Biochemical Response of the Endogeic Earthworm (Balanteodrilus extremus) Exposed to Tropical Soils.

This work evaluated the biochemical responses of the endogeic earthworm Balanteodrilus extremus exposed for 14 and 48 days (d) to soils collected from two tropical agricultural systems: maize-sorghum (MS) and soybean-sorghum (SS). A soil without agricultural management (WAM) and the use of pesticides was selected as a reference. The presence of organochlorine (OC) and organophosphate (OP) pesticide residues was quantified in MS and SS soils. Biomarkers of detoxification [glutathione S transferase (GST)], neurotoxicity [acetylcholinesterase (AChE)] and oxidative stress [superoxide dismutase (SOD), catalase (CAT) and lipoperoxidation (LPO)] were evaluated in B. extremus. The concentration of OP pesticide residues was higher in SS than in MS. Activity of AChE in B. extremus exposed to SS soil for 14 d was significantly more inhibited (78%) than in MS soil (68%). B. extremus has been shown to be a good bioindicator of contaminated soils in tropical regions.

Tipos y circunstancias de unión conyugal en la violencia física de pareja en Chiapas, México, 2016

La violencia en contra de las mujeres en la pareja heterosexual, además de ser un tema muy complejo, es un problema de salud pública. Este trabajo contribuye a profundizar no solamente en el tipo de unión conyugal (cohabitación y matrimonio), sino también toma en cuenta las circunstancias en donde ocurre para explicar tanto en mujeres indígenas como no indígenas su relación con la magnitud y la gravedad de las expresiones de maltrato físico en Chiapas, México. El estudio fue realizado a través de un enfoque cuantitativo con base en los datos de la Encuesta Nacional sobre la Dinámica de las Relaciones en los Hogares 2016 (ENDIREH); se incluyeron 2604 mujeres de 15 a 49 años, actualmente unidas, indígenas y mestizas. Los resultados mostraron que la unión libre es más frecuente en las indígenas y se asocia significativamente con una mayor probabilidad de violencia física en sus distintas formas; adicionalmente, las circunstancias en las cuales esta se establece dan cuenta de la variación en la frecuencia de las agresiones, sobre todo cuando las mujeres son forzadas a unirse. La desventaja social de las mujeres subyace al tipo y las circunstancias de unión, destaca su participación o ausencia al decidir y los aspectos normativos que rigen la materia en Chiapas. Se discuten los hallazgos a la luz del cambio reproductivo y el compromiso de los varones en el establecimiento de la unión como elementos constitutivos de la cohabitación y el matrimonio, así como de la violencia íntima de pareja.

Violence against women in heterosexual couples is not only a very complex issue, but also a public health problem. The work contributes to the study not only in the type of conjugal union (cohabitation and marriage) but also taking into account the circumstances in which the union occurs, to explain both in indigenous and non-indigenous women their relationship with the magnitude and severity of the expressions of physical violence against women in Chiapas. The study was conducted through a quantitative approach taking as a basis data from the National Survey on the Dynamics of Household Relationships 2016 (ENDIREH); 2604 women aged 15 to 49 years, currently in union, indigenous and mestizo were included. The results show that free union is more frequent in indigenous women and that this type of union is significantly associated with a higher probability of occurrence of physical violence in its different expressions. Additionally, the circumstances in which the union is established provide evidence of differences in the frequency of physical violence in them, particularly when women are forced to join. The social disadvantage of women underlies the type and circumstances in which the union occurs, highlighting the participation or not of women in the decision to join and the normative aspects that govern unions in Chiapas, Mexico. Results are discussed in light of reproductive change and male involvement in the establishment of the union as elements underlying both cohabitation or marriage and intimate partner violence.

Use of bone char prepared from an invasive species, pleco fish (Pterygoplichthys spp.), to remove fluoride and Cadmium(II) in water.

In this study, bone char (BC) from pleco fish (Pterygoplichthys spp.) was synthesized, and their textural and physicochemical properties, as well as its adsorption capacity towards fluoride and Cd(II) from single and binary aqueous solutions, were determined. The results showed that the properties of the BCs were independent of the type of bone used and the surface areas were close to 110 m2 g-1. The effect of solution pH revealed that the adsorption capacity of BC towards fluoride from water raised by decreasing the solution pH. This trend was attributed to the electrostatic interaction between the positively charged surface and the fluoride in aqueous solution. On the contrary, the capacity of BC for adsorbing Cd(II) was enhanced by increasing the solution pH, indicating that electrostatic interactions were also essential but with a contrary effect in comparison with fluoride adsorption due to the negatively charged surface at pH above the point zero charge (pHPZC = 8.16). The experimental data for binary adsorption of fluoride and Cd(II) were interpreted satisfactorily using the modified Freundlich multicomponent isotherm (EFMI), and the experimental data revealed that Cd(II) have an antagonistic effect on the adsorption of fluoride, whereas the presence of fluoride does not affect the capacity of BC for adsorbing Cd(II). Thermogravimetric, XRD diffraction and IR spectroscopy analysis corroborated that the adsorption of fluoride in BC is due to electrostatic attractions, ion exchange or chemisorption and physisorption. Besides, the removal of Cd(II) occurs by physical adsorption and ion exchange. It was concluded that BC is an alternative material for the removal of fluoride and Cd(II) from aqueous solutions, and it is a possible application for using the bones of this invasive fish species.

Impacto del Programa Comedores Comunitarios SINHAMBRE sobre la desnutrición en Chiapas rural mediante el enfoque de Seguridad Alimentaria / Impact of the SINHAMBRE Community Kitchen Program on malnutrition in rural Chiapas through the Food Security approach

Resumen: Introducción: La prevalencia de desnutrición en menores de 5 años en el contexto rural indígena se encuentra entre las más alarmantes, al mismo tiempo que sus poblaciones se ven afectadas por el hambre y la pobreza; esta problemática ha sido abordara a través de programas sociales como el Programa de Comedor Comunitario (PCC) de la Cruzada Nacional contra el Hambre (CNCH). Objetivo: analizar el impacto del PCC sobre la desnutrición de niñez en edad escolar en un ejido rural indígena de la zona alta cafetalera de Tapachula, Chiapas, México, tras dos años de su instrumentación, se analizó bajo el enfoque de seguridad alimentaria. Metodología: Se realizó un estudio de casos explicativo en el que se evaluó el estado de nutrición de 31 menores de cinco años en 2014 y posteriormente en 2016. Se realizaron mediciones antropométricas y encuestas a la jefa o el jefe de hogar para la obtención de información sociodemográfica de los hogares. Se analizaron los resultados de ambas intervenciones (2014 y 2016) considerándose relevantes los ingresos, programas sociales presentes en el ejido y gastos en el interior de los hogares. Resultados: Se identificó que, para el 2016, hubo un impacto positivo marginalmente significativo en el indicador de talla para la edad (t=1.83, p=0.077) y un impacto negativo en los indicadores de peso para la talla (t=-4.03, p<0.001) y peso para la edad (t=-3.584, p=0.001). Conclusión: Los niños y las niñas se encuentran en un estado de desnutrición relacionada a una fase de enfermedades o a hábitos alimentarios inadecuados. El PCC no mostró suficiente evidencia de su impacto tras dos años de su implementación.

Abstract: Introduction: Undernutrition in children under five years old, especially in the rural-indigenous context, where hunger and poverty prevail remain a public health concern, is alarming. This problem has been addressed by social programs such as the Community Dining Program (PCC) of the National Crusade Against Hunger (CNCH). Objective: To assess the impact of the PCC over school children after two years of enforcement at an indigenous rural common land in the coffee highlands of Tapachula, Chiapas, Mexico, through the food security approach. Methods: We conducted an explanatory case study were nutritional status of 31 children under five years old was evaluated in 2014 and again in 2016. We carried out anthropometric measurements and applied household surveys to obtain socio-demographic information. The results of both interventions (2014 and 2016) were analyzed, including income, social programs executed in the common land and the household expenditure. Results: We identified that by 2016 there was a marginal positive impact on the length-for-age z-scores (t=1.83, p=0.077); however, there was a negative impact in the weight-for-height (indicating an increase in acute malnutrition) and weight-for-age z-scores. Conclusion: Children undernourishment in the studied area persists and might be related to a phase of illness and inadequate food intake. The PCC did not show evidence of its impact after two years of enforcement.

Exposure Assessment to Environmental Chemicals in Children from Ciudad Juarez, Chihuahua, Mexico.

It has been demonstrated that the human biomonitoring of susceptible populations is a valuable method for the identification of critical contaminants. Therefore, the purpose of this study was to assess the exposure profile for arsenic (As), lead (Pb), mercury (Hg), 1-hydroxypyrene (1-OHP), 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) in children living in Ciudad Juarez, Chihuahua, Mexico (a major manufacturing center in Mexico). In 2012, we evaluated a total of 135 healthy children living in Ciudad Juarez since birth. The total PBDEs levels ranged from nondetectable (< LOD) to 215 ng/g lipid, with a mean total PBDEs level of 29.5 ± 53.0 ng/g lipid (geometric mean ± standard deviation). The mean total PCBs level in the study participants was 29.0 ± 10.5 ng/g lipid (range 4.50-50.0 ng/g lipid). The mean concentration of total DDT (DDT + DDE) was 11.9 ± 6.70 ng/g lipid (range 3.00-26.0 ng/g lipid). The mean 1-OHP levels was 1.2 ± 1.1 µmol/mol creatinine (range

Persistent Organic Pollutants and Heavy Metal Concentrations in Soil from the Metropolitan Area of Monterrey, Nuevo Leon, Mexico.

The purpose of this study was to assess the levels of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethane (DDE), and four heavy metals (arsenic, cadmium, and lead) in outdoor surface soils (50 samples) collected from the metropolitan area of Monterrey in Mexico. Total PBDEs levels ranged from 1.80 to 127 µg/kg, with mean total PBDEs level of 14.2 ± 21.5 µg/kg (geometric mean ± standard deviation). For PCBs, the mean total level in the studied soils was 23.5 ± 20.2 µg/kg (range 4.0-65.5 µg/kg). An important finding in our study was that all soil samples (100%) had detectable levels of the metabolite p,p'-DDE. Moreover, the mean total DDT level (∑p'p-DDT and p'p-DDE) was approximately 132 ± 175 µg/kg. The mean levels for arsenic, cadmium, and lead in soil were 5.30 ± 1.35 (range 1.55-7.85) mg/kg, 2.20 ± 1.20 (range 0.65-6.40) mg/kg, and 455 ± 204 (range 224-1230) mg/kg, respectively. Our study has several limitations, the most notable of which is the small sample of soils evaluated. However, this screening study provided concentration data for the occurrence of POPs and four heavy metals in soil from the metropolitan area of Monterrey, Nuevo Leon, Mexico, and taking into consideration that soil is an important pathway of exposure for people, a biomonitoring program for the surveillance of the general population in the metropolitan area of Monterrey, Nuevo Leon is deemed necessary.

Genotoxicological response of the common carp (Cyprinus carpio) exposed to spring water in Tlaxcala, México.

This study evaluated the genotoxic impact of anthropic activities in Huactzinco Spring, using Cyprinus carpio as a biomonitor. In situ and in vivo experimental designs were compared by means of simultaneous 2-week exposures. The water from the spring generated mean micronuclei frequency values (108.6 ± 32 MN/1,000) and DNA fragmentation values (143.4 ± 35 au) which were statistically higher than those for the negative control (10.9 ± 6 MN/1,000 and 67.6 ± 23 au). The in situ and in vivo experiments supported one another. The comet assay proved to be the most sensitive test, with an EC50 value (11.4 % ± 3.4 %) being less than that determined for the micronuclei test (54.8 % ± 3.2 %). The results of this study confirm the usefulness of C. carpio as an environmental contamination biomonitor, and suggest that Huactzinco Spring water constitutes a latent risk to human health and the environment.

Blood lead levels, δ-ALAD inhibition, and hemoglobin content in blood of giant toad (Rhinella marina) to assess lead exposure in three areas surrounding an industrial complex in Coatzacoalcos, Veracruz, Mexico.

The Coatzacoalcos Region in Veracruz, Mexico houses one of the most important industrial complexes in Mexico and Latin America. Lead is an ubiquitous environmental pollutant which represents a great risk to human health and ecosystems. Amphibian populations have been recognized as biomonitors of changes in environmental conditions. The purpose of this research is to measure exposure to lead and evaluate hematological and biochemical effects in specimens of giant toads (Rhinella marina) taken from three areas surrounding an industrial complex in the Coatzacoalcos River downstream. Lead levels in toads' blood are between 10.8 and 70.6 µg/dL and are significantly higher in industrial sites. We have found a significant decrease in the delta-aminolevulinic acid dehydratase (δ-ALAD) activity in blood from 35.3 to 78 % for the urban-industrial and industrial sites, respectively. In addition, we have identified a strong inverse relationship between the δ-ALAD activity and the blood lead levels (r = -0.84, p < 0.001). Hemoglobin and mean corpuscular hemoglobin levels, as well as the condition factor, are found to be lower at industrial sites compared with the reference sites. Our results suggest that the R. marina can be considered a good biomonitor of the δ-ALAD activity inhibition and hematological alterations at low lead concentrations.

Assessment of the levels of DDT and DDE in soil and blood samples from Tabasco, Mexico.

In Mexico, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) was used until the year 2000, principally in agriculture and anti-paludal program health campaigns. The southeastern region of Mexico was an important area of malaria, and from 1957 DDT was applied indoors every 6 months, with a coverage of 2 g/m(2). The current study was performed in Tabasco, a Mexican state located in the southeastern region of Mexico. DDT and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethene (DDE) were analyzed by gas chromatography/mass spectrometry. In general, low levels were found in household outdoor samples; the levels of DDT ranged from not detectable to 0.048 mg/kg, and of DDE from 0.001 to 0.068 mg/kg. An important finding was that, in all communities where DDT in blood was analyzed, exposure to DDT was found, indicating both past and present exposure. Although the levels found in this study were lower than other studies in Mexico, there is a need to evaluate whether the people living in the study area are at risk.

Wild rodents (Dipodomys merriami) used as biomonitors in contaminated mining sites.

Mining is one of the most important industrial activities globally; however, mining processes have critical environmental impacts, as mining is a major source of metals and metalloids that contribute significantly to the pollution of soil, sediment, water and air. Heavy metals can impact the health of exposed human populations and nonhuman receptors. This study focused on arsenic because its genotoxicity is well-known. Previously, we proposed a methodology to evaluate and integrate risk from a single source affecting different biologic receptors. Here, we propose an alternative approach estimating arsenic exposure in children and kangaroo rats using probabilistic simulation with Monte Carlo modeling. The estimates are then associated to measured DNA damage and compared to both populations of children and rodents living in contaminated and in reference areas. Finally, based on the integrated analysis of the generated information, we evaluate the potential use of wild rodents (Dipodomys merriami) as a biomonitor at mining sites. Results indicate that the variation of genotoxicity in children of the reference site is approximately 2 units when compared to the children of the contaminated site. In the rodents we observed a variation of approximately 4 units between those of the reference site when compared to those living on the contaminated site. We propose that D. merriami can be used as a biomonitor organism in sites with mining activity, and that a non-lethal test can be used to evaluate risk from metal exposure.

Revisión de las metodologías sobre evaluación de riesgos en salud para el estudio de comunidades vulnerables en América Latina / Health risk assessment methodologies for the study of vulnerable communities in Latin America / Revisão das metodologias sobre avaliação de riscos na saúde para o estudo de comunidades vulneráveis na América Latina

Los métodos para evaluar el riesgo en salud se basan, en general, en el monitoreo ambiental y en la estimación de la exposición a través de modelos matemáticos. La incertidumbre de tal estrategia es grande. En consecuencia, para incrementar la certidumbre sobre la evaluación de la exposición a los contaminantes, se ha propuesto el empleo de biomarcadores. No obstante, la complejidad de los nuevos escenarios de riesgo obliga a evaluar no solamente a las poblaciones humanas sino también al resto de la biota. Asimismo, factores ambientales, sociales y de salud, al afectar la vulnerabilidad, también deben ser considerados para la caracterización del riesgo. Estos factores de vulnerabilidad pueden evaluarse a través de indicadores. Al final, con los análisis ambientales, el uso de biomarcadores y el manejo de indicadores ambientales, sociales y de salud, puede evaluarse el riesgo de manera integrada (humanos y biota). En esta revisión se presentan las diversas estrategias empleadas por este grupo de trabajo para evaluar el riesgo en sitios contaminados, comunidades marginadas y en áreas afectadas por el cambio global climático.

The most commonly used methods for risk assessment are based on environmental analysis and the use of mathematical models for the estimation of exposure. However, the uncertainty of this approach is high, as the models are based on scenarios that may be not the correct ones. In order to decrease the uncertainty, the use of biomarkers has been proposed. Furthermore, considering the complexity of pollution in some sites, these biomarkers can be used both in humans and biota in order to obtain better information for the definition of risks at those sites. In addition to biomarkers, social, health and environmental indicators have to be applied for risk characterization, as different factors of vulnerability can modify the extent of health risks in some communities. At the end, with environmental monitoring and the use of biomarkers and indicators of vulnerability, health risks in humans and biota (integrated risk assessment) can be assessed in different scenarios. In this paper we present the strategies that our group developed for the study of hazardous waste sites, vulnerable communities and areas impacted by climate change.

Os métodos para avaliar o risco na saúde se baseiam, em geral, no monitoramento ambiental e na estimação da exposição através de modelos matemáticos. A incerteza de tal estratégia é grande. Em consequência, para incrementar a certeza sobre a avaliação da exposição aos contaminantes, tem sido proposta a utilização de biomarcadores. No entanto, a complexidade dos novos cenários de risco obriga a avaliar não somente as populações humanas mas também ao resto da biota. Da mesma forma, fatôres ambientais, sociais e de saúde, ao afetar a vulnerabilidade, também devem ser considerados para a caracterização do risco. Estes fatôres de vulnerabilidade podem avaliar-se através de indicadores. Finalmente, com as análises ambientais, o uso de biomarcadores e o manejo de indicadores ambientais, sociais e de saúde, pode-se avaliar o risco de maneira integrada (humanos e biota). Nesta revisão se apresentam as diversas estratégias empregadas por este grupo de trabalho para avaliar o risco em lugares contaminados, comunidades marginalizadas e em áreas afetadas pela mudança global climática.

Indoor air pollution in a Mexican indigenous community: evaluation of risk reduction program using biomarkers of exposure and effect.

Indoor air pollution can be an important risk factor for human health, considering that people spend more than 60% of their time indoors. Fifty percent of the world population and approximately 90% of the rural population in developing countries are using biomass as energy source. Latin America represents 12% of the global consumption of biomass; in Mexico, 27 million people use wood as an energy source. Therefore, in this study we evaluated a 3-stage risk reduction program. The stages were: 1) removal of indoor soot adhered to roofs and internal walls; 2) paving the dirt floors; and 3) introduction of a new wood stove with a metal chimney that expels smoke outdoors. The complete intervention program was applied. In 20 healthy subject residents from an indigenous community in San Luis Potosí, Mexico, we measured blood carboxyhemoglobin (% COHb), DNA damage (comet assay) in nucleated blood cells, and urinary 1-OHP levels before and after the program. Before intervention individuals had a geometric mean COHb level of 4.93% and 53% of the population presented levels above 2.5% considered a safe level. However, in all the studied individuals the levels of COHb were reduced to below 2.5% (mean level 1.0%) one month after the intervention. Moreover, when compared, DNA damage in people exposed before the intervention was higher (5.8+/-1.3 of Tail Moment) than when the program was introduced (2.8+/-0.9 of Tail Moment) (P>0.05) and a same trend was observed with urinary 1-OHP levels; 6.71+/-3.58 micromol/mol creatinine was the concentration before intervention; whereas, 4.80+/-3.29 micromol/mol creatinine was the one after the program. The results suggest that the intervention program offers an acceptable risk reduction to those families that use biomass for food cooking.

An integrated health risk assessment approach to the study of mining sites contaminated with arsenic and lead.

In order to test the value of an integrated approach for the analysis of health risks at contaminated sites, an integrated health risk assessment in a mining area was performed following 3 steps: 1) Environmental monitoring of surface soil, 2) assessment of exposure to metals in children and native rodents, and 3) DNA damage evaluation (comet assay) in children and rodents. These aspects also were studied in less exposed populations. Our results in humans showed that children living in the most polluted area (Villa de la Paz, Mexico) had higher lead blood concentrations (geometric mean of 13.8 microg/dL) and urinary arsenic levels (geometric mean of 52.1 microg/g creatinine) compared to children living in a control area (Matehuala, Mexico; blood lead of 7.3 microg/dL; urinary arsenic of 16.8 microg/g creatinine). Furthermore, the exposed children also had increased DNA damage (tail moment mean in Villa de la Paz of 4.8 vs 3.9 in Matehuala; p < 0.05). Results in rodents were identical. Animals captured in the polluted area had higher levels of arsenic (geometric mean of 1.3 microg/g in liver and 1.8 microg/g in kidney), lead (0.2 microg/g in liver and 0.9 microg/g in kidney), and cadmium (0.8 microg/g in liver and 2.2 microg/g in kidney), and increased DNA damage (tail moment mean of 18.2) when compared to control animals (arsenic in liver of 0.08 microg/g and kidney of 0.1 microg/g; lead in liver of 0.06 microg/g and kidney of 0.3 microg/g; cadmium in liver of 0.06 microg/g and kidney of 0.6 microg/g; and tail moment of 14.2). With the data in children and rodents, the weight-of-evidence for health risks (in this case DNA damage) associated with metal exposure in Villa de la Paz was strengthened. Therefore, a remediation program was easier to justify, and a feasibility study at this site is under way.

Environmental health assessment of deltamethrin in a malarious area of Mexico: environmental persistence, toxicokinetics, and genotoxicity in exposed children.

We reported previously that children are exposed to deltamethrin in malarious areas. In the present work we explored the levels of this insecticide in soil samples and also obtained relevant toxicokinetic data of deltamethrin in exposed children. Results show that, after spraying, indoor levels of deltamethrin in soil samples were higher than outdoor levels. The mean half-life estimated with these data was 15.5 days for outdoor samples and 15.4 days for indoor samples. Children's exposure to deltamethrin was assessed using as biomarkers the urinary concentrations of the metabolites 3-phenoxybenzoic acid (3-PBA) and cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (Br2CA). The mean level of both biomarkers reached a peak within the first 24 hr postexposure; 6 months after the initial exposure, urinary levels of 3-PBA and Br2CA were found at levels observed before exposure. Approximately 91% of the total 3-PBA or Br2CA was excreted during the first 3 days after exposure. Therefore, we estimated a half-life for this period, the values for 3-PBA and Br2CA being almost identical (13.5 vs. 14.5 hr). Finally, considering reports about the genotoxicity of deltamethrin, we assessed DNA damage in children before and 24 hr after indoor spraying of deltamethrin; we found no differences in the comet assay end points. In conclusion, we observed exposure to deltamethrin in children, but we did not find any relationship between soil concentrations of deltamethrin and urinary levels of the metabolites. At least for genotoxicity, the exposed children appeared not to be at risk.