New study below [1]. Not just for Iowans.
There are many risk associations for PCa. Arsenic is just one, & exposure need not be due to pollution.
"Inorganic arsenic is a toxic naturally occurring element in soil and water in many regions of the US including the Midwest."
"As drinking water from groundwater sources is a major source of arsenic exposure, we conducted an ecologic study to evaluate prostate cancer and arsenic in drinking water from public water sources and private wells in Iowa, where exposure levels are low, but duration of exposure can be long.
"County averages of water arsenic levels varied from 1.08 to 18.6 ppb, with three counties above the current 10 ppb limit."
"Based on the tertiles of arsenic levels, counties were divided into three groups":
... low (1.08-2.06 ppb) ... (relative risk [RR] = 1.0)
... medium (2.07-2.98 ppb) ... RR = 1.23
... (2.99-18.6 ppb) ... RR = 1.28
"The RR increased to 1.36 in the high group when analyses were restricted to aggressive prostate cancers (Gleason score ≥ 7)."
"... may suggest that 10 ppb is not protective for human health"
...
Another new study, from Taiwan, [2] shows that risk is more complicated than [1] might suggest. Chemical elements have complex interactions in the body. Supplementation with one essential element can inhibit the effectiveness of another. On the other hand, when exposed to a toxic element, one might need more of an essential element. For example, zinc protects against cadmium, and selenium protects against arsenic.
"We found that plasma selenium levels displayed a significant dose-dependent inverse association with PC."
"participants with a urinary total arsenic concentration >29.28 μg/L had a significantly higher OR (1.75 ...) for PC than participants with ≤29.89 μg/L."
"The combined presence of a low plasma selenium level and a high urinary total arsenic concentration exponentially increased the OR for PC, and additively interacted with PSA at levels ≥20 ng/mL."
-Patrick
[1] ncbi.nlm.nih.gov/pubmed/288...
Environ Res. 2017 Aug 22;159:338-343. doi: 10.1016/j.envres.2017.08.026. [Epub ahead of print]
Low-level arsenic exposure from drinking water is associated with prostate cancer in Iowa.
Roh T1, Lynch CF2, Weyer P3, Wang K4, Kelly KM5, Ludewig G6.
Author information
1
Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, United States.
2
Department of Epidemiology, University of Iowa, Iowa City, IA 52242, United States.
3
Center for Health Effects of Environmental Contamination, University of Iowa, Iowa City, IA 52242, United States.
4
Department of Biostatistics, University of Iowa, Iowa City, IA 52242, United States.
5
Department of Occupational and Environmental Health, University of Iowa, Iowa City, IA 52242, United States.
6
Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, United States; Department of Occupational and Environmental Health, University of Iowa, Iowa City, IA 52242, United States. Electronic address: gabriele-ludewig@uiowa.edu.
Abstract
Inorganic arsenic is a toxic naturally occurring element in soil and water in many regions of the US including the Midwest. Prostate cancer is the second most common type of cancer in men in Iowa, surpassed only by non-melanotic skin cancer. Epidemiology studies have evaluated arsenic exposure from drinking water and prostate cancer, but most have focused on high-level exposures outside the US. As drinking water from groundwater sources is a major source of arsenic exposure, we conducted an ecologic study to evaluate prostate cancer and arsenic in drinking water from public water sources and private wells in Iowa, where exposure levels are low, but duration of exposure can be long. Arsenic data from public water systems were obtained from the Iowa Safe Drinking Water Information System for the years 1994-2003 and for private wells from two Iowa Well Water Studies, the Iowa Community Private Well Study (ICPWS, 2002-2003) and Iowa Statewide Rural Well Water Survey Phase 2 (SWIRL2, 2006-2008) that provided data for 87 Iowa counties. Prostate cancer incidence data from 2009 to 2013 for Iowa were obtained from Surveillance, Epidemiology and End Results' SEER*Stat software. County averages of water arsenic levels varied from 1.08 to 18.6 ppb, with three counties above the current 10 ppb limit. Based on the tertiles of arsenic levels, counties were divided into three groups: low (1.08-2.06 ppb), medium (2.07-2.98 ppb), and high (2.99-18.6 ppb). Spatial Poisson regression modeling was conducted to estimate the risk ratios (RR) of prostate cancer by tertiles of arsenic level at a county level, adjusted for demographic and risk factors. The RR of prostate cancer were 1.23 (95% CI, 1.16-1.30) and 1.28 (95% CI, 1.21-1.35) in the medium and high groups, respectively, compared to the low group after adjusting for risk factors. The RR increased to 1.36 (95% CI, 1.28-1.45) in the high group when analyses were restricted to aggressive prostate cancers (Gleason score ≥ 7). This study shows a significant dose-dependent association between low-level arsenic exposure and prostate cancer, and if this result is replicated in future individual-level studies, may suggest that 10 ppb is not protective for human health.
Copyright © 2017 Elsevier Inc. All rights reserved.
KEYWORDS:
Arsenic; Drinking water; Iowa; Private well water; Prostate cancer
PMID: 28841521 DOI: 10.1016/j.envres.2017.08.026
...
[2] ncbi.nlm.nih.gov/pubmed/286...
Food Chem Toxicol. 2017 Sep;107(Pt A):167-175. doi: 10.1016/j.fct.2017.06.031. Epub 2017 Jun 17.
Levels of plasma selenium and urinary total arsenic interact to affect the risk for prostate cancer.
Hsueh YM1, Su CT2, Shiue HS3, Chen WJ4, Pu YS5, Lin YC6, Tsai CS4, Huang CY7.
Author information
1
Department of Family Medicine, Taipei Medical University Hospital, Taipei, Taiwan; Department of Public Health, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
2
Department of Family Medicine, Taipei Medical University Hospital, Taipei, Taiwan; School of Public Health, College of Public Health, Taipei Medical University, Taipei, Taiwan.
3
Department of Chinese Medicine, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan.
4
School of Public Health, College of Public Health, Taipei Medical University, Taipei, Taiwan.
5
Department of Urology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan.
6
Department of Family Medicine, Shung Ho Hospital, Taipei Medical University, Taipei, Taiwan; Department of Health Examination, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan; Division of Family Medicine, School of Medicine, Taipei Medical University, Taipei, Taiwan.
7
Department of Urology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Urology, National Taiwan University Hospital, Hsin Chu Branch, Hsin Chu City, Taiwan. Electronic address: cyh540909@gmail.com.
Abstract
This study investigated whether plasma selenium levels modified the risk for prostate cancer (PC) related to arsenic exposure. We conducted a case-control study that included 318 PC patients and 318 age-matched, healthy control subjects. Urinary arsenic profiles were examined using HPLC-HG-AAS and plasma selenium levels were measured by ICP-MS. We found that plasma selenium levels displayed a significant dose-dependent inverse association with PC. The odds ratio (OR) and 95% confidence interval (CI) for PC was 0.07 (0.04-0.13) among participants with a plasma selenium level >28.06 μg/dL vs. ≤19.13 μg/dL. A multivariate analysis showed that participants with a urinary total arsenic concentration >29.28 μg/L had a significantly higher OR (1.75, 1.06-2.89) for PC than participants with ≤29.89 μg/L. The combined presence of a low plasma selenium level and a high urinary total arsenic concentration exponentially increased the OR for PC, and additively interacted with PSA at levels ≥20 ng/mL. This is the first epidemiological study to examine the combined effects of plasma selenium and urinary total arsenic levels on the OR for PC. Our data suggest a low plasma selenium level coupled with a high urinary total arsenic concentration creates a significant risk for aggressive PC.
Copyright © 2017 Elsevier Ltd. All rights reserved.
KEYWORDS:
Arsenic; Prostate cancer; Selenium
PMID: 28634111 DOI: 10.1016/j.fct.2017.06.031
