CHEEC Seed Grants: FY 1991

Assessment of exposures to bioaerosols in "sick" and "healthy" buildings
PS Thorne, Institute of Agricultural Medicine and Occupational Health, Department of Preventive Medicine and Environmental Health, The University of Iowa

A preliminary survey of Radon222, Radium226, and Radium228 in private well-water supplies in Iowa
RW Field, Department of Preventive Medicine and Environmental Health, KL Cherryholmes, University Hygienic Laboratory, The University of Iowa

Development of a water quality database to assess the factors associated with low birthweight and intrauterine growth retardation
KL Cherryholmes, WJ Hausler, University Hygienic Laboratory: EP Isacson, Department of Preventive Medicine and Environmental Health, The University of Iowa

Building and environmental factors associated with elevated radon levels in rural Iowa homes
L Fuortes, L Weih, Department of Preventive Medicine and Environmental Health, The University of Iowa

Investigation of pesticides and synthetic organic compounds with adverse reproductive outcomes
MD Kramer, CF Lynch, Department of Preventive Medicine and Environmental Health, The University of Iowa

Radon and radium release into drinking water from distribution system deposits
RL Valentine, Department of Civil and Environmental Engineering, The University of Iowa

Development of a database of environmental exposures among infertile couples
K Clark, College of Nursing; EM Smith, L Fuortes, Department of Preventive Medicine and Environmental Health, The University of Iowa

 


Assessment of exposure to bioaerosols in "sick" and "healthy" buildings 
Investigators: PS Thorne, J DeKoster, Institute of Agricultural Medicine and Occupational Health, Department of Preventive Medicine and Environmental Health, The University of Iowa 
This study characterized the levels of bioaerosol contamination of indoor air environments. Significant findings of the study include: 1) Fungi and respirable bacteria concentrations were significantly higher in basements, while CO2 levels were higher on the main floor; 2) Healthy homes had indoor viable fungal concentrations 30 to 50% of the outdoor levels, whereas sick homes had levels over 60%. Strong seasonal effect was seen from measurements of outside fungi but this was not reflected in indoor concentrations; 3) CO2 concentration was not associated with bioaerosol concentration; basement relative humidity was associated with increased airborne fungi; central air conditioning and increased air conditioner use were associated with lower microbial concentrations; lower Penicillium and Aspergillus airborne spores were associated with high efficiency furnace filters; and homes with finished basements had significantly lower microbial concentrations; 4) Tests of association using survey results showed age of occupant and the presence of smokers in the house to be significantly associated with increased self-reported health symptoms, including watery eyes, drowsiness, backaches, muscle/joint pain, indigestion, nausea, and flaky skin; and 5) Methodologies using the Anderson microbial sampler and the Burkard spore sampler demonstrated excellent agreement between theses two methods of air sampling.

Publication:  DeKoster JA, Thorne PS; Bioaerosol Concentrations in Noncomplaint, Complaint, and Intervention Homes in the Midwest. American Industrial Hygienic Association Journal. 1995; 56:573-580

A preliminary survey of radon-222, radium-226, and radium-228 in private well-water supplies in Iowa 
Investigators: RW Field, Department of Preventive Medicine and Environmental Health; KL Cherryholmes, University Hygienic Laboratory, The University of Iowa 
This study represents the first statewide random sampling of private water-borne radon-222 in the nation, and also collected information on radium-226 and radium-228. The health risks of water-borne radon-222 are considered high, and the U.S. EPA has proposed a maximum contaminant level (MCL) of 300 pCi/ L for public water supplies. Study findings include: 1) Participant collected samples at the point-of-use are comparable to samples professionally collected; 2) Fifty-two percent of the wells sampled had waterborne radon-222 concentrations that exceeded the proposed MCL; 3) Radon-222 concentrations in private well-water are slightly higher than groundwater supplies. (This is attributed to a higher percentage of private wells drilled into Pleistocene till which often produce higher waterborne radon-222 concentrations, while public supplies are preferentially drilled into alluvial deposit, which generally contain less radon-222 precursor material); 4) The western part of the state has the highest mean radon-222 well-water concentrations as a result of the large number of wells drilled into the Pleistocene; 5) Radon-222 samples did not vary temporally during the one year collection period; 6) The contribution of well-water derived indoor air radon-222 is minimal compared to subsurface soil and rock radon-222 sources in Iowa; and 7) Well depth, well-water radium-226, well-water radium-228, and indoor screening of radon-222 are all extremely poor predictors of well-water radon-222 concentrations. Additionally, because of the huge variations of waterborne radon-222 concentrations noted for the specific aquifer type, their usefulness as a predictor of waterborne radon-222 concentration is limited.

Publication:  Field RW, Kross BC; Intercomparison of Waterborne radon-222 Collection Methods: Professional Vs. Homeowner Collection. GWMR. 1996; 16:106-112

Development of a water quality database to assess the factors associated with low birth weight (LBW) rates and intrauterine growth retardation (IUGR)
Investigators: KL Cherryholmes, WJ Hausler, University Hygienic Laboratory; EP Isacson, Department of Preventive Medicine and Environmental Health, The University of Iowa. 
In order to investigate possible relationships between exposures to water contaminants and the development of birth defects in the Rathbun Lake area, water samples were collected and analyzed and the results linked to incidence rates of adverse health outcomes by community. The University Hygienic Laboratory collected and analyzed water samples from Rathbun Lake, from the Rathbun Regional Water Association water treatment plant, and from various points along the water distribution system to assess the seasonal fluctuation of herbicides, nutrients, and total coliforms. A database containing the results was developed and utilized by CHEEC researchers to continue assessment of factors affecting LBW and IUGR in communities served by the Rathbun Regional Water Association.

Building and environmental factors associated with elevated radon levels in rural Iowa homes 
Investigators: L Fuortes, L Weih, Department of Preventive Medicine and Environmental Health, The University of Iowa 
The goal of this project was to assess the joint influence of home construction and environmental (soil) characteristics in predicting radon concentration in homes. The first part of this work found the relationship between radon concentration and home construction factors was dependent on location of the radon test in homes. In basements, wall construction and degree of energy efficiency predominated in predicting radon concentration. On upper floors, age of home predominated in predicting radon concentration, with a general decrease in radon concentration with age of home. The second part of the study found texture of the soil on which the home is located was the most important predictor of radon concentration for homes tested in the basements. Precipitation totals in the year preceding the screening test were negatively correlated with radon concentration in homes, but the relationship was only apparent when basement wall type and soil texture was accounted for.

Investigation of pesticides and synthetic organic compounds with adverse reproductive outcomes 
Investigators: MD Kramer, CF Lynch, Department of Preventive Medicine and Environmental Health, The University of Iowa 
The potential reproductive effects of long-term, low-dose exposure to chloroform have received little attention despite the known, acute toxicity of high exposures and the widespread occurrence of low concentrations of chloroform in drinking water. The association of waterborne chloroform was studied with low birth weight, prematurity, and intrauterine growth retardation. Cases were not mutually exclusive, but each outcome was analyzed independently. Exposures to chloroform and other trihalomethanes were ecological variables based on maternal residence and 1987 municipal water survey. After adjustment for maternal age, parity, adequacy of prenatal care, marital status , education, and maternal smoking by multiple logistic regression, residence in municipalities where chloroform concentration in water supplies was 10 ug/liter was associated with an increased risk for intrauterine growth retardation. The major limitations of this study involve the ascertainment and classification of exposures to trihalomethanes, including such issues as the imprecision of using aggregate municipal measures for classifying exposures at the level of the individual, the potential misclassification due to residential mobility, and the fluctuation of trihalomethane levels.

Publication:  Kramer MD, Lynch CF, Isacson P, Hanson JW; The Association of Waterborne Chloroform with Intrauterine Growth Retardation. Epidemiology. 1992; 3(5):407-413

Radon and radium release into drinking water from distribution system deposits
Investigators: RL Valentine, SW Stearns, Department of Civil and Environmental Engineering, The University of Iowa 
The purpose of this study was to determine if evidence of radon formation exists in water distribution systems exposed to radium bearing water. The significance of radium bearing deposits in an actual distribution system depends on a number of factors, including radium content of the pipe deposit, the amount and distribution of pipe deposits, the type of deposits, and the time in which a given water volume is in contact with deposits. The study concludes that radon produced in radium-bearing deposits in the distribution system may cause radon to significantly increase in concentration. Even though the source of the deposit within a distribution system may be small in comparison to a geological source and impact only a very small fraction of the population, the importance must be gauged by the proposed maximum contamination level (MCL) of 300 pCi/L. Radon production within the distribution system may cause radon content to exceed the MCL for some users, even if compliance of the point of entry is achieved. The linkage between radium deposition and radon release may need to be considered in the final EPA radionuclide regulations.

Publication:  Valentine RL, Stearns SW; Formation of Radon from Water Distribution Systems Deposits. ES&T. 1994; 28(3):534-537

Development of a database of environmental exposures among infertile couples 
Investigators: K Clark, College of Nursing; E Smith, L Fuortes Department of Preventive Medicine and Environmental Health, The University of Iowa 
This study developed a database of environmental exposures among infertile couples and identified risk factors for infertility including occupational and chemical exposures, medical, sociodemographic and lifestyle factors. The study was enhanced by enlisting a control group of fertile couples. Crude analysis showed farm exposure was adversely associated with overall and primary infertility, but not secondary infertility. Endometriosis and adjusted age were consistent and adversely associated with all types of infertility. Using step-wise logistical regression procedure and adjusting for all variables, women who reported having lived or worked on a farm for at least 6 months remained at significant increased risk for overall and primary infertility.

Publications:  Fuortes L, Clark K, Kirchner H, Smith EH; Associations Between Female Infertility and Agricultural Work History. American Journal of Industrial Medicine. 1997; 31(4):445-451

Smith E, Hammonds-Ehlers M, Clark K, Kirchner H, Fuortes L; Occupational Exposures and Risk of Female Infertility. Journal of Occupational and Environmental Medicine. 1997; 39(2):138-147