CHEEC Seed Grants: FY 1997

Bioaugmentation of the Poplar rhizosphere with genetically engineered microorganisms
PJJ Alvarez, JL Schnoor, Department of Civil and Environmental Engineering, The University of Iowa

Climate effects on human health in Iowa: Preliminary assessment of health implications of climate change 
GR Carmichael, Department of Chemical and Biochemical Engineering, The University of Iowa

Investigating the presence and fate of aflatoxin B1 in soil and aerosolized dust 
MI Selim, JM Starr, Department of Preventive Medicine and Environmental Health, The University of Iowa

Exploratory studies of an innovative reactor system for the destruction of organic contaminants in water 
RL Valentine, Department of Civil and Environmental Engineering, The University of Iowa

A geographic information systems approach for assessing the impacts of chemical hazards on vulnerable populations 
MP Armstrong, J Chakraborty, Department of Geography, The University of Iowa

Measuring low level arsenic exposure through drinking water 
JB Simeonsson, Department of Chemistry and Center for Global and Regional Environmental Research, The University of Iowa

Respiratory health effects of soybean fungal bioaerosols 
PS Thorne, CJ Roy, Department of Preventive Medicine and Environmental Health, The University of Iowa

 


Bioaugmentation of the poplar rhizosphere with genetically engineered microorganisms 
Investigators: PJ Alvarez, JL Schnoor, Department of Civil and Environmental Engineering, The University of Iowa 
Phytoremediation, the use of plants to remove environmental pollutants, holds great promise to reduce health risks associated with groundwater and soil contamination. Poplar trees can enhance site remediation by vegetative uptake of the contaminant or by enhancing its microbial degradation in the rhizosphere. This latter mechanism is not very effective for removing nitroaromatic contaminants. This project will evaluate the potential for a nitroaromatic-degrading, genetically-engineered microorganism (E. Coli DH5 [pDTG800]) to enhance bioremediation of 2,4,6-trinitrotoluene (TNT) in the poplar rhizosphere. The fate of both 14C-labeled TNT and E. Coli DH5 [pDTG800] will be studied in soil and plant bioreactors. The hypotheses are that 1) bioaugmentation of the poplar rhizosphere with this clone will enhance the mineralization of TNT; and 2) the added clone will maintain its nitroaromatic degradation activity and survive for a longer period of time in soil rhizosphere compared to background (control) soil. This research may lead to a better understanding and a more widespread acceptance of bioremediation in the rhizosphere as an additional tool for reducing health risks associated with environmental pollution.

Publication:  Jordahl J, Foster L, Schnoor J, Alvarez P; Effect of hybrid poplar trees on microbial populations important to hazardous waste bioremediation. Environ Toxicol Chem. 1997; 16(6):1318-1321

Climate effects on human health in Iowa: Preliminary assessment of health implications of climate change 
Investigators: GR Carmichael, Department of Chemical and Biochemical Engineering, The University of Iowa 
This project will perform a preliminary assessment of climate effects on human health in Iowa. A database will be compiled which consists of a historical fifty year record of daily meteorological factors (temperature, relative humidity, etc.) consisting of one site per county, along with meteorological quantities predicted for future climates based on Global Climate Model (GCM) results. Basic health-related weather quantities will be derived (heat stress index), and will be made available for studies relating weather attributes to morbidity and mortality. The data set will then be used in a preliminary assessment of the future risks associated with climate change. This will be accomplished by combining this data set with population and health-related statistics (hospital admissions, deaths by disease/cause, etc.)

Publication:  Carmichal G, Folk G, Schnoor J; Preparing for global change: a midwest perspective.Climatic Change. 1997; 37(6):1

Investigating the presence, levels, and fate of aflatoxin B1 in soil and aerosolized soil dust 
Investigators: MI Selim, JM Starr, Department of Preventive Medicine and Environmental Health, The University of Iowa 
The presence of aflatoxin B1 in agricultural soil poses a potential health risk to farmers from exposure to aerosolized soil dust during plowing and cultivation activities. In addition, aflatoxin B1 may constitute a health risk through contamination of surface water or groundwater. The primary purpose of this project is to investigate the presence and concentrations of aflatoxin B1 in Iowa. Supercritical fluid extraction (SFE), flow injection renewable surface immunoassay (FIRSI) with fluorescence detection, and HPLC/ES/MS methods will be developed and used for the determination of aflatoxin B1 and its transformation products in soil. This study will provide needed data to support external funding of a more detailed regional investigation of the fate and potential health risk of aflatoxin B1, as well as potential control and detoxification mechanisms.

Publications:  Selim M, Juchems A, Popendorf W; Assessing Airoborne Aflatoxin B1 during on-farm grain handling activities. American Industrial Hygiene Assocation Journal. 1998; 59(4):252-256

Starr JM, Selim MI; Supercritical fluid extraction of aflatoxin B(1) from soil. J Chromatogr A. 2008; 1209(1-2):37-43

Exploratory studies of an innovative reactor system for the destruction of organic contaminants in water 
Investigator: RL Valentine, Department of Civil and Environmental Engineering, The University of Iowa 
A need exists for improved methods to destroy organic contaminants in drinking water, industrial waste waters, and to remediate contaminated aquifers. Advanced oxidation technologies, which involve the formation of highly reactive hydroxyl radicals, are an emerging class of technologies finding increasing use to treat a variety of these contaminated waters. Application of currently available processes are limited, however, because they require relatively expensive components, have high operating costs, involve complex reactor configurations and process control, and require a relatively high level of training to operate. A need exists for a simple and inexpensive method of oxidizing contaminants using hydroxyl radicals. Recent work at The University of Iowa has resulted in an improved understanding of the reaction mechanism describing hydrogen peroxide decomposition in the presence of iron coated media, and realization of how to possibly exploit this in an innovative fixed-bed reactor system for the destruction of organic contaminants. This project will evaluate the application of this reactor system to oxidize selected contaminants under a variety of reaction conditions, and will gather preliminary design information of use in estimating its capabilities, limitations, and costs.

A geographic information systems approach for assessing the impacts of chemical hazards on vulnerable populations
Investigators: MP Armstrong, J Chakraborty, Department of Geography, The University of Iowa 
Advances in technology have created a multitude of airborne hazards that can affect the health and welfare of the population. Airborne toxic releases occur rapidly and the dispersed hazardous chemicals often present immediate acute health effects. The objective of this research is to develop a practical, workable approach for assessing the population at risk to accidents involving airborne toxic hazards. Methods based on the application of geographic information system (GIS) technology will be developed to achieve this goal. A particular emphasis will be placed on the identification of vulnerable population groups, including institutions (e.g., schools and hospitals) and their relationship to locations of potential hazardous material generation sites. In addition to integrating the key components of hazard analysis, the study will also extend and implement a new approach, known as geographic plume analysis, that accounts for directional biases in the distribution of hazards by using a chemical dispersion model to identify the area that is likely to be exposed to airborne toxic releases. Cedar Rapids, IA, will be used as a test-bed for developing these procedures.

Publication:  Chakraborty J, Armstrong M; Assessing the Impact of Airborne Toxic Releases on Populations with Special Needs. Professional Geographer. 2001; 53(1)

Measuring low level arsenic exposure through drinking water 
Investigator: JB Simeonsson, Department of Chemistry and Center for Global and Regional Environmental Research, The University of Iowa
A major limitation to assessing the health related impact of environmental arsenic (As) is the inadequacy of current analytical methods, especially in regards to providing speciation information of environmental As compounds. The lack of information on speciation is problematic as it is well known that different As species have considerable differences in bioavailability, toxicity and presumably in carcinogenicity. The primary objective of this project is to develop analytical procedures suitable for characterizing and speciating low levels of As in drinking water and biological fluid samples. Ultra sensitive laser induced fluorescence (LIF) approaches will be developed to measure ultra trace levels of As in various sample matrices. These studies will establish the efficacy of the LIF approach and demonstrate its utility for characterizing very low levels of As species in a variety of sample materials.

Publications:  Pacquette HL, Elwood SA, Ezer M, Swart DJ, Simeonsson JB; Hydride generation laser-induced fluorescence of arsenic and selenium in the inductively coupled plasma and electrothermal atomizer. Applied Spectroscopy. 2000; 54(1): 89-93

Swart DJ, Simeonsson JB; Development of an electrothermal atomization laser excited atomic fluorescence spectrometry procedure for direct measurements of arsenic in diluted serum. Analytical Chemistry. 1999; 71(21): 4951-4955

Respiratory health effects of soybean fungal bioaerosols 
Investigators: PS Thorne, CJ Roy, Department of Preventive Medicine and Environmental Health, The University of Iowa 
Exposures to grain dust aerosols in agricultural work environments have been linked to a variety of respiratory diseases, including occupational asthma, chronic bronchitis, and hypersensitivity pneumonitis. Agricultural workers are exposed daily to grain dust through combining, grain handling, mixing of feeds, or grain processing operations. Soybeans, which account for 1/4 of the crop value in Iowa, have been damaged increasingly by Sclerotinia sclerotiorum or "white mold", a fungal pathogen. There has been an increase in health complaints of Iowa soybean farmers following exposure to white mold as the proportion of the soybean crop infected with the mold has increased. Yang (1997) reported a doubling in the extent of white mold infestation since 1995. This project will investigate the respiratory health effects of exposure to S. Sclerotiorum and other soybean bioaerosols through inhalation toxicology studies using established animal models.

Publication:  Roy CJ, Thorne PS; Exposure to particulates, microorganisms, beta(1-3) -glucans, and endotoxins during soybean harvesting. AIHA J (Fairfax, Va.) 2003; 64(4):487-95