Intoxicación por arsénico / Arsenic poisoning

Resumen El agua que es consumida por los seres humanos diariamente, también conlleva la ingesta de algunos compuestos químicos, como lo es el arsénico, metaloide que al ser consumido crónicamente es perjudicial para la salud, mismo al que algunos trabajadores podrían estar expuestos en su lugar de trabajo. En las pericias médico forenses los metales toman relevancia cuando producen intoxicaciones, teniendo que discernir si dichas intoxicaciones están en relación con la actividad laboral que desempeña el evaluado o si por el contrario, se deben a la exposición ambiental por consumo en agua o alimentos contaminados en sus hogares. El arsénico es un compuesto muy tóxico, que al no tener sabor ni olor se puede consumir en el agua inadvertidamente, causando un hidroarsenicismo agudo o crónico. Se ha comprobado que el mismo tiene impactos a nivel del sistemas dermatológico, cardiovascular, inmunológico, neurológico, hepático, renal y respiratorio, con influencia en el desarrollo embrionario y con propiedades carcinogénicas importantes. Se realizó una revisión bibliográfica en diferentes bases de datos, de los artículos publicados referentes al tema de los últimos doce años, con el objetivo de estudiar las características del Arsénico, su metabolismo y su impacto en la salud de los seres humanos. Se concluye que en Costa Rica es necesario un estudio de poblaciones de riesgo de exposición a arsénico, debido a que es un país con múltiples actividades económicas básicas antropogénicas y por presentar una alta cantidad de volcanes distribuidos en su territorio. Por su parte el médico forense al realizar peritajes en casos de intoxicación debe de analizar ampliamente la relación de causalidad antes de asegurar o descartar la relación laboral.

Abstract The water that is consumed by human beings on a daily basis, also entails the intake of some chemical compounds, such as arsenic, a metalloid that when consumed chronically is harmful to health, the same to which some workers could be exposed in their workplace. In forensic medical expertise, metals become relevant when they produce intoxications, having to discern if such intoxications are related to the work activity performed by the person being evaluated or if, on the contrary, they are due to environmental exposure by consumption of contaminated water or food in their homes. Arsenic is a very toxic compound that, since it has no taste or odor, can be consumed inadvertently in water, causing acute or chronic hydroarsenicism. It has been proven that it has impacts on the dermatological, cardiovascular, immunological, neurological, hepatic, renal and respiratory systems, with influence on embryonic development and with important carcinogenic properties. A bibliographic review was made in different databases, of the articles published on the subject in the last twelve years, with the objective of studying the characteristics of arsenic, its metabolism and its impact on the health of human beings. It is concluded that a study of populations at risk of exposure to arsenic is necessary in Costa Rica, due to the fact that it is a country with multiple basic anthropogenic economic activities and because it has a high number of volcanoes distributed in its territory. The forensic doctor, on the other hand, when performing expert opinions in cases of intoxication, should analyze the causal relationship before assuring or discarding the work relationship.

Diseño y aplicación de un Programa de Comunicación de Riesgos para la salud ambiental infantil en un sitio contaminado con plomo y arsénico / Designing and application of a Risk Communication Program for children environmental health on a lead and arsenic contaminated location

Una industria metalúrgica en la ciudad de San Luis Potosí, México ha contaminado el sitio con plomo (Pb) y arsénico (As) principalmente. Desde 1989 se han reportado por nuestro grupo altas concentraciones de Pb en sangre (PbS) y As en orina (AsO) en los niños del lugar. En el presente estudio se generó un Programa de Comunicación Riesgos (PCR) para informar a los niños sobre los riesgos ambientales del sitio donde viven y que cambiaran conductas para disminuir la exposición al Pb y al As. Se trabajó con 170 niños (5 a 7 años) de la zona. Se aplicó el PCR y se realizó la evaluación mediante análisis de dibujos, cuestionarios y monitoreo biológico. En los dibujos de los niños se encontraron elementos tóxicos tales como el Pb, la tierra contaminada, entre otros. En los cuestionarios aplicados a los niños y a los padres de familia se pudo apreciar un cambio en los conocimientos y en algunas conductas respecto a los contaminantes, sus efectos y su exposición. No se encontró una disminución en los niveles de PbS ni de AsO. Esto quizás porque la principal ruta de exposición no es únicamente el suelo, como se había contemplado anteriormente.

A metallurgical industry in San Luis Potosí city, México, has contaminated the zone by lead (Pb) and arsenic (As). Since 1989 were reported by our group high concentrations of Pb in blood (PbB) and As in urine (AsU) in the local children. In present work, a Risk Communication Program (RCP) was generated to inform the children about the environmental risks of the site where they live, and to change conducts to diminish the exposure to Pb and As. We worked with 170 children (5 to 7 years) of the zone. The RCP was applied and the evaluation was realized by means of analysis of drawings, questionnaires and biological monitoring. In drawings of the children appeared toxic elements such as Pb, contaminated soil, cigarettes, among others. In the questionnaires applied to the children and family parents it was possible to estimate a change in the knowledge and in some conducts with regard to the pollutants, their effects and their exposure. There was not a decrease in the levels of PbB and in the levels of AsU. These were due probably because the principal route of exposure is not only the soil that had been contemplated previously.

Hidroarsenisismo crónico regional endémico: un desafío diagnóstico y de prevención / Chronic endemic regional hydroarsenicism: a challenge for diagnosis and prevention

El arsénico (As) es un semi-metal, ampliamente distribuido en la naturaleza en aguas y suelos. La contaminación de los cursos de agua, tanto superficiales como profundos, constituye el principal problema ambiental generado por este elemento. La intoxicación con As se denomina hidroarsenicismo crónico regional endémico (HACRE). Su importancia de la intoxicación crónica con As en la infancia está dada por los conocidos efectos asociados a la exposición acumulada desde el período prenatal en bajas concentraciones. El HACRE se desarrolla progresivamente, comprometiendo diversos órganos y sistemas, principalmente la piel. Una de las complicaciones más importantes del HACRE es el desarrollo de neoplasias, principalmente tumores cutáneos. El HACRE es una enfermedad prevenible. La salud ambiental infantil representa un desafío del nuevo milenio y los profesionales de la salud cumplen un rol fundamental frente a las amenazas ambientales como las que presentala intoxicación crónica con arsenico.

Arsenic (As) is a semimetal that is widely distributed in nature, in water and soil. In Argentine, the contamination of both waterways and groundwater represents the main environmental problem caused by this element. Chronic As poisoning is known as Chronic endemic regional hydroarsenicism (C.E.R.HA.). Long-term exposure to low concentrations of the element from the prenatal period onward results in the well-known symptoms of chronic As poisoning. CERHA develops progressively, compromising different organs and systems, most importantly the skin. One of the most important complications of CERHA is de development of neoplasias, mainly skin tumors. Childhood environmental health is a challenge in the new millennium and health care professionals play a fundamental role in the protection against environmental hazards such as chronic arsenic poisoning.

Zinc supplement on tissue arsenic concentration in rats.

To examine the effect of zinc in the removal of accumulated arsenic from different tissues (liver, kidneys, spleen and lungs), rats were initially allowed to drink high concentration (400 microg/kg/day) of arsenic for two months followed by a period of cessation (one month). Administration of zinc (2 mg/kg/day) during the third month in arsenic-treated and non-treated groups were compared. In arsenic-treated rats, the mean (+/- SD) amounts of total arsenic in liver, kidneys, spleen and lungs were 12.3 +/- 0.7, 20.5 +/- 1.0, 31.4 +/- 1.0 and 25.6 +/- 1.1 microg/g of tissues respectively. Administration of zinc to arsenic-treated rats reduced the arsenic concentrations of those tissues to 7.8, 10.7, 23.0 and 14.0 microg/g of tissues. This in vivo study suggests that zinc removes the accumulated arsenic from different tissues significantly (p < 0.001).

Review of coagulation technology for removal of arsenic: case of Chile.

Coagulation technology has been used since 1970 in northern Chile for removing arsenic from drinking-water. This experience suggests that coagulation is an effective technology for the removal of arsenic. It is currently possible to reduce arsenic from 400 microg/L to 10 microg/L at a rate of 500 L/sec, assuming pH, oxidizing and coagulation agents are strictly controlled. The Chilean experience with the removal of arsenic demonstrates that the water matrix dictates the selection of the arsenic-removal process. This paper presents a summary of the process, concepts, and operational considerations for the use of coagulation technology for removal of arsenic in Chile.

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.

Knowledge of arsenic in drinking-water: risks and avoidance in Matlab, Bangladesh.

Widespread contamination of arsenic in Bangladesh has been jeopardizing the health of millions of people. Residents of Matlab, Bangladesh, are among the millions at risk. Using bivariate models in the analysis of survey data, knowledge of health risks and avoidance of arsenic exposure in response to widespread contamination of arsenic for residents of Matlab were estimated. The models examined individuals' knowledge of an arsenic problem in the household and knowledge of specific illnesses caused by arsenic exposure. The likelihood of avoiding exposure to arsenic contamination was further examined. Results of the estimation showed that individual's knowledge of arsenic problems in the household was gathered through awareness campaigns and by word of mouth and that knowledge of illnesses was predicated on education, health, presence of children, elderly and young women. Adoption of avoidance measures was not affected by exposure to arsenic-information sources, but level of education had a statistically significant positive effect on the decision to avoid arsenic exposure. Lack of convenience of safe drinking-water practices lead people to persist in drinking arsenic-contaminated water.

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.

A conceptual model to be used for community-based drinking-water improvements.

A conceptual model that can be applied to improve community-based drinking-water in crisis-type situations has been developed from the original general science and technology/development bridging concept and from a case study in Northwest Bangladesh. The main feature of this model is the strengthened role of communities in identifying and implementing appropriate drinking-water improvements with facilitation by multi-disciplinary collaborative regional agency networks. These combined representative community/regional agency networks make decisions and take actions that involve environmental and health data, related capacity factors, and appropriateness of drinking-water improvements. They also progressively link regional decisions and actions together, expanding them nationally and preferably within a sustainable national policy-umbrella. This use of the model reflects stronger community control and input with more appropriate solutions to such drinking-water crisis situations and minimization of risk from potentially-inappropriate 'externally-imposed' processes. The application here is not intended as a generic or complete poverty-alleviation strategy by itself but as a crisis-solving intervention, complementary to existing and developing sustainable national policies and to introduce how key principles and concepts can relate in the wider context. In terms of the Bangladesh arsenic crisis, this translates into community/regional networks in geographic regions making assessments on the appropriateness of their drinking-water configuration. Preferred improvement options are decided and acted upon in a technological framework. Options include: pond-sand filters, rainwater harvesting, dugwell, deep-protected tubewell, and shallow tubewell with treatment devices. Bedding in the regional drinking-water improvement configuration protocols then occurs. This involves establishing ongoing representative monitoring and screening, clear delineation of arsenic-contaminated wells with inter-regional linking, and national expansion within national drinking-water policy frameworks.