Perceived versus actual water quality: Community studies in rural Oaxaca, Mexico.

Compromised water quality risks public health, which becomes particularly acute in economically marginalized communities. Although the majority of the clean-water-deprived population resides in Sub-Saharan Africa and Asia, a significant portion (32 million) lives in Meso- and Latin-America. Oaxaca is one of the marginalized southern states of Mexico, which has experienced high morbidity from infectious diseases and also has suffered from a high rate of infant mortality. However, there has been a paucity of reports on the status of water quality of culturally diverse rural Oaxaca. This study follows community-based participatory research methods to address the data gap by reporting on water quality (chemical and microbiological) and by exploring social realities and water use practices within and among communities. Surveys and water quality analyses were conducted on 73 households in three rural communities, which were selected based on the choice of water sources (i.e., river water, groundwater, and spring water). Statistically significant variations among communities were observed including the sanitation infrastructure (p-value 0.001), public perception on water quality (p-value 0.007), and actual microbiological quality of water (p-value 0.001). Results indicate a high prevalence of diarrheal diseases, a desire to improve water quality and reduce the cost of water, and a need for education on water quality and health in all the surveyed communities. The complexities among the three studied communities highlight the need for undertaking appropriate policies and water treatment solutions.

Mercurio en la minería del oro: impacto en las fuentes hídricas destinadas para consumo humano / Mercury in ASGM and its impact on water resources used for domestic water supply

En regiones afectadas por la minería del oro, la inhalación de vapores de mercurio junto con la ingesta de peces contaminados, constituyen las principales fuentes de contaminación con este metal, el cual afecta la salud humana de múltiples maneras. No obstante, otra fuente adicional reconocida por la Organización Mundial de la Salud (OMS) es el consumo de agua contaminada. Aunque por lo general las aguas superficiales contienen bajos nivelesde mercurio debido a que este es rápidamente consumido por microorganismos acuáticos, se ha encontrado que bajo ciertas circunstancias su concentración en el agua puede alcanzar valores alarmantes, superando incluso los2,0 μg/L -valor estipulado en la legislación colombianapara aquellas fuentes hídricas destinadas para consumo humano y doméstico-. En algunos municipios colombianos se handetectado concentraciones de mercurio en aguas superficiales por encima de los 3,0 μg/L y en otros lugares del mundo por encima de los 8,0 μg/L. Si bien es cierto que el consumo de agua contaminada con mercurio constituye un problema menor en comparación con otras fuentes de contaminación, estas bajas concentraciones también contribuyen gradualmente a la carga contaminante que afecta la salud humana, tal como ha sido reportado por diferentes investigadores.(AU)

In regions affected by artisanal and small-scale gold mining (ASGM), the inhalation of mercury vapor and the ingestion of fish contaminated with this metal constitute the main sources of mercury contamination that affect human health. Nevertheless, according to the World Health Organization, another source of contamination is polluted water. Although mercury in freshwater is usually found in very low concentrations because it is swiftly consumed by aquatic microorganisms, evidence shows that under specific circumstances its concentration in water can reach high levels, even surpassing the 2.0 μg/L stipulated by Colombian legislation for use as a domestic water supply. Mercury concentrations above 3.0 μg/L have been found in some Colombian municipalities, and above 8.0 μg/L in other regions around the world. Even though mercury consumption via water is a minor concern, along with other alimentary sources this low mercury concentration contributes to the total burden that affects human health.(AU)

[Mercury in ASGM and its impact on water resources used for domestic water supply]. / Mercurio en la minería del oro: impacto en las fuentes hídricas destinadas para consumo humano.

In regions affected by artisanal and small-scale gold mining (ASGM), the inhalation of mercury vapor and the ingestion of fish contaminated with this metal constitute the main sources of mercury contamination that affect human health. Nevertheless, according to the World Health Organization, another source of contamination is polluted water. Although mercury in freshwater is usually found in very low concentrations because it is swiftly consumed by aquatic microorganisms, evidence shows that under specific circumstances its concentration in water can reach high levels, even surpassing the 2.0 µg/L stipulated by Colombian legislation for use as a domestic water supply. Mercury concentrations above 3.0 µg/L have been found in some Colombian municipalities, and above 8.0 µg/L in other regions around the world. Even though mercury consumption via water is a minor concern, along with other alimentary sources this low mercury concentration contributes to the total burden that affects human health.