Lung cancer and arsenic concentrations in drinking water in Chile

Dietary exposure to arsenic and human health risks in western Tibet

The health effects of drinking water exposure to inorganic arsenic are well known but are less well defined for dietary exposure. The rising concerns of arsenic risks from diet motivated this study of arsenic concentrations in highland barley, vegetables, meat, and dairy products to evaluate arsenic exposure source and to assess health risks among rural residents of Ngari area, western Tibet. Total arsenic and arsenic speciation were measured by inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography combined with ICP-MS (HPLC-ICP-MS) respectively. Average total arsenic concentrations of 0.18 ± 0.21 (n = 45, median: 0.07 mg·kg^-1), 0.40 ± 0.57 (n = 17, median: 0.15 mg·kg^-1), 0.21 ± 0.16 (n = 12, median: 0.17 mg·kg^-1), and 0.18 ± 0.08 (n = 11, median: 0.22 mg·kg^-1) were observed in highland barley, vegetables, meat, and dairy products, respectively. Inorganic arsenic was determined to be the main species of arsenic in highland barley, accounting for about 64.4 to 99.3% (average 83.3%) of total arsenic. Nearly half (44.4%) of the local residents had ingested >3.0 × 10^-4 mg·kg^-1·d^-1 daily dose of arsenic from highland barley alone, above the maximum oral reference dose recommended by the United States Environmental Protection Agency (USEPA). The inorganic arsenic daily intake from highland barley was 3.6 × 10^-4 mg·kg^-1·d^-1. Dietary exposure to inorganic arsenic alone increased the cancer risk probability to 5.4 in 10,000, assuming that the inorganic arsenic in highland barley has the same carcinogenic effects as that in water.

Chronic and acute arsenic exposure enhance EGFR expression via distinct molecular mechanisms

The impacts of acute arsenic exposure (i.e. vomiting, diarrhea, and renal failure) are distinct from those brought about by sustained, low level exposure from environmental sources or drinking of contaminated well water. Chronic arsenic exposure is a risk factor for the development of pulmonary diseases, including lung cancer. How arsenic exposure leads to pulmonary disease is not fully understood. Both acute versus chronic arsenic exposure increase EGFR expression, but do so via distinct molecular mechanisms. BEAS-2B cells were exposed to either acute sodium arsenite (5 μM for 24 h) or chronic sodium arsenite (100 nM for 24 weeks). Cells treated with acute arsenic exhibited a decrease in viability, changes in morphology, and increased mRNA level of BTC. In contrast, during 24 weeks of arsenic exposure, the cells had increased EGFR expression and activity, and increased mRNA and protein levels of TGFα. Further, chronic arsenic treatment caused an increase in cell migration in the absence of exogenous ligand. Elevated TGFα and EGFR expression are features of many non-small cell lung cancers. We propose that lung epithelial cells chronically exposed to low level arsenic increases EGFR signaling via TGFα production to enhance ligand-independent cell migration.

Cytotoxicity Assessment of Gallium- and Indium-Based Nanoparticles Toward Human Bronchial Epithelial Cells Using an Impedance-Based Real-Time Cell Analyzer

The semiconductor manufacturing sector plans to introduce III/V film structures (eg, gallium arsenide (GaAs), indium arsenide (InAs) onto silicon wafers due to their high electron mobility and low power consumption. Aqueous solutions generated during chemical and mechanical planarization of silicon wafers can contain a mixture of metal oxide nanoparticles (NPs) and soluble indium, gallium, and arsenic. In this work, the cytotoxicity induced by Ga- and In-based NPs (GaAs, InAs, Ga₂O₃, In₂O₃) and soluble III-V salts on human bronchial epithelial cells (16HBE14o-) was evaluated using a cell impedance real-time cell analysis (RTCA) system. The RTCA system provided inhibition data at different concentrations for multiple time points, for example, GaAs (25 mg/L) caused 60% inhibition after 8 hours of exposure and 100% growth inhibition after 24 hours. Direct testing of As(III) and As(V) demonstrated significant cytotoxicity with 50% growth inhibition concentrations after 16-hour exposure (IC₅₀) of 2.4 and 4.5 mg/L, respectively. Cell signaling with rapid rise and decrease in signal was unique to arsenic cytotoxicity, a precursor of strong cytotoxicity over the longer term. In contrast with arsenic, soluble gallium(III) and indium(III) were less toxic. Whereas the oxide NPs caused low cytotoxicity, the arsenide compounds were highly inhibitory (IC₅₀ of GaAs and InAs = 6.2 and 68 mg/L, respectively). Dissolution experiments over 7 days revealed that arsenic was fully leached from GaAs NPs, whereas only 10% of the arsenic was leached out of InAs NPs. These results indicate that the cytotoxicity of GaAs and InAs NPs is largely due to the dissolution of toxic arsenic species.

Molecular Mechanisms of Arsenic-Induced Disruption of DNA Repair

Exposure to arsenic in contaminated drinking water is an emerging public health problem that impacts more than 200 million people worldwide. Accumulating lines of evidence from epidemiological studies revealed that chronic exposure to arsenic can result in various human diseases including cancer, type 2 diabetes, and neurodegenerative disorders. Arsenic is also classified as a Group I human carcinogen. In this review, we survey extensively different modes of action for arsenic-induced carcinogenesis, with focus being placed on arsenic-mediated impairment of DNA repair pathways. Inorganic arsenic can be bioactivated by methylation, and the ensuing products are highly genotoxic. Bioactivation of arsenicals also elicits the production of reactive oxygen and nitrogen species (ROS and RNS), which can directly damage DNA and modify cysteine residues in proteins. Results from recent studies suggest zinc finger proteins as crucial molecular targets for direct binding to As3+ or for modifications by arsenic-induced ROS/RNS, which may constitute a common mechanism underlying arsenic-induced perturbations of DNA repair.

Arsenic exposure is associated with significant upper tract urothelial carcinoma health care needs and elevated mortality rates

PURPOSE

The aim of the study was to assess upper tract urothelial carcinoma (UTUC) health care needs and specific mortality rates in an arsenic-exposed region in Northern Chile and compare them to those of the rest of the country.

MATERIAL AND METHODS

Arsenic levels of drinking water were correlated with UTUC hospital discharges and cancer-specific mortality rates. Mortality and hospital admission rate ratios were estimated using a Poisson regression model.

RESULTS

There were 257 UTUC-specific deaths in Chile between 1990 and 2016; 81 (34%) of them occurred in Antofagasta, where only 3.5% of the population lives. The peak mortality rate observed in Antofagasta was 2.15/100,000 compared to 0.07/100,000 in the rest of the country. Mortality in the exposed region was significantly higher when compared to the rest of the country (MRR 17.6; 95%CI: 13.5-22.9). The same trend was observed for UTUC hospital discharges (RR 14.8; 95%CI: 11.5-19.1).

CONCLUSION

Even stronger than for bladder cancer, exposure to arsenic is related to a significant need for UTUC health care and high mortality rates, even 25 years after having controlled arsenic levels in drinking-water. Awareness of this ecologic factor in these affected regions is therefore mandatory.

Arsenic Toxicity: Molecular Targets and Therapeutic Agents

High arsenic (As) levels in food and drinking water, or under some occupational conditions, can precipitate chronic toxicity and in some cases cancer. Millions of people are exposed to unacceptable amounts of As through drinking water and food. Highly exposed individuals may develop acute, subacute, or chronic signs of poisoning, characterized by skin lesions, cardiovascular symptoms, and in some cases, multi-organ failure. Inorganic arsenite(III) and organic arsenicals with the general formula R-As²⁺ are bound tightly to thiol groups, particularly to vicinal dithiols such as dihydrolipoic acid (DHLA), which together with some seleno-enzymes constitute vulnerable targets for the toxic action of As. In addition, R-As²⁺-compounds have even higher affinity to selenol groups, e.g., in thioredoxin reductase that also possesses a thiol group vicinal to the selenol. Inhibition of this and other ROS scavenging seleno-enzymes explain the oxidative stress associated with arsenic poisoning. The development of chelating agents, such as the dithiols BAL (dimercaptopropanol), DMPS (dimercapto-propanesulfonate) and DMSA (dimercaptosuccinic acid), took advantage of the fact that As had high affinity towards vicinal dithiols. Primary prevention by reducing exposure of the millions of people exposed to unacceptable As levels should be the prioritized strategy. However, in acute and subacute and even some cases with chronic As poisonings chelation treatment with therapeutic dithiols, in particular DMPS appears promising as regards alleviation of symptoms. In acute cases, initial treatment with BAL combined with DMPS should be considered.

Circulating Arsenic is Associated with Long-Term Risk of Graft Failure in Kidney Transplant Recipients: A Prospective Cohort Study

Arsenic is toxic to many organ systems, the kidney being the most sensitive target organ. We aimed to investigate whether, in kidney transplant recipients (KTRs), the nephrotoxic exposure to arsenic could represent an overlooked hazard for graft survival. We performed a prospective cohort study of 665 KTRs with a functional graft ≥1 year, recruited in a university setting (2008‒2011), in The Netherlands. Plasma arsenic was measured by ICP-MS, and dietary intake was comprehensively assessed using a validated 177-item food-frequency questionnaire. The endpoint graft failure was defined as restart of dialysis or re-transplantation. Median arsenic concentration was 1.26 (IQR, 1.04‒2.04) µg/L. In backwards linear regression analyses we found that fish consumption (std β = 0.26; p < 0.001) was the major independent determinant of plasma arsenic. During 5 years of follow-up, 72 KTRs developed graft failure. In Cox proportional-hazards regression analyses, we found that arsenic was associated with increased risk of graft failure (HR 1.80; 95% CI 1.28-2.53; p = 0.001). This association remained materially unaltered after adjustment for donor and recipient characteristics, immunosuppressive therapy, eGFR, primary renal disease, and proteinuria. In conclusion, in KTRs, plasma arsenic is independently associated with increased risk of late graft failure.

Arsenic reduction to <1 µg/L in Dutch drinking water

Arsenic (As) is a highly toxic element which naturally occurs in drinking water. In spite of substantial evidence on the association between many illnesses and chronic consumption of As, there is still a considerable uncertainty about the health risks due to low As concentrations in drinking water. In the Netherlands, drinking water companies aim to supply water with As concentration of <1 μg/L - a water quality goal which is tenfold more stringent than the current WHO guideline. This paper provides (i) an account on the assessed lung cancer risk for the Dutch population due to pertinent low-level As in drinking water and cost-comparison between health care provision and As removal from water, (ii) an overview of As occurrence and mobility in drinking water sources and water treatment systems in the Netherlands and (iii) insights into As removal methods that have been employed or under investigation to achieve As reduction to <1 µg/L at Dutch water treatment plants. Lowering of the average As concentration to <1μg/L in the Netherlands is shown to result in an annual benefit of 7.2-14 M€. This study has a global significance for setting drinking water As limits and provision of safe drinking water.

An integrated study of health, environmental and socioeconomic indicators in a mining-impacted community exposed to metal enrichment

The occurrence of toxic metals and metalloids associated with mine tailings is a serious public health concern for communities living in mining areas. This work explores the relationship between metal occurrence (e.g., spatial distribution in street dusts), human health indicators (e.g., metals in urine samples, lifestyle and self-reported diseases) and socioeconomic status (SES) using Chañaral city (in northern Chile) as study site, where a copper mine tailing was disposed in the periurban area. This study model may shed light on the development of environmental and health surveillance plans on arid cities where legacy mining is a sustainability challenge. High concentrations of metals were found in street dust, with arsenic and copper concentrations of 24 ± 13 and 607 ± 911 mg/kg, respectively. The arsenic concentration in street dust correlated with distance to the mine tailing (r = - 0.32, p-value = 0.009), suggesting that arsenic is dispersed from this source toward the city. Despite these high environmental concentrations, urinary levels of metals were low, while 90% of the population had concentrations of inorganic arsenic and its metabolites in urine below 33.2 µg/L, copper was detected in few urine samples (< 6%). Our results detected statistically significant differences in environmental exposures across SES, but, surprisingly, there was no significant correlation between urinary levels of metals and SES. Despite this, future assessment and control strategies in follow-up research or surveillance programs should consider environmental and urinary concentrations and SES as indicators of environmental exposure to metals in mining communities.

Metabolic and epigenetic reprogramming in the arsenic-induced cancer stem cells

At present, the belief that genetic mutations control every aspect of tumorigenesis is still very popular. Even for the highly debated "bad luck" theory of cancers, it ascertained that random mutation of genes during the self-renewal of somatic stem cells is responsible for cancer initiation. Logically, most of the new therapeutic strategies so far, from molecular targeting to precision medicine or personalized medicine, are genome-obsessed and focused on identifying and targeting these mutated genes. Accordingly, a rather simplified therapeutic regimen was formulated: cancers with the same mutations, e.g., lung cancer, pancreatic cancer, breast cancer, ovarian cancer, etc, were managed with the same chemo or targeting medicine, whereas for a particular cancer, such as breast cancer or lung cancer, with different mutational spectrums was treated with different, so-called personalized medicine. The outcomes of this strategy, however, are mixed with encouraging and disappointing findings. In this review article, we will address the importance of non-genetic factors, the metabolic and epigenetic reprogramming, during the induction of cancer stem cells in response to arsenic, a major environmental human carcinogen. The information provided may not only advance our understanding of carcinogenic mechanism to a new level but also help in designing new strategies through targeting the metabolic and epigenetic signaling pathways for cancer therapy.

Low-Level Exposure to Arsenic in Drinking Water and Risk of Lung and Bladder Cancer: A Systematic Review and Dose-Response Meta-Analysis

BACKGROUND

Exposure to high levels of arsenic in drinking water has been associated with an increased risk of lung and bladder cancer, but the presence of an increased risk at low levels is questionable.

METHODS

A systematic review and a dose-response meta-analysis were conducted on risk estimates of lung and bladder cancer for exposure to arsenic in drinking water up to 150 µg/L, using a 2-stage approach based on a random-effects model.

RESULTS

Five studies of lung cancer were identified; the meta-relative risk (RR) for an increase of 10 µg/L arsenic level was 1.03 (95% confidence interval [CI]: 0.99-1.06; P heterogeneity = .05). The meta-analysis of bladder cancer included 8 studies; the meta-RR for an increase of 10 µg/L arsenic level was 1.02 (95% CI: 0.97-1.07, P heterogeneity = .01). Sensitivity analyses, including a 1-stage meta-regression, confirmed the main findings.

CONCLUSION

This systematic review and meta-analysis provided evidence of a lack of an increased risk of lung and bladder cancer for exposure to arsenic in drinking water up to 150 µg/L, the highest concentration studied.

A Simple and Label-Free Detection of As3+ using 3-nitro-L-tyrosine as an As3+-chelating Ligand

A simple and rapid As³⁺ detection method using 3-nitro-L-tyrosine (N-Tyr) is reported. We discovered the specific property of N-Tyr, which specifically chelates As³⁺. The reaction between As³⁺ and N-Tyr induces a prompt color change to vivid yellow, concomitantly increasing the absorbance at 430 nm. The selectivity for As³⁺ is confirmed by competitive binding experiments with various metal ions (Hg²⁺, Pb²⁺, Cd²⁺, Cr³⁺, Mg²⁺, Ni²⁺, Cu²⁺, Fe²⁺, Ca²⁺, Zn²⁺, and Mn²⁺). Also, the N-Tyr binding site, binding affinity, and As³⁺/N-Tyr reaction stoichiometry are investigated. The specific reaction is utilized to design a sensor that enables the quantitative detection of As³⁺ in the 0.1-100 μM range with good linearity (R² = 0.995). Furthermore, the method's applicability for the analysis of real samples, e.g., tap and river water, is successfully confirmed, with good recoveries (94.32-109.15%) using As³⁺-spiked real water samples. We believe that our discovering and its application for As³⁺ analysis can be effectively utilized in environmental analyses such as those conducted in water management facilities, with simplicity, rapidity, and ease.

A Meta-analysis of Arsenic Exposure and Lung Function: Is There Evidence of Restrictive or Obstructive Lung Disease?

PURPOSE OF REVIEW

Hundreds of millions of people worldwide are exposed to arsenic via contaminated water. The goal of this study was to identify whether arsenic-associated lung function deficits resemble obstructive- or restrictive-like lung disease, in order to help illuminate a mechanistic pathway and identify at-risk populations.

RECENT FINDINGS

We recently published a qualitative systematic review outlining the body of research on arsenic and non-malignant respiratory outcomes. Evidence from several populations, at different life stages, and at different levels of exposure showed consistent associations of arsenic exposure with chronic lung disease mortality, respiratory symptoms, and lower lung function levels. The published review, however, only conducted a broad qualitative description of the published studies without considering specific spirometry patterns, without conducting a meta-analysis, and without evaluating the dose-response relationship. We searched PubMed and Embase for studies on environmental arsenic exposure and lung function. We performed a meta-analysis using inverse-variance-weighted random effects models to summarize adjusted effect estimates for arsenic and forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), and FEV₁/FVC ratio. Across nine studies, median water arsenic levels ranged from 23 to 860 μg/L. The pooled estimated mean difference (MD) comparing the highest category of arsenic exposure (ranging from > 11 to > 800 μg/L) versus the lowest (ranging from < 10 to < 100 μg/L) for each study for FEV₁ was - 42 mL (95% confidence interval (CI) - 70, - 16) and for FVC was - 50 mL (95% CI - 63, - 37). Three studies reported effect estimates for FEV₁/FVC, for which there was no evidence of an association; the pooled estimated MD was 0.01 (95% CI - 0.005, 0.024). This review supports that arsenic is associated with restrictive impairments based on inverse associations between arsenic and FEV₁ and FVC, but not with FEV₁/FVC. Future studies should confirm whether low-level arsenic exposure is a restrictive lung disease risk factor in order to identify at-risk populations in the USA.

Towards a dietary-exposome assessment of chemicals in food: An update on the chronic health risks for the European consumer

An informed opinion to a hugely important question, whether the food on the Europeans' plate is safe to eat, is provided. Today, the Europeans face food-borne health risks from non-communicable diseases induced by excess body weight, outbreaks caused by pathogens, antimicrobial resistance and exposures to chemical contaminants. In this review, these risks are first put in an order of importance. Then, not only potentially injurious dietary chemicals are discussed but also beneficial factors of the food. This review can be regarded as an attempt towards a dietary-exposome evaluation of the chemicals, the average European adult consumers could chronically expose to during their life-times. Risk ranking reveals that currently the European adults are chronically exposed to a mixture of potentially genotoxic-carcinogenic contaminants, particularly food process contaminants, at the potential risk levels. Furthermore, several of the contaminants whose dietary exposures pose risks appear to be carcinogens operating with a genotoxic mode of action targeting the liver. This suggests that combined health risks from the exposure to a mixture of the chemical contaminants poses a greater potential risk than the risks assessed for single compounds. Over 100 European-level risk assessments are examined. Finally, the importance of a diversified and balanced diet is emphasized.

Socioeconomic status and the association between arsenic exposure and type 2 diabetes

OBJECTIVE

Evaluate whether arsenic-related diabetes risks differ between people of low and high socioeconomic status (SES).

METHODS

We used data collected between October 2007-December 2010 from a population-based cancer case-control study (N = 1301) in Northern Chile, an area with high arsenic water concentrations (>800 µg/L) and comprehensive records of past exposure. Information on lifetime exposure and potential confounders were obtained using structured interviews, questionnaires, and residential histories. Type 2 diabetes was defined as physician-diagnosed diabetes or oral hypoglycemic medication use. SES was measured using a 14-point scale based on ownership of household appliances, cars, internet access, or use of domestic help. Logistic regression was used to assess the relationship between arsenic and diabetes within strata of SES.

RESULTS

Among those with low SES, the odds ratio (OR) for diabetes comparing individuals in the highest to lowest tertile of lifetime average arsenic exposure was 2.12 (95% confidence interval (CI) 1.29-3.49, p = 0.004). However, those in the high SES group were not at increased risk (OR = 1.12 [95% CI = 0.72-1.73]).

CONCLUSIONS

Our findings provide evidence that risks of arsenic-related diabetes may be higher in Chile in people with low versus high SES.

Natural resource extraction and mortality in the United States

This article further develops the literature on the local consequences of natural resource extraction by using newly collected county data from 1964 to 1988 to capture both short- and long-term mortality effects. The article identifies the net impact on mortality and provides evidence that throughout the majority of its distribution, increases in extractive industry activity are associated with small decreases in total and cancer mortality on a year-to-year basis. However, increases in extractive activity are associated with net increases in county-level total, cancer, and infant mortality in the long run, and at very high levels of activity, and are strongly impacted by coal mining activity. Additional analysis is required regarding the short- and long-run mechanisms, but the paper provides preliminary evidence that extractive activity and local community pollution are positively related.

Oncogenic role of arsenic exposure in lung cancer: A forgotten risk factor

Several drinkable water sources worldwide have been highly contaminated with arsenic, which means that an estimated 160 million people have been exposed to this chemical agent. If we analyse exposure by region, we will find a high correlation between arsenic contamination and the incidence of lung cancer (among other malignancies). In order to determine what the risks of these exposures are, we need to understand how this chemical is processed in our body and how it is linked to cancer. In this article we reviewed how biotransformation of ingested arsenic may lead to cancer by modulating the activation of several essential signalling pathways such as EGFR, PI3K/AKT, RTK/Ras/PI3K, JNK/STAT3 and Nrf2-KEAP1; by producing epigenetics modifications and by disrupting normal expression of miRNAs. In order to design effective health policies, educational strategies, decontaminations plans and effective medical treatments are necessary to understand the impact of arsenic pollution and the relevance of the environment in our health.

Association between skin lesion and arsenic concentration in hair by mixed bivariate model in chronic arsenic exposure

Skin lesion is one of the important health hazards caused by high intake of arsenic through drinking water and diet, and the other hazards include several types of cancers (viz. skin, lung and urinary bladder), ischemic heart disease, hypertension, etc. Two most important biomarkers to measure arsenic intake in a human body are arsenic concentration in urine and hair. The primary interest of this paper is the association between skin lesion and arsenic concentration in hair for participants with chronic arsenic exposure from West Bengal, India, using bivariate regression model based on copula function. The result showed participants with high arsenic concentration in hair had higher incidence of developing skin lesion. Arsenic concentration in hair was significantly higher for the participants with an arsenic concentration in water > 10 mg/L.

Cancers related to lifestyle and environmental factors in France in 2015

BACKGROUND

Cancer is a major cause of premature illness and death in France. To quantify how cancer prevention could reduce the burden, we present estimates of the contribution of lifestyle and environmental risk factors to cancer incidence in France in 2015, comparing these with other high-income countries.

METHOD

Prevalences of, and relative risks for tobacco smoking, alcohol consumption, inadequate diet, overweight and obesity, physical inactivity, exogenous hormones, suboptimal breastfeeding, infectious agents, ionising radiation, air pollution, ultraviolet exposure, occupational exposures, arsenic in drinking water and indoor benzene were obtained to estimate the population attributable fraction (PAF) and the number of attributable cancers by the cancer site and sex.

RESULTS

In 2015, 41% (or 142,000 of 346,000) of all new cancers diagnosed in France could be attributed to the aforementioned risk factors. The numbers and PAF were slightly higher in men than in women (84,000 versus 58,000 cases and 44% versus 37%, respectively). Smoking (PAF: 20%), alcohol consumption (PAF: 8%), dietary factors (PAF: 5%) and excess weight (PAF: 5%) were the most important factors. Infections and occupational exposures each contributed to an additional 4% of the cancer cases in 2015.

CONCLUSION

Today, two-fifths of cancers in France are attributable to preventable risk factors. The variations in the key amenable factors responsible in France relative to other economically similar countries highlight the need for tailored approaches to cancer education and prevention. Reducing smoking and alcohol consumption and the adoption of healthier diet and body weight remain important targets to reduce the increasing number of new cancer patients in France in the decades to follow.

Obesity and increased susceptibility to arsenic-related type 2 diabetes in Northern Chile

BACKGROUND

The prevalence of type 2 diabetes (T2D) has nearly doubled since 1980. Elevated body mass index (BMI) is the leading risk factor for T2D, mediated by inflammation and oxidative stress. Arsenic shares similar pathogenic processes, and may contribute to hyperglycemia and β-cell dysfunction.

OBJECTIVES

We assessed a unique situation of individuals living in Northern Chile with data on lifetime arsenic exposure to evaluate the relationship between arsenic and T2D, and investigate possible interactions with BMI.

METHODS

We analyzed data collected from October 2007-December 2010 from an arsenic-cancer case-control study. Information on self-reported weight, height, smoking, diet, and other factors were obtained. Diabetes was defined by self-reported physician-diagnoses or use of hypoglycemic medication. A total of 1053 individuals, 234 diabetics and 819 without known diabetes were included.

RESULTS

The T2D odds ratio (OR) for cumulative arsenic exposures of 610-5279 and ≥ 5280 μg/L-years occurring 40 years or more before interview were 0.97 (95% CI: 0.66-1.43) and 1.53 (95% CI: 1.05-2.23), respectively. Arsenic-associated T2D ORs were greater in subjects with increased BMIs. For example, the ORs for past cumulative exposures ≥ 5280 μg/L-years was 1.45 (95% CI: 0.74-2.84) in participants with BMIs < 25 kg/m² but 2.64 (95% CI: 1.14-6.11) in those with BMIs ≥ 30 kg/m² (synergy index = 2.49, 95% CI: 0.87-7.09). Results were similar when people with cancer were excluded.

CONCLUSIONS

These findings identify increased odds of T2D with arsenic exposure, which are significantly increased in individuals with excess BMI.

Age at Exposure to Arsenic in Water and Mortality 30-40 Years After Exposure Cessation

Arsenic in drinking water is known to cause cancer and noncancer diseases, but little is known about its association with age at exposure. Here, we investigated age at arsenic exposure and mortality in Antofagasta, Chile, 30-40 years after a distinct period of very high water arsenic concentrations (1958-1970). We calculated standardized mortality ratios (SMRs) comparing Antofagasta with the rest of Chile for 2001-2010 by sex and age at potential first exposure. A remarkable relationship with age at first exposure was found for bronchiectasis, with increased risk in adults 30-40 years after exposure being confined to those who were in utero (SMR = 11.7, 95% confidence interval (CI): 4.3, 25.4) or aged 1-10 years (SMR = 5.4, 95% CI: 1.1, 15.8) during the high-exposure period. Increased SMRs for lung, bladder, and laryngeal cancer were evident for exposures starting at all ages, but the highest SMRs were for exposures beginning at birth (for bladder cancer, SMR = 16.0 (95% CI: 10.3, 23.8); for laryngeal cancer, SMR = 6.8 (95% CI: 2.2, 15.8); for lung cancer, SMR = 3.8 (95% CI: 2.9, 4.9)). These findings suggest that interventions targeting early-life arsenic exposure could have major impacts in reducing long-term mortality due to arsenic 30-40 years after exposure ends.

Taurine Ameliorates Arsenic-Induced Apoptosis in the Hippocampus of Mice Through Intrinsic Pathway

Our group previously reported that arsenic (As) exposure induced apoptosis in hippocampus neurons. The aim of the present study was to clarify the protective capacity of taurine (Tau) on As-induced neuronal apoptosis and the related mechanism in mouse hippocampus. Mice were divided into: control group, Tau control group, As exposure group and Tau protective group, randomly. The apoptotic rate of mouse hippocampus was determined by TUNEL staining. The levels of Bcl-2 and Bax gene and protein were analyzed by real time RT-PCR and WB, respectively. Furthermore, cytochrome c (Cyt C) release, and the activity of caspase-8 and caspase-3 were also determined. The results showed that Tau treatment induced the decrease of TUNEL-positive cells, prohibited the disturbance of Bcl-2 and Bax expression, and inhibited Cyt C release and caspase-8 and caspase-3 activation significantly. The results indicated that Tau supplement markedly ameliorates As-induced apoptosis by mitochondria-related pathway in mouse hippocampus.

Association between lung cancer risk and inorganic arsenic concentration in drinking water: a dose-response meta-analysis

High dose arsenic in drinking water (≥100 μg L^-1) is known to induce lung cancer, but lung cancer risks at low to moderate arsenic levels and its dose-response relationship remains inconclusive. We conducted a systematic review of cohort and case-control studies that quantitatively reported the association between arsenic concentrations in drinking water and lung cancer risks by searching the PubMed database till June 14, 2018. Pooled relative risks (RRs) of lung cancer associated with full range (10 μg L^-1-1000 μg L^-1) and low to moderate range (<100 μg L^-1) of water arsenic concentrations were calculated using random-effects models. A dose-response meta-analysis was performed to estimate the pooled associations between restricted cubic splines of log-transformed water arsenic and the lung cancer risks. Fifteen studies (9 case-control and 6 cohort studies) involving a total of 218 481 participants met the inclusion criteria. Meta-analysis identified significantly increased risks of lung cancer on exposure to both full range (RR = 1.21; 95% confidence interval [CI] = 1.05-1.37; heterogeneity I ² = 54.3%) and low to moderate range (RR = 1.18; 95%CI = 1.00-1.35; I ² = 56.3%) of arsenic-containing water. In the dose-response meta-analysis of eight case-control studies, we found no evidence of non-linearity, although statistical power was limited. The corresponding pooled RRs and their 95%CIs for exposure to 10 μg L^-1, 50 μg L^-1, and 100 μg L^-1 water arsenic were 1.02 (1.00-1.03), 1.10 (1.04-1.15), and 1.20 (1.08-1.32), respectively. We provide evidence on the association between increased lung cancer risks and inorganic arsenic in drinking water across low, moderate and high levels. Minimizing arsenic levels in drinking water may be of public health importance.

A review on arsenic carcinogenesis: Epidemiology, metabolism, genotoxicity and epigenetic changes

Long-term exposure to arsenic (inorganic arsenic) is a world-wide environmental health concern. Arsenic is classified as the Group 1 human carcinogen by the International Agency for Research on Cancer (IARC). Epidemiological studies have established a strong association between inorganic arsenic (iAs) exposure in drinking water and an increased incidence of cancer including bladder, liver, lung, prostate, and skin cancer. iAs also increases the risk of other diseases such as cardiovascular disease, hypertension and diabetes. The molecular mechanisms of carcinogenesis of iAs remain poorly defined, several mechanisms have been proposed, including genotoxicity, altered cell proliferation, oxidative stress, changes to the epigenome, disturbances of signal transduction pathways, cytotoxicity and regenerative proliferation. In this article, we will summarize current knowledge on the mechanisms of arsenic carcinogenesis and focus on integrating all these issues to garner a broader perspective.

Health effects among a cohort exposed to low-level arsenic in a geothermal area of Tuscany, Italy

BACKGROUND

Studies on low-level As exposure have not found an association with cancer, while increased risks were reported for skin lesions, respiratory and cardiovascular diseases and reproductive outcomes. Prospective observational studies with individual exposure measures are needed to study low-level As exposure effects. In a geothermal area in Southern Tuscany (Italy), characterized by a natural presence of As in drinking water (< 50 µg/l), As urinary concentrations were measured in a survey in 1998 and cohort members were followed to evaluate the effects on health.

METHODS

Around 900 subjects (20-55 years old) randomly sampled in 4 municipalities of the area (Monte Amiata), have been followed from 1999 to 2015, by hospitalisation and mortality registries. Standardized Hospitalisation Ratios (SHRs) were performed, compared to a reference area. Competing-risks regression models were performed to test the association between As urinary concentration and risk of first hospitalisation.

RESULTS

SHRs show various increased risks, more frequently among males. Internal analyses show a positive association between As and skin diseases in the general population, the Hazard Ratio (HR) for 1 µg/l increase of As urinary concentration is 1.06 (90%CI 1.01-1.11) and in males, HR 1.08 (90%CI 1.02-1.14), between As and circulatory system diseases in males, HR 1.03 (90%CI 1.01-1.05).

CONCLUSIONS

The results suggest an effect on skin diseases and circulatory system diseases and, considering the relative young age of cohort members, they could be considered also as predictive of future severer diseases.

Cerium dioxide (CeO2) nanoparticles decrease arsenite (As(III)) cytotoxicity to 16HBE14o- human bronchial epithelial cells

The production and application of engineered nanoparticles (NPs) are increasing in demand with the rapid development of nanotechnology. However, there are concerns that some of these novel materials could lead to emerging environmental and health problems. Some NPs are able to facilitate the transport of contaminants into cells/organisms via a "Trojan Horse" effect which enhances the toxicity of the adsorbed materials. In this work, we evaluated the toxicity of arsenite (As(III)) adsorbed onto cerium dioxide (CeO2) NPs to human bronchial epithelial cells (16HBE14o-) using the xCELLigence real time cell analyzing system (RTCA). Application of 0.5 mg/L As(III) resulted in 81.3% reduction of cell index (CI, an RTCA measure of cell toxicity) over 48 h when compared to control cells exposed to medium lacking As(III). However, when the cells were exposed to 0.5 mg/L As(III) in the presence of CeO2 NPs (250 mg/L), the CI was only reduced by 12.9% compared to the control. The CeO2 NPs had a high capacity for As(III) adsorption (20.2 mg/g CeO2) in the bioassay medium, effectively reducing dissolved As(III) in the aqueous solution and resulting in reduced toxicity. Transmission electron microscopy was used to study the transport of CeO2 NPs into 16HBE14o- cells. NP uptake via engulfment was observed and the internalized NPs accumulated in vesicles. The results demonstrate that dissolved As(III) in the aqueous solution was the decisive factor controlling As(III) toxicity of 16HBE14o- cells, and that CeO2 NPs effectively reduced available As(III) through adsorption. These data emphasize the evaluation of mixtures when assaying toxicity.

ABCA1 Is Coordinated with ABCB1 in the Arsenic-Resistance of Human Cells

Arsenic is one of the most widespread global environmental toxicants associated with endemic poisoning. ATP-binding cassette (ABC) proteins are transmembrane channels that transport and dispose of lipids and metabolic products across the plasma membrane. The majority of ABC family members (including ABCB1 and ABCC1) are reported to play a role in the development of arsenic and drug resistance in mammals. Previously, we established a human arsenic-resistant ECV-304 (AsRE) cell line and identified ABCA1 as a novel arsenic resistance gene. In the current study, we further investigated the potential contribution of ABCA1, ABCB1, and ABCC1 to arsenic resistance through measurement of survival rates and arsenic accumulation in AsRE cells with RNA interference. The arsenic resistance capacity of ABCC1 was the strongest among the three genes, while those of ABCA1 and ABCB1 were similar. Double or triple gene knockdown of ABCA1, ABCB1, and ABCC1 via RNA interference led to a decrease significant in arsenic resistance when ABCA1/ABCB1 or ABCB1/ABCC1 were simultaneously silenced. Interestingly, no differences were evident between cells with ABCA1/ABCC1 and ABCC1 only knockdown. Our findings suggest that ABCA1 and ABCB1 proteins display similar arsenic resistance capabilities and possibly coordinate to promote arsenic resistance in AsRE cells.

Lung, Bladder, and Kidney Cancer Mortality 40 Years After Arsenic Exposure Reduction

Background

Region II in northern Chile (population 442 570) experienced a sudden major increase in arsenic water concentrations in 1958 in the main city of Antofagasta, followed by a major reduction in exposure when an arsenic removal plant was installed in 1970. It provides a unique opportunity to study latency effects of exposure to arsenic, and this is the first study with mortality data up to 40 years after exposure reduction.

Methods

We previously identified high mortality rates in Region II up to the year 2000. Here we present rate ratios (RRs) for Region II compared with all the rest of Chile from 2001 to 2010, and with unexposed Region V (population 1 539 852) for all years from 1950 to 2010. All statistical tests were one-sided.

Results

From 2001 to 2010, comparing Region II with the rest of Chile, lung and bladder mortality were still greatly elevated (RR = 3.38, 95% confidence interval [CI] = 3.19 to 3.58, P < .001 for lung cancer in men; RR = 2.41, 95% CI = 2.20 to 2.64, P < .001 for lung cancer in women; RR = 4.79, 95% CI = 4.20 to 5.46, P < .001 for bladder cancer in men; RR = 6.43, 95% CI = 5.49 to 7.54, P < .001 for bladder cancer in women). Kidney cancer mortality was also elevated (RR = 1.75, 95% CI = 1.49 to 2.05, P < .001 for men; RR = 2.09, 95% CI = 1.69 to 2.57, P < .001 for women). Earlier short latency acute myocardial infarction mortality increases had subsided.

Conclusions

Lung, bladder, and kidney cancer mortality due to arsenic exposure have very long latencies, with increased risks manifesting 40 years after exposure reduction. Our findings suggest that arsenic in drinking water may involve one of the longest cancer latencies for a human carcinogen.

Immunotherapy in Lung Cancer: A New Age in Cancer Treatment

The management of Non-Small Cell Lung Cancer (NSCLC) has changed dramatically in the last 10 years with an increase in the understanding of the biology and with the development of new and multiple treatments. Chemotherapy being the first systemic treatment used in the setting of advanced disease, proving benefit for patients over palliative care. With the identification of oncogenic drivers, innovative targeted therapies were developed and tested, leading to important changes in the management of certain patients and giving to some of them the possibility to be treated in first line with oral inhibitors. Immunotherapy was then explored as a potential option, with promising results, and data of impact in important endpoints in lung cancer treatments. This chapter explores the different CTLA-4 inhibitors that have been investigated in NSCLC: ipilimumab and tremelimumab, as well as the different immune checkpoint inhibitors: anti PD-1 (nivolumab and pembrolizumab) and PD-L1 (atezolizumab, durvalumab, avelumab, BMS-936559) medications. It also analyzes the different studies that have been developed for NSCLC with these medications, the evidence obtained, and the possible role in the management of patients. Immunotherapy has definitely changed the paradigm on NSCLC treatment, and the future is promising for the benefit of patients.

Recent views of heavy metals as possible risk factors and potential preventive and therapeutic agents in prostate cancer

Prostate cancer is the most common cancer in men in many industrialized countries. A role for androgens in prostate tumor progression is well recognized, while estrogens may cooperate with androgens in prostate carcinogenesis. The incidence of prostate cancer is highly variable in the different countries, suggesting an important role of environmental factors. Heavy metals are common environmental contaminants and some of them are confirmed or suspected human carcinogens. Some metals are endowed with estrogenic and/or androgenic activities and may play a role as cancer risk factors through this mechanism. Moreover, prostate cancer may present alterations in the intracellular balance of trace metals, such as zinc and copper, which are involved in several regulatory proteins. Herein, we review the possible role of environmental heavy metals and of metal-dyshomeostasis in prostate cancer development and promotion as well as the potential use of some metals in the prevention and therapy of prostate cancer.

Quantification of health risks in Ecuadorian population due to dietary ingestion of arsenic in rice

In Ecuador alone, 500,000 people in rural areas are estimated to have been exposed to high concentrations of As from water and food, but no quantitative evaluation of health risk has yet been made. The present study quantifies exposure and health risk for the Ecuadorian population from the ingestion of arsenic in white rice. Estimated exposure is correlated with published data on tap water quality and biomarkers of exposure for the population of two towns in the metropolitan area of Quito. Estimated daily intake (EDI) of arsenic for infants living in urban areas of Ecuador is around four times that of European infants, being equal for those livings in rural areas. EDI for the population as a whole is almost twice that of Europe, but between a half and a third of that of Brazil, Bangladesh, and India. Estimated excess lifetime risk (ELTR) for adults is 3 per 10,000, while for infants varies between 10 per 10,000 in rural areas and 20 per 10,000 in urban areas. Future research on arsenic impacts on human health in Ecuador should consider in particular poor populations living in regions where environmental arsenic concentrations are highest, including cross-sectional and longitudinal epidemiologic studies.

Investigation of Health Effects According to the Exposure of Low Concentration Arsenic Contaminated Ground Water

Recent epidemiological studies have reported adverse health effects, including skin cancer, due to low concentrations of arsenic via drinking water. We conducted a study to assess whether low arsenic contaminated ground water affected health of the residents who consumed it. For precise biomonitoring results, the inorganic (trivalent arsenite (As III) and pentavalent arsenate (As V)) and organic forms (monomethylarsonate (MMA) and dimethylarsinate (DMA)) of arsenic were separately quantified by combining high-performance liquid chromatography and inductively coupled plasma mass spectroscopy from urine samples. In conclusion, urinary As III, As V, MMA, and hair arsenic concentrations were significantly higher in residents who consumed arsenic contaminated ground water than control participants who consumed tap water. But, most health screening results did not show a statistically significant difference between exposed and control subjects. We presume that the elevated arsenic concentrations may not be sufficient to cause detectable health effects. Consumption of arsenic contaminated ground water could result in elevated urinary organic and inorganic arsenic concentrations. We recommend immediate discontinuation of ground water supply in this area for the safety of the residents.

Cyclin D1 promoter -56 and -54bp CpG un-methylation predicts invasive progression in arsenic-induced Bowen's disease

BACKGROUND

Patients with arsenic-induced Bowen's disease (As-BD) are at risk of developing invasive cancers in the skin, lung, and urinary bladder. However, a longitudinal follow-up study on the association between As-BD and invasive cancers is still lacking.

OBJECTIVES

This study aims to investigate the underlying molecular mechanisms of this malignant progression in the skin and internal organs.

METHODS

This is a biopsy-based follow-up study. We tested the DNA histograms, Cyclin D1 (CCND1) protein expression and CCND1 promoter DNA methylation in 40 pathologically confirmed specimens from As-BD patients to correlate with individual's invasive cancer occurrence in the 5-year follow-up.

RESULTS

Flow cytometric DNA histogram analysis of skin specimens showed aneuploid (n=15), G2/M arrest (n=22), and normal (n=3) DNA histograms. No patients with normal DNA histograms developed invasive cancers, whereas 13 developed invasive cancers in the aneuploid group and 2 developed invasive cancers in the G2/M arrest group. The aneuploid group showed a high risk of invasive cancer development. In all assessed aneuploid specimens, the CCND1 promoter hypomethylation was observed. Statistically, percentage of un-methylation more than 55.85% among 17 detected CpG sites showed extremely high predictive power in the occurrence of invasive arsenical cancers. Furthermore, the un-methylation at -56 and -54bp CpG sites was statistically significantly associated with invasive arsenical cancer development (p=1.29×10^-5).

CONCLUSIONS

As-BD lesions showing an aneuploid DNA histogram had a high risk of invasive cancer development. Un-methyaltion at -56 and -54bp CpG in the CCND1 promoter serves as a predictor for invasive progression in As-BD patients.

Low-level arsenic exposure during pregnancy and its association with postpartum depression: A cohort study of women from Arica, Chile

BACKGROUND

While the relationship between inorganic arsenic exposure and psychological impairment has been studied previously, the association between low-level arsenic exposure during pregnancy and postpartum depression has not yet been examined. The objective is to estimate the association between low-level arsenic exposure during pregnancy and the Edinburgh score.

METHODS

A sample of 223 women was collected from five public health services in Arica, Chile. Participation was voluntary and written consent was mandatory. Sociodemographic data related to arsenic exposure and urine samples for total inorganic arsenic assessments were collected during the second trimester. Postpartum depression symptoms were estimated by the Edinburgh Postpartum Depression scale. We examined descriptive statistics and ran multiple linear regressions. The modifying effect of age and depression history was evaluated separately.

RESULTS

The median for total urinary inorganic arsenic was 14.6μg/L (range: 2-69.2μg/L), the median for postpartum depression score was 8 points (range: 0-27 points) and 20.6% of women were considered as postpartum depressed. For women older than 25years old without depression history, the adjusted coefficient for the total urinary natural logarithm of inorganic arsenic in multiple linear regressions was -2.51 (95% CI: -4.54, -0.48; P-value=0.02). For women older than 25years old with a depression history, this value was 2.09 (95% CI: -0.90, 5.08; P-value=0.16).

CONCLUSIONS

In this cohort, the number of children, physical perception, depression history, stressful maternity, and age were associated with postpartum depression score. The Edinburgh score was associated with inorganic arsenic in women older than 25years without depression history.

Assessment of some potential harmful trace elements (PHTEs) in the borehole water of Greater Giyani, Limpopo Province, South Africa: possible implications for human health

The present investigation was conducted in order to evaluate the occurrence and distribution patterns of some potentially harmful trace elements in the borehole water of the Greater Giyani area, Limpopo, South Africa, and their possible implications on human health. Twenty-nine borehole water samples were collected in the dry season (July/August 2012) and another 27 samples from the same localities in the wet season (March 2013) from the study area. The samples were analysed for trace elements arsenic (As), cadmium (Cd), chromium (Cr), selenium (Se), and lead (Pb) using the inductively coupled plasma mass spectrometry technique. The average concentrations of As, Cd, Cr, Se, and Pb were 11.3, 0.3, 33.1, 7.1, and 6.0 µg/L in the dry season and 11.0, 0.3, 28.3, 4.2, and 6.6 µg/L in the wet season, respectively. There was evidence of seasonal fluctuations in concentrations of all analysed elements except for As, though Cd and Pb displayed low concentrations (<0.2 and <6.0 µg/L, respectively) in almost all sampled boreholes. Se and Cr concentrations slightly exceed the South African National Standard permissible limits for safe drinking water in few boreholes. A total of four boreholes exceeded the water quality guideline for As with two of these boreholes containing five times more As than the prescribed limit. The spatial distribution patterns of elevated As closely correlate with the underlying geology. The findings of this investigation have important implications for human health of the communities drinking from the affected boreholes.

The impact of BMI on non-malignant respiratory symptoms and lung function in arsenic exposed adults of Northern Chile

BACKGROUND

Elevated body mass index (BMI) and arsenic are both associated with cancer and with non-malignant lung disease. Using a unique exposure situation in Northern Chile with data on lifetime arsenic exposure, we previously identified the first evidence of an interaction between arsenic and BMI for the development of lung cancer.

OBJECTIVES

We examined whether there was an interaction between arsenic and BMI for the development of non-malignant lung disease.

METHODS

Data on lifetime arsenic exposure, respiratory symptoms, spirometry, BMI, and smoking were collected from 751 participants from cities in Northern Chile with varying levels of arsenic water concentrations. Spirometry values and respiratory symptoms were compared across subjects in different categories of arsenic exposure and BMI.

RESULTS

Adults with both a BMI above the 90th percentile (>33.9kg/m²) and arsenic water concentrations ≥11µg/L exhibited high odds ratios (ORs) for cough (OR = 10.7, 95% confidence interval (CI): 3.03, 50.1), shortness of breath (OR = 14.2, 95% CI: 4.79, 52.4), wheeze (OR = 14.4, 95% CI: 4.80, 53.7), and the combined presence of any respiratory symptom (OR = 9.82, 95% CI: 4.22, 24.5). In subjects with lower BMIs, respiratory symptom ORs for arsenic water concentrations ≥11µg/L were markedly lower. In never-smokers, reductions in forced vital capacity associated with arsenic increased as BMI increased. Analysis of the FEV₁/FVC ratio in never-smokers significantly increased as BMI and arsenic concentrations increased. Similar trends were not observed for FEV₁ alone or in ever-smokers.

CONCLUSIONS

This study provides preliminary evidence that BMI may increase the risk for arsenic-related non-malignant respiratory disease.

Arsenic and breast cancer: a systematic review of epidemiologic studies

INTRODUCTION

Arsenic is one of the heavy metals known to be a cause of cancer and many other serious human health problems. The International Agency for Research on Cancer (IARC), has classified arsenic as a Group 1 carcinogen. Studies were performed in different populations to investigate the association between arsenic and breast cancer and the present paper attempts to review these studies.

METHODS AND MATERIALS

Accessible electronic resources including, PubMed, Web of Knowledge, Science Direct and Scopus and Google Scholar were searched, with relevant phrases up to October 30, 2016. All articles were reviewed by two people separately and among them, original epidemiologic studies that investigated the association between breast cancer and exposure to arsenic were included.

RESULTS

Eventually seven articles were selected from 126 retrieved articles. Although three studies (one case-control and two ecological) were not able to show a significant affect, others provide some evidence of a relation between arsenic and breast cancer in specific subgroups.

CONCLUSION

Exposure to arsenic may increase the risk of breast cancer. The strength of this relation can vary due to regional and individual differences.

Biological effects and epidemiological consequences of arsenic exposure, and reagents that can ameliorate arsenic damage in vivo

Through contaminated diet, water, and other forms of environmental exposure, arsenic affects human health. There are many U.S. and worldwide "hot spots" where the arsenic level in public water exceeds the maximum exposure limit. The biological effects of chronic arsenic exposure include generation of reactive oxygen species (ROS), leading to oxidative stress and DNA damage, epigenetic DNA modification, induction of genomic instability, and inflammation and immunomodulation, all of which can initiate carcinogenesis. High arsenic exposure is epidemiologically associated with skin, lung, bladder, liver, kidney and pancreatic cancer, and cardiovascular, neuronal, and other diseases. This review briefly summarizes the biological effects of arsenic exposure and epidemiological cancer studies worldwide, and provides an overview for emerging rodent-based studies of reagents that can ameliorate the effects of arsenic exposure in vivo. These reagents may be translated to human populations for disease prevention. We propose the importance of developing a biomarker-based precision prevention approach for the health issues associated with arsenic exposure that affects millions of people worldwide.

Relationships between arsenic concentrations in drinking water and lung and bladder cancer incidence in U.S. counties

Increased risks of lung and bladder cancer have been observed in populations exposed to high levels of inorganic arsenic. However, studies at lower exposures (i.e., less than 100 μg/l in water) have shown inconsistent results. We therefore conducted an ecological analysis of the association between historical drinking water arsenic concentrations and lung and bladder cancer incidence in U.S. counties. We used drinking water arsenic concentrations measured by the U.S. Geological Survey and state agencies in the 1980s and 1990s as proxies for historical exposures in counties where public groundwater systems and private wells are important sources of drinking water. Relationships between arsenic levels and cancer incidence in 2006-2010 were explored by Poisson regression analyses, adjusted for groundwater dependence and important demographic covariates. The median and 95th percentile county mean arsenic concentrations were 1.5 and 15.4 μg/l, respectively. Water arsenic concentrations were significant and positively associated with female and male bladder cancer, and with female lung cancer. Our findings support an association between low water arsenic concentrations and lung and bladder cancer incidence in the United States. However, the limitations of the ecological study design suggest caution in interpreting these results.

Occurrence and Distribution of Arsenic, Antimony and Selenium in Shallow Groundwater Systems of Ibadan Metropolis, Southwestern Nigerian

BACKGROUND

Arsenic, antimony and selenium contamination of groundwater is of great concern due to the potential detrimental effects to human health.

OBJECTIVES

This study investigates the occurrence and distribution of arsenic, antimony and selenium in the shallow groundwater system of Ibadan metropolis, southwestern Nigeria.

METHODS

A total of 210 groundwater samples were collected from 35 shallow wells (3.15-7.86 m) within the residential, commercial, industrial and agricultural areas of the metropolis during the dry and wet seasons. The average daily dose intake (ADD), hazard quotient (HQ) and hazard index (HI) of arsenic, antimony and selenium exposure in groundwater were calculated from these four studied areas for children and adults.

RESULTS

Average concentrations of arsenic, antimony and selenium in groundwater ranged between 2.17±3.49 to 33.8±37.2 μg/L, 13.5±15.0 to 33.2±36.8 μg/L and 7.33±6.22 to 46.3±22.4 μg/L, respectively. A corresponding analysis relay plot showed the order of occurrence of these trace metals in groundwater to be antimony>selenium>arsenic. The principal component analysis biplot showed that arsenic, antimony and selenium were fairly distributed in all of the study areas, suggesting the influence of geogenic factors. A total of 74.3% of sampling locations had antimony levels slightly above the World Health Organization (WHO) safe limit of 20 μg/L. Statistical t testing (0.05 confidence limit) showed a significant difference in seasonal levels of groundwater antimony concentration, with the dry season recording significantly higher levels with 100% of samples exceeding WHO safe limits. The chemical of highest potential human health concern is antimony, with a non-carcinogenic HQ risk factor >2 for both age groups. The overall non-carcinogenic HI was highest in the commercial area, 4.1989 for adults and 5.2487 for children.

CONCLUSIONS

Antimony in groundwater within the Ibadan metropolis raises health concerns and a concerted effort is needed to identify its sources to avoid the risk of antimony toxicity.

Mitigating dietary arsenic exposure: Current status in the United States and recommendations for an improved path forward

Inorganic arsenic (iAs) is a well-characterized carcinogen, and recent epidemiologic studies have linked chronic exposures to non-cancer health outcomes, including cardiovascular disease, diabetes, skin lesions and respiratory disorders. Greater vulnerability has been demonstrated with early life exposure for health effects including lung and bladder cancer, immunotoxicity and neurodevelopment. Despite its well-known toxicity, there are important gaps in the regulatory oversight of iAs in food and in risk communication. This paper focuses on the US regulatory framework in relation to iAs in food and beverages. The state of existing regulatory agency toxicological assessments, monitoring efforts, standard setting, intervention policies and risk communication are explored. Regarding the approach for standard setting, risk-based evaluations of iAs in particular foods can be informative but are insufficient to create a numeric criterion, given current uncertainties in iAs toxicology and the degree to which traditional risk targets can be exceeded by dietary exposures. We describe a process for prioritizing dietary exposures for different lifestages and recommend a relative source contribution-based approach to setting criteria for arsenic in prioritized foods. Intervention strategies begin with an appropriately set criterion and a monitoring program that documents the degree to which this target is met for a particular food. This approach will promote improvements in food production to lower iAs contamination for those foods which initially do not meet the criterion. Risk communication improvements are recommended to ensure that the public has reliable information regarding sources and alternative dietary choices. A key recommendation is the consideration of meal frequency advice similar to what is currently done for contaminants in fish. Recent action level determinations by FDA for apple juice and infant rice cereal are evaluated and used as illustrations of how our recommended approach can further the goal of exposure mitigation from key sources of dietary iAs in the US.

Hypertension among adults exposed to drinking water arsenic in Northern Chile

BACKGROUND

A growing number of studies have identified an association between exposure to inorganic arsenic and hypertension. However, results have not been consistent across studies. Additional studies are warranted, given the global prevalence of both arsenic exposure and morbidity attributable to hypertension.

METHODS

We analyzed data collected from October 2007-December 2010 for a population-based cancer case-control study in northern Chile. Data included lifetime individual arsenic exposure estimates and information on potential confounders for a total of 1266 subjects. Those self-reporting either a physician diagnosis of hypertension or use of an anti-hypertensive medication were classified as having hypertension (n=612). The association between hypertension and drinking water arsenic exposure was analyzed using logistic regression models.

RESULTS

Compared to those in the lowest category for lifetime highest 5-year average arsenic exposure (<60µg/L), those in the middle (60-623μg/L) and upper (>623μg/L) exposure categories had adjusted hypertension ORs of 1.49 (95% CI: 1.09, 2.05) and 1.65 (95% CI: 1.18, 2.32), respectively. Similar results were observed in analyses of lifetime cumulative exposures and analyses restricted to exposures from the distant past.

CONCLUSIONS

We identified evidence of increased odds of hypertension with exposure to arsenic in drinking water among study participants. Our findings add to the growing body of research supporting this association, which could have important public health implications.

Assessment of arsenic, fluoride, bacteria, and other contaminants in drinking water sources for rural communities of Kasur and other districts in Punjab, Pakistan

High levels of arsenic contamination in drinking water of two villages, Badarpur and Ibrahimabad of district Kasur, central Punjab, Pakistan is reported first time in present studies. Groundwater quality situation was found to be impaired when samples of different rural areas of district Kasur were monitored according to Pakistan Standards and Quality Control Authority (PSQCA) for all significant water quality constituents and analyzed for trace elements, physico-chemical, and microbiological parameters. Out of 35water sources, 97 % were found unsafe and only 3 % of the sources were within safe limits. High concentrations of arsenic, fluoride, and bacteria were found in 91, 74, and 77 % sources of drinking water, respectively. Very high concentrations of arsenic ranging 58-3800 μg/L were found in the water samples obtained from Badarpur and Ibrahimabad. A decrease in water contamination was observed with increase in source depth. The health issues like arsenicosis and skeletal/dental flourosis were observed in the residents of the monitored areas. Drinking water quality conditions of some rural areas of northen and southern districts of Punjab was also analyzed and compared with Kasur district. High levels of nitrates were found in the samples of Islamabad and Rawalpindi, while high levels of arsenic, iron, fluoride, and TDS were found in Bahawalpur district. Graphical abstract ᅟ.

Immunotherapy in NSCLC: A Promising and Revolutionary Weapon

Lung cancer is the leader malignancy worldwide accounting 1.5 millions of deaths every year. In the United States the 5 year-overall survival is less than 20% for all the newly diagnosed patients. Cisplatin-based cytotoxic chemotherapy for unresectable or metastatic NSCLC patients in the first line of treatment, and docetaxel in the second line, have achieved positive results but with limited benefit in overall survival. Targeted therapies for EGFR and ALK mutant patients have showed better results when compared with chemotherapy, nevertheless most of patients will fail and need to be treated with chemotherapy if they still have a good performance status.Immunotherapy recently has become the most revolutionary treatment in solid tumors patients. First results in unresectable and metastatic melanoma patients treated with an anti CTLA-4 monoclonal antibody showed an unexpected 3-year overall survival of at least 25%.Lung cancer cells have multiple immunosuppressive mechanisms that allow to escape of the immune system and survive, however blocking CTLA-4 pathway with antibodies as monotherapy treatment have not achieved same results than in melanoma patients. PD-1 expression has been demonstrated in different tumor types, suggesting than PD-1 / PD-L1 pathway is a common mechanism used by tumors to avoid immune surveillance and favoring tumor growth. Anti PD-1 and anti PD-L1 antibodies have showed activity in non-small cell lung cancer patients with significant benefit in overall survival, long lasting responses and good safety profile, including naïve and pretreated patients regardless of the histological subtype. Even more, PD-1 negative expression patients achieve similar results in overall survival when compared with patients treated with chemotherapy. In the other side high PD-1 expression patients that undergo immunotherapy treatment achieve better results in terms of survival with lesser toxicity. Combining different immunotherapy treatments, combination of immunotherapy with chemotherapy or with targeted treatment are under research with some promising PRELIMINARY results in non-small cell lung cancer patients.This chapter attempts to summarize the development of immunotherapy treatment in non-small cell lung cancer patients and explain the results that have leaded immunotherapy as a new standard of treatment in selected NSCLC patients.

High risks of lung disease associated with early-life and moderate lifetime arsenic exposure in northern Chile

BACKGROUND

Arsenic in drinking water has been associated with increases in lung disease, but information on the long-term impacts of early-life exposure or moderate exposure levels are limited.

METHODS

We investigated pulmonary disease and lung function in 795 subjects from three socio-demographically similar areas in northern Chile: Antofagasta, which had a well-described period of high arsenic water concentrations (860μg/L) from 1958 to 1970; Iquique, which had long-term arsenic water concentrations near 60μg/L; and Arica, with long-term water concentrations ≤10μg/L.

RESULTS

Compared to adults never exposed >10μg/L, adults born in Antofagasta during the high exposure period had elevated odds ratios (OR) of respiratory symptoms (e.g., OR for shortness of breath=5.56, 90% confidence interval (CI): 2.68-11.5), and decreases in pulmonary function (e.g., 224mL decrease in forced vital capacity in nonsmokers, 90% CI: 97-351mL). Subjects with long-term exposure to arsenic water concentrations near 60μg/L also had increases in some pulmonary symptoms and reduced lung function.

CONCLUSIONS

Overall, these findings provide new evidence that in utero or childhood arsenic exposure is associated with non-malignant pulmonary disease in adults. They also provide preliminary new evidence that long-term exposures to moderate levels of arsenic may be associated with lung toxicity, although the magnitude of these latter findings were greater than expected and should be confirmed.