CHEEC Seed Grants: FY 1993

Chloramine decomposition product studies 
RL Valentine, M St. Clair, Department of Civil and Environmental Engineering, The University of Iowa

Source of drinking water and cancer incidence in Iowa 
CF Lynch, MD Zhang, D Olson, Department of Preventive Medicine and Environmental Health; PJ Weyer, KD Sesker, CHEEC, The University of Iowa

Comparison of trihalomethanes in residential water using surface source water and indoor air with residential water using source groundwater and indoor air 
SJ May, PA Kostle, GM Breuer, University Hygienic Laboratory, The University of Iowa

A historical cohort study of cancer among urban vs. rural residents and farmers vs. non-farmers in Iowa 
CF Lynch, H Song, Department of Preventive Medicine and Environmental Health, The University of Iowa

A preliminary study of temporal variability of 222Radon in rural community water supplies 
EL Fisher, LJ Fuortes, Department of Preventive Medicine and Environmental Health, The University of Iowa

 


Chloramine decomposition product studies 
Investigators: RL Valentine, M St. Clair, Department of Civil and Environmental Engineering, The University of Iowa 
Monochloramine (NH2Cl) produced from the reaction of free chlorine and ammonia in a process called chloramination, is generally considered to be a leading candidate as an alternative disinfectant to replace free chlorine which is known to produce a variety of potentially mutagenic and carcinogenic organic by-products. However, while chloramination produces fewer organic byproducts, recent work has shown that at least one unidentified inorganic decomposition product is formed. The existence of an unidentified product should be a cause of concern because of potential health effects. This research focus on the characterization, identification, and quantification of the unknown(s) produced in chloraminated drinking water under a variety of reaction conditions. This will be done by 1) conducting detailed mass balances on chlorine and nitrogen, 2) developing methodology to separate and concentrate the unknown(s), and 3) applying mass spectrometry and NMR techniques to characterize structure. Expanded research is being funded by a grant from AWWARF.

Publications:  Ozekin K, Valentine RL, Vikesland PJ; Modeling Chloramine Decay an Natural Waters.American Chemical Society (ACS) Symposium Series 649, Water Disinfection and Natural Organic Matter. 1996; 113-125

Vikesland PJ, Valentine RL, Ozekin K; Application of Product Studies in the Elucidation of Chloramine Reaction Pathways. American Chemical Society (ACS) Symposium Series 649, Water Disinfection and Natural Organic Matter. 1996; 105-114

Vikesland PJ, Ozekin K, Valentine RL; Effect of Natural Organic Matter on Monochloramine Decomposition: Pathway Elucidation Through the Use of Mass and Redox Balances. ES&T. 1998; 32(10):1409-1416

Source of drinking water and cancer incidence in Iowa
Investigators: CF Lynch, M Zhang, D Olsen, Department of Preventive Medicine and Environmental Health; PJ Weyer, KD Sesker, Center for Health Effects of Environmental Contamination, The University of Iowa 
The potential impacts of exposure to various contaminants in drinking water on cancer incidence have been investigated. This study was an ecological investigation as a follow-up to a previous study that looked at incidence rates and time trends of cancer by source of drinking water and size of municipality in Iowa. Cancer incidence ratios for the 16 most common cancers in Iowa were analyzed by size of municipality, by source of drinking water, and by well depth and aquifer for groundwater sources. Time trends were also evaluated. The following results were found: 1) Male and female lung cancers increased as size of community population increased; 2) There is a significantly higher incidence of female lung cancer in towns population 1,000-10,000 using surface water; 3) For communities using groundwater as their source of drinking water, the study found higher rates of lung cancer and total cancers in females in towns with shallow wells compared to towns using deep wells; and 4) Findings show a significant increase in trend over time for lung cancer in both sexes, regardless of water source or well depth, and show a significant increase in the incidence of male bladder cancer in towns with shallow wells, as well as a significant decease in the incidence of several other types of cancer in groundwater communities at various well depths. This study did not support all the findings of previous studies. In the future, this type of analysis will be conducted on a periodic basis, to continue the mission of CHEEC. Technical Report Available.

Comparison of trihalomethanes in residential water using source surface water and indoor air with residential water using source groundwater and indoor air 
Investigators: SJ May, PA Kostle, GM Breuer, University Hygienic Laboratory, The University of Iowa 
The purpose of this study was to assess exposure of four trihalomethanes (THMs-chloroform, dichlorobromomethane, dibromochloromethane, and bromoform) in tap water and indoor air. Measurements of tap water and indoor air during and after showering were taken in residential homes. Houses using private well water (non-chlorinated), public groundwater supply (chlorinated), and public surface water sources (chlorinated) were all evaluated in the study. Water and air samples were collected for each event. THM concentration was taken in the tap water during showering, air samples were collected in the bathroom prior to shower, during showering, and a third air sample was collected in the living room area 30 minutes after showering. Results showed highest THMs in public surface supply, followed by the public groundwater supply. No THMs were detected in the private well water. The public groundwater supply was the only water sampled with all four THMs present. In air samples for the public surface water supply, dibromochloromethane and chloroform were detected. During shower air samples showed an increase in THMs, thus indicating volatilization from the water. In the public groundwater supply, chloroform was the most frequently observed THM. The study reports that while THM concentrations within public groundwater supplies tended be low (5 ppb), THMs were consistently present in the air samples in the living room area. For private wells with no chlorination, THMs were not present in the water, nor were they consistently present in air samples. When there was a positive detection in the air, it was attributed to a running dishwasher in the kitchen that used a detergent containing chlorine bleach. This study shows that showerers are exposed to low levels of THMs in the air during a shower and it may be worthwhile to further quantitate effects of water temperature or bathroom ventilation to be able to recommend ways of minimizing exposure. Technical Report Available.

A historical cohort study of cancer among urban vs. rural residents and farmers vs. non-farmers in Iowa 
Investigators: CF Lynch, H Song, Department of Preventive Medicine and Environmental Health, The University of Iowa 
The aims of this study were to 1) Calculate and analyze "smoking-related" cancer incidence by urban vs. rural residents and farmers vs. non-farmers for 1977-1992; 2) Calculate and analyze incidence rates for the "farming-related" cancers by farmers vs. non-farmers (only males) for 1977-1992, and 3) Evaluate variations between urban and rural residents and farmers and non-farmers in lifestyle (consumption of tobacco and alcohol). Data were used from two previously conducted population-based case-control studies. These studies were "Case-Control Study of Cancer and Drinking Water Contaminants" and "Iowa Portion of the National Collaborative Bladder Cancer Study". Statistically significant findings include: 1) The percentage of current smokers and ex-smokers in urban areas exceeded those in rural areas, males and females in urban areas smoked more cigarettes and consumed more alcohol on a per day basis, and men smoked more and drank more alcohol per day than females; 2) Urban-rural differences of SIR (total observed events in a population/ total expected events in a population) were significant for smoking related cancers as a group, due in part to higher rates of smoking and drinking in urban residents; 3) The risk of smoking-related cancers was significantly greater in non-farmers than in farmers. Completion of this study demonstrated the feasibility of doing a cohort study by linking multiple, distinct, yet complimentary databases. The resulting database is a unique resource for additional studies of cancer. These results have provided preliminary data to support grant proposals to federal agencies to conduct further investigations.

A preliminary study of temporal variable of 222Radon in rural community water supplies 
Investigators: EL Fisher, LJ Fuortes; Department of Preventive Medicine and Environmental Health, The University of Iowa Seasonal and short-term temporal variations of radon suggest that one-time sampling of water supplies may not produce a representative sample of well water. Obtaining concentration levels of water supplies at or near the proposed U.S. EPA Maximum Contaminant Level is complicated by these variations. The aims of this research are to determine temporal variations in 222Radon in community water supplies looking specifically at water use, temperature, precipitation, and barometric pressure; determine the relationship between raw and finished water 222Radon concentrations over time in water supplies where 222Radon in finished water exceeds that in raw water; and propose a sampling scheme which will provide a representative 222Radon water concentration.

Publications:  Fisher EL, Valentine RL, Kross B; Radium-Bearing Pipe Scale Deposits: Implications for National Waterborne Radon Sampling Methodologies. American Journal of Public Health. 1995; 85:567-570

Fisher EL, Valentine RL, Kross B; Occupational Exposure of Water Plant Operators to High Concentrations of radon-222 Gas. Journal of Occupational and Environmental Medicine. 1996; 38(8):759-764

Fisher EL; Temporal and Spatial Variation of Waterborne Point-of-Use radon-222 in Three Water Distribution Systems. Health Physics. 1998; 74(2):242-248