Lab Matters Spring 2024 | Page 7

FROM THE BENCH

By Don Simmons , PhD , manager , Environmental Laboratory , State Hygienic Laboratory at the University of Iowa ; and Michael Schueller , MS , associate director , Environmental Health Division , State Hygienic Laboratory at the University of Iowa

Iowa is well known as an agricultural state , and for its hydrogeological characteristics that increase the potential for groundwater contamination . The total population of Iowa is approximately 3.2 million people ( 2021 USCB ), with about 1.1 million (~ 36 %) residing in rural areas . Many rural residents lack access to municipal water supplies and rely on community or private wells for drinking water . Private wells do not fall under mandated state or national water quality standards , and community wells lack adequate regulations , with far less stringent standards than municipal water supplies .

The biomonitoring program at SHL kicked off in 2019 with three objectives :

1 . Enhance the laboratory capacity for biomonitoring analysis

2 . Develop a state-specific output database that focused on Iowa ’ s rural population exposure

3 . Communicate and educate exposure risks .

Iowa has 99 counties , and the majority are rural counties . Eleven of these counties are participating in the State Hygienic Laboratory at the University of Iowa ( SHL ) biomonitoring program . As of May 31 , 2023 , SHL had recruited and enrolled 1,189 participants from households across those 11 counties . The total population of the participating counties ranges from 8,717 to 105,607 and has a moderate to high density of private wells .

Making Contact with Rural Communities

Originally , county sanitarians were to assist with the recruitment and collection of survey information and specimens . However , due to the COVID-19 pandemic , home visits were not possible because of the risk of exposure to SARS-CoV-2 . The recruitment of participants pivoted to electronic and hard copy formats of engagement . We recruited participants by mail and once a participant registered and completed the eligibility survey , a follow-up phone call was made to determine final eligibility . Eligible participants took a more comprehensive survey and committed to the study . The survey consisted of 180 questions in the categories of general background information , water supply source , geographical area of residence , diet , general health behaviors , occupation , pesticide exposure , personal care product use and tobacco use . Enrollees were limited to one adult participant per household on private well water .

Sample collection kits were mailed to each participant to collect water samples from the spigot of their primary source of drinking water and urine specimens . We achieved a 13.2 % enrollment rate and 85 % sample submission rate by enrollees .

Reporting Results

Water and urine specimens were chilled on ice during transport to the laboratory . Once in the laboratory , water samples were held at 4 ° C until analysis , and urine specimens were frozen at -80 ° C until testing . Test results focused on metals with documented health action levels and included lead , cadmium , arsenic and uranium . Results for private well participants were reported back to the submitter . Results above the established action level were sent to a physician toxicologist for review and discussion with the individuals .

SHL is working on data analysis with biostatisticians from the US Centers for Disease Control and Prevention ( CDC ) and the Department of Epidemiology at the University of Iowa College of Public Health . We have thus far looked at the results of metals in water samples and at unadjusted versus creatinineadjusted metals in urine . We looked at distributions of urine results , both adjusted and unadjusted , relative to NHANES reported numbers from 2017 – 2018 for the adult population .

The results will be shared with the boards of health in the participating counties , and SHL plans to publish the results in the future . This project has been a wonderful opportunity for rural Iowans using private well water to know more about the water that they ingest every day . For those with results above expected levels , they can now be informed about their well water and take remedial action if an unusual result was discovered . g