Household arsenic and acrolein exposures and risk of urothelial cell carcinoma

Abstract

Background: Smoking accounts for about half of bladder cancer cases in the United States; however, the etiology of up to one-third of urothelial cell carcinoma (UCC) remains poorly understood. Acrolein and arsenic are known bladder carcinogens with documented household exposures. Aim: This study aimed to (i) determine whether urinary and household exposures to acrolein and inorganic arsenic (iAs) are higher in newly diagnosed UCC patients than in those with benign urologic disease, (ii) assess whether urinary concentrations reach genotoxic thresholds, and (iii) evaluate how these exposures vary by urbanicity and area deprivation indices. Methods: Patients were recruited from the Urology Clinic at the University of Wisconsin-Madison and provided urine, drinking water, and household dust samples. Results: Acrolein exposures (as its stable metabolite 3-hydroxy-propyl-mercapturic acid) did not differ between cases and controls. Urinary arsenic concentrations were higher in cases than in controls but did not reach statistical significance (p=0.08). Unadjusted urinary iAs concentrations (reflecting urothelial exposures) ranged from 0.01 to 0.71 μM in cases and 0.02 - 0.14 μM in controls (p=0.05). No patients reached genotoxic urinary concentrations of iAs (10 μM) at a single time point. Arsenic concentrations in household dust were higher in UCC (0.42 ng/cm2) compared to control households (0.29 ng/cm2; p=0.007). Dust arsenic levels also correlated with urinary iAs across all patients (r = 0.41; p=0.004). Drinking water arsenic was associated with higher area deprivation percentiles (r = 0.30, p=0.046) and with households from more rural areas (p=0.039) but did not differ significantly between cases and controls. Conclusion: Our data suggest that indoor dust arsenic, rather than arsenic in drinking water, was a likely source of urinary arsenic exposure in this primarily non-smoking population. Relevance for patients: Simple in-home arsenic mitigation strategies, such as using high-efficiency particulate air vacuum cleaners and air filtration units, may help reduce exposure for patients diagnosed with UCC.

Keywords

Bladder cancer / Non-smokers / Household dust / Inorganic arsenic / Drinking water