian Influenza: Sources, Fate, and Transport in the Environment}, author={Simmons, O.D., III}, year={2015} }
 @inproceedings{gutierrez-rodriguez_chapman_strawn_ducharme_gunter_macmullan_simmons_2015, title={Identifying Risks in a Fresh Produce Packing House}, author={Gutierrez-Rodriguez, E. and Chapman, B. and Strawn, L. and Ducharme, D.T. and Gunter, C. and MacMullan, A. and Simmons, O.D., III}, year={2015}, month={Jan} }
 @misc{simmons_2015, title={Irrigation Water: Updates to Pending FSMA Regulations and a NC Case Study}, author={Simmons, O.D., III}, year={2015} }
 @misc{simmons_jaykus_2015, title={Noroviruses: Some Facts to Ponder Before Having Lunch!}, author={Simmons, O.D., III and Jaykus, L.A.}, year={2015}, month={May} }
 @article{hu_wang-li_simmons iii_classen_osborne_2015, title={Spatiotemporal Variations of Bioaerosols  in the Vicinity of an Animal Feeding  Operation Facility in the US}, volume={6}, ISSN={2152-2197 2152-2219}, url={http://dx.doi.org/10.4236/jep.2015.66056}, DOI={10.4236/jep.2015.66056}, abstractNote={Bioaerosol emissions from animal feeding operation (AFO) facilities are of increasing interest due to the magnitude of the emissions and their potential health effect on local communities. There is limited information about fate and transport of AFO bioaerosol emissions. In this study, concentrations of airborne bacteria and fungi were measured at four ambient stations in four wind directions surrounding an egg production farm through winter, spring and summer using Andersen six-stage samplers. Mean concentrations of ambient bacteria and fungi ranged from 8.7 × 102 CFU m-3 to 1.3 × 103 CFU m-3 and from 2.8 × 102 CFU m-3 to 1.4 × 103 CFU m-3, respectively. Ambient bacterial concentrations were not significantly different over the seasons, while ambient fungal concentrations were the highest in summer and the lowest in winter. There were significant differences between downwind and upwind bacterial concentrations (p < 0.0001). Downwind bacterial and fungal concentrations responded differently to the influencing factors. Bacterial concentrations were quadratically correlated with wind vector (combined effects of wind speed and direction) and emission rate, were positively correlated with temperature, and were negatively correlated with solar radiation. Fungal concentrations were positively correlated with temperature, RH, and emission rate, and were negatively correlated with wind vector.}, number={6}, journal={Journal of Environmental Protection}, publisher={Scientific Research Publishing, Inc.}, author={Hu, Di and Wang-Li, Lingjuan and Simmons III, Otto D. and Classen, John J. and Osborne, Jason A.}, year={2015}, month={Jun}, pages={614–627} }
 @inproceedings{simmons_ducharme_gutierrez-rodriguez_2015, title={The Food Safety Modernization Act (FSMA): Implementation of the Produce Safety and Preventive Controls Rules and a Plan to Meet the Training Requirements}, author={Simmons, O.D., III and Ducharme, D.T. and Gutierrez-Rodriguez, E.}, year={2015}, month={Dec} }
 @misc{simmons_2015, title={USDA-NIFA Food Virology Collaborative Executive Board Update: Activity 5.5 Outreach to the Molluscan Shellfish Industry}, author={Simmons, O.D., III}, year={2015} }
 @article{hu_wang-li_simmons_classen_osborne_byfield_2014, title={Bioaerosol concentrations and emissions from tunnel-ventilated high-rise layer houses in North Carolina}, volume={57}, number={3}, journal={Transactions of the ASABE}, author={Hu, D. and Wang-Li, L. and Simmons, O. D. and Classen, J. J. and Osborne, J. A. and Byfield, G. E.}, year={2014}, pages={915–925} }
 @inproceedings{ducharme_gunter_perkins-veazie_simmons_zheng_son_brown_bell_jaykus_2014, title={Detection and Characterization of Salmonella spp. and Correlation with Microbial Indicators in NC Tomato Production Environments}, url={https://cdn.ymaws.com/ashs.org/resource/resmgr/Files/2014_program.pdf}, author={Ducharme, D. and Gunter, C. and Perkins-Veazie, P. and Simmons, O.D., III and Zheng, J. and Son, I. and Brown, E. and Bell, R. and Jaykus, L.A.}, year={2014}, month={Jul} }
 @inproceedings{ducharme_gunter_perkins-veazie_simmons_zheng_son_brown_bell_jaykus_2014, title={Environmental Reservoirs of Salmonella spp. in Field and Water Samples Associated with N.C. Tomato Production}, booktitle={Field and Water Samples Associated with N.C. Tomato Production”}, author={Ducharme, D. and Gunter, C. and Perkins-Veazie, P. and Simmons, O.D., III and Zheng, J. and Son, I. and Brown, E. and Bell, R. and Jaykus, L.A.}, year={2014}, month={Aug} }
 @inproceedings{ducharme_gunter_perkins-veazie_simmons_zheng_son_brown_bell_jaykus_2014, title={Environmental Sampling of NC Tomato Production Systems for Salmonella spp}, author={Ducharme, D. and Gunter, C. and Perkins-Veazie, P. and Simmons, O.D., III and Zheng, J. and Son, I. and Brown, E. and Bell, R. and Jaykus, L.A.}, year={2014}, month={Mar} }
 @article{gensel_simmons_jaykus_2014, title={Food Virology Collaborative: NoroCORE Tackles Foodborne Viruses}, volume={20}, number={2}, journal={Food Safety Magazine}, author={Gensel, C.L. and Simmons, O.D., III and Jaykus, L.A.}, year={2014}, month={Apr} }
 @inproceedings{simmons_2014, title={Irrigation Water for Fresh Produce: Impacts to Food Safety}, author={Simmons, O.D., III}, year={2014}, month={Nov} }
 @article{jenny_simmons_shatalov_ducoste_2014, title={Modeling a continuous flow ultraviolet Light Emitting Diode reactor using computational fluid dynamics}, volume={116}, ISSN={["1873-4405"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84902352092&partnerID=MN8TOARS}, DOI={10.1016/j.ces.2014.05.020}, abstractNote={The use of ultraviolet (UV) light for water treatment disinfection has become increasingly popular due to its ability to inactivate chlorine-resistant microorganisms without the production of known disinfection by-products. Currently, mercury-based lamps are the most commonly used UV disinfection source; however, these lamps are toxic if broken during installation or by foreign object strike during normal operation. In addition, disposal of degraded, hazardous mercury lamps can be challenging in rural and developing countries for point-of-use (POU) drinking water disinfection applications. UV Light Emitting Diodes (LEDs) offer an alternative, non-toxic UV source that will provide design flexibility due to their small size, longer operating life, and fewer auxiliary electronics than traditional mercury-based lamps. Modeling of UV reactor performance has been a significant approach to the engineering of UV reactors in drinking water treatment. Yet, no research has been performed on the experimental and modeling of a continuous flow UV-LED reactor. A research study was performed to validate a numerical computational fluid dynamics (CFD) model of a continuous flow UV-LED water disinfection process. Reactor validation consisted of the following: (1) hydraulic analysis using tracer tests, (2) characterization of the average light distribution using chemical actinometry, and (3) microbial dose–response and inactivation using biodosimetry. Results showed good agreement between numerical simulations and experimental testing. Accuracy of fluid velocity profile increased as flow rate increased from 109 mL/min to 190 mL/min, whereas chemical actinometry saw better agreement at the low flow rate. Biodosimetry testing was compared only at the low flow rate and saw good agreement for log inactivation of bacteriophage Qβ and MS-2 at 92% and 80% UV transmittance (UVT). The results from this research can potentially be used for the design of alternative point-of-use drinking water disinfection reactors in developing countries using UV LEDs.}, journal={CHEMICAL ENGINEERING SCIENCE}, author={Jenny, Richard M. and Simmons, Otto D., III and Shatalov, Max and Ducoste, Joel J.}, year={2014}, month={Sep}, pages={524–535} }
 @misc{simmons_2014, title={Stakeholder Update: A Perspective from the Fresh Produce Industry}, author={Simmons, O.D., III}, year={2014} }
 @inproceedings{simmons_jaykus_2014, title={The USDA-NIFA Food Virology Collaborative: NoroCORE}, author={Simmons, O.D., III and Jaykus, L.A.}, year={2014} }
 @misc{simmons_jaykus_2014, title={Viral Contamination of Berries: Information All Growers Should Know!}, author={Simmons, O.D., III and Jaykus, L.A.}, year={2014}, month={Nov} }
 @misc{simmons_jaykus_2014, title={Viruses and Fresh Produce: Important Information that Every Producer Should Know!}, author={Simmons, O.D., III and Jaykus, L.A.}, year={2014}, month={Dec} }
 @article{mixson_stikeleather_simmons_wilson_burkholder_2014, title={pH-induced flocculation, indirect electrocoagulation, and hollow fiber filtration techniques for harvesting the saltwater microalga Dunaliella}, volume={26}, ISSN={0921-8971 1573-5176}, url={http://dx.doi.org/10.1007/s10811-013-0232-z}, DOI={10.1007/s10811-013-0232-z}, number={4}, journal={Journal of Applied Phycology}, publisher={Springer Science and Business Media LLC}, author={Mixson, Stephanie M. and Stikeleather, Larry F. and Simmons, Otto D., III and Wilson, Cameron W. and Burkholder, JoAnn M.}, year={2014}, month={Jan}, pages={1701–1709} }
 @misc{simmons_2013, title={Enhancing Food Security through Pre-Harvest Food Safety: Current Research and Outreach for Practical Solutions}, author={Simmons, O.D., III}, year={2013}, month={Nov} }
 @inproceedings{jenny_simmons_ducoste_2013, title={Experimental and numerical evaluation of a UV-LED point of use device}, author={Jenny, R.M. and Simmons, O.D., III and Ducoste, J.J.}, year={2013}, month={Nov} }
 @misc{simmons_2013, title={Food Safety in the United States: Current Trends}, author={Simmons, O.D., III}, year={2013} }
 @inproceedings{simmons_jaykus_2013, title={Fruit and Vegetable}, author={Simmons, O.D., III and Jaykus, L.A.}, year={2013} }
 @inproceedings{ducharme_gunter_jaykus_perkins-veazie_simmons_zheng_burrows_wang_arce_muruvanda_et al._2013, title={Incidence and Persistence of Salmonella and Escherichia coli in Environmental Samples from North Carolina Tomato Production Systems}, author={Ducharme, D. and Gunter, C. and Jaykus, L. and Perkins-Veazie, P. and Simmons, O.D., III and Zheng, J. and Burrows, E. and Wang, C. and Arce, G.C. and Muruvanda, T. and et al.}, year={2013}, month={Jul} }
 @misc{ducharme_gunter_jaykus_perkins-veazie_simmons_zheng_burrows_wang_arce_muruvanda_et al._2013, title={Incidence and Persistence of Salmonella and Escherichia coli in Environmental Samples from North Carolina Tomato Production Systems.}, author={Ducharme, D. and Gunter, C. and Jaykus, L.A. and Perkins-Veazie, P. and Simmons, O.D., III and Zheng, J. and Burrows, E. and Wang, C. and Arce, G.C. and Muruvanda, T. and et al.}, year={2013}, month={Aug} }
 @inproceedings{ducharme_zheng_allard_burrows_wang_arce_muruvanda_keys_melka_simmons_et al._2013, title={Prevalence and diversity of Salmonella associated with North Carolina tomato growing environments}, author={Ducharme, D. and Zheng, J. and Allard, S.E. and Burrows, W. and Wang, C.Y. and Arce, G.C. and Muruvanda, T. and Keys, C.E. and Melka, D. and Simmons, O.D., III and et al.}, year={2013}, month={May} }
 @misc{simmons_jaykus_2013, place={Charlotte, NC}, title={Seafood Safety}, url={https://www.foodprotection.org/annualmeeting/archive/2013/}, author={Simmons, O.D., III and Jaykus, L.A.}, year={2013}, month={Jul} }
 @inproceedings{simmons_jaykus_2013, place={Charlotte, NC}, title={Seafood Safety}, author={Simmons, O.D., III and Jaykus, L.A.}, year={2013}, month={Jul} }
 @inproceedings{kim_simmons_sobsey_2013, title={The Cysticidal Activity of Bromine on Cryptosporidium parvum Oocysts}, author={Kim, J.J. and Simmons, O.D., III and Sobsey, M.D.}, year={2013}, month={May} }
 @inproceedings{kim_simmons_sobsey_2013, title={The Cysticidal Activity of Bromine on Cryptosporidium parvum Oocysts}, author={Kim, J.J. and Simmons, O.D., III and Sobsey, M.D.}, year={2013}, month={Nov} }
 @article{wu_simmons_sobsey_2013, title={Uncertainty analysis of the recovery of hollow-fiber ultrafiltration for multiple microbe classes from water: A Bayesian approach}, volume={93}, ISSN={["1872-8359"]}, DOI={10.1016/j.mimet.2013.03.005}, abstractNote={In this study, we introduce a Bayesian approach to address uncertainty of microbial recoveries from hollow-fiber ultrafilters (HFUF) and to determine any sources of uncertainty. Microbial recoveries were measured under twenty conditions, including two types of water, two types of ultrafilters, and five types of microorganisms. The probability distributions of the recoveries were approximated using Bayesian statistics with Markov chain Monte Carlo sampling after integrating the likelihood function of the recovery data and prior information about the data. Then a variance-decomposition method was used for examining influential factors on microbial recovery by HFUF. The results revealed that HFUF efficiently recovered Escherichia coli KO11, E. coli O157:H7 and bacteriophage MS2, but recoveries for Bacillus atrophaeus spores and adenovirus 41 were markedly different between source and treated waters. The uncertainty analysis indicated that the probability distributions for recoveries had dissimilar patterns under different conditions. Among these test factors, the type of microorganisms and associated interaction effects had great impacts on the recovery. To sum up, the Bayesian approach to uncertainty analysis shows advantages in evaluating the recovery of HFUF by providing its full probability distribution.}, number={3}, journal={JOURNAL OF MICROBIOLOGICAL METHODS}, author={Wu, Jianyong and Simmons, Otto D., III and Sobsey, Mark D.}, year={2013}, month={Jun}, pages={161–167} }
 @inproceedings{simmons_jaykus_2013, place={Charlotte, NC}, title={Updates on NoroCORE activities for IAFP Professional Development Groups (PDGs)”}, author={Simmons, O.D., III and Jaykus, L.A.}, year={2013}, month={Jul} }
 @misc{simmons_jaykus_2013, place={Savannah, GA}, title={Viruses in Fresh Produce: What Every Producer Should Know!}, author={Simmons, O.D., III and Jaykus, L.A.}, year={2013}, month={Jan} }
 @misc{simmons_jaykus_2013, title={Viruses in Shellfish and other Foods: Are they really that important??}, author={Simmons, O.D., III and Jaykus, L.A.}, year={2013} }
 @misc{simmons_jaykus_2013, title={Viruses in Shellfish: What all Commercial Fishermen Should Know!”}, author={Simmons, O.D., III and Jaykus, L.A.}, year={2013}, month={Jan} }
 @inproceedings{simmons_jaykus_2013, place={Charlotte, NC}, title={Water Safety and Quality}, author={Simmons, O.D., III and Jaykus, L.A.}, year={2013}, month={Jul} }
 @misc{simmons_2013, title={What’s that in your pomegranate seeds?? Recent microbial threats linked to fresh fruits and vegetables.}, author={Simmons, O.D., III}, year={2013} }
 @inproceedings{simmons_jaykus_2012, place={Savannah, GA}, title={Control of Human Virus Contamination in Molluscan Shellfish: Where we are and where we need to be?}, author={Simmons, O.D., III and Jaykus, L.A.}, year={2012}, month={Apr} }
 @misc{chapman_gunter_simmons_2012, title={Farm Commodity Recall Workshop}, author={Chapman, B. and Gunter, C. and Simmons, O.D., III}, year={2012}, month={Aug} }
 @inproceedings{gunter_barrier_simmons_2012, title={Irrigation Water Concerns and Recommendations for Fruit and Vegetable Growers}, author={Gunter, C. and Barrier, H. and Simmons, O.D., III}, year={2012} }
 @inproceedings{hu_wang-li_o.d. simmons_osborne_classen_2012, title={Measurement and Analysis of Temporal and Spatial Variations of Bioaerosol Concentrations in a High-rise Egg Production House}, author={Hu, D. and Wang-Li, L. and O.D. Simmons, O.D., III and Osborne, J.A. and Classen, J.J.}, year={2012}, month={Apr} }
 @inproceedings{simmons_2012, title={Safe Feedstock Handling For Vermiculture Operations}, author={Simmons, O.D., III}, year={2012}, month={Nov} }
 @inproceedings{hu_wang-li_simmons_osborne_classen_2012, title={Temporal and Spatial Variations of Bioaerosols Emitted from an Egg Production Facility in Southeast U.S Part II - Concentrations in the Vicinity}, author={Hu, D. and Wang-Li, L. and Simmons, O.D., III and Osborne, J.A. and Classen, J.J.}, year={2012}, month={Jul} }
 @inproceedings{hu_wang-li_simmons_osborne_classen_2012, title={Temporal and Spatial Variations of Bioaerosols Emitted from an Egg Production Facility in Southeast U.S.: Part III – Size Distributions and Viable Versus Non-Viable}, author={Hu, D. and Wang-Li, L. and Simmons, O.D., III and Osborne, J.A. and Classen, J.J.}, year={2012}, month={Jul} }
 @inproceedings{simmons_2012, title={The Role of Water for Maintaining the Microbial Quality of Fresh Produce During Production"}, author={Simmons, O.D., III}, year={2012} }
 @misc{simmons_jaykus_2012, title={Viruses in Fresh Produce: What Every Producer Should Know!}, author={Simmons, O.D., III and Jaykus, L.A.}, year={2012}, month={Nov} }
 @inproceedings{hu_wang-li_simmons_osborne_classen_2011, title={Concentration of bioaerosols in the vicinity of a commercial egg production farm in Southeast U.S}, author={Hu, D. and Wang-Li, L. and Simmons, O.D., III and Osborne, J.A. and Classen, J.J.}, year={2011}, month={Aug} }
 @article{classen_rice_mcneill_simmons_2011, title={Design and evaluation of a discreet sampler for waste treatment lagoons}, volume={27}, DOI={10.13031/2013.40621}, abstractNote={A lagoon sampler was designed to collect 300-mL samples from depths up to 2.82 m at 15.2-cm intervals. Design parameters required the device to collect discrete samples through the entire lagoon column without cross contamination during raising or lowering of the device through the lagoon and to leave the liquid column undisturbed so subsequent samples could be taken from lower depths at the same location. An evaluation protocol was developed to test the device in a 55.9-cm diameter, 3.35-m tall PVC test column. This test column was of sufficient depth to be representative of lagoons and of sufficient diameter to avoid interference, or edge effects, associated with the sampling device. The evaluation protocol used dissolved solids (sodium chloride) as the test parameter in 30.5-cm deep layers of sodium chloride of decreasing concentrations to fill the test column from the bottom and simulated different solids concentrations that may be found in a lagoon. Samples were collected at six depths from 122 to 198 cm. Based on electrical conductivity measurements, samples collected with the device were slightly more dilute than the expected value at all sample depths. Further tests showed that operation of the device did not cause mixing of the layered salt solutions. The sampler was used to collect samples from various depths in a lagoon; results suggested there was little interference among samples taken at specific locations through subsequent depths.}, number={6}, journal={Applied Engineering in Agriculture}, author={Classen, John and Rice, J. M. and McNeill, J. P. and Simmons, Otto}, year={2011}, pages={1007–1014} }
 @misc{ducharne_simmons_2011, place={Raleigh, NC}, title={In-Service Good Agricultural Practices (GAP) Training}, author={Ducharne, D. and Simmons, O.D., III}, year={2011} }
 @misc{ducharme_simmons_turner_2011, title={In-Service Good Agricultural Practices (GAP) Training}, author={Ducharme, D. and Simmons, O.D., III and Turner, L.}, year={2011}, month={Dec} }
 @misc{hathaway_simmons_hunt_2011, title={Microbes and Stormwater 101: An Introduction to Pathogens and Indicator Bacteria in Urban Stormwater Runoff}, author={Hathaway, J. and Simmons, O.D., III and Hunt, W.F., III}, year={2011} }
 @misc{simmons_gunter_2011, title={Water Management for Safe Strawberries}, author={Simmons, O.D., III and Gunter, C.G.}, year={2011}, month={Nov} }
 @misc{simmons_2011, title={Water Testing Updates for Tier 2 Good Agricultural Practices (GAP) Training}, author={Simmons, O.D., III}, year={2011} }
 @misc{simmons_2010, title={Alternative Systems for Managing Microbial Pathogens on CAFOs}, author={Simmons, O.D., III}, year={2010} }
 @inproceedings{wang_simmons_2010, title={Bioaerosol Measurement in Animal Environments}, author={Wang, L. and Simmons, O.D., III}, year={2010}, month={Sep} }
 @inproceedings{wu_rodriguez_simmons_stewart_sobsey_2010, title={Concentrating Adenovirus 41 in Drinking Water using Electronegative Membrane Filtration and Hollow Fiber Utrafiltration}, author={Wu, J. and Rodriguez, R. and Simmons, O.D., III and Stewart, J.R. and Sobsey, M.D.}, year={2010}, month={May} }
 @inproceedings{simmons_garzon_2010, title={Copper Ionization for Inactivating E. coli, Coliphage MS2, and Bacillus Atrophaeus Spores in Irrigation Water for Fruits and Vegetables}, author={Simmons, O.D., III and Garzon, J.}, year={2010}, month={May} }
 @article{ko_simmons, iii_likirdopulos_worley-davis_williams_sobsey_2010, title={Endotoxin Levels at Swine Farms Using Different Waste Treatment and Management Technologies}, volume={44}, ISSN={0013-936X 1520-5851}, url={http://dx.doi.org/10.1021/es9026024}, DOI={10.1021/es9026024}, abstractNote={Concentrated animal feeding operations (CAFOs) are a major source of airborne endotoxins, which are air pollutants that can cause adverse health effects to both on-site farmers and neighbors. Release of airborne endotoxins to the environment can be reduced using proper waste treatment and management technologies. In this study, the levels of endotoxins released from two swine CAFOs using conventional lagoon-sprayfield technology were compared to those of 15 farms using various alternative waste management technologies in North Carolina. Over a 2-year period, 236 endotoxin samples were collected from the 17 farm units and analyzed using the Limulus amebocyte lysate (LAL) test. Concentrations of airborne endotoxins near barn exhaust fans were significantly higher than at the upwind boundary of the farm and at other farm sites. For most of the study sites, mean concentrations of endotoxins at the downwind boundary of the farm were higher than those at the upwind boundary of the farm, indicating the release of endotoxins from swine CAFOs to the neighboring environment. Endotoxin levels were significantly associated with concentrations of airborne bacteria but not fungi. Environmental factors, such as temperature, relative humidity, and wind velocity, affected the levels of airborne endotoxins at the farms. Based on the ratios of airborne endotoxins in downwind and upwind samples from the farm units, at least five different alternative waste management technologies significantly reduced the release of endotoxins from swine CAFOs. These results suggest that swine CAFOs are important sources of airborne endotoxins, the levels of which can be reduced by applying more robust and effective waste management technologies.}, number={9}, journal={Environmental Science & Technology}, publisher={American Chemical Society (ACS)}, author={Ko, GwangPyo and Simmons, III, Otto D. and Likirdopulos, Christina A. and Worley-Davis, Lynn and Williams, C. M. and Sobsey, Mark D.}, year={2010}, month={May}, pages={3442–3448} }
 @article{hathaway_hunt_simmons_2010, title={Statistical Evaluation of Factors Affecting Indicator Bacteria in Urban Storm-Water Runoff}, volume={136}, ISSN={0733-9372 1943-7870}, url={http://dx.doi.org/10.1061/(ASCE)EE.1943-7870.0000278}, DOI={10.1061/(asce)ee.1943-7870.0000278}, abstractNote={An urban watershed in Raleigh, North Carolina, was monitored for indicator bacteria during 20 rain events. Results showed elevated levels of E. coli, enterococci, and fecal coliform. Samples were compared based on seasonality and were found to be statistically different ( p<0.05 ) , with pairwise comparisons indicating significantly lower concentrations of E. coli and fecal coliform during the winter ( p<0.05 ) . Enterococci concentrations were substantially lower in the winter and fall, but no significant differences were found between seasons during pairwise comparisons ( p<0.05 ) . Correlation analyses showed multiple significant relationships between antecedent climate parameters, flow characteristics, and indicator bacteria concentrations. More detailed multiple linear regression yielded explanatory variables related to antecedent climate conditions. Variables were generally related to temperature and moisture conditions in the atmosphere and soil. The results of this study show indicator bacteria co...}, number={12}, journal={Journal of Environmental Engineering}, publisher={American Society of Civil Engineers (ASCE)}, author={Hathaway, J. M. and Hunt, W. F. and Simmons, O. D., III}, year={2010}, month={Dec}, pages={1360–1368} }
 @inproceedings{wang_li_esch_simmons_classen_beasley_2009, place={St. Joseph, MI}, title={Biological Characteristics of Aerosols Emitted From A Layer Operation In Southeastern U.S.}, url={http://dx.doi.org/10.13031/2013.28035}, DOI={10.13031/2013.28035}, abstractNote={This preliminary study was to investigate biological characteristics of aerosols emitted from a commercial layer farm (egg production farm). Bioaerosol samples were taken on this farm at five sampling locations covering emission source (inside a layer barn) and four ambient stations at four wind directions. All glass impingers (AGI) were used for the field sampling. The AGI fluid samples were plated in duplicate on Trypticase Soy Agar (TSA) for growth of bacteria and Sabouraud Dextrose Agar (SDA) for growth of fungi. The most prominent bacterial colony types were identified using a combination of methods that include recording characteristics of colony morphology; performing a Gram staining method and metabolic analyses using the Biolog system. Results from one group of bioaerosol samples at the five stations indicate that the sampling duration played an important role in accurately determining bacteria concentration in air samples; there were significant reductions in total bacteria concentrations in the samples collected from ambient stations compared to the sample collected in the layer house; the most prominent bacteria species differed among all five stations and three of the most prominent bacteria from samples taken at all five stations were gram-positive; fungal type differed from station to station.}, booktitle={Proceedings of the American Society of Agricultural and Biological Engineers Annual International Meeting}, publisher={American Society of Agricultural and Biological Engineers}, author={Wang, Lingjuan and Li, Qianfeng and Esch, Keith and Simmons, Otto D, III and Classen, John and Beasley, David B}, year={2009} }
 @article{cizek_characklis_krometis_hayes_simmons_di lonardo_alderisio_sobsey_2008, title={Comparing the partitioning behavior of Giardia and Cryptosporidium with that of indicator organisms in stormwater runoff}, volume={42}, ISSN={0043-1354}, url={http://dx.doi.org/10.1016/j.watres.2008.06.020}, DOI={10.1016/j.watres.2008.06.020}, abstractNote={Microbial association with particles can significantly affect the fate and transport characteristics of microbes in aquatic systems as particle-associated organisms will be less mobile in the environment than their free phase (i.e. unattached) counterparts. As such, similarities or dissimilarities in the partitioning behavior of indicator organisms and pathogens may have an impact on the suitability of a particular indicator to act as a surrogate for a pathogen. This research analyzed the partitioning behavior of two pathogens (Cryptosporidium, Giardia) and several common indicator organisms (fecal coliform, Escherichia coli, Enterococci, Clostridium perfringens spores, and coliphage) in natural waters under both dry and wet weather conditions. Samples were taken from several streams in two distinct sampling phases: (i) single grab samples; and (ii) intrastorm samples obtained throughout the duration of four storms. Partitioning behavior varied by microbial type, with 15–30% of bacterial indicators (fecal coliform, E. coli, and Enterococci) associated with settleable particles compared to 50% for C. perfringens spores. Both pathogens exhibited similar levels of particle association during dry weather (roughly 30%), with increased levels observed during wet weather events (Giardia to 60% and Cryptosporidium to 40%). The settling velocities of particle-associated microbes were also estimated, with those of the bacterial indicators (fecal coliform, E. coli, and Enterococci), as well as C. perfringens spores, being similar to that of the Giardia and Cryptosporidium, suggesting these organisms may exhibit similar transport behavior. With respect to intrastorm analysis, the highest microbial concentrations, in both particle-associated and free phase, occurred during the earlier stages of a storm. The total loadings of both indicators and pathogens were also estimated over the course of individual storms.}, number={17}, journal={Water Research}, publisher={Elsevier BV}, author={Cizek, Adrienne R. and Characklis, Gregory W. and Krometis, Leigh-Anne and Hayes, Jeffrey A. and Simmons, Otto D., III and Di Lonardo, Steve and Alderisio, Kerri A. and Sobsey, Mark D.}, year={2008}, month={Nov}, pages={4421–4438} }
 @inproceedings{casteel_guarin_simmons_2008, title={Improved Hollow-fiber Ultrafiltration and Real-time PCR Detection for the Recovery and Detection of Waterborne Microbes}, author={Casteel, M.J. and Guarin, H.G. and Simmons, O.D., III}, year={2008} }
 @inproceedings{andersen_lee_casteel_sobsey_simmons_2008, title={Improved Recovery of Multiple Microbial Indicator Organisms from Source and Treated Drinking Waters by Optimized Hydraulic Modification to Hollow-fiber Ultrafilters}, author={Andersen, E. and Lee, H. and Casteel, M.J. and Sobsey, M.D. and Simmons, O.D., III}, year={2008}, month={Jun} }
 @article{ko_simmons iii_likirdopulos_worley-davis_williams_sobsey_2008, title={Investigation of Bioaerosols Released from Swine Farms using Conventional and Alternative Waste Treatment and Management Technologies}, volume={42}, ISSN={0013-936X 1520-5851}, url={http://dx.doi.org/10.1021/es801091t}, DOI={10.1021/es801091t}, abstractNote={Microbial air pollution from concentrated animal feeding operations (CAFOs) has raised concerns about potential public health and environmental impacts. We investigated the levels of bioaerosols released from two swine farms using conventional lagoon-sprayfield technology and ten farms using alternative waste treatment and management technologies in the United States. In total, 424 microbial air samples taken at the 12 CAFOs were analyzed for several indicator and pathogenic microorganisms, including culturable bacteria and fungi, fecal coliform, Escherichia coli, Clostridium perfringens, bacteriophage, and Salmonella. At all of the investigated farms, bacterial concentrations at the downwind boundary were higher than those at the upwind boundary, suggesting that the farms are sources of microbial air contamination. In addition, fecal indicator microorganisms were found more frequently near barns and treatmenttechnology sites than upwind or downwind of the farms. Approximately 4.5% (19/424), 1.2% (5/424), 22.2% (94/424), and 12.3% (53/424) of samples were positive for fecal coliform, E. coli, Clostridium, and total coliphage, respectively. Based on statistical comparison of airborne fecal indicator concentrations at alternative treatment technology farms compared to control farms with conventional technology, three alternative waste treatment technologies appear to perform better at reducing the airborne release of fecal indicator microorganisms during on-farm treatment and management processes. These results demonstrate that airborne microbial contaminants are released from swine farms and pose possible exposure risks to farm workers and nearby neighbors. However, the release of airborne microorganisms appears to decrease significantly through the use of certain alternative waste management and treatment technologies.}, number={23}, journal={Environmental Science & Technology}, publisher={American Chemical Society (ACS)}, author={Ko, GwangPyo and Simmons III, Otto D. and Likirdopulos, Christina A. and Worley-Davis, Lynn and Williams, Mike and Sobsey, Mark D.}, year={2008}, month={Dec}, pages={8849–8857} }
 @inproceedings{simmons_2008, title={Methods to Monitor Source Water for Microbial Contaminants}, author={Simmons, O.D., III}, year={2008} }
 @inproceedings{lee_simmons_sobsey_2008, title={Optimized Secondary Concentration of Adenovirus and Echovirus by Polyethylene glycol (PEG) Precipitation of Primary Water Concentrates}, author={Lee, H. and Simmons, O.D., III and Sobsey, M.D.}, year={2008}, month={Jun} }
 @book{bull_meyer_rice_simmons_2008, title={Recent Changes in Food Animal Production and Impacts on Animal Waste Management}, volume={Putting Meat on the Table: Industrial Farm Animal Production in America}, url={http://www.pcifapia.org/_images/PCIFAP_FW_FINAL1.pdf}, institution={Pew Commission on Industrial Farm Animal Production}, author={Bull, L.S. and Meyer, D. and Rice, J.M. and Simmons, O.D., III}, year={2008} }
 @inproceedings{simmons_2008, title={What We Know and What We Don’t Know about Microbial Pathogens Associated with Confined Animal Agriculture}, author={Simmons, O.D., III}, year={2008}, month={May} }