Pesticide Exposure Modifies DNA Methylation of Coding Region of WRAP53α, an Antisense Sequence of p53, in a Mexican Population.

The influence of pesticide exposure in alteration of DNA methylation patterns of specific genes is still limited, specifically in natural antisense transcripts (NAT), such as the WRAP53α gene. The aim of this study was to determine the methylation of the WRAP53α gene in mestizo and indigenous populations as well as its relationship with internal (age, sex, and body mass index) and external factors (pesticide exposure and micronutrient intake). A cross-sectional study was conducted including 91 mestizo individuals without occupational exposure to pesticides, 164 mestizo urban sprayers and 189 indigenous persons without occupational exposure to pesticides. Acute pesticide exposure was evaluated by measurement of urinary dialkylphosphate (DAP) concentration by gas chromatograph coupled to a mass spectrometer. Anthropometric characteristics, unhealthy habits, and chronic pesticide exposure were assessed using a structured questionnaire. The frequency of macro- and micronutrient intake was determined using SNUT software. DNA methylation of the WRAP53α gene was determined by pyrosequencing of bisulfite-modified DNA. The mestizo sprayers group had the higher values of %5mC. In addition, this group had the most DAP urinary concentration with respect to the indigenous and reference groups. Bivariate analysis showed an association between %5mC of the WRAP53α gene with micronutrient intake and pesticide exposure in mestizo sprayers, whereas changes in %5mC of the WRAP53α gene was associated with body mass index in the indigenous group. These data suggest that the %5mC of the WRAP53α gene can be influenced by pesticide exposure and ethnicity in the study population, and changes in the WRAP53α gene might cause an important cell process disturbance.

Severe Illness from Methyl Bromide Exposure at a Condominium Resort--U.S. Virgin Islands, March 2015.

On March 22, 2015, the Agency for Toxic Substances and Disease Registry (ATSDR) was notified by the U.S. Environmental Protection Agency (EPA) of four cases of suspected acute methyl bromide toxicity among family members vacationing at a condominium resort in the U.S. Virgin Islands. Methyl bromide is a pesticide that has been banned in the United States for use in homes and other residential settings. An investigation conducted by the U.S. Virgin Islands Department of Health (VIDOH), the U.S. Virgin Islands Department of Planning and Natural Resources (DPNR), and EPA confirmed that methyl bromide had been used as a fumigant on March 18 in the building where the family had been residing, 2 days before they were transported to the hospital; three family members had life-threatening illness. On March 25, 2015, a stop-use order for methyl bromide was issued by DPNR to the pest control company that had performed the fumigation. Subsequent investigation revealed that previous fumigation with methyl bromide had occurred on October 20, 2014, at the same condominium resort. In addition to the four ill family members, 37 persons who might have been exposed to methyl bromide as a result of the October 2014 or March 2015 fumigations were identified by VIDOH and ATSDR. Standardized health questionnaires were administered to 16 of the 20 persons for whom contact information was available; six of 16 had symptoms consistent with methyl bromide exposure, including headache and fatigue. Pest control companies should be aware that use of methyl bromide is banned in homes and other residential settings, and clinicians should be aware of the toxicologic syndrome that exposure to methyl bromide can cause.

[Cultural dimensions of dengue that help or hinder its prevention in Mexico]. / Dimensiones culturales del dengue que favorecen o dificultan su prevención en México.

OBJECTIVE: To describe the cultural dimensions that might help or hinder dengue prevention in two Mexican localities having different experiences related to this disease. METHODS: A cognitive-cultural anthropological study was conducted involving the participation of 160 adults selected through purposeful sampling. The techniques of free lists and pile-sorting were used for investigating terms associated with the concept "dengue." A consensus analysis was carried out by the factoring of principal components, hierarchical cluster analysis, and multidimensional scaling. RESULTS: Greater consensus was observed among participants from the population having more historical experience with dengue-Santiago Ixcuintla, Nayarit-as well as more structured cultural and complex dimensions than in Guadalajara. In the latter case, participants showed a more fragmented conception of dengue, with insufficient information on its symptoms, mechanisms of transmission, and vector reservoirs. Three cultural dimensions were identified as hindering dengue prevention: confusing and insufficient information, placing responsibility for prevention on other people or on public agencies, and excessive confidence in fumigation as a preventive measure. CONCLUSIONS: These obstacles will need to be taken into account in the design and implementation of future prevention campaigns, disseminating information that explains the risks of fumigation and the importance of citizens and authorities jointly participating in the search for a comprehensive and sustainable solution to the dengue problem.

Dimensiones culturales del dengue que favorecen o dificultan su prevención en México / Cultural dimensions of dengue that help or hinder its prevention in Mexico

OBJETIVO: Describir las dimensiones culturales que podrían favorecer u obstaculizar la prevención del dengue en dos entidades mexicanas con diferentes experiencias vinculadas a esta enfermedad. MÉTODOS: Se realizó un estudio antropológico cultural cognitivo en el que participaron 160 personas adultas seleccionadas por muestreo propositivo. Se utilizaron las técnicas de listados libres y de sorteo de montones, indagando los términos asociados al concepto "dengue". El análisis de consenso fue realizado mediante factorización de componentes principales, análisis de conglomerados jerárquicos y escalas multidimensionales. RESULTADOS: Se observó mayor consenso entre los participantes de la población de mayor experiencia histórica con el dengue -Santiago Ixcuintla, Nayarit- así como dimensiones culturales más estructuradas y complejas que en Guadalajara, donde los participantes mostraron una concepción más fragmentada sobre el dengue, con información insuficiente en torno a los síntomas, el mecanismo de transmisión y los reservorios del vector. Se identificaron tres dimensiones culturales que obstaculizan la prevención del dengue: información confusa e insuficiente, la atribución de la responsabilidad de prevenir a otras personas u organismos públicos y la excesiva confianza en la fumigación como medida preventiva. CONCLUSIONES: Será necesario considerar estas barreras en el diseño e implementación de las futuras campañas de prevención, difundiendo información que explique los riesgos de la fumigación y la importancia de que ciudadanos y autoridades participen conjuntamente en la búsqueda de una solución integral y sostenible al problema del dengue.

OBJECTIVE: To describe the cultural dimensions that might help or hinder dengue prevention in two Mexican localities having different experiences related to this disease. METHODS: A cognitive-cultural anthropological study was conducted involving the participation of 160 adults selected through purposeful sampling. The techniques of free lists and pile-sorting were used for investigating terms associated with the concept "dengue." A consensus analysis was carried out by the factoring of principal components, hierarchical cluster analysis, and multidimensional scaling. RESULTS: Greater consensus was observed among participants from the population having more historical experience with dengue-Santiago Ixcuintla, Nayarit-as well as more structured cultural and complex dimensions than in Guadalajara. In the latter case, participants showed a more fragmented conception of dengue, with insufficient information on its symptoms, mechanisms of transmission, and vector reservoirs. Three cultural dimensions were identified as hindering dengue prevention: confusing and insufficient information, placing responsibility for prevention on other people or on public agencies, and excessive confidence in fumigation as a preventive measure. CONCLUSIONS: These obstacles will need to be taken into account in the design and implementation of future prevention campaigns, disseminating information that explains the risks of fumigation and the importance of citizens and authorities jointly participating in the search for a comprehensive and sustainable solution to the dengue problem.

Chemical composition and fumigant toxicity of the essential oils from 16 species of Eucalyptus against Haematobia irritans (Diptera: Muscidae) adults.

Oils extracted from various species of Eucalyptus (Eucalyptus badjensis Beuzev & Welch, Eucalyptus badjensis x Eucalyptus nitens, Eucalyptus benthamii variety dorrigoensis Maiden & Cambage, Eucalyptus botryoides Smith, Eucalyptus dalrympleana Maiden, Eucalyptus fastigata Deane & Maiden, Eucalyptus nobilis L.A.S. Johnson & K. D. Hill, Eucalyptus polybractea R. Baker, Eucalyptus radiata ssp. radiata Sieber ex Spreng, Eucalyptus resinifera Smith, Eucalyptus robertsonii Blakely, Eucalyptus rubida Deane & Maiden, Eucalyptus smithii R. Baker, Eucalyptus elata Dehnh, Eucalyptus fraxinoides Deane & Maiden, E. obliqua L'Hér) were obtained by hydrodistillation. The chemical composition of essential oils was determined by gas chromatography coupled to mass spectrometry. Essential oils were mainly composed of 1,8-cineole, alpha-pinene, alpha-terpineol, 4-terpineol, and p-cymene. Vapors from these essential oils and their major components were found to be toxic to Haematobia irritans (L.) (Diptera: Muscidae) adults. An aliquot of each oil was placed in a cylindrical test chamber, and the number of knocked down flies was recorded as a function of time. Knockdown time 50% was then calculated. Results showed that essential oil of E. polybractea had the highest knockdown activity of 3.44 min. A correlation was observed between the content of 1,8-cineole in the Eucalyptus essential oils and the corresponding toxic effect.

Acceptability and perceived side effects of insecticide indoor residual spraying under different resistance management strategies.

OBJECTIVE: To assess household acceptability and perceived side effects of residual indoor pyrethroid (PYR), carbamate and organophosphate insecticides sprayed by annual rotation (ROT), spatial mosaic (MOS), and a single insecticide (DDT or PYR) in communities of the coastal plain of Chiapas, Mexico. MATERIAL AND METHODS: A questionnaire to assess the acceptability and perceived side effects of indoor insecticides was administered to one member of 30% of the families in eight villages of Chiapas. The association of different insecticide treatments with their responses was evaluated (Chi-square). The intensity of side effects indicated under different treatments was compared in an ordered logistic model, using a severity index as the response variable. RESULTS: Insecticide spraying as a probable cause of symptoms was identified by 2.1% of interviewees. A significantly high percentage of persons with blurred vision, dizziness, sneezing, coughing, numbness, watery eyes, and itching lived in villages under MOS and ROT and a high severity index was significantly associated with ROT treatment. Reduction of mosquito bites and cockroaches were the perceived main benefits, and most villagers that perceived no benefits lived in DDT treated villages. Most of the interviewees welcomed spraying (83.7%), but the smell and having to remove furniture from houses were the main arguments against it. CONCLUSIONS: Acceptability correlated with insecticide spray coverage, although the most frequent suggestion for improvement was to increase the understanding of the objectives of spraying in the communities. The frequency of side effects was low, but higher in localities where a combination of insecticides was applied. This is a limitation for the use of this type of resistance management strategy in public health.

Acceptability and perceived side effects of insecticide indoor residual spraying under different resistance management strategies

OBJETIVO: Evaluar la aceptabilidad y los efectos secundarios del rociado intradomiciliar de insecticidas pyrethroides (PYR), carbamato y organophosphato rociados en rotación anual (ROT), en mosaico espacial (MOS), o solos (DDT o PYR) en hogares de comunidades de la costa de Chiapas. México.MATERIAL Y MÉTODOS: Se aplicó un cuestionario a un miembro de 30% de las familias de ocho localidades de Chiapas para evaluar aceptabilidad y efectos secundarios del rociado. Se usaron análisis de ji cuadrada para determinar la asociación de los insecticidas rociados con las respuestas y se comparó la intensidad de efectos secundarios referidos bajo los diferentes tratamientos en un modelo logístico ordenado usando un índice de severidad como variable de respuesta.RESULTADOS: Los insecticidas rociados como causa probable de síntomas fueron referidos por 2.1% de entrevistados, pero 12% de ellos asociaron los síntomas con otras causas. Un porcentaje significativamente alto de personas que refirieron visión borrosa, vértigo, estornudos, tos, entumecimiento, lagrimeo y comezón vivía en bajo MOS y ROT, mientras que el índice de severidad se asoció con el rociado ROT. La reducción en la picadura de mosquitos y en el número de cucarachas fueron los principales beneficios percibidos, y la mayoría de los lugareños que no percibieron los beneficios vivía en localidades tratadas con DDT. La mayoría de entrevistados aceptaron bien el rociado (83.7%), pero el mal olor y tener que sacar los muebles de las casas fueron los argumentos principales en contra.CONCLUSIONES: La cobertura de rociado correlacionó con la aceptabilidad, aunque la sugerencia más frecuente para incrementarla fue la de explicar los objetivos del rociado en las comunidades. La frecuencia de efectos secundarios fue baja, pero mayor en localidades donde se aplicó una combinación de insecticidas, lo que representa una limitación para el uso de esta estrategia de manejo de resistencia a estos químicos en salud pública.

Diagnóstico situacional del uso del DDT y el control de la malaria. informe final / Situational diagnosis use of the DDT and control of malaria

En el presente documento se realiza una revisión del problema del paludismo en Nicaragua y el uso del DDT. Además de su aplicación para el control de malaria en los primeros años de la década de los 50, el uso del DDT, estuvo fuertemente ligado al cultivo del algodón que inició su siembra en gran escala a lo largo de la costa del pacífico en 1950. Los estudios efectuados para establecer efectos del DDT en la salud Humna, se realizaron en la zona de Chinandega en 1994, obteniéndose detección del DDT y sus principales metabolitos en: leche materna, sangre del cordon umbilical, sangre venosa y en tejido adiposo. Igualmente los estudios sobre el efecto ambiental del DDT consignados se iniciaron en 1993, efectuados en suelo, agua, alimentos, peces; en las zonas de Chinandega, Río San Juan, Lago Cocibolca, León. En estos estudios se detectaron DDT y sus metabolitos sobre todo en las zonas de Chinandega y León...

[Assessment of neurotoxic effects of methyl bromide in exposed workers]. / Estudio de los efectos neurotóxicos del bromuro de metilo sobre trabajadores expuestos.

BACKGROUND: Methyl bromide is an aliphatic hydrocarbon derivative used as a pesticide that causes skin, kidney, respiratory, liver and neurological damage. AIM: To assess the neurological and psychiatric damage caused by methyl bromide in exposed workers of seed and fruit export industries in a rural area near Santiago. SUBJECTS AND METHODS: We studied prospectively 15 male middle age workers before and after a fumigation period with methyl bromide, that lasted two to four weeks. According to the initial assessment, 5 of these subjects had a chronic exposure to the chemical. As controls, 10 non exposed workers matched for age, sex and working conditions were studied in two occasions. The evaluation included the WHO Neuro Behavior Core Test Battery, dynamometric and vibrator assessment of peripheral nerve function, the Nothingham test for psychological functioning and Titmus test for visual acuity. Methyl bromide levels were measured in blood and urine. RESULTS: Blood methyl bromide levels increased from 13.3 to 30 mg/dl after exposure. Symptoms that appeared with a higher frequency in exposed workers were insomnia, headache, paresthesiae, mood changes and loss of memory and concentration. In these subjects, the threshold for the Vibraton test increased from 2.4 to 2.85 sec, dynamometry showed a strength reduction in the right side from 51.4 to 47.2 kg and there was an increase in the score for negative auto-perception in the Nothingham test from 11.2 to 13.6. No deterioration in these tests were observed in unexposed workers. CONCLUSIONS: Acute and chronic methyl bromide exposure causes important psychological and neurological derangement.

Estudio de los efectos tóxicos de los insecticidas organofosforados en pilotos agrícolas y mezcladores / Study on the toxic effects of organophosphate insecticides in agricultural pilots and mixers

Se analizaron 33 muestras de sangre de 19 pilotos agrícolas y 14 mezcladores, en contacto con insecticidas organofosforados, para determinar los siguientes parámetros: actividad de la enzima acetilcolinesterasa y su correlación con manifestaciones clínicas; indicadores de funcionalismo hepático y su posible relación con patologías hepáticas y acetilcolinesterasa; glucosa sanguínea en la relación con acetilcolinesterasa. Se evaluaron mediante cuestionario, las condiciones de exposición ocupacional de los trabajadores mencionados. El grupo control, estuvo constituido por 40 pilotos comerciales. Todos los parámetros fueron analizados 2 veces: inmediatamente antes de la temporada de fumigación, pre-exposición y en la época "pico" de la fumigación, Post-exposición. Los parámetros estudiados: glicemia, transaminasas glutámico pirúvica y glutámico oxalacética, bilirrubina total, indirecta y fosfatasas alcalinas, resultaron normales en los grupos estudio y control, y no mostraron diferencias significativas entre ambos muestreos. La bilirrubina directa, estuvo ligeramente elevada en los grupos estudio y control, en el muestreo pre-exposición. La diferencia entre los promedios de este último parámetro, entre el muestreo pre y post-expoción, resultó significativa (p<0,02). Aunque todos los 33 casos del Grupo estudio resultaron normales para la acetilcolinesterasa, existe una diferencia significativa entre el muestreo pre y post-exposición, siendo los valores de último, más bajos, como se esperaba. Se analizan las causas de esta aparente baja toxicidad, teniendo presente los efectos sutiles que bajas dosis de organofosforados, por tiempo prolongado, pueden producir en los pilotos, afectando el estado de alerta y la ejecución de los mismo. Se hacen las recomedaciones pertinentes para estudios posteriores de forma tal que se evalué más profundamente la relación dosis de exposición/efecto y se apliquen las medidas adecuadas de prevención y control del riesgo

Toxicidad crónica por organofosforados en trabajadores agricolas / Organophosphate esticides chronical toxicity in agriculture workers

El estudio se realizó en 55 agricultores que cumplian labores de fumigación manual; su edad media fue de 40 años y su duración media de exposición continua a los plaguicidas organofosforados fue de 14 años. El oficio lo aprendieron por imitación, atraidos por los buenos resultados de estos productos químicos en el control de plagas. En su trabajo carecían de medios adecuados de protección y desconocían la peligrosidad de dichos plaguicidas. Se estudió un grupo control de 35 personas, que realizaba fumigaciones y cuya edad media fue de 39 años. Los grupos experimental y control habitaban el mismo asentamiento donde se efectuaban el trabajo agricola y los rociamientos. Las dolencias funcionales fueron frecuentes, predominando en el grupo experimental; los síntomas encontrados corresponden a los descritos en los tres síndromes de intoxicación: muscarínico, nicotínico y del sistema nervioso central. Entre los hallazgos del examen físico y del laboratorio, tanto en los fumigadores como en los controles, pueden mencionarse: hipertensión arterial, bradicardia, disminución de la agudeza visual, bloques de rama izquierda del haz de Hiss, trastornos de la repolarización del miocardio, valores altos de la hemoglobina y del hematocrito, y cifras elevadas de la serie blanca. Sólo en el grupo experimental se constató la presencia de células sanguineas inmaduras, hipoglucemia e hipocolesterolemia. Las pruebas hepáticas dieron valores normales. La actividad de la colinesterasa eritrocitoria se encontró en su mayoría con cifras variables dentro de los valores normales, fuertemente disminuidas en dos fumigadores y elevada en siete. No hubo diferencia significativa entre las cifras medias de esta enzima en los grupos experimental y control. El organofosforado en sangre estuvo presente en un 45% de los fumigadores y en un 24% del grupo control. Los resultados anteriormente descritos hablan en favor de la existencia de una "intoxicación crónica" tanto en los fumigadores como en el grupo control, que puede presentarse con valores normales y/o altos de actividad de la colinesterasa