espanolObjetivo: El objetivo de este estudio fue evaluar la asociacion entre la exposicion a polvo de tiza y trastornos respiratorios en un colectivo de maestros. Metodos: Estudio transversal realizado entre enero y mayo de 2010 a una muestra de 420 maestros de siete colegios de las provincias de Barcelona, Girona, Navarra y Valencia que contestaron un cuestionario auto-cumplimentado sobre factores determinantes de la exposicion a polvo de tiza y trastornos respiratorios. Se evaluaron las asociaciones entre seis variables indicadoras de exposicion a polvo de tiza y siete variables relacionadas con efectos adversos sobre el aparato respiratorio. Se calcularon odds ratio de prevalencia (ORP) e intervalos de confianza del 95% (IC95%) mediante regresion logistica multivariada, ajustando por las variables sexo, edad, habito tabaquico e indice de masa corporal. Resultados: La tasa de respuesta fue del 96,7%. El 68% de los maestros usaban tiza durante al menos una hora al dia y un 24% sacudia el borrador en clase. Los trastornos mas prevalentes fueron afonia, sintomatologia frecuente de vias altas (SFRS) y bronquitis cronica. Sacudir y/o usar frecuentemente el borrador y/o usar tiza en clase se asocio significativamente a una mayor prevalencia de sibilancias (ORPa=4,04; IC95%=1,73-9,42), infecciones respiratorias frecuentes (IRF) (ORPa=5,64; IC95%=1,32-24,04), SFRS (ORPa=2,42; IC95%=1,33-4,43) y afonia (ORPa=1,75; IC95%=1,01-3,04). Para sibilancias, IRF, SFRS y afonia la prevalencia disminuyo con la edad. Conclusiones: Los trastornos respiratorios se asocian a la exposicion al polvo de tiza. La relacion inversa con la edad para sibilancias, IRF, SFRS y afonia sugiere un efecto de seleccion, debiendose investigar si hay maestros que abandonan la profesion por motivos de salud respiratoria. EnglishObjective: The aim of this study was to evaluate the associations between exposure to chalk dust and respiratory tract symptoms and diseases in a sample of school teachers. Methods: A cross-sectional study was carried out between January and May 2010, in a sample of 420 teachers of seven schools from Barcelona, Girona, Navarra and Valencia who answered a self- administrated questionnaire, focused on determinants of chalk dust occupational exposure, respiratory disorders and demographic variables. We evaluated the associations between six variables related with determinants of chalk dust occupational exposure and seven respiratory tract symptoms and diseases. Odds ratio of prevalence (ORP) and confidence intervals 95% (IC 95%) were calculated using multivariate logistic regressions to assess the associations, adjusting by the variables sex, age, smoking and body mass index (BMI). Results: Overall survey response rate was 96.7%. The percentage of teachers who used chalk for at least an hour a day was 68% and 24% indicated shaking the eraser in class to eliminate the adhered dust. The most prevalent disorders were hoarseness, frequent upper respiratory tract symptoms (FURS) and chronic bronchitis. Shaking and/or frequent use of the eraser and/ or using chalk in class was significantly associated with an increased prevalence of wheezing (ORPa=4.04;IC95%=1.73-9.42), frequent respiratory infections (FRI) (ORPa=5.64;IC95%=1.32-24.04), FURS (ORPa=2.42;IC95%=1.33-4.43), and hoarseness (ORPa=1.75;IC95%=1.01-3.04). The prevalence of wheezing, FRI, FURS and hoarseness decreased with age. Conclusions: Respiratory disorders are associated with exposure to chalk dust among teachers. The inverse relationship with age for wheezing, FRI, FURS and hoarseness suggests a selection effect, and justifies research to determine whether teachers are leaving the profession because of respiratory health.