Horacio Tovalín Ahumada

Condiciones de salud de la población vecina a una planta recicladora de residuos en México

El presente estudio se realizo en Mexico en una poblacion vecina a una planta recicladora de cinc y de otros polvos metalicos ante la posibilidad de que estas sustancias entraran en contacto con la poblacion y produjeran diferentes efectos nocivos sobre la salud. La planta se situa en un municipio cercano a Monterrey, que es la tercera ciudad mas poblada de Mexico y la segunda mas industrializada. Se aplico un diseno transversal comparativo para llevar a cabo la investigacion, que duro de septiembre a noviembre de 1994. Mediante un muestreo por cuotas se seleccionaron viviendas en dos zonas --una zona expuesta por vecindad a la planta y otra no expuesta que sirvio de control-- hasta lograr el tamano muestral deseado (621 individuos, a un promedio de cinco por vivienda). En cada domicilio un estudiante de psicologia adiestrado aplico un cuestionario a un familiar mayor de edad para recoger datos sobre la presencia de afecciones agudas y cronicas, trastornos del embarazo y enfermedades congenitas en los integrantes del hogar. En la poblacion expuesta se aplicaron 127 cuestionarios, que arrojaron informacion sobre 596 personas, y en la poblacion no expuesta se administraron 147, que proporcionaron datos sobre 743 personas. Las distribuciones por sexo y edad fueron semejantes en las dos poblaciones y el tiempo de residencia en la zona fue ligeramente mayor en los individuos no expuestos. Los problemas de salud mas frecuentes en la poblacion expuesta fueron irritacion ocular y de vias respiratorias superiores, alergias, trastornos del sueno, bronquitis, cansancio excesivo, problemas cutaneos, otitis y anemias. Las razones de prevalencias fueron significativas en el caso de erupciones y otras enfermedades cutaneas, cansancio excesivo, trastornos del sueno, infecciones respiratorias superiores, otitis, bronquitis y alergias. Cuando se compararon los dos grupos de mujeres no se encontraron diferencias significativas en las prevalencias de problemas obstetricos, abortos espontaneos o hijos con malformaciones congenitas o bajo peso al nacer. La sensibilidad del cuestionario utilizado para detectar problemas de salud es pobre y podria haber causado una subestimacion de algunas afecciones. No obstante, diferentes sesgos de informacion fueron controlados y ello permite concluir que la poblacion expuesta tiene un mayor riesgo de padecer ciertas enfermedades y trastornos que la poblacion no expuesta.This study was conducted in Mexico among residents of an area near a recycling plant for zinc and other metallic dusts to find out if these substances produce various adverse health effects in the population that may come in contact with them. The plant is in a municipality close to Monterrey, which is Mexicos third most populous and second most industrialized city. A cross-sectional comparative design was used for the research, which took place from September to November 1994. By means of quota sampling, houses were selected in two areas--one exposed, by virtue of its proximity to the plant, and the other unexposed, which served as a control--until the desired sample size was reached (621 individuals, an average of five per household). In each dwelling, a trained psychology student administered a questionnaire to one of the older family members to gather data on the presence of acute and chronic illnesses, problems during pregnancy, and congenital illnesses among the household members. In the exposed population, 127 questionnaires were completed, providing information on 596 persons; in the unexposed population, data on 743 persons were gathered via 147 questionnaires. The sex and age distributions were similar in the two populations, and the length of residence in their respective area was slightly longer among unexposed individuals. The most frequently reported health problems in the exposed population were irritation of the eyes and upper respiratory tract, allergies, sleep disturbances, bronchitis, fatigue, skin problems, ear infections, and anemia. The prevalence ratios for the exposed versus unexposed populations were significant with regard to skin eruptions and other skin diseases, fatigue, sleep disturbances, upper respiratory infections, ear infections, bronchitis, and allergies. Women from the two groups did not show significant differences in the prevalence of obstetric problems, miscarriages, or children born with congenital deformities or low birthweight. The sensitivity of the questionnaire used to detect health problems was poor, which could have resulted in an underestimation of some disorders. Nevertheless, various types of information bias were controlled, permitting the conclusion that the exposed population had a greater risk of suffering certain diseases and disorders than the unexposed population.

Health conditions in a population living near an industrial waste recycling plant in Mexico

The present study was conducted in a population living near a recycling plant for zinc and other metallic dusts to determine whether exposures to these substances were occurring and producing adverse health effects. The plant is situated in a suburb of Monterrey, which is the third most populous city in Mexico and the second most industrialized. A cross-sectional study design was used for the investigation, which was carried out from September 1994 to November 1994. Using cluster sampling procedures, homes in two areas were selected--one exposed through proximity to the plant, and the other unexposed to serve as a control--until the desired sample size was achieved (621 individuals, with an average of five per dwelling). A specially trained psychology student administered a questionnaire to an adult member of each family, soliciting data on the presence of acute and chronic infections, complications of pregnancy, and congenital diseases among the family members. One hundred twenty-seven questionnaires were administered in the exposed population, yielding information on 596 individuals. In the unexposed population, 147 questionnaires were administered furnishing data on 743 individuals. The sex and age distributions of the two populations were similar. The unexposed population had a slightly longer average duration of residence. The most common health problems in the exposed population were irritation of the eyes and upper respiratory tract, allergies, sleep disturbances, bronchitis, excessive fatigue, skin problems, otitis, and anemia. The exposed population had significantly higher risks for skin eruptions and diseases, excessive fatigue, sleep disturbances, upper respiratory infections, otitis, bronchitis, and allergies. Exposed and unexposed women had comparable prevalences of obstetrical problems, spontaneous abortions, congenitally malformed offspring, and low birthweight. The questionnaire used to detect health problems has low sensitivity and may have generated underestimates of some conditions. Nevertheless, the analysis controlled for several different biases, and thus it can be concluded that a positive association exists between environmental exposure to these wastes and increased risk of disease.