Arsenic in drinking water and prostate cancer in Illinois counties: An ecologic study

Abstract

Background Inorganic arsenic is a lung, bladder, and skin carcinogen. One of the major sources of exposure to arsenic is through naturally contaminated drinking water. While positive associations have been observed between arsenic in drinking water and prostate cancer, few studies have explored this association in the United States. Objectives To evaluate the association between inorganic arsenic concentrations in community water systems and prostate cancer incidence in Illinois using an ecologic study design. Methods Illinois Environmental Protection Agency data on arsenic concentrations in drinking water from community water systems throughout the state were linked with county-level prostate cancer incidence data from 2007 to 2011 from the Illinois State Cancer Registry. Incidence rates were indirectly standardized by age to calculate standardized incidence ratios (SIRs) for each county. A Poisson regression model was used to model the association between county-level SIRs and mean arsenic tertile (0.33 to 0.72, 0.73 to 1.60, and 1.61 to 16.23 ppb), adjusting for potential confounders. Results For counties with mean arsenic levels in the second tertile, the SIR was 1.05 (95% CI: 0.96–1.16). For counties with mean arsenic levels in the third tertile, the SIR was 1.10 (95% CI: 1.03–1.19). There was a significant linear dose-response relationship observed between mean arsenic levels and prostate cancer incidence (p for trend = 0.003). Conclusions In this ecologic study, counties with higher mean arsenic levels in community water systems had significantly higher prostate cancer incidence. Individual-level studies of prostate cancer incidence and low-level arsenic exposure are needed.

Heating Changes Bio-Schwertmannite Microstructure and Arsenic(III) Removal Efficiency

“…The peak at 692 cm −1 and broad absorption peak at 860 cm −1 can be attributed to Fe-O stretching and -O-H deformation [42]. Spectra shown in Figure 2 for heated bio-schwertmannite show that the peaks corresponding to the deformation of H-O-H (at 1635 cm −1 ), -O-H stretching (at 2900-3700 cm −1 ), and -O-H deformation (at 860 cm −1 ), gradually weakened (albeit only slightly) when the heating temperature increased to 350 • C. In addition, the band for structural SO 4 2− also showed a slight weakening trend.…”

“…The maximum arsenic(III) adsorption capacity of bio-schwertmannite was higher than that of other adsorption materials under similar pH conditions, such as 1-4 mg/g for activated alumina [16], 27.1 mg/g for FeCl 3 −based materials [17], 64.2 mg/g for chitosan-functionalized graphene oxide [18], and 15.28 mg/g for calix pyrrole [4,20]. Therefore, the removal arsenic(III) from groundwater or other contaminated water sources using bio-schwertmannite has great commercial value.…”

“…In nature, schwertmannite is commonly found in sulfate-rich environments such as acid sulfate soil or acid mine drainage systems [24][25][26], and is typified by a "hedgehog-like" or "spherical" morphological shape and porous structure [26,27]. In addition, researchers generally accept that the pores in schwertmannite are connected and form tunnels, and that nearly all OH − groups and one-third of the SO 4 2− are adsorbed on the material's surface, with the remaining SO 4 2− located in the tunnel structures [28]. In general, the OH − and SO 4 2− groups on the schwertmannite surface or in tunnel structures can ligand-exchange with arsenic(III) species, a process that determines the arsenic(III) removal efficiency [13,29,30].…”

“…In addition, researchers generally accept that the pores in schwertmannite are connected and form tunnels, and that nearly all OH − groups and one-third of the SO 4 2− are adsorbed on the material's surface, with the remaining SO 4 2− located in the tunnel structures [28]. In general, the OH − and SO 4 2− groups on the schwertmannite surface or in tunnel structures can ligand-exchange with arsenic(III) species, a process that determines the arsenic(III) removal efficiency [13,29,30]. Besides occurring naturally, schwertmannite can be produced by different synthesis techniques through biotic and abiotic methods; these are becoming essential for the treatment of arsenic(III)-contaminated drinking water [15,27].…”

“…Schwertmannite [15], activated alumina [16], FeCl 3 -based materials [17], chitosan-functionalized graphene oxide [18], bismuth impregnated biochar [19], calix [4] pyrrole [20], and other adsorbents have been used for arsenic(III) removal. Schwertmannite, which is a poorly crystalline Fe(III)-oxyhydroxy-sulfate mineral whose chemical formula is Fe 8 O 8 (OH) 8-2x (SO 4 ) x (1 < x < 1.75) [21,22] that acts as a good adsorbent for arsenic(III), has gained increasing attention in recent years [23].…”