Oral Squamous Cell Carcinoma Associated with Arsenic Exposure: A Case Series from Argentina / Carcinoma Oral de Células Escamosas Asociado con la Exposición al Arsénico: Una Serie de Casos de Argentina

ABSTRACT: Many areas of South America are directly affected by Arsenic (As) contaminated groundwater. A high percentage of the water samples taken in multiple areas of Argentina had As concentrations above the WHO level recommended guidelines. This condition was previously associated with an increased risk of chronic diseases, including different cancers. Long-term As exposure was proposed as a risk factor for Oral Squamous Cell Carcinoma (OSCC). The aim of this study is to present a series cases of Argentine patients diagnosed with OSCC who have consumed water contaminated with As for more than 10 years. Clinical data were obtained from the archive of Clinical Records Histories of the Oral Medicine Department of the Dentistry School, Universidad Nacional de Córdoba and Universidad Católica de Córdoba, Argentina. 15 cases of OSCC were included. The male: female sex ratio was 2:1. The average age was 66 years (31-89 years). Regarding location, the gum or edentulous alveolar ridge was the most prevalent site (6/15; 40 %), followed by the tongue margin. The average years of exposure to arsenical waters were 24 years (13 - 40 years of exposure). The majority of the presented cases were non drinkers non smokers. 60 % of the tumors were diagnosed at advanced stages. the epidemiological studies carried out in As-contaminated areas that address oral cancer should always incorporate the record of variables related to As exposure. Patients who live or lived at As-contaminated areas must be regularly followed up for early diagnosis of potentially malignant or malignant lesions. The high frequency of gum cancer among these cases, should raise awareness of periodontic specialists to perform a careful and thorough periodontal examination.

RESUMEN: Muchas regiones de América del Sur están directamente afectadas por aguas subterráneas contaminadas con arsénico (As). Un alto porcentaje de las muestras de agua tomadas en múltiples áreas de Argentina tenían concentraciones de As superiores al nivel aprobado por la OMS. Esta condición se asociaba previamente con un mayor riesgo de enfermedades crónicas, incluidos diferentes tipos de cáncer. La exposición a largo plazo se propuso como un factor de riesgo para el carcinoma oral de células escamosas (OSCC). El objetivo de este estudio es presentar una serie de casos de pacientes diagnosticados con OSCC que han consumido agua contaminada con As durante más de 10 años. Se obtuvieron datos clínicos del archivo de Historias de registros clínicos del Departamento de Medicina Oral de la Facultad de Odontología, Universidad Nacional de Córdoba y Universidad Católica de Córdoba, Argentina. Se incluyeron 15 casos de OSCC. La relación de género masculino: femenino fue de 2: 1. La edad promedio fue de 66 años (31-89 años). En cuanto a la ubicación, la encía o la cresta alveolar edéntula fue el sitio más frecuente (6/15; 40 %), seguido del borde de la lengua. El promedio de años de exposición a las aguas arsenicales fue de 24 años (13 - 40 años de exposición). La mayoría de los casos presentados fueron de pacientes no bebedores y no fumadores. El 60 % de los tumores fueron diagnosticados en etapas avanzadas. Los estudios epidemiológicos realizados en áreas contaminadas con As que abordan el cáncer oral siempre deben incorporar el registro de variables relacionadas con la exposición a As. Se debe hacer un seguimiento continuo de los pacientes que viven o que vivieron en áreas contaminadas con As para el diagnóstico temprano de lesiones potencialmente malignas. La alta frecuencia de cáncer de encías en estos casos, debe concienciar a los especialistas en periodoncia para que realicen un examen periodontal cuidadoso y completo.

Analysis of the association between bladder carcinoma and arsenic concentration in soil and water in southeast Brazil

ABSTRACT In approximately 50% of cases of bladder carcinoma, an associated predisposing factor can be established. The main factors are exposure to tobacco, arsenic (As) ore and aromatic compounds. Arsenic is a metalloid with a low average concentration in the earth's crust, and one of the most dangerous substances for human health. The present study aims to evaluate the incidence of hospitalization and mortality from bladder neoplasia and its possible association with As concentration in water and soil in two of the most critical regions of Brazil: the states of São Paulo and Minas Gerais. We have investigated bladder cancer hospitalization and mortality in the states of Sao Paulo and Minas Gerais during 2010-2014. Water and soil samples were analyzed and As concentrations were established. Data were obtained through the Department of Informatics of the Brazilian Unified Health System. Correlation was made with water samples from São Paulo and with data on soil analysis from Minas Gerais. The results revealed no direct association in the distinctive municipalities. Areas with high environmental As concentration had a low bladder cancer rate, while areas with normal as levels had similar cancer rates. The quantitative variables did not present a normal distribution (p < 0.05). In conclusion, we did not observe a correlation between as concentration in water or soil and bladder cancer's hospitalization and mortality rates in the states of São Paulo and Minas Gerais.

Ingesta de arsénico: el impacto en la alimentación y la salud humana / Arsenic Intake: Impact in Human Nutrition and Health

RESUMEN El arsénico es un elemento que se encuentra ampliamente distribuido en todo el medio ambiente. Sus compuestos se hallan principalmente en estado de oxidación pentavalente y trivalente; y en formas inorgánicas y orgánicas. Las especies arsenicales varían en su grado de toxicidad, siendo los compuestos inorgánicos más tóxicos que los orgánicos, y los compuestos trivalentes más tóxicos que los pentavalentes. Habría interconversión entre las especies menos tóxicas a otras más toxicas y los métodos de cocción y de procesamiento podrían afectarla. El arsénico es un agente carcinogénico y ocasiona múltiples efectos negativos sobre la salud humana a corto y largo plazo. La exposición humana no ocupacional al arsénico se da principalmente por agua y alimentos. La normativa es variable para cada país, y se basa en los estándares de la OMS, Codex Alimentarius y la Unión Europea. Muchos estudios se enfocan en determinar el contenido total de arsénico mas no identifican las especies arsenicales en alimentos. A nivel global, pescado y mariscos, pollo, carnes, arroz y algas marinas tienen niveles elevados de arsénico. En Perú, hay escasos estudios sobre contenido de arsénico total y especies arsenicales en alimentos a pesar que tenemos zonas con altos niveles de contaminación ambiental. El objetivo de esta revisión es discutir la exposición al arsénico a través de la ingesta de alimentos y agua, la normativa relacionada, toxicidad, consecuencias en la salud humana y principales alimentos que contribuyen a su ingesta.

ABSTRACT Arsenic is an element that is widely distributed throughout the environment. Its compounds are mainly in the state of pentavalent and trivalent oxidation; and in inorganic and organic forms. Arsenical species vary in their degree of toxicity, with inorganic compounds being more toxic than organic and trivalent compounds more toxic than pentavalent compounds. There would be interconversion between the less toxic species and other more toxic species and the cooking and processing methods could affect it. Arsenic is a carcinogenic agent and causes multiple negative effects on human health in the short and long term. Non-occupational human exposure to arsenic occurs mainly through water and food. The regulation is variable for each country and is based on WHO standards, the Codex Alimentarius, and the European Union. Many studies focus on determining the total arsenic content but do not identify arsenical species in foods. Globally, fish and seafood, chicken, meat, rice, and seaweed have high levels of arsenic. In Peru, there are few studies on total arsenic content and arsenical species in food despite the fact that we have areas with high levels of environmental contamination. The objective of this review is to discuss exposure to arsenic through food and water intake, related regulations, toxicity, consequences on human health and main foods that contribute to its intake.

Efecto deletéreo de la luz ultravioleta y arsénico en adultos mayores de antofagasta / Deleterious effect of ultraviolet light and arsenic in older adults in antofagasta

Investigamos patologías dermatológicas de adultos mayores provocadas por RUV o arsénico en un periodo de treinta años en Antofagasta, ciudad con alto índice de RUV y que tuvo hidroarsenicismo. De 4360 adultos mayores, 20,5 por ciento presentaba una dermatosis relacionada con RUV o arsénico. RUV generó 13,1 por ciento de los diagnósticos, siendo más frecuente en mujeres que en hombres. Arsénico generó 5,9 por ciento de los diagnósticos, siendo más frecuente en hombres que en mujeres. El 1,5 por ciento restante se considera que fue por ambos. 43,8 por ciento de las patologías fueron cánceres de piel, 39 por ciento lesiones premalignas y solo 17,2 por ciento lesiones benignas. Además, el comportamiento epidemiológico del carcinoma basocelular y del espinocelular es diferente a lo descrito en estudios nacionales e internacionales.

We investigated dermatological pathologies in over 60 years old adults provoked by ultraviolet radiation (UVR) or arsenic in a thirty years period in Antofagasta, city with high index of UVR and that had hydroarsenicism. Of 4360 adults, 20,5 percent presented a dermatosis related to UVR or arsenic. UVR generated 13,1 percent of the diagnoses, being more frequent in women than in men. Arsenic generated 5,9 percent of the diagnoses, being more frequent in men than in women. It is considered that the 1,5 percent remaining was for both reasons. 43,8 percent of the pathologies were skin cancers , 39 percent premalignant lesions and only 17,2 percent benign lesions. In addition, the epidemiological behavior of basocellular carcinoma and squamous cell carcinoma, is different to the one described in other national and international studies.

Arsenical keratoses and non-Hodgkin's lymphoma: arsenic-induced or coincidental conditions?

Arsenic, a naturally occurring metal, is best known as a poison and can generate both acute and chronic toxicity. Exposure can occur through air, water, soil, and food. Chronic arsenic toxicity is usually asymptomatic and the first sign may be cutaneous findings. Arsenic keratosis is a precancerous lesion related to chronic arsenism. Non-Hodgkin's lymphoma [NHL] is a T or B cell malignancy usually originating from lymph nodes and fewer in every other organ.We report a concomitant occurrence of arsenic keratosis and NHL in a Caucasian man.To our knowledge, this is the first such reported case

Luis Prunés Risetti: un gran maestro de la dermatología chilena: su biografía y archivo fotográfico / Luis Prunés Risetti: a great master of Chilean dermatology: his biography and photo archive

El doctor Luis Prunés fue uno de los grandes maestros de la dermatología chilena. Se formó como dermatólogo en el hospital Saint-Louis en París. En la década 1920 ingresó al Hospital San Luis de Santiago y en 1938 asumió como profesor titular de la cátedra “Clínica Universitaria de Piel y Sífilis” del Hospital San Vicente de Paul. En 1938 fue el primer presidente de la Sociedad Chilena de Dermato-sifilología. Fue un gran investigador de patologías cutáneas; estudió principalmente la lepra y las lesiones cutáneas asociadas a minerales. Es recordado por preconizar la importancia de la biopsia cutánea. Jubiló en 1954 dejándonos un importante legado dermatológico. El Dr. Prunés recopiló sus mejores casos en más de 20archivos fotográficos, los cuales se encuentran en la biblioteca del Departamento de Dermatología del Hospital Clínico de la Universidad de Chile. El objetivo de este trabajo es presentar parte de su archivo fotográfico, mostrando imágenes impresionantes de tumores cutáneos y lesiones cutáneas inducidas por arsénico.

Dr. Luis Prunés is one of the masters of the Chilean dermatology. He was trained as dermatologist at the Saint-Louis hospital in Paris. Since 1920 he worked as dermatologist at the San Luis Hospital in Santiago and in 1938 he took over as Professor and Chairman of the “University Clinic of Skin and Syphilis” at San Vicente de Paul Hospital. In 1938, he was the first president of the Chilean Society of Dermatology. He studied leprosy and skin lesions associated with minerals. He is also remembered for advocating the importance of skin biopsy. He retired in 1954, leaving an important legacy. Dr. Prunés compiled his best clinical cases in more than 20 photographic archives, which are located at the Library of the Dermatology Department in the University of Chile Clinical Hospital. The purpose of this paper is to present part of his photographic archive, showing stunning images of large cutaneous tumors and arsenic-induced skin lesions.

Effects of soil types and forms of arsenical pesticide on rice growth and development

For decades, repeated and widespread use of arsenical pesticides has significantly contributed to arsenic contamination in soils. Residues from the overuse of these arsenicals may result in phytotoxicity to crops, which will depend on soil types, plant species and the toxicity of arsenical pesticides. A greenhouse column study was conducted to evaluate the effect of two pesticides, i.e. one organic [dimethylarsinic acid] and one inorganic [sodium arsenate], on the vegetative response of rice as a function of soil properties. Four soils with varying arsenic retention capabilities at two different pesticide amendment rates [675 and 1500 mg/kg] representing the worst case scenarios in superfund sites were used. Results showed that arsenic availability to rice was mainly influenced by soil physico-chemical properties. The soil with the lowest arsenic retention capacity had the highest arsenic concentration in the leachate as well as in the plant tissue. In contrast, for soils with higher arsenic retention capacity, higher concentrations of arsenic were found in the surface soil which resulted in the inhibition of plant growth. There was no significant difference between labile arsenic / plant-available arsenic irrespective of the form of arsenical pesticide used. Plant growth parameters such as biomass, shoot height, root length decreased with increased arsenic concentrations in all soils. A significant negative correlation [P<0.05] was observed between the phytoavailable arsenic and plant growth response. Interestingly, the form of arsenical pesticide used did not impact arsenic uptake or shoot growth but significantly impacted root growth

Carcinoma basoescamoso: reporte de un caso con exposición crónica a arsénico ambiental / Basosquamous carcinoma: a case report with chronic environmental arsenic exposition

Basosquamous carcinoma is a relatively rare cutaneous tumour that shares some characteristics of both basal cell and squamous cell carcinoma. Currently most dermatologists consider that it represents a subtype of basal cell carcinoma with a more aggressive behaviour. The clinical presentation is non-specific and in general the diagnosis is made after the histopathological studies. The prevalence is higher in male patients, during the seventh decade and it tends to appear on sun exposed areas. Many authors compare its behaviour with squamous cell carcinoma. We present the case of a 44 years old male patient with a history of chronic arsenic exposure that presented a firm tumor in the left inguinal region and the biopsy showed basosquamous carcinoma with lymphatic involvement. This case shows an atypical presentation because of its localization and the appearance 20 years before the mean age reported in the literature. This could be explained by chronic environmental arsenic exposure, a well known risk factor for the development of cutaneous tumours.

El carcinoma basoescamoso es una neoplasia cutánea relativamente rara que reúne características de carcinoma basocelular y espinocelular. Actualmente la mayoría de los dermatólogos reconocen que este es un subtipo del carcinoma basocelular con comportamiento muchísimo más agresivo. Su presentación clínica es inespecífica y en general su diagnóstico se realiza sólo después de la biopsia. Predomina en pacientes de sexo masculino durante la séptima década de la vida y tiende a aparecer en regiones fotoexpuestas. Muchos autores igualan su comportamiento al del carcinoma espinocelular. Se presenta el caso de un paciente, de sexo masculino, de 44 años de edad, con antecedente de exposición a arsénico medioambiental crónica, que presentó aumento de volumen, duro en la región inguinal izquierda, cuya biopsia fue compatible con carcinoma basoescamoso con compromiso linfático. El caso de nuestro paciente muestra una presentación atípica por su localización y por la aparición 20 años antes de la media de edad reportada en la literatura. Esto podría ser explicado por la exposición crónica a arsénico, conocido factor de riesgo para carcinogénesis cutánea.

Modulación del efecto citotóxico del arsénico por moléculas bioactivas / Modulation of the cytotoxic effects of arsenic by bioactive molecules

El arsénico es un contaminante ampliamente distribuido en el medio ambiente, siendo un cancerígeno humano de acuerdo a evidencias epidemilógicas, clínicas y experiementales. Se estima que en Argentina existen alrededor de 5 millones de personas que sonsumen agua con niveles tóxicos del mismo. Se postula que la toxicidad inducida por arsénico podría ser modulada por sustancias diatarias antioxidantes, que intervendrían sobre sus mecanismos prooxidantes, dependiendo de la magnitud de la exposición y del grado de diferenciación celular. Entonces, el objetivo de esta tesis fue determinar el efecto modulador de los flavonoides quercetina y silimarina sobre la toxicidad por arsenito sódico, desarrollando modelos celulares para evaluar diferentes biomarcadores: viabilidad y muerte celular, niveles de especies reactivas, respuestas celulares y moleculares asociadas, integridad y susceptibilidad redox de las membranas biológicas.

Cáncer en la región de Antofagasta, con especial referencia al cáncer vesical y al cáncer pulmonar / Cancer in the Antofagasta region of Chile, with special reference

Se presenta el perfil oncológico de la Región de Antofagasta. Mediante la comparación de la mortalidad regional por las distintas localizaciones de cáncer con la mortalidad nacional y de otras áreas se deduce que persiste un exceso de mortalidad por cáncer vesical (2002-2004) y broncopulmonar (2001-2004), en hombres y en mujeres; y que hay un exceso de cáncer renal y hepático en varones y un exceso de cáncer pancreático en mujeres. Se descarta el papel del envejecimiento poblacional en lo que respecta a los cánceres de vejiga y de pulmón. Se discuten las características de estos cánceres en Chile y en otros países: mortalidad, incidencia, tendencias, relación con el sexo y con otros factores posibles. Se citan las investigaciones nacionales relativas a la presencia y papel del arsénico en el aire, agua, alimentos y procesos laborales en la región. Las diferencias por sexo sugieren que: el cáncer vesical se relaciona con el ambiente general más que con el ambiente laboral (los excesos son similares en ambos sexos); el cáncer pulmonar, con el ambiente general y con el ambiente laboral (proceso metalúrgico); el cáncer renal y el del hígado, con circunstancias atingentes al género masculino pero probablemente no con el arsénico en el caso del cáncer hepático; y el cáncer de páncreas, posiblemente con el ambiente general. En Antofagasta y regiones vecinas hay menos mortalidad por cánceres digestivos y de próstata y ovario. Esta extensión en el espacio contrasta con la especificidad regional de los excesos. Se recomienda continuar e intensificar la investigación, monitoreo y control multisectorial de aquellos cánceres cuyo exceso persiste desde hace varias décadas en la Región de Antofagasta.

We present the oncological profile of Antofagasta Region, within a general regional approach to the state of health of the population. Through the comparison of regional mortality for the different cancer localizations with mortality in the country and in other regions, we show a persistent excess of bladder and lung cancer in men and women; an excess in kidney and liver cancer in men, and an excess of pancreatic cancer in women. The role of age structure is discarded, at least as far as bladder and lung cancer are concerned. The characteristics of these cancers in Chile and other countries are discussed: mortality, incidence, trends, relationships with gender, and to other possible factors. The previous national investigations related to the presence and the role of arsenic in the air, in drinking water, in food and in occupational processes in the region are cited. Gender associations suggest that: bladder cancer is related to the general environment more than to occupation (the excess is similar for both sexes); lung cancer is related both with the general and the occupational (copper smelting) environment; kidney and liver cancer, with men-related circumstances but probably not with arsenic, in the case of hepatic cancer; and pancreatic cancer, possibly with the general environment. In both Antofagasta and neigh boring regions there is less mortality than in the country as a whole from cancers of the digestive tract and of prostate and ovary. This spatial extension does not apply to the cancers found to be in excess in Antofagasta. We conclude that research, monitoring and multisector control must continue and be intensified regarding the types of cancer for which a regional excess has persisted over several decades.

Risk assessment of arsenic mitigation options in Bangladesh.

The provision of alternative water sources is the principal arsenic mitigation strategy in Bangladesh, but can lead to risk substitution. A study of arsenic mitigation options was undertaken to assess water quality and sanitary condition and to estimate the burden of disease associated with each technology in disability-adjusted life years (DALYs). Dugwells and pond-sand filters showed heavy microbial contamination in both dry and monsoon seasons, and the estimated burden of disease was high. Rainwater was of good quality in the monsoon but deteriorated in the dry season. Deep tubewells showed microbial contamination in the monsoon but not in the dry season and was the only technology to approach the World Health Organization's reference level of risk of 10-6 DALYs. A few dugwells and one pond-sand filter showed arsenic in excess of 50 microg/L. The findings suggest that deep tubewells and rainwater harvesting provide safer water than dugwells and pond-sand filters and should be the preferred options.

Current status and prevention strategy for coal-arsenic poisoning in Guizhou, China.

Arsenic exposure from burning coal with high arsenic contents occurs in southwest Guizhou, China. Coal in this region contains extremely high concentrations of inorganic arsenic. Arsenic exposure from coal-burning is much higher than exposure from arsenic-contaminated water in other areas of China. The current status and prevention strategies for arsenic poisoning from burning high-arsenic coal in southwest Guizhou, China, is reported here. Over 3,000 arsenic-intoxicated patients were diagnosed based on skin lesions and urinary arsenic excretion. Non-cancerous toxicities and malignancies were much more common and severe in these patients than in other arsenic-affected populations around the world. The high incidence of cancer and arsenic-related mortality in this cohort is alarming. Chelation therapy was performed but the long-term therapeutic effects are not satisfactory. The best prevention strategy is to eliminate arsenic exposure. Funds from the Chinese Government are currently available to solve this arsenic exposure problem. Strategies include the installation of vented stoves, the use of marsh gas to replace coal, health education, the improvement of nutritional status, and the use of various therapies to treat arsenic-induced skin and liver diseases.

Access to drinking-water and arsenicosis in Bangladesh.

The discovery of arsenic contamination in groundwater has challenged efforts to provide safe drinking-water to households in rural Bangladesh. Two nationally-representative surveys in 2000 and 2002 investigated water-usage patterns, water-testing, knowledge of arsenic poisoning, and behavioural responses to arsenic contamination. Knowledge of arsenicosis rose between the two surveys among women from 42% to 64% but awareness of consequences of arsenic remained limited; only 13% knew that it could lead to death. Behavioural responses to arsenic have been limited, probably in part because of the lack of concern but also because households are uncertain of how best to respond and have a strong preference for tubewell water even when wells are known to be contaminated. Further work conducted by the survey team highlighted the difficulties in providing alternative sources of water, with many households switching back to their original sources of water.

Genotoxicidad en niños que viven en una zona metalúrgica del estado de San Luis Potosí, México / Genotoxicity in children living in a smelter area in San Luis Potosí, Mexico

Al poniente de la Ciudad de San Luis Potosí, México, se encuentra ubicadauna metalúrgica alrededor de la cual se ha encontrado contaminación por arsénico y plomo tanto en aire como en suelo/polvo. Varios estudios han mostrado que los niños que habitan cerca de este lugar están expuestos a dichos metales. Considerando lo anterior y tomando en cuenta reportes de genotoxicidad asociada al arsénico y al plomo, en este trabajo se evaluó el daño al ADN en los niños expuestos empleando el ensayo cometa. Los resultados indican que casi la mitad de los niños que viven en este lugar presentan valores por encima de los límites de acción que marca CDC para arsénico (50 ug/g de creatinina) y paraplomo (10 ug/dL de sangre). En cuanto al daño al ADN el 35% de los niños sobrepasa el máximo valor de daño encontrado en la población control.

A smelter area where arsenic and lead have been found in air and soil/dust is located in San Luis Potosi, México. Some studies have reported that children living in this area are exposed to those metals. Therefore, DNA damage usingthe comet assay was assessed in the exposed children. Our results showed that almost 50% of the studied children had urinary arsenic and blood lead levels higher than the CDC´s guidelines (50 ug/g creatinin for urinary arsenic and 10 ug/dL for lead in blood). With regard to DNA damage 35% of the children had damage values above the control population.

Levels of arsenic in drinking-water and cutaneous lesions in Inner Mongolia.

The most common health effects from drinking-water containing dissolved arsenic are skin abnormalities and lesions that are typically diagnosed as keratosis and pigment disorder. It was previously reported that the prevalence of cutaneous lesions was about 44% in arsenic-affected villages. However, there has been little research on the relationship between levels of arsenic in drinking-water and cutaneous lesions in Inner Mongolia. One study examined the association between the prevalence of keratosis and levels of arsenic exposure and the relationship between pigment disorder and levels of arsenic exposure among villagers aged 18 years or older in the arsenic-affected village of Hetao Plain in Inner Mongolia, PR China. The study included 227 participants who were affected by cutaneous lesions and 221 participants who were not affected by cutaneous lesions diagnosed in 1996 and 1998. Well-water drunk by the participants was collected to analyze arsenic content. Adjusting for age, sex, and smoking, logistic regression was applied to calculate the risks that arsenic in drinking-water will lead to cutaneous lesions. The results from the logistic regression showed that, with the increase of arsenic concentration in water, the risk of pigment disorder also increased (odds ratio [OR]=5.25, 95% confidence interval [CI] 1.32-83.24 for 50-199 microg/L; OR=10.97, 95% CI 1.50-79.95 for 200-499 [microg/L; OR=10.00, 95% CI 1.39-71.77 for > or = 500 microg/L (p=0.000), but the association between risk of keratosis and levels of arsenic was not significant (p=0.346). The findings suggest that keratosis is an early feature of arsenic poisoning, and the development of pigment disorder depends on higher doses of arsenic intake rather than keratosis. Further studies are needed to confirm that cutaneous lesions and other adverse health effects occur at low levels of arsenic exposure.

Electrocardiographic abnormalities among arsenic-exposed persons through groundwater in Bangladesh.

This study was carried out among arsenic-exposed and non-exposed people of Bangladesh to assess and compare their cardiac status based on electrocardiographic (ECG) findings. For the purpose of the study, participants were included in three groups: arsenic-exposed persons with arsenicosis (arsenicosis group), arsenic-exposed persons without arsenicosis (non-arsenicosis group), and persons not exposed to arsenic (non-exposed group). Each group included 50 respondents. In this study, no significant difference in heart rate, rhythm, axis, and pulse rate interval was detected among the arsenicosis, non-arsenicosis and non-exposed groups. A significant difference in corrected QT interval between the arsenicosis and the non-exposed group (p<0.05) was observed. On the contrary, no statistically significant difference in corrected QT interval between the non-arsenicosis and the non-exposed group was found. Abnormal QRS complex was found among 14%, 8%, and 2% of the arsenicosis, non-arsenicosis, and non-exposed groups respectively. ECG findings, indicative of left ventricular hypertrophy, ischaemic heart disease, and right bundle branch block, were high among the arsenicosis group. Overall, abnormal ECG findings were high (58%) among the respondents of the arsenicosis group and were highly significant (p<0.001). The findings revealed that there was a significant association between ECG abnormalities and arsenic exposure.

Arsenic in drinking-water and reproductive health outcomes: a study of participants in the Bangladesh Integrated Nutrition Programme.

This study examined 2,006 pregnant women chronically exposed to a range of naturally-occurring concentrations of arsenic in drinking-water in three upazilas in Bangladesh to find out relationships between arsenic exposure and selected reproductive health outcomes. While there was a small but statistically significant association between arsenic exposure and birth-defects (odds ratio=1.005, 95% confidence interval 1.001-1.010), other outcomes, such as stillbirth, low birth-weight, childhood stunting, and childhood under-weight, were not associated with arsenic exposure. It is possible that the association between arsenic exposure from drinking-water and birth-defects may be a statistical anomaly due to the small number of birth-defects observed. Future studies should look more closely at birth-defects, especially neural tube defects, to elucidate any potential health effects associated with arsenic exposure from drinking-water. Further, given the knowledge that serious health effects can result from chronic arsenic exposure, efforts to find alternatives of safe drinking-water for the population must continue.

Association between chronic exposure to arsenic and slow nerve conduction velocity among adolescents in Taiwan.

The association between chronic exposure to arsenic and peripheral neuropathy has been controversial in previous studies, which may be due to the influence of factors, such as age, gender, chronic diseases, occupational injuries, and arsenic exposure. To clarify the question of this association, a cross-sectional study was designed. In total, 130 junior high school students aged 12-14 years were included and examined for the motor and sensory nerve conduction velocity of peripheral nerves in their right-upper and lower limbs. Concentrations of arsenic in well-water and history of drinking well-water were retrieved from a baseline database created in 1991. After adjustment for gender and height, a significant odds ratio of 2.9 (95% confidence interval [CI] 1.1-7.5) was observed for the development of slow nerve conduction velocity of the sural sensory action potential (SAP) among the study subjects with a cumulative arsenic dosage of>100.0 mg. In addition, a borderline statistical significance with odds ratio of 7.8 (95% CI 1.001-69.5) for the development of slow nerve conduction velocity of sural SAP was also observed among the study subjects who drank well-water containing arsenic concentrations of >50.0 microg/L and with a cumulative arsenic dosage of >100.0 mg. The study found that chronic exposure to arsenic might induce peripheral neuropathy. It also found that the slowing of the nerve conduction velocity of sural SAP might be an early marker of chronic arsenic neuropathy.

Arsenic exposure and its impact on health in Chile.

The problem of arsenic in Chile was reviewed. In Chile, the population is exposed to arsenic naturally via drinking-water and by air pollution resulted from mining activities. The sources of arsenic were identified to estimate the exposure of population to arsenic through air, water, and food. Health effects, particularly early effects, observed in children and adults, such as vascular diseases (premature cardiac infarct), respiratory illnesses (bronchiectasis), and skin lesions have been described. Chronic effects, such as lung and bladder cancers, were reported 20 years after peak exposure and persisted 27 years after mitigation measures for removing arsenic from drinking surface water were initiated. Although the effects of arsenic are similar in different ethnic and cultural groups (e.g. Japanese, Chinese, Indian, Bangladeshi, American, and Taiwanese), variations could be explained by age at exposure, the dose received, smoking, and nutrition. Since health effects were observed at arsenic levels of 50 microg/L in drinking-water, it is advised that Chile follows the World Health Organization's recommendation of 10 microg/L. The Chilean experience in removal of arsenic suggests that it is feasible to reach this level using the conventional coagulation process.