CHEEC Seed Grants: FY 1994

The use of vegetation to enhance bioremediation of soils in Iowa contaminated with pesticide wastes 
JR Coats, TA Anderson, Pesticide Toxicology Laboratory, Department of Entomology, Iowa State University

Air quality studies and health assessments of individuals living in the vicinity of swine confinement operations 
KJ Donham, KM Thu, PS Thorne, SJ Reynolds, Institute of Agricultural Medicine and Occupational Health, Department of Preventive Medicine and Occupational Health, The University of Iowa

Synthetic soils from industrial wastes, Phase II: health related analysis of leachates and crops 
L Drake, K Krupp, M Maxwell, Department of Geology, The University of Iowa

Assessment of exposures to bioaerosols among Midwest farmers - effects of flooding 
PS Thorne, N Lynch, J Lange, J DeKoster, Institute of Agricultural Medicine and Occupational Health, Department of Preventive Medicine and Environmental Health, The University of Iowa

Development of a database to accommodate management of exposure and environmental data within a Geographic Information System 
US Tim, Department of Agricultural and Biosystems Engineering, Iowa State University

Exploratory studies of the effects of corrosion control strategies on radium accumulation in distribution system deposits and radon release into drinking water 
RL Valentine, Department of Civil and Environmental Engineering, The University of Iowa

 


The use of vegetation to enhance bioremediation of soils in Iowa contaminated with pesticide wastes 
Investigators: JR Coats, TA Anderson, Pesticide Toxicology Laboratory, Department of Entomology, Iowa State University 
(This is a continuation of a previously CHEEC funded study on pesticide contamination. See FY 1992.) Evidence for enhanced microbial degradation of xenobiotic chemicals in the rhizosphere, a zone of increased microbial activity at the root-soil interface, continue to accrue, suggesting that vegetation may play an important role in facilitating bioremediation of contaminated surface soils. For sites tainted with pesticide wastes, such as at agrochemical dealerships, establishing vegetation may be problematic because of the presence of herbicide mixtures at concentrations several fold above field application rates. Nonetheless, herbicide-tolerant plants exist that can survive in these environments, and they are ideal candidates for testing the influence of rhizosphere microbial communities on the degradation of pesticide waste. Laboratory experiments have tested whether a commodity plant such as soybeans could survive in soil from a pesticide-contaminated site containing a mixture of three predominant herbicides, atrazine, metolachlor, and trifluraline, and if its presence could enhance biodegradation. Although soybean survival in this soil was high, its presence did not enhance the degradation of the chemicals. Tests with nonvegetated soils and rhizosphere soils from Kochia sp., a herbicide-tolerant plant, showed enhanced degradation of these chemicals in rhizosphere soil. Also, Kochia sp. seedlings have emerged from rhizosphere soils spiked with additional concentrations of the three test chemicals, indicating the ability of these plants to survive in soils containing high concentrations of herbicide mixtures.

Publications:  Anderson TA, Kruger EL, Coats JR; Biological Degradation of Pesticide Wastes in the Root Zone of Soils Collected at an Agrochemical Dealership; in Bioremediation through Rhizoshpere Technology. American Chemical Society. 1994; Chapter 16:199-209

Anderson TA, Kruger EL, Coats JR; Rhizosphere Microbial Communities of Herbicide-Tolerant Plants as Potential Bioremedials of Soils Contaminated with Agrochemicals; in Bioremediation of Pollutants in Soil and Water. American Society for Testing and Materials. 1995; 149-157

Anderson TA, Coats JR; Screening Rhizosphere Soil Samples for the Ability to Mineralize Elevated Concentrations of Atrazine and Metolachlor. Journal of Science and Health. 1995; B30(4):473-484

Anderson TA, Kruger EL, Coats JR; Enhanced Degradation of a Mixture of Three Herbicides in the Rhizosphere of a Herbicide-Tolerant Plant. Chemosphere. 1994;28(8):1551-1557

Anderson TA, Coats JR; The Role of the Rhizosphere in Facilitating Biological Degradation of Hazardous Organic Chemicals; in Bioremediation Science and Technology. Soil Society of America 1995

Perkovich BS, Anderson TA, Kruger EL, Coats JR; Enhanced Mineralization of 14C-atrazine in Kochia Scoparia Rhizosphere Soil from a Pesticide-Contaminated Site. Pesticide Science. 1996; 46(4):391-396.

Air Quality studies and health assessments of individuals living in the vicinity of swine confinement operations 
Investigators: KJ Donham, KM Thu, PS Thorne, SJ Reynolds, Institute of Agricultural Medicine and Occupational Health, Department of Preventive Medicine and Environmental Health, The University of Iowa 
This project will provide information on environmental health issues concerning air quality in the vicinity of swine confinement operations in Iowa. The investigation utilizes a questionnaire distributed to residents who live near hog production facilities. The questionnaire measures physical or psychological symptoms associated with nearby hog confinements. Site selection of hog facilities included non-confined hog lots, lagoon/large hog confinements (1000 plus hogs), and medium sized hog confinements with open lagoons. Air samples were taken upwind, downwind, and next to each facility to determine the levels of dust, hydrogen sulfide, and ammonia concentrations present.

Publications:  Thu K, Donham KJ, Ziegenhorn R, Reynolds SJ, Thorne PS, Subramanian P, Whitten W, Stookesberry J; A Control Study of Health and Quality of Life of Residents Living in the Vicinity of Large Scale Swine Production. J. Agri. Health and Safety. 1997; 3(1):13-26

Reynolds SJ, Donham KJ, Stookesberry J, Thorne PS, Subramanian P, Thu K, Whitten P; Air Quality Assessments in the Vicinity of Swine Production Facilities. J. AgroMedicine. 1997; 4:37-45

Subramanian P, Reynolds SJ, Thorne PS, Donham KJ, Stookesberry J, Thu K; Environmental Assessment of Ammonia in Swine Farming Environment by Enzymatic Fluorimetric Method. Intern. J. Environ. Anal. Chem. 1996; 64:301-312

Synthetic soils from industrial wastes, Phase II: Health-related analysis of leachates and crops 
Investigators: L Drake, M Maxwell, Department of Geology, The University of Iowa 
The aims of this study were to determine whether bulk municipal and industrial wastes can be blended to create synthetic soils which are not detrimental to human health and which present minimal risks to groundwater quality and natural ecological systems. Such soils could potentially be used to safely reclaim abandoned strip mines. Eighty different blends of synthetic soil were created, and two types of native soils were used as controls. Four annual species of vegetables were grown in pots outdoors utilizing the different soil blends. Experimental results demonstrated that some of the blends of synthetic soil can support good-to-excellent plant growth compared to native soil controls. Quantitative analysis was done on the fruit produced from the plants to assess total weight and total dry weight of the fruit. A follow-up to the study hopes to assess if the longer term responses of perennials to the synthetic soils is similar to short term annuals. Additionally, the ten most promising soils are being leached and evaluated for heavy metals and other parameters relevant to human health.The project has expanded to field scale test plots in an orphan mine in south-central Iowa with additional funding from a National Mine Land Reclamation Center Grant. Cargill Corporation has also agreed to sponsor the project by providing a field test site, machinery, and operators to implement the projects on a field scale.

Publication:  Ririe GT, Drake LD, Olson SS(1997); Reclamation and groundwater remediation at a hydrocarbon site in Alaska:Petroleum Hydrocarbons and Organic chemicals In Groundwater Conference. A. Stanley, Editor, National Groundwater Assn., 1997; 266-297.

Assessment of exposures to bio-aerosols among Midwest farmers - Effects of flooding
Investigators: P Thorne, N Lynch, J Lange, J DeKoster, Institute of Agricultural Medicine and Occupational Health, Department of Preventive Medicine and Environmental Health, The University of Iowa 
Numerous climatic conditions and individual management aspects potentially effect bioaerosol concentrations in agricultural confinement buildings. The unprecedented flooding and heavy summer rainfall of 63.0 cm during 1993 in the state of Iowa provided the opportunity to compare bioaerosol concentrations in dairy barns that used hay and feed grown under wet conditions with bioaerosol concentrations in dairy barns that used hay and feed grown with a normal rainfall of 25.5 cm. Geometric mean time-weighted average viable bioaerosol concentrations in all 40 stanchion dairy barns sampled with an all-glass impinger (AGI) were 2 x 104 cfu/m3 for yeast, 0.9 x 104 cfu/m3 for molds, 80 x 104 cfu/m3 for mesophilic bacteria, and 0.3 x 104 cfu/m3 for thermophilic bacteria. Microorganism concentrations ranged 2-3 orders of magnitude between different barns. Correlation between the variance in microorganism concentrations and climate at time of sampling, ventilation systems, individual management practices, feed type, bed materials, and barn characteristics was assessed. The proportion of variance in microorganism concentrations associated with these variables, as determined by the squared multiple correlation coefficient ranged from 31% to 45%. Important individual variables that correlated with high bioaerosol concentrations were sampling during the distribution of bedding, the use of low storage moisture feeds, and mixing fan type ventilation. Variables that were correlated with low bioaerosol concentrations were tunnel ventilation and the use of high storage moisture feeds. For the 4 classes of microorganisms studied, no correlation (all p0.20) was found with rainfall. Thus, these data refute the common assumption that in-barn use of hay and feed grown under wet conditions leads to significantly higher bioaerosol concentrations. Additional funding to continue research has been provided by the Center for Disease Control, National Institute of Occupational Safety and Health.

Publications:  Lange JL, Thorne PS, Kullman GJ; Determinants of viable bioaerosol concentrations in dairy barns. Ann. Agric. Environ. Med. 1997; 4:187-194 

Lange JL, Thorne PS, Lynch N; Application of flow cytometry and flourescent in situ hybridization for assessment of exposures to airborne bacteria. Appl. Environ. Microbial. 1997; 63(4):1557-1663

Thorne PS, Lange JL, Bloebaum P, Kullman GJ; Bioaerosol Sampling in Field Studies: Can Samples be Express Mailed? Am. Ind. Hyg. Assoc. 1994; 55:1072-1079

Development of a database to accommodate management of exposure and environmental data within geographic information system 
Investigators: US Tim, Department of Agricultural and Biosystems Engineering, Iowa State University 
A variety of pesticides have been added to the environment to enhance agricultural production and control pests, weeds, and vector-based diseases. The use of pesticides has led to substantial improvements over the past four decades in the quality and variety of the nation's diet. Also, Iowa's economic well being has been enhanced due to the ability to produce crops efficiently, in part due to use of these pesticides. On the negative side, pesticide use in agriculture has led to their detection in drinking water wells in the state. Many of the pesticides are known to be harmful and present health risks. To assess the human health risks posed by pesticides in Iowa's drinking water supplies, information is needed regarding the spatial extent, magnitude of the contamination and exposed population. Much of the available information on pesticide pollution and human health effects is in the form of tabular summaries and spreadsheets. It is important that this information be compiled into a common format in order to make accurate observations and informed decisions. This research project developed a computer-based prototype system, consisting of a database management system and geographic information system, for recording, processing, and displaying spatial, analytical, environmental, and human exposure data collected in Iowa. The various modules of the system allows the user to enter or retrieve data, prepare standard and ad hoc reports, and generate maps for risk analysis and decision making. A prototype was developed and demonstrated, and can be used for environmental health applications.

Publication:  Sunday Tim U; The Application of GIS in Environmental Health Sciences: Opportunities and Limitations. Environmental Research. 1995; 71:75-88

Exploratory studies of the effect corrosion control strategies on radium accumulation in distribution system deposits and radon release into drinking water 
Investigators: RL Valentine, J Jackson, Department of Civil and Environmental Engineering, The University of Iowa 
Strategies used to control lead and copper corrosion often produce insoluble surface coatings on distribution system pipes. Changes in overall water chemistry resulting from treatment alterations could have a major impact on the nature of distribution system deposits. Increased incorporation of radium could occur resulting in an increase in radon in the distribution system. This study explored the incorporation of radium into and radon release from deposit material formed when several corrosion control strategies used in water distribution systems are implemented. Phosphate containing coatings and deposits are a concern because phosphate bearing minerals can accumulate large amounts of radium. Of particular interest is determining the radium content of deposits under experimentally difficult conditions where small amounts of deposits are formed and little radium is actually removed from the water, but where the amount of radium per unit mass of deposits could be very high. Experimental results conclude: 1) Radium activity of pure calcium carbonate was much lower than the solid produced when either iron or zinc phosphate was added. The removal mechanism appears to be surface adsorption; 2) Addition of zinc phosphate greatly reduced the quantity of solids produced in the presence of calcium; 3) Radium removed from water when iron was added with zinc phosphate was significantly greater than that obtained with iron only; 4) Presence of calcium reduced radium removal from solution in the presence of iron and greatly increased the mass of deposit formed when phosphate was no present; 5) Percentage of radium removed from solution using orthophosphate in the presence of iron was approximately the same as that obtained using zinc phosphate at comparable dosages as phosphate; 6) Contrary to what might be expected from a cation sorption mechanism, the radium activity per unit mass of solid actually decreased as the pH increased; and 7) Results indicate zinc phosphate in the presence of 160 mg Ca/L and phosphate significantly increased radium accumulation.

Publications:  Field RW, Fisher EL, Valentine RL, Kross BC; Radium bearing pipe-scale deposits: implications for national waterborne radon sampling methods. American Journal of Public Health. 1995; 85(4):567-570

Fisher EL, Fuortes L, Valetine RL, Mehrroff M, Field RW; Dissolution of 225Radium from pipe-scale deposits in a public water supply. Environment International. 2000; 26(1-2):69-73