Milken Institute School of Public Health Poster Presentations (Marvin Center & Video)
Toxic metals in private drinking well water and urinary tract outcomes in North Carolina
Poster Number
48
Document Type
Poster
Status
Postdoc
Abstract Category
Environmental and Occupational Health
Keywords
End stage renal disease; kidney cancer; bladder cancer; private well water; toxic inorganic metals
Publication Date
4-2017
Abstract
We investigated the association between levels of inorganic arsenic, cadmium, lead and manganese in private well water, incidence of bladder and kidney cancer and end stage renal disease [ESRD] prevalence in 100 counties in North Carolina, a state that has among the highest proportion of well water consumption in the country.
Between 1998-2010, samples from private wells across counties were used to determine levels of inorganic arsenic, cadmium, lead and manganese (n=63,836, n=22,915, n=70,675 and n=65,535 measurements, respectively) and geocoded. Bladder and kidney cancer incidence for each county between 1990 and 2011 were obtained from the North Carolina Department of Health and Human Services. Prevalent cases of ESRD overall and subtypes were obtained from the US Renal Data System administrative data for all counties from 1991-2011. Counties with fewer than 11 cases or fewer than 10 well measurements for any metal were excluded from the analysis. County-level data on potential confounders were obtained from US Census Bureau data (2010) and the Behavioral Risk Factor Surveillance Study (2003, 2005). For each analyte, county-level mean concentration was calculated and divided into tertiles. We then used Poisson regression to estimate incidence rate ratio (IRR) for cancer outcomes and prevalence ratio (PR) for ESRD, 95% confidence interval (CI) between exposures and urinary tract outcomes, adjusting for age, gender, race, education, physical activity, smoking, diabetes, hypertension and residential well water supply using counties as the unit of analysis.
Altogether, there were 24,989 kidney cancer and 34,270 bladder cancer cases and 2,76,091 ESRD cases. Elevated IRRs for kidney cancer were observed for both the 2nd tertile (0.60-0.98 ppb: IRR=1.07 (95% CI 1.03, 1.11)) and 3rd tertiles (0.99-11.44 ppb: IRR=1.06 (95% CI 1.01, 1.10)) of inorganic arsenic. For arsenic and ESRD, the 3rd tertile 0.99-11.44 ppb, vs. the 1st tertile (0.50-0.59 ppb), the prevalence risk was observed to be 1.05 (95% CI, 1.04, 1.07) for ESRD overall, and elevated for subtypes: 1.06 (95% CI: 1.03, 1.08) for diabetic nephropathy, 1.46 (95% CI: 1.42, 1.50) for hypertensive nephropathy, and 1.17 (95% CI: 1.13, 1.22) for glomerulonephritis. A dose response was observed for kidney and bladder cancer incidence in manganese exposure but not for ESRD and ESRD subtypes. Higher levels of cadmium and lead moderately increased the incidence risk of bladder cancer only.
The conclusions are limited by the ecological approach, but the consistency of the associations suggests that the influence of metals, especially inorganic arsenic in private well water, on urinary tract outcomes deserves additional investigation.
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Open Access
1
Toxic metals in private drinking well water and urinary tract outcomes in North Carolina
We investigated the association between levels of inorganic arsenic, cadmium, lead and manganese in private well water, incidence of bladder and kidney cancer and end stage renal disease [ESRD] prevalence in 100 counties in North Carolina, a state that has among the highest proportion of well water consumption in the country.
Between 1998-2010, samples from private wells across counties were used to determine levels of inorganic arsenic, cadmium, lead and manganese (n=63,836, n=22,915, n=70,675 and n=65,535 measurements, respectively) and geocoded. Bladder and kidney cancer incidence for each county between 1990 and 2011 were obtained from the North Carolina Department of Health and Human Services. Prevalent cases of ESRD overall and subtypes were obtained from the US Renal Data System administrative data for all counties from 1991-2011. Counties with fewer than 11 cases or fewer than 10 well measurements for any metal were excluded from the analysis. County-level data on potential confounders were obtained from US Census Bureau data (2010) and the Behavioral Risk Factor Surveillance Study (2003, 2005). For each analyte, county-level mean concentration was calculated and divided into tertiles. We then used Poisson regression to estimate incidence rate ratio (IRR) for cancer outcomes and prevalence ratio (PR) for ESRD, 95% confidence interval (CI) between exposures and urinary tract outcomes, adjusting for age, gender, race, education, physical activity, smoking, diabetes, hypertension and residential well water supply using counties as the unit of analysis.
Altogether, there were 24,989 kidney cancer and 34,270 bladder cancer cases and 2,76,091 ESRD cases. Elevated IRRs for kidney cancer were observed for both the 2nd tertile (0.60-0.98 ppb: IRR=1.07 (95% CI 1.03, 1.11)) and 3rd tertiles (0.99-11.44 ppb: IRR=1.06 (95% CI 1.01, 1.10)) of inorganic arsenic. For arsenic and ESRD, the 3rd tertile 0.99-11.44 ppb, vs. the 1st tertile (0.50-0.59 ppb), the prevalence risk was observed to be 1.05 (95% CI, 1.04, 1.07) for ESRD overall, and elevated for subtypes: 1.06 (95% CI: 1.03, 1.08) for diabetic nephropathy, 1.46 (95% CI: 1.42, 1.50) for hypertensive nephropathy, and 1.17 (95% CI: 1.13, 1.22) for glomerulonephritis. A dose response was observed for kidney and bladder cancer incidence in manganese exposure but not for ESRD and ESRD subtypes. Higher levels of cadmium and lead moderately increased the incidence risk of bladder cancer only.
The conclusions are limited by the ecological approach, but the consistency of the associations suggests that the influence of metals, especially inorganic arsenic in private well water, on urinary tract outcomes deserves additional investigation.
Comments
Poster to be presented at GW Research Days 2017.